/usr/share/doc/gcc-4.9-base/libgomp.html is in gcc-4.9-doc 4.9.3-13ubuntu2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 2294 2295 2296 2297 2298 2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 2319 2320 2321 2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 2351 2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447 2448 2449 2450 2451 2452 2453 2454 2455 2456 2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473 2474 2475 2476 2477 2478 2479 2480 2481 2482 2483 2484 2485 2486 2487 2488 2489 2490 2491 2492 2493 2494 2495 2496 2497 2498 2499 2500 2501 2502 2503 2504 2505 2506 2507 2508 2509 2510 2511 2512 2513 2514 2515 2516 2517 2518 2519 2520 2521 2522 2523 2524 2525 2526 2527 2528 2529 2530 2531 2532 2533 2534 2535 2536 2537 2538 2539 2540 2541 2542 2543 2544 2545 2546 2547 2548 2549 2550 2551 2552 2553 2554 2555 2556 2557 2558 2559 2560 2561 2562 2563 2564 2565 2566 2567 2568 2569 2570 2571 2572 2573 2574 2575 2576 2577 2578 2579 2580 2581 2582 2583 2584 2585 2586 2587 2588 2589 2590 2591 2592 2593 2594 2595 2596 2597 2598 2599 2600 2601 2602 2603 2604 2605 2606 2607 2608 2609 2610 2611 2612 2613 2614 2615 2616 2617 2618 2619 2620 2621 2622 2623 2624 2625 2626 2627 2628 2629 2630 2631 2632 2633 2634 2635 2636 2637 2638 2639 2640 2641 2642 2643 2644 2645 2646 2647 2648 2649 2650 2651 2652 2653 2654 2655 2656 2657 2658 2659 2660 2661 2662 2663 2664 2665 2666 2667 2668 2669 2670 2671 2672 2673 2674 2675 2676 2677 2678 2679 2680 2681 2682 2683 2684 2685 2686 2687 2688 2689 2690 2691 2692 2693 2694 2695 2696 2697 2698 2699 2700 2701 2702 2703 2704 2705 2706 2707 2708 2709 2710 2711 2712 2713 2714 2715 2716 2717 2718 2719 2720 2721 2722 2723 2724 2725 2726 2727 2728 2729 2730 2731 2732 2733 2734 2735 2736 2737 2738 2739 2740 2741 2742 2743 2744 2745 2746 2747 2748 2749 2750 2751 2752 2753 2754 2755 2756 2757 2758 2759 2760 2761 2762 2763 2764 2765 2766 2767 2768 2769 2770 2771 2772 2773 2774 2775 2776 2777 2778 2779 2780 2781 2782 2783 2784 2785 2786 2787 2788 2789 2790 2791 2792 2793 2794 2795 2796 2797 2798 2799 2800 2801 2802 2803 2804 2805 2806 2807 2808 2809 2810 2811 2812 2813 2814 2815 2816 2817 2818 2819 2820 2821 2822 2823 2824 2825 2826 2827 2828 2829 2830 2831 2832 2833 2834 2835 2836 2837 2838 2839 2840 2841 2842 2843 2844 2845 2846 2847 2848 2849 2850 2851 2852 2853 2854 2855 2856 2857 2858 2859 2860 2861 2862 2863 2864 2865 2866 2867 2868 2869 2870 2871 2872 2873 2874 2875 2876 2877 2878 2879 2880 2881 2882 2883 2884 2885 2886 2887 2888 2889 2890 2891 2892 2893 2894 2895 2896 2897 2898 2899 2900 2901 2902 2903 2904 2905 2906 2907 2908 2909 2910 2911 2912 2913 2914 2915 2916 2917 2918 2919 2920 2921 2922 2923 2924 2925 2926 2927 2928 2929 2930 2931 2932 2933 2934 2935 2936 2937 2938 2939 2940 2941 2942 2943 2944 2945 2946 2947 2948 2949 2950 2951 2952 2953 2954 2955 2956 2957 2958 2959 2960 2961 2962 2963 2964 2965 2966 2967 2968 2969 2970 2971 2972 2973 2974 2975 2976 2977 2978 2979 2980 2981 2982 2983 2984 2985 2986 2987 2988 2989 2990 2991 2992 2993 2994 2995 2996 2997 2998 2999 3000 3001 3002 3003 3004 3005 3006 3007 3008 3009 3010 3011 3012 3013 3014 3015 3016 3017 3018 3019 3020 3021 3022 3023 3024 3025 3026 3027 3028 3029 3030 3031 3032 3033 3034 3035 3036 3037 3038 3039 3040 3041 3042 3043 3044 3045 3046 3047 3048 3049 3050 3051 3052 3053 3054 3055 3056 3057 3058 3059 3060 3061 3062 3063 3064 3065 3066 3067 3068 3069 3070 3071 3072 3073 3074 3075 3076 3077 3078 3079 3080 3081 3082 3083 3084 3085 3086 3087 3088 3089 3090 3091 3092 3093 3094 3095 3096 3097 3098 3099 3100 3101 3102 3103 3104 3105 3106 3107 3108 3109 3110 3111 3112 3113 3114 3115 3116 3117 3118 3119 3120 3121 3122 3123 3124 3125 3126 3127 3128 3129 3130 3131 3132 3133 3134 3135 3136 3137 3138 3139 3140 3141 3142 3143 3144 3145 3146 3147 3148 3149 3150 3151 3152 3153 3154 3155 3156 3157 3158 3159 3160 3161 3162 3163 3164 3165 3166 3167 3168 3169 3170 3171 3172 3173 3174 3175 3176 3177 3178 3179 3180 3181 3182 3183 3184 3185 3186 3187 3188 3189 3190 3191 3192 3193 3194 3195 3196 3197 3198 3199 3200 3201 3202 3203 3204 3205 3206 3207 3208 3209 3210 3211 3212 3213 3214 3215 3216 3217 3218 3219 3220 3221 3222 3223 3224 3225 3226 3227 3228 3229 3230 3231 3232 3233 3234 3235 3236 3237 3238 3239 3240 3241 3242 3243 3244 3245 3246 3247 3248 3249 3250 3251 3252 3253 3254 3255 3256 3257 3258 3259 3260 3261 3262 3263 3264 3265 3266 3267 3268 3269 3270 3271 3272 3273 3274 3275 3276 3277 3278 3279 3280 3281 3282 3283 3284 3285 3286 3287 3288 3289 3290 3291 3292 3293 3294 3295 3296 3297 3298 3299 3300 3301 3302 3303 3304 3305 3306 3307 3308 3309 3310 3311 3312 3313 3314 3315 3316 3317 3318 3319 3320 3321 3322 3323 3324 3325 3326 3327 3328 3329 3330 3331 3332 3333 3334 3335 3336 3337 3338 3339 3340 3341 3342 3343 3344 3345 3346 3347 3348 3349 3350 3351 3352 3353 3354 3355 3356 3357 3358 3359 3360 3361 3362 3363 3364 3365 3366 3367 3368 3369 3370 3371 3372 3373 3374 3375 3376 3377 3378 3379 3380 3381 3382 3383 3384 3385 3386 3387 3388 3389 3390 3391 3392 3393 3394 3395 3396 3397 3398 3399 3400 3401 3402 3403 3404 3405 3406 3407 3408 3409 3410 3411 3412 3413 3414 3415 3416 3417 3418 3419 3420 3421 3422 3423 3424 3425 3426 3427 3428 3429 3430 3431 3432 3433 3434 3435 3436 3437 3438 3439 3440 3441 3442 3443 3444 3445 3446 3447 3448 3449 3450 3451 3452 3453 3454 3455 3456 3457 3458 3459 3460 3461 3462 3463 3464 3465 3466 3467 3468 3469 3470 3471 3472 3473 3474 3475 3476 3477 3478 3479 3480 3481 3482 3483 3484 3485 3486 3487 3488 3489 3490 3491 3492 3493 3494 3495 3496 3497 3498 3499 3500 3501 3502 3503 3504 3505 3506 3507 3508 3509 3510 3511 3512 3513 3514 3515 3516 3517 3518 3519 3520 3521 3522 3523 3524 3525 3526 3527 3528 3529 3530 3531 3532 3533 3534 3535 3536 3537 3538 3539 3540 3541 3542 3543 3544 3545 3546 3547 3548 3549 3550 3551 3552 3553 3554 3555 3556 3557 3558 3559 3560 3561 3562 3563 3564 3565 3566 3567 3568 3569 3570 3571 3572 3573 3574 3575 3576 3577 3578 3579 3580 3581 3582 3583 3584 3585 3586 3587 3588 3589 3590 3591 3592 3593 3594 3595 3596 3597 3598 3599 3600 3601 3602 3603 3604 3605 3606 3607 3608 3609 3610 3611 3612 3613 3614 3615 3616 3617 3618 3619 3620 3621 3622 3623 3624 3625 3626 3627 3628 3629 3630 3631 3632 3633 3634 3635 3636 3637 3638 3639 3640 3641 3642 3643 3644 3645 3646 3647 3648 3649 3650 3651 3652 3653 3654 3655 3656 3657 3658 3659 3660 3661 3662 3663 3664 3665 3666 3667 3668 3669 3670 3671 3672 3673 3674 3675 3676 3677 3678 3679 3680 3681 3682 3683 3684 3685 3686 3687 3688 3689 3690 3691 3692 3693 3694 3695 3696 3697 3698 3699 3700 3701 3702 3703 3704 3705 3706 3707 3708 3709 3710 3711 3712 3713 3714 3715 3716 3717 3718 3719 3720 3721 3722 3723 3724 3725 3726 3727 3728 3729 3730 3731 3732 3733 3734 3735 3736 3737 3738 3739 3740 3741 3742 3743 3744 3745 3746 3747 3748 3749 3750 3751 3752 3753 3754 3755 3756 3757 3758 3759 3760 3761 3762 3763 3764 3765 3766 3767 3768 3769 3770 3771 3772 3773 3774 3775 3776 3777 3778 3779 3780 3781 3782 3783 3784 3785 3786 3787 3788 3789 3790 3791 3792 3793 3794 3795 3796 3797 3798 3799 3800 3801 3802 3803 3804 3805 3806 3807 3808 3809 3810 3811 3812 3813 3814 3815 3816 3817 3818 3819 3820 3821 3822 3823 3824 3825 3826 3827 3828 3829 3830 3831 3832 3833 3834 3835 3836 3837 3838 3839 3840 3841 3842 3843 3844 3845 3846 3847 3848 3849 3850 3851 3852 3853 3854 3855 3856 3857 3858 3859 3860 3861 3862 3863 3864 3865 3866 3867 3868 3869 3870 3871 3872 3873 3874 3875 3876 3877 3878 3879 3880 3881 3882 3883 3884 3885 3886 3887 3888 3889 3890 3891 3892 3893 3894 3895 3896 3897 3898 3899 3900 3901 3902 3903 3904 3905 3906 3907 3908 3909 3910 3911 3912 3913 3914 3915 3916 3917 3918 3919 3920 3921 3922 3923 3924 3925 3926 3927 3928 3929 3930 3931 3932 3933 3934 3935 3936 3937 3938 3939 3940 3941 3942 3943 3944 3945 3946 3947 3948 3949 3950 3951 3952 3953 3954 3955 3956 3957 3958 3959 3960 3961 3962 3963 3964 3965 3966 3967 3968 3969 3970 3971 3972 3973 3974 3975 3976 3977 3978 3979 3980 3981 3982 3983 3984 3985 3986 3987 3988 3989 3990 3991 3992 3993 3994 3995 3996 3997 3998 3999 4000 4001 4002 4003 4004 4005 4006 4007 4008 4009 4010 4011 4012 4013 4014 4015 4016 4017 4018 4019 4020 4021 4022 4023 4024 4025 4026 4027 4028 4029 4030 4031 4032 4033 4034 4035 4036 4037 4038 4039 4040 4041 4042 4043 4044 4045 4046 4047 4048 4049 4050 4051 4052 4053 4054 4055 4056 4057 4058 4059 4060 4061 4062 4063 4064 4065 4066 4067 4068 4069 4070 4071 4072 4073 4074 4075 4076 4077 4078 4079 4080 4081 4082 4083 4084 4085 4086 4087 4088 4089 4090 4091 4092 4093 4094 4095 4096 4097 4098 4099 4100 4101 4102 4103 4104 4105 4106 4107 4108 4109 4110 4111 4112 4113 4114 4115 4116 4117 4118 4119 4120 4121 4122 4123 4124 4125 4126 4127 4128 4129 4130 4131 4132 4133 4134 4135 4136 4137 4138 4139 4140 4141 4142 4143 4144 4145 4146 4147 4148 4149 4150 4151 4152 4153 4154 4155 4156 4157 4158 4159 4160 4161 4162 4163 4164 4165 4166 4167 4168 4169 4170 4171 4172 4173 4174 4175 4176 4177 4178 4179 4180 4181 4182 4183 4184 4185 4186 4187 4188 4189 4190 4191 4192 4193 4194 4195 4196 4197 4198 4199 4200 4201 4202 4203 4204 4205 4206 4207 4208 4209 4210 4211 4212 4213 4214 4215 4216 4217 4218 4219 4220 4221 4222 4223 4224 4225 4226 4227 4228 4229 4230 4231 4232 4233 4234 4235 4236 4237 4238 4239 4240 4241 4242 4243 4244 4245 4246 4247 4248 4249 4250 4251 4252 4253 4254 4255 4256 4257 4258 4259 4260 4261 4262 4263 4264 4265 4266 4267 4268 4269 4270 4271 4272 | <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<!-- Copyright (C) 2006-2014 Free Software Foundation, Inc.
Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.3 or
any later version published by the Free Software Foundation; with the
Invariant Sections being "Funding Free Software", the Front-Cover
texts being (a) (see below), and with the Back-Cover Texts being (b)
(see below). A copy of the license is included in the section entitled
"GNU Free Documentation License".
(a) The FSF's Front-Cover Text is:
A GNU Manual
(b) The FSF's Back-Cover Text is:
You have freedom to copy and modify this GNU Manual, like GNU
software. Copies published by the Free Software Foundation raise
funds for GNU development. -->
<!-- Created by GNU Texinfo 6.1, http://www.gnu.org/software/texinfo/ -->
<head>
<title>GNU libgomp</title>
<meta name="description" content="GNU libgomp">
<meta name="keywords" content="GNU libgomp">
<meta name="resource-type" content="document">
<meta name="distribution" content="global">
<meta name="Generator" content="makeinfo">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<link href="#Top" rel="start" title="Top">
<link href="#Library-Index" rel="index" title="Library Index">
<link href="#SEC_Contents" rel="contents" title="Table of Contents">
<link href="dir.html#Top" rel="up" title="(dir)">
<style type="text/css">
<!--
a.summary-letter {text-decoration: none}
blockquote.indentedblock {margin-right: 0em}
blockquote.smallindentedblock {margin-right: 0em; font-size: smaller}
blockquote.smallquotation {font-size: smaller}
div.display {margin-left: 3.2em}
div.example {margin-left: 3.2em}
div.lisp {margin-left: 3.2em}
div.smalldisplay {margin-left: 3.2em}
div.smallexample {margin-left: 3.2em}
div.smalllisp {margin-left: 3.2em}
kbd {font-style: oblique}
pre.display {font-family: inherit}
pre.format {font-family: inherit}
pre.menu-comment {font-family: serif}
pre.menu-preformatted {font-family: serif}
pre.smalldisplay {font-family: inherit; font-size: smaller}
pre.smallexample {font-size: smaller}
pre.smallformat {font-family: inherit; font-size: smaller}
pre.smalllisp {font-size: smaller}
span.nolinebreak {white-space: nowrap}
span.roman {font-family: initial; font-weight: normal}
span.sansserif {font-family: sans-serif; font-weight: normal}
ul.no-bullet {list-style: none}
-->
</style>
</head>
<body lang="en">
<h1 class="settitle" align="center">GNU libgomp</h1>
<a name="SEC_Overview"></a>
<h2 class="shortcontents-heading">Short Table of Contents</h2>
<div class="shortcontents">
<ul class="no-bullet">
<li><a name="stoc-Enabling-OpenMP-1" href="#toc-Enabling-OpenMP-1">1 Enabling OpenMP</a></li>
<li><a name="stoc-Runtime-Library-Routines-1" href="#toc-Runtime-Library-Routines-1">2 Runtime Library Routines</a></li>
<li><a name="stoc-Environment-Variables-1" href="#toc-Environment-Variables-1">3 Environment Variables</a></li>
<li><a name="stoc-The-libgomp-ABI-1" href="#toc-The-libgomp-ABI-1">4 The libgomp ABI</a></li>
<li><a name="stoc-Reporting-Bugs-1" href="#toc-Reporting-Bugs-1">5 Reporting Bugs</a></li>
<li><a name="stoc-GNU-General-Public-License" href="#toc-GNU-General-Public-License">GNU General Public License</a></li>
<li><a name="stoc-GNU-Free-Documentation-License-1" href="#toc-GNU-Free-Documentation-License-1">GNU Free Documentation License</a></li>
<li><a name="stoc-Funding-Free-Software" href="#toc-Funding-Free-Software">Funding Free Software</a></li>
<li><a name="stoc-Library-Index-1" href="#toc-Library-Index-1">Library Index</a></li>
</ul>
</div>
<a name="SEC_Contents"></a>
<h2 class="contents-heading">Table of Contents</h2>
<div class="contents">
<ul class="no-bullet">
<li><a name="toc-Enabling-OpenMP-1" href="#Enabling-OpenMP">1 Enabling OpenMP</a></li>
<li><a name="toc-Runtime-Library-Routines-1" href="#Runtime-Library-Routines">2 Runtime Library Routines</a>
<ul class="no-bullet">
<li><a name="toc-omp_005fget_005factive_005flevel-_002d_002d-Number-of-parallel-regions" href="#omp_005fget_005factive_005flevel">2.1 <code>omp_get_active_level</code> – Number of parallel regions</a></li>
<li><a name="toc-omp_005fget_005fancestor_005fthread_005fnum-_002d_002d-Ancestor-thread-ID" href="#omp_005fget_005fancestor_005fthread_005fnum">2.2 <code>omp_get_ancestor_thread_num</code> – Ancestor thread ID</a></li>
<li><a name="toc-omp_005fget_005fcancellation-_002d_002d-Whether-cancellation-support-is-enabled" href="#omp_005fget_005fcancellation">2.3 <code>omp_get_cancellation</code> – Whether cancellation support is enabled</a></li>
<li><a name="toc-omp_005fget_005fdefault_005fdevice-_002d_002d-Get-the-default-device-for-target-regions" href="#omp_005fget_005fdefault_005fdevice">2.4 <code>omp_get_default_device</code> – Get the default device for target regions</a></li>
<li><a name="toc-omp_005fget_005fdynamic-_002d_002d-Dynamic-teams-setting" href="#omp_005fget_005fdynamic">2.5 <code>omp_get_dynamic</code> – Dynamic teams setting</a></li>
<li><a name="toc-omp_005fget_005flevel-_002d_002d-Obtain-the-current-nesting-level" href="#omp_005fget_005flevel">2.6 <code>omp_get_level</code> – Obtain the current nesting level</a></li>
<li><a name="toc-omp_005fget_005fmax_005factive_005flevels-_002d_002d-Maximum-number-of-active-regions" href="#omp_005fget_005fmax_005factive_005flevels">2.7 <code>omp_get_max_active_levels</code> – Maximum number of active regions</a></li>
<li><a name="toc-omp_005fget_005fmax_005fthreads-_002d_002d-Maximum-number-of-threads-of-parallel-region" href="#omp_005fget_005fmax_005fthreads">2.8 <code>omp_get_max_threads</code> – Maximum number of threads of parallel region</a></li>
<li><a name="toc-omp_005fget_005fnested-_002d_002d-Nested-parallel-regions" href="#omp_005fget_005fnested">2.9 <code>omp_get_nested</code> – Nested parallel regions</a></li>
<li><a name="toc-omp_005fget_005fnum_005fdevices-_002d_002d-Number-of-target-devices" href="#omp_005fget_005fnum_005fdevices">2.10 <code>omp_get_num_devices</code> – Number of target devices</a></li>
<li><a name="toc-omp_005fget_005fnum_005fprocs-_002d_002d-Number-of-processors-online" href="#omp_005fget_005fnum_005fprocs">2.11 <code>omp_get_num_procs</code> – Number of processors online</a></li>
<li><a name="toc-omp_005fget_005fnum_005fteams-_002d_002d-Number-of-teams" href="#omp_005fget_005fnum_005fteams">2.12 <code>omp_get_num_teams</code> – Number of teams</a></li>
<li><a name="toc-omp_005fget_005fnum_005fthreads-_002d_002d-Size-of-the-active-team" href="#omp_005fget_005fnum_005fthreads">2.13 <code>omp_get_num_threads</code> – Size of the active team</a></li>
<li><a name="toc-omp_005fget_005fproc_005fbind-_002d_002d-Whether-theads-may-be-moved-between-CPUs" href="#omp_005fget_005fproc_005fbind">2.14 <code>omp_get_proc_bind</code> – Whether theads may be moved between CPUs</a></li>
<li><a name="toc-omp_005fget_005fschedule-_002d_002d-Obtain-the-runtime-scheduling-method" href="#omp_005fget_005fschedule">2.15 <code>omp_get_schedule</code> – Obtain the runtime scheduling method</a></li>
<li><a name="toc-omp_005fget_005fteam_005fnum-_002d_002d-Get-team-number" href="#omp_005fget_005fteam_005fnum">2.16 <code>omp_get_team_num</code> – Get team number</a></li>
<li><a name="toc-omp_005fget_005fteam_005fsize-_002d_002d-Number-of-threads-in-a-team" href="#omp_005fget_005fteam_005fsize">2.17 <code>omp_get_team_size</code> – Number of threads in a team</a></li>
<li><a name="toc-omp_005fget_005fthread_005flimit-_002d_002d-Maximum-number-of-threads" href="#omp_005fget_005fthread_005flimit">2.18 <code>omp_get_thread_limit</code> – Maximum number of threads</a></li>
<li><a name="toc-omp_005fget_005fthread_005fnum-_002d_002d-Current-thread-ID" href="#omp_005fget_005fthread_005fnum">2.19 <code>omp_get_thread_num</code> – Current thread ID</a></li>
<li><a name="toc-omp_005fin_005fparallel-_002d_002d-Whether-a-parallel-region-is-active" href="#omp_005fin_005fparallel">2.20 <code>omp_in_parallel</code> – Whether a parallel region is active</a></li>
<li><a name="toc-omp_005fin_005ffinal-_002d_002d-Whether-in-final-or-included-task-region" href="#omp_005fin_005ffinal">2.21 <code>omp_in_final</code> – Whether in final or included task region</a></li>
<li><a name="toc-omp_005fis_005finitial_005fdevice-_002d_002d-Whether-executing-on-the-host-device" href="#omp_005fis_005finitial_005fdevice">2.22 <code>omp_is_initial_device</code> – Whether executing on the host device</a></li>
<li><a name="toc-omp_005fset_005fdefault_005fdevice-_002d_002d-Set-the-default-device-for-target-regions" href="#omp_005fset_005fdefault_005fdevice">2.23 <code>omp_set_default_device</code> – Set the default device for target regions</a></li>
<li><a name="toc-omp_005fset_005fdynamic-_002d_002d-Enable_002fdisable-dynamic-teams" href="#omp_005fset_005fdynamic">2.24 <code>omp_set_dynamic</code> – Enable/disable dynamic teams</a></li>
<li><a name="toc-omp_005fset_005fmax_005factive_005flevels-_002d_002d-Limits-the-number-of-active-parallel-regions" href="#omp_005fset_005fmax_005factive_005flevels">2.25 <code>omp_set_max_active_levels</code> – Limits the number of active parallel regions</a></li>
<li><a name="toc-omp_005fset_005fnested-_002d_002d-Enable_002fdisable-nested-parallel-regions" href="#omp_005fset_005fnested">2.26 <code>omp_set_nested</code> – Enable/disable nested parallel regions</a></li>
<li><a name="toc-omp_005fset_005fnum_005fthreads-_002d_002d-Set-upper-team-size-limit" href="#omp_005fset_005fnum_005fthreads">2.27 <code>omp_set_num_threads</code> – Set upper team size limit</a></li>
<li><a name="toc-omp_005fset_005fschedule-_002d_002d-Set-the-runtime-scheduling-method" href="#omp_005fset_005fschedule">2.28 <code>omp_set_schedule</code> – Set the runtime scheduling method</a></li>
<li><a name="toc-omp_005finit_005flock-_002d_002d-Initialize-simple-lock" href="#omp_005finit_005flock">2.29 <code>omp_init_lock</code> – Initialize simple lock</a></li>
<li><a name="toc-omp_005fset_005flock-_002d_002d-Wait-for-and-set-simple-lock" href="#omp_005fset_005flock">2.30 <code>omp_set_lock</code> – Wait for and set simple lock</a></li>
<li><a name="toc-omp_005ftest_005flock-_002d_002d-Test-and-set-simple-lock-if-available" href="#omp_005ftest_005flock">2.31 <code>omp_test_lock</code> – Test and set simple lock if available</a></li>
<li><a name="toc-omp_005funset_005flock-_002d_002d-Unset-simple-lock" href="#omp_005funset_005flock">2.32 <code>omp_unset_lock</code> – Unset simple lock</a></li>
<li><a name="toc-omp_005fdestroy_005flock-_002d_002d-Destroy-simple-lock" href="#omp_005fdestroy_005flock">2.33 <code>omp_destroy_lock</code> – Destroy simple lock</a></li>
<li><a name="toc-omp_005finit_005fnest_005flock-_002d_002d-Initialize-nested-lock" href="#omp_005finit_005fnest_005flock">2.34 <code>omp_init_nest_lock</code> – Initialize nested lock</a></li>
<li><a name="toc-omp_005fset_005fnest_005flock-_002d_002d-Wait-for-and-set-nested-lock" href="#omp_005fset_005fnest_005flock">2.35 <code>omp_set_nest_lock</code> – Wait for and set nested lock</a></li>
<li><a name="toc-omp_005ftest_005fnest_005flock-_002d_002d-Test-and-set-nested-lock-if-available" href="#omp_005ftest_005fnest_005flock">2.36 <code>omp_test_nest_lock</code> – Test and set nested lock if available</a></li>
<li><a name="toc-omp_005funset_005fnest_005flock-_002d_002d-Unset-nested-lock" href="#omp_005funset_005fnest_005flock">2.37 <code>omp_unset_nest_lock</code> – Unset nested lock</a></li>
<li><a name="toc-omp_005fdestroy_005fnest_005flock-_002d_002d-Destroy-nested-lock" href="#omp_005fdestroy_005fnest_005flock">2.38 <code>omp_destroy_nest_lock</code> – Destroy nested lock</a></li>
<li><a name="toc-omp_005fget_005fwtick-_002d_002d-Get-timer-precision" href="#omp_005fget_005fwtick">2.39 <code>omp_get_wtick</code> – Get timer precision</a></li>
<li><a name="toc-omp_005fget_005fwtime-_002d_002d-Elapsed-wall-clock-time" href="#omp_005fget_005fwtime">2.40 <code>omp_get_wtime</code> – Elapsed wall clock time</a></li>
</ul></li>
<li><a name="toc-Environment-Variables-1" href="#Environment-Variables">3 Environment Variables</a>
<ul class="no-bullet">
<li><a name="toc-OMP_005fCANCELLATION-_002d_002d-Set-whether-cancellation-is-activated" href="#OMP_005fCANCELLATION">3.1 <code>OMP_CANCELLATION</code> – Set whether cancellation is activated</a></li>
<li><a name="toc-OMP_005fDISPLAY_005fENV-_002d_002d-Show-OpenMP-version-and-environment-variables" href="#OMP_005fDISPLAY_005fENV">3.2 <code>OMP_DISPLAY_ENV</code> – Show OpenMP version and environment variables</a></li>
<li><a name="toc-OMP_005fDEFAULT_005fDEVICE-_002d_002d-Set-the-device-used-in-target-regions" href="#OMP_005fDEFAULT_005fDEVICE">3.3 <code>OMP_DEFAULT_DEVICE</code> – Set the device used in target regions</a></li>
<li><a name="toc-OMP_005fDYNAMIC-_002d_002d-Dynamic-adjustment-of-threads" href="#OMP_005fDYNAMIC">3.4 <code>OMP_DYNAMIC</code> – Dynamic adjustment of threads</a></li>
<li><a name="toc-OMP_005fMAX_005fACTIVE_005fLEVELS-_002d_002d-Set-the-maximum-number-of-nested-parallel-regions" href="#OMP_005fMAX_005fACTIVE_005fLEVELS">3.5 <code>OMP_MAX_ACTIVE_LEVELS</code> – Set the maximum number of nested parallel regions</a></li>
<li><a name="toc-OMP_005fNESTED-_002d_002d-Nested-parallel-regions" href="#OMP_005fNESTED">3.6 <code>OMP_NESTED</code> – Nested parallel regions</a></li>
<li><a name="toc-OMP_005fNUM_005fTHREADS-_002d_002d-Specifies-the-number-of-threads-to-use" href="#OMP_005fNUM_005fTHREADS">3.7 <code>OMP_NUM_THREADS</code> – Specifies the number of threads to use</a></li>
<li><a name="toc-OMP_005fPROC_005fBIND-_002d_002d-Whether-theads-may-be-moved-between-CPUs" href="#OMP_005fPROC_005fBIND">3.8 <code>OMP_PROC_BIND</code> – Whether theads may be moved between CPUs</a></li>
<li><a name="toc-OMP_005fPLACES-_002d_002d-Specifies-on-which-CPUs-the-theads-should-be-placed" href="#OMP_005fPLACES">3.9 <code>OMP_PLACES</code> – Specifies on which CPUs the theads should be placed</a></li>
<li><a name="toc-OMP_005fSTACKSIZE-_002d_002d-Set-default-thread-stack-size" href="#OMP_005fSTACKSIZE">3.10 <code>OMP_STACKSIZE</code> – Set default thread stack size</a></li>
<li><a name="toc-OMP_005fSCHEDULE-_002d_002d-How-threads-are-scheduled" href="#OMP_005fSCHEDULE">3.11 <code>OMP_SCHEDULE</code> – How threads are scheduled</a></li>
<li><a name="toc-OMP_005fTHREAD_005fLIMIT-_002d_002d-Set-the-maximum-number-of-threads" href="#OMP_005fTHREAD_005fLIMIT">3.12 <code>OMP_THREAD_LIMIT</code> – Set the maximum number of threads</a></li>
<li><a name="toc-OMP_005fWAIT_005fPOLICY-_002d_002d-How-waiting-threads-are-handled" href="#OMP_005fWAIT_005fPOLICY">3.13 <code>OMP_WAIT_POLICY</code> – How waiting threads are handled</a></li>
<li><a name="toc-GOMP_005fCPU_005fAFFINITY-_002d_002d-Bind-threads-to-specific-CPUs" href="#GOMP_005fCPU_005fAFFINITY">3.14 <code>GOMP_CPU_AFFINITY</code> – Bind threads to specific CPUs</a></li>
<li><a name="toc-GOMP_005fSTACKSIZE-_002d_002d-Set-default-thread-stack-size" href="#GOMP_005fSTACKSIZE">3.15 <code>GOMP_STACKSIZE</code> – Set default thread stack size</a></li>
<li><a name="toc-GOMP_005fSPINCOUNT-_002d_002d-Set-the-busy_002dwait-spin-count" href="#GOMP_005fSPINCOUNT">3.16 <code>GOMP_SPINCOUNT</code> – Set the busy-wait spin count</a></li>
</ul></li>
<li><a name="toc-The-libgomp-ABI-1" href="#The-libgomp-ABI">4 The libgomp ABI</a>
<ul class="no-bullet">
<li><a name="toc-Implementing-MASTER-construct-1" href="#Implementing-MASTER-construct">4.1 Implementing MASTER construct</a></li>
<li><a name="toc-Implementing-CRITICAL-construct-1" href="#Implementing-CRITICAL-construct">4.2 Implementing CRITICAL construct</a></li>
<li><a name="toc-Implementing-ATOMIC-construct-1" href="#Implementing-ATOMIC-construct">4.3 Implementing ATOMIC construct</a></li>
<li><a name="toc-Implementing-FLUSH-construct-1" href="#Implementing-FLUSH-construct">4.4 Implementing FLUSH construct</a></li>
<li><a name="toc-Implementing-BARRIER-construct-1" href="#Implementing-BARRIER-construct">4.5 Implementing BARRIER construct</a></li>
<li><a name="toc-Implementing-THREADPRIVATE-construct-1" href="#Implementing-THREADPRIVATE-construct">4.6 Implementing THREADPRIVATE construct</a></li>
<li><a name="toc-Implementing-PRIVATE-clause-1" href="#Implementing-PRIVATE-clause">4.7 Implementing PRIVATE clause</a></li>
<li><a name="toc-Implementing-FIRSTPRIVATE-LASTPRIVATE-COPYIN-and-COPYPRIVATE-clauses-1" href="#Implementing-FIRSTPRIVATE-LASTPRIVATE-COPYIN-and-COPYPRIVATE-clauses">4.8 Implementing FIRSTPRIVATE LASTPRIVATE COPYIN and COPYPRIVATE clauses</a></li>
<li><a name="toc-Implementing-REDUCTION-clause-1" href="#Implementing-REDUCTION-clause">4.9 Implementing REDUCTION clause</a></li>
<li><a name="toc-Implementing-PARALLEL-construct-1" href="#Implementing-PARALLEL-construct">4.10 Implementing PARALLEL construct</a></li>
<li><a name="toc-Implementing-FOR-construct-1" href="#Implementing-FOR-construct">4.11 Implementing FOR construct</a></li>
<li><a name="toc-Implementing-ORDERED-construct-1" href="#Implementing-ORDERED-construct">4.12 Implementing ORDERED construct</a></li>
<li><a name="toc-Implementing-SECTIONS-construct-1" href="#Implementing-SECTIONS-construct">4.13 Implementing SECTIONS construct</a></li>
<li><a name="toc-Implementing-SINGLE-construct-1" href="#Implementing-SINGLE-construct">4.14 Implementing SINGLE construct</a></li>
</ul></li>
<li><a name="toc-Reporting-Bugs-1" href="#Reporting-Bugs">5 Reporting Bugs</a></li>
<li><a name="toc-GNU-General-Public-License" href="#Copying">GNU General Public License</a></li>
<li><a name="toc-GNU-Free-Documentation-License-1" href="#GNU-Free-Documentation-License">GNU Free Documentation License</a>
<ul class="no-bullet">
<li><a name="toc-ADDENDUM_003a-How-to-use-this-License-for-your-documents" href="#ADDENDUM_003a-How-to-use-this-License-for-your-documents">ADDENDUM: How to use this License for your documents</a></li>
</ul></li>
<li><a name="toc-Funding-Free-Software" href="#Funding">Funding Free Software</a></li>
<li><a name="toc-Library-Index-1" href="#Library-Index">Library Index</a></li>
</ul>
</div>
<a name="Top"></a>
<div class="header">
<p>
Next: <a href="#Enabling-OpenMP" accesskey="n" rel="next">Enabling OpenMP</a>, Up: <a href="dir.html#Top" accesskey="u" rel="up">(dir)</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="Introduction"></a>
<h1 class="top">Introduction</h1>
<a name="index-Introduction"></a>
<p>This manual documents the usage of libgomp, the GNU implementation of the
<a href="http://www.openmp.org">OpenMP</a> Application Programming Interface (API)
for multi-platform shared-memory parallel programming in C/C++ and Fortran.
</p>
<table class="menu" border="0" cellspacing="0">
<tr><td align="left" valign="top">• <a href="#Enabling-OpenMP" accesskey="1">Enabling OpenMP</a>:</td><td> </td><td align="left" valign="top">How to enable OpenMP for your applications.
</td></tr>
<tr><td align="left" valign="top">• <a href="#Runtime-Library-Routines" accesskey="2">Runtime Library Routines</a>:</td><td> </td><td align="left" valign="top">The OpenMP runtime application programming
interface.
</td></tr>
<tr><td align="left" valign="top">• <a href="#Environment-Variables" accesskey="3">Environment Variables</a>:</td><td> </td><td align="left" valign="top">Influencing runtime behavior with environment
variables.
</td></tr>
<tr><td align="left" valign="top">• <a href="#The-libgomp-ABI" accesskey="4">The libgomp ABI</a>:</td><td> </td><td align="left" valign="top">Notes on the external ABI presented by libgomp.
</td></tr>
<tr><td align="left" valign="top">• <a href="#Reporting-Bugs" accesskey="5">Reporting Bugs</a>:</td><td> </td><td align="left" valign="top">How to report bugs in GNU OpenMP.
</td></tr>
<tr><td align="left" valign="top">• <a href="#Copying" accesskey="6">Copying</a>:</td><td> </td><td align="left" valign="top">GNU general public license says
how you can copy and share libgomp.
</td></tr>
<tr><td align="left" valign="top">• <a href="#GNU-Free-Documentation-License" accesskey="7">GNU Free Documentation License</a>:</td><td> </td><td align="left" valign="top">
How you can copy and share this manual.
</td></tr>
<tr><td align="left" valign="top">• <a href="#Funding" accesskey="8">Funding</a>:</td><td> </td><td align="left" valign="top">How to help assure continued work for free
software.
</td></tr>
<tr><td align="left" valign="top">• <a href="#Library-Index" accesskey="9">Library Index</a>:</td><td> </td><td align="left" valign="top">Index of this documentation.
</td></tr>
</table>
<hr>
<a name="Enabling-OpenMP"></a>
<div class="header">
<p>
Next: <a href="#Runtime-Library-Routines" accesskey="n" rel="next">Runtime Library Routines</a>, Previous: <a href="#Top" accesskey="p" rel="prev">Top</a>, Up: <a href="#Top" accesskey="u" rel="up">Top</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="Enabling-OpenMP-1"></a>
<h2 class="chapter">1 Enabling OpenMP</h2>
<p>To activate the OpenMP extensions for C/C++ and Fortran, the compile-time
flag <code>-fopenmp</code> must be specified. This enables the OpenMP directive
<code>#pragma omp</code> in C/C++ and <code>!$omp</code> directives in free form,
<code>c$omp</code>, <code>*$omp</code> and <code>!$omp</code> directives in fixed form,
<code>!$</code> conditional compilation sentinels in free form and <code>c$</code>,
<code>*$</code> and <code>!$</code> sentinels in fixed form, for Fortran. The flag also
arranges for automatic linking of the OpenMP runtime library
(<a href="#Runtime-Library-Routines">Runtime Library Routines</a>).
</p>
<p>A complete description of all OpenMP directives accepted may be found in
the <a href="http://www.openmp.org">OpenMP Application Program Interface</a> manual,
version 4.0.
</p>
<hr>
<a name="Runtime-Library-Routines"></a>
<div class="header">
<p>
Next: <a href="#Environment-Variables" accesskey="n" rel="next">Environment Variables</a>, Previous: <a href="#Enabling-OpenMP" accesskey="p" rel="prev">Enabling OpenMP</a>, Up: <a href="#Top" accesskey="u" rel="up">Top</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="Runtime-Library-Routines-1"></a>
<h2 class="chapter">2 Runtime Library Routines</h2>
<p>The runtime routines described here are defined by Section 3 of the OpenMP
specification in version 4.0. The routines are structured in following
three parts:
</p>
<table class="menu" border="0" cellspacing="0">
<tr><th colspan="3" align="left" valign="top"><pre class="menu-comment">Control threads, processors and the parallel environment. They have C
linkage, and do not throw exceptions.
</pre></th></tr><tr><td align="left" valign="top">• <a href="#omp_005fget_005factive_005flevel" accesskey="1">omp_get_active_level</a>:</td><td> </td><td align="left" valign="top">Number of active parallel regions
</td></tr>
<tr><td align="left" valign="top">• <a href="#omp_005fget_005fancestor_005fthread_005fnum" accesskey="2">omp_get_ancestor_thread_num</a>:</td><td> </td><td align="left" valign="top">Ancestor thread ID
</td></tr>
<tr><td align="left" valign="top">• <a href="#omp_005fget_005fcancellation" accesskey="3">omp_get_cancellation</a>:</td><td> </td><td align="left" valign="top">Whether cancellation support is enabled
</td></tr>
<tr><td align="left" valign="top">• <a href="#omp_005fget_005fdefault_005fdevice" accesskey="4">omp_get_default_device</a>:</td><td> </td><td align="left" valign="top">Get the default device for target regions
</td></tr>
<tr><td align="left" valign="top">• <a href="#omp_005fget_005fdynamic" accesskey="5">omp_get_dynamic</a>:</td><td> </td><td align="left" valign="top">Dynamic teams setting
</td></tr>
<tr><td align="left" valign="top">• <a href="#omp_005fget_005flevel" accesskey="6">omp_get_level</a>:</td><td> </td><td align="left" valign="top">Number of parallel regions
</td></tr>
<tr><td align="left" valign="top">• <a href="#omp_005fget_005fmax_005factive_005flevels" accesskey="7">omp_get_max_active_levels</a>:</td><td> </td><td align="left" valign="top">Maximum number of active regions
</td></tr>
<tr><td align="left" valign="top">• <a href="#omp_005fget_005fmax_005fthreads" accesskey="8">omp_get_max_threads</a>:</td><td> </td><td align="left" valign="top">Maximum number of threads of parallel region
</td></tr>
<tr><td align="left" valign="top">• <a href="#omp_005fget_005fnested" accesskey="9">omp_get_nested</a>:</td><td> </td><td align="left" valign="top">Nested parallel regions
</td></tr>
<tr><td align="left" valign="top">• <a href="#omp_005fget_005fnum_005fdevices">omp_get_num_devices</a>:</td><td> </td><td align="left" valign="top">Number of target devices
</td></tr>
<tr><td align="left" valign="top">• <a href="#omp_005fget_005fnum_005fprocs">omp_get_num_procs</a>:</td><td> </td><td align="left" valign="top">Number of processors online
</td></tr>
<tr><td align="left" valign="top">• <a href="#omp_005fget_005fnum_005fteams">omp_get_num_teams</a>:</td><td> </td><td align="left" valign="top">Number of teams
</td></tr>
<tr><td align="left" valign="top">• <a href="#omp_005fget_005fnum_005fthreads">omp_get_num_threads</a>:</td><td> </td><td align="left" valign="top">Size of the active team
</td></tr>
<tr><td align="left" valign="top">• <a href="#omp_005fget_005fproc_005fbind">omp_get_proc_bind</a>:</td><td> </td><td align="left" valign="top">Whether theads may be moved between CPUs
</td></tr>
<tr><td align="left" valign="top">• <a href="#omp_005fget_005fschedule">omp_get_schedule</a>:</td><td> </td><td align="left" valign="top">Obtain the runtime scheduling method
</td></tr>
<tr><td align="left" valign="top">• <a href="#omp_005fget_005fteam_005fnum">omp_get_team_num</a>:</td><td> </td><td align="left" valign="top">Get team number
</td></tr>
<tr><td align="left" valign="top">• <a href="#omp_005fget_005fteam_005fsize">omp_get_team_size</a>:</td><td> </td><td align="left" valign="top">Number of threads in a team
</td></tr>
<tr><td align="left" valign="top">• <a href="#omp_005fget_005fthread_005flimit">omp_get_thread_limit</a>:</td><td> </td><td align="left" valign="top">Maximum number of threads
</td></tr>
<tr><td align="left" valign="top">• <a href="#omp_005fget_005fthread_005fnum">omp_get_thread_num</a>:</td><td> </td><td align="left" valign="top">Current thread ID
</td></tr>
<tr><td align="left" valign="top">• <a href="#omp_005fin_005fparallel">omp_in_parallel</a>:</td><td> </td><td align="left" valign="top">Whether a parallel region is active
</td></tr>
<tr><td align="left" valign="top">• <a href="#omp_005fin_005ffinal">omp_in_final</a>:</td><td> </td><td align="left" valign="top">Whether in final or included task region
</td></tr>
<tr><td align="left" valign="top">• <a href="#omp_005fis_005finitial_005fdevice">omp_is_initial_device</a>:</td><td> </td><td align="left" valign="top">Whether executing on the host device
</td></tr>
<tr><td align="left" valign="top">• <a href="#omp_005fset_005fdefault_005fdevice">omp_set_default_device</a>:</td><td> </td><td align="left" valign="top">Set the default device for target regions
</td></tr>
<tr><td align="left" valign="top">• <a href="#omp_005fset_005fdynamic">omp_set_dynamic</a>:</td><td> </td><td align="left" valign="top">Enable/disable dynamic teams
</td></tr>
<tr><td align="left" valign="top">• <a href="#omp_005fset_005fmax_005factive_005flevels">omp_set_max_active_levels</a>:</td><td> </td><td align="left" valign="top">Limits the number of active parallel regions
</td></tr>
<tr><td align="left" valign="top">• <a href="#omp_005fset_005fnested">omp_set_nested</a>:</td><td> </td><td align="left" valign="top">Enable/disable nested parallel regions
</td></tr>
<tr><td align="left" valign="top">• <a href="#omp_005fset_005fnum_005fthreads">omp_set_num_threads</a>:</td><td> </td><td align="left" valign="top">Set upper team size limit
</td></tr>
<tr><td align="left" valign="top">• <a href="#omp_005fset_005fschedule">omp_set_schedule</a>:</td><td> </td><td align="left" valign="top">Set the runtime scheduling method
</td></tr>
<tr><th colspan="3" align="left" valign="top"><pre class="menu-comment">
Initialize, set, test, unset and destroy simple and nested locks.
</pre></th></tr><tr><td align="left" valign="top">• <a href="#omp_005finit_005flock">omp_init_lock</a>:</td><td> </td><td align="left" valign="top">Initialize simple lock
</td></tr>
<tr><td align="left" valign="top">• <a href="#omp_005fset_005flock">omp_set_lock</a>:</td><td> </td><td align="left" valign="top">Wait for and set simple lock
</td></tr>
<tr><td align="left" valign="top">• <a href="#omp_005ftest_005flock">omp_test_lock</a>:</td><td> </td><td align="left" valign="top">Test and set simple lock if available
</td></tr>
<tr><td align="left" valign="top">• <a href="#omp_005funset_005flock">omp_unset_lock</a>:</td><td> </td><td align="left" valign="top">Unset simple lock
</td></tr>
<tr><td align="left" valign="top">• <a href="#omp_005fdestroy_005flock">omp_destroy_lock</a>:</td><td> </td><td align="left" valign="top">Destroy simple lock
</td></tr>
<tr><td align="left" valign="top">• <a href="#omp_005finit_005fnest_005flock">omp_init_nest_lock</a>:</td><td> </td><td align="left" valign="top">Initialize nested lock
</td></tr>
<tr><td align="left" valign="top">• <a href="#omp_005fset_005fnest_005flock">omp_set_nest_lock</a>:</td><td> </td><td align="left" valign="top">Wait for and set simple lock
</td></tr>
<tr><td align="left" valign="top">• <a href="#omp_005ftest_005fnest_005flock">omp_test_nest_lock</a>:</td><td> </td><td align="left" valign="top">Test and set nested lock if available
</td></tr>
<tr><td align="left" valign="top">• <a href="#omp_005funset_005fnest_005flock">omp_unset_nest_lock</a>:</td><td> </td><td align="left" valign="top">Unset nested lock
</td></tr>
<tr><td align="left" valign="top">• <a href="#omp_005fdestroy_005fnest_005flock">omp_destroy_nest_lock</a>:</td><td> </td><td align="left" valign="top">Destroy nested lock
</td></tr>
<tr><th colspan="3" align="left" valign="top"><pre class="menu-comment">
Portable, thread-based, wall clock timer.
</pre></th></tr><tr><td align="left" valign="top">• <a href="#omp_005fget_005fwtick">omp_get_wtick</a>:</td><td> </td><td align="left" valign="top">Get timer precision.
</td></tr>
<tr><td align="left" valign="top">• <a href="#omp_005fget_005fwtime">omp_get_wtime</a>:</td><td> </td><td align="left" valign="top">Elapsed wall clock time.
</td></tr>
</table>
<hr>
<a name="omp_005fget_005factive_005flevel"></a>
<div class="header">
<p>
Next: <a href="#omp_005fget_005fancestor_005fthread_005fnum" accesskey="n" rel="next">omp_get_ancestor_thread_num</a>, Up: <a href="#Runtime-Library-Routines" accesskey="u" rel="up">Runtime Library Routines</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="omp_005fget_005factive_005flevel-_002d_002d-Number-of-parallel-regions"></a>
<h3 class="section">2.1 <code>omp_get_active_level</code> – Number of parallel regions</h3>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>This function returns the nesting level for the active parallel blocks,
which enclose the calling call.
</p>
</dd>
<dt><em>C/C++</em></dt>
<dd><table>
<tr><td width="20%"><em>Prototype</em>:</td><td width="80%"><code>int omp_get_active_level(void);</code></td></tr>
</table>
</dd>
<dt><em>Fortran</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Interface</em>:</td><td width="80%"><code>integer function omp_get_active_level()</code></td></tr>
</table>
</dd>
<dt><em>See also</em>:</dt>
<dd><p><a href="#omp_005fget_005flevel">omp_get_level</a>, <a href="#omp_005fget_005fmax_005factive_005flevels">omp_get_max_active_levels</a>, <a href="#omp_005fset_005fmax_005factive_005flevels">omp_set_max_active_levels</a>
</p>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 3.2.20.
</p></dd>
</dl>
<hr>
<a name="omp_005fget_005fancestor_005fthread_005fnum"></a>
<div class="header">
<p>
Next: <a href="#omp_005fget_005fcancellation" accesskey="n" rel="next">omp_get_cancellation</a>, Previous: <a href="#omp_005fget_005factive_005flevel" accesskey="p" rel="prev">omp_get_active_level</a>, Up: <a href="#Runtime-Library-Routines" accesskey="u" rel="up">Runtime Library Routines</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="omp_005fget_005fancestor_005fthread_005fnum-_002d_002d-Ancestor-thread-ID"></a>
<h3 class="section">2.2 <code>omp_get_ancestor_thread_num</code> – Ancestor thread ID</h3>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>This function returns the thread identification number for the given
nesting level of the current thread. For values of <var>level</var> outside
zero to <code>omp_get_level</code> -1 is returned; if <var>level</var> is
<code>omp_get_level</code> the result is identical to <code>omp_get_thread_num</code>.
</p>
</dd>
<dt><em>C/C++</em></dt>
<dd><table>
<tr><td width="20%"><em>Prototype</em>:</td><td width="80%"><code>int omp_get_ancestor_thread_num(int level);</code></td></tr>
</table>
</dd>
<dt><em>Fortran</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Interface</em>:</td><td width="80%"><code>integer function omp_get_ancestor_thread_num(level)</code></td></tr>
<tr><td width="20%"></td><td width="80%"><code>integer level</code></td></tr>
</table>
</dd>
<dt><em>See also</em>:</dt>
<dd><p><a href="#omp_005fget_005flevel">omp_get_level</a>, <a href="#omp_005fget_005fthread_005fnum">omp_get_thread_num</a>, <a href="#omp_005fget_005fteam_005fsize">omp_get_team_size</a>
</p>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 3.2.18.
</p></dd>
</dl>
<hr>
<a name="omp_005fget_005fcancellation"></a>
<div class="header">
<p>
Next: <a href="#omp_005fget_005fdefault_005fdevice" accesskey="n" rel="next">omp_get_default_device</a>, Previous: <a href="#omp_005fget_005fancestor_005fthread_005fnum" accesskey="p" rel="prev">omp_get_ancestor_thread_num</a>, Up: <a href="#Runtime-Library-Routines" accesskey="u" rel="up">Runtime Library Routines</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="omp_005fget_005fcancellation-_002d_002d-Whether-cancellation-support-is-enabled"></a>
<h3 class="section">2.3 <code>omp_get_cancellation</code> – Whether cancellation support is enabled</h3>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>This function returns <code>true</code> if cancellation is activated, <code>false</code>
otherwise. Here, <code>true</code> and <code>false</code> represent their language-specific
counterparts. Unless <code>OMP_CANCELLATION</code> is set true, cancellations are
deactivated.
</p>
</dd>
<dt><em>C/C++</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Prototype</em>:</td><td width="80%"><code>int omp_get_cancellation(void);</code></td></tr>
</table>
</dd>
<dt><em>Fortran</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Interface</em>:</td><td width="80%"><code>logical function omp_get_cancellation()</code></td></tr>
</table>
</dd>
<dt><em>See also</em>:</dt>
<dd><p><a href="#OMP_005fCANCELLATION">OMP_CANCELLATION</a>
</p>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 3.2.9.
</p></dd>
</dl>
<hr>
<a name="omp_005fget_005fdefault_005fdevice"></a>
<div class="header">
<p>
Next: <a href="#omp_005fget_005fdynamic" accesskey="n" rel="next">omp_get_dynamic</a>, Previous: <a href="#omp_005fget_005fcancellation" accesskey="p" rel="prev">omp_get_cancellation</a>, Up: <a href="#Runtime-Library-Routines" accesskey="u" rel="up">Runtime Library Routines</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="omp_005fget_005fdefault_005fdevice-_002d_002d-Get-the-default-device-for-target-regions"></a>
<h3 class="section">2.4 <code>omp_get_default_device</code> – Get the default device for target regions</h3>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>Get the default device for target regions without device clause.
</p>
</dd>
<dt><em>C/C++</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Prototype</em>:</td><td width="80%"><code>int omp_get_default_device(void);</code></td></tr>
</table>
</dd>
<dt><em>Fortran</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Interface</em>:</td><td width="80%"><code>integer function omp_get_default_device()</code></td></tr>
</table>
</dd>
<dt><em>See also</em>:</dt>
<dd><p><a href="#OMP_005fDEFAULT_005fDEVICE">OMP_DEFAULT_DEVICE</a>, <a href="#omp_005fset_005fdefault_005fdevice">omp_set_default_device</a>
</p>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 3.2.24.
</p></dd>
</dl>
<hr>
<a name="omp_005fget_005fdynamic"></a>
<div class="header">
<p>
Next: <a href="#omp_005fget_005flevel" accesskey="n" rel="next">omp_get_level</a>, Previous: <a href="#omp_005fget_005fdefault_005fdevice" accesskey="p" rel="prev">omp_get_default_device</a>, Up: <a href="#Runtime-Library-Routines" accesskey="u" rel="up">Runtime Library Routines</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="omp_005fget_005fdynamic-_002d_002d-Dynamic-teams-setting"></a>
<h3 class="section">2.5 <code>omp_get_dynamic</code> – Dynamic teams setting</h3>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>This function returns <code>true</code> if enabled, <code>false</code> otherwise.
Here, <code>true</code> and <code>false</code> represent their language-specific
counterparts.
</p>
<p>The dynamic team setting may be initialized at startup by the
<code>OMP_DYNAMIC</code> environment variable or at runtime using
<code>omp_set_dynamic</code>. If undefined, dynamic adjustment is
disabled by default.
</p>
</dd>
<dt><em>C/C++</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Prototype</em>:</td><td width="80%"><code>int omp_get_dynamic(void);</code></td></tr>
</table>
</dd>
<dt><em>Fortran</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Interface</em>:</td><td width="80%"><code>logical function omp_get_dynamic()</code></td></tr>
</table>
</dd>
<dt><em>See also</em>:</dt>
<dd><p><a href="#omp_005fset_005fdynamic">omp_set_dynamic</a>, <a href="#OMP_005fDYNAMIC">OMP_DYNAMIC</a>
</p>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 3.2.8.
</p></dd>
</dl>
<hr>
<a name="omp_005fget_005flevel"></a>
<div class="header">
<p>
Next: <a href="#omp_005fget_005fmax_005factive_005flevels" accesskey="n" rel="next">omp_get_max_active_levels</a>, Previous: <a href="#omp_005fget_005fdynamic" accesskey="p" rel="prev">omp_get_dynamic</a>, Up: <a href="#Runtime-Library-Routines" accesskey="u" rel="up">Runtime Library Routines</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="omp_005fget_005flevel-_002d_002d-Obtain-the-current-nesting-level"></a>
<h3 class="section">2.6 <code>omp_get_level</code> – Obtain the current nesting level</h3>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>This function returns the nesting level for the parallel blocks,
which enclose the calling call.
</p>
</dd>
<dt><em>C/C++</em></dt>
<dd><table>
<tr><td width="20%"><em>Prototype</em>:</td><td width="80%"><code>int omp_get_level(void);</code></td></tr>
</table>
</dd>
<dt><em>Fortran</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Interface</em>:</td><td width="80%"><code>integer function omp_level()</code></td></tr>
</table>
</dd>
<dt><em>See also</em>:</dt>
<dd><p><a href="#omp_005fget_005factive_005flevel">omp_get_active_level</a>
</p>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 3.2.17.
</p></dd>
</dl>
<hr>
<a name="omp_005fget_005fmax_005factive_005flevels"></a>
<div class="header">
<p>
Next: <a href="#omp_005fget_005fmax_005fthreads" accesskey="n" rel="next">omp_get_max_threads</a>, Previous: <a href="#omp_005fget_005flevel" accesskey="p" rel="prev">omp_get_level</a>, Up: <a href="#Runtime-Library-Routines" accesskey="u" rel="up">Runtime Library Routines</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="omp_005fget_005fmax_005factive_005flevels-_002d_002d-Maximum-number-of-active-regions"></a>
<h3 class="section">2.7 <code>omp_get_max_active_levels</code> – Maximum number of active regions</h3>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>This function obtains the maximum allowed number of nested, active parallel regions.
</p>
</dd>
<dt><em>C/C++</em></dt>
<dd><table>
<tr><td width="20%"><em>Prototype</em>:</td><td width="80%"><code>int omp_get_max_active_levels(void);</code></td></tr>
</table>
</dd>
<dt><em>Fortran</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Interface</em>:</td><td width="80%"><code>integer function omp_get_max_active_levels()</code></td></tr>
</table>
</dd>
<dt><em>See also</em>:</dt>
<dd><p><a href="#omp_005fset_005fmax_005factive_005flevels">omp_set_max_active_levels</a>, <a href="#omp_005fget_005factive_005flevel">omp_get_active_level</a>
</p>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 3.2.16.
</p></dd>
</dl>
<hr>
<a name="omp_005fget_005fmax_005fthreads"></a>
<div class="header">
<p>
Next: <a href="#omp_005fget_005fnested" accesskey="n" rel="next">omp_get_nested</a>, Previous: <a href="#omp_005fget_005fmax_005factive_005flevels" accesskey="p" rel="prev">omp_get_max_active_levels</a>, Up: <a href="#Runtime-Library-Routines" accesskey="u" rel="up">Runtime Library Routines</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="omp_005fget_005fmax_005fthreads-_002d_002d-Maximum-number-of-threads-of-parallel-region"></a>
<h3 class="section">2.8 <code>omp_get_max_threads</code> – Maximum number of threads of parallel region</h3>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>Return the maximum number of threads used for the current parallel region
that does not use the clause <code>num_threads</code>.
</p>
</dd>
<dt><em>C/C++</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Prototype</em>:</td><td width="80%"><code>int omp_get_max_threads(void);</code></td></tr>
</table>
</dd>
<dt><em>Fortran</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Interface</em>:</td><td width="80%"><code>integer function omp_get_max_threads()</code></td></tr>
</table>
</dd>
<dt><em>See also</em>:</dt>
<dd><p><a href="#omp_005fset_005fnum_005fthreads">omp_set_num_threads</a>, <a href="#omp_005fset_005fdynamic">omp_set_dynamic</a>, <a href="#omp_005fget_005fthread_005flimit">omp_get_thread_limit</a>
</p>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 3.2.3.
</p></dd>
</dl>
<hr>
<a name="omp_005fget_005fnested"></a>
<div class="header">
<p>
Next: <a href="#omp_005fget_005fnum_005fdevices" accesskey="n" rel="next">omp_get_num_devices</a>, Previous: <a href="#omp_005fget_005fmax_005fthreads" accesskey="p" rel="prev">omp_get_max_threads</a>, Up: <a href="#Runtime-Library-Routines" accesskey="u" rel="up">Runtime Library Routines</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="omp_005fget_005fnested-_002d_002d-Nested-parallel-regions"></a>
<h3 class="section">2.9 <code>omp_get_nested</code> – Nested parallel regions</h3>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>This function returns <code>true</code> if nested parallel regions are
enabled, <code>false</code> otherwise. Here, <code>true</code> and <code>false</code>
represent their language-specific counterparts.
</p>
<p>Nested parallel regions may be initialized at startup by the
<code>OMP_NESTED</code> environment variable or at runtime using
<code>omp_set_nested</code>. If undefined, nested parallel regions are
disabled by default.
</p>
</dd>
<dt><em>C/C++</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Prototype</em>:</td><td width="80%"><code>int omp_get_nested(void);</code></td></tr>
</table>
</dd>
<dt><em>Fortran</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Interface</em>:</td><td width="80%"><code>logical function omp_get_nested()</code></td></tr>
</table>
</dd>
<dt><em>See also</em>:</dt>
<dd><p><a href="#omp_005fset_005fnested">omp_set_nested</a>, <a href="#OMP_005fNESTED">OMP_NESTED</a>
</p>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 3.2.11.
</p></dd>
</dl>
<hr>
<a name="omp_005fget_005fnum_005fdevices"></a>
<div class="header">
<p>
Next: <a href="#omp_005fget_005fnum_005fprocs" accesskey="n" rel="next">omp_get_num_procs</a>, Previous: <a href="#omp_005fget_005fnested" accesskey="p" rel="prev">omp_get_nested</a>, Up: <a href="#Runtime-Library-Routines" accesskey="u" rel="up">Runtime Library Routines</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="omp_005fget_005fnum_005fdevices-_002d_002d-Number-of-target-devices"></a>
<h3 class="section">2.10 <code>omp_get_num_devices</code> – Number of target devices</h3>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>Returns the number of target devices.
</p>
</dd>
<dt><em>C/C++</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Prototype</em>:</td><td width="80%"><code>int omp_get_num_devices(void);</code></td></tr>
</table>
</dd>
<dt><em>Fortran</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Interface</em>:</td><td width="80%"><code>integer function omp_get_num_devices()</code></td></tr>
</table>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 3.2.25.
</p></dd>
</dl>
<hr>
<a name="omp_005fget_005fnum_005fprocs"></a>
<div class="header">
<p>
Next: <a href="#omp_005fget_005fnum_005fteams" accesskey="n" rel="next">omp_get_num_teams</a>, Previous: <a href="#omp_005fget_005fnum_005fdevices" accesskey="p" rel="prev">omp_get_num_devices</a>, Up: <a href="#Runtime-Library-Routines" accesskey="u" rel="up">Runtime Library Routines</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="omp_005fget_005fnum_005fprocs-_002d_002d-Number-of-processors-online"></a>
<h3 class="section">2.11 <code>omp_get_num_procs</code> – Number of processors online</h3>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>Returns the number of processors online on that device.
</p>
</dd>
<dt><em>C/C++</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Prototype</em>:</td><td width="80%"><code>int omp_get_num_procs(void);</code></td></tr>
</table>
</dd>
<dt><em>Fortran</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Interface</em>:</td><td width="80%"><code>integer function omp_get_num_procs()</code></td></tr>
</table>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 3.2.5.
</p></dd>
</dl>
<hr>
<a name="omp_005fget_005fnum_005fteams"></a>
<div class="header">
<p>
Next: <a href="#omp_005fget_005fnum_005fthreads" accesskey="n" rel="next">omp_get_num_threads</a>, Previous: <a href="#omp_005fget_005fnum_005fprocs" accesskey="p" rel="prev">omp_get_num_procs</a>, Up: <a href="#Runtime-Library-Routines" accesskey="u" rel="up">Runtime Library Routines</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="omp_005fget_005fnum_005fteams-_002d_002d-Number-of-teams"></a>
<h3 class="section">2.12 <code>omp_get_num_teams</code> – Number of teams</h3>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>Returns the number of teams in the current team region.
</p>
</dd>
<dt><em>C/C++</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Prototype</em>:</td><td width="80%"><code>int omp_get_num_teams(void);</code></td></tr>
</table>
</dd>
<dt><em>Fortran</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Interface</em>:</td><td width="80%"><code>integer function omp_get_num_teams()</code></td></tr>
</table>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 3.2.26.
</p></dd>
</dl>
<hr>
<a name="omp_005fget_005fnum_005fthreads"></a>
<div class="header">
<p>
Next: <a href="#omp_005fget_005fproc_005fbind" accesskey="n" rel="next">omp_get_proc_bind</a>, Previous: <a href="#omp_005fget_005fnum_005fteams" accesskey="p" rel="prev">omp_get_num_teams</a>, Up: <a href="#Runtime-Library-Routines" accesskey="u" rel="up">Runtime Library Routines</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="omp_005fget_005fnum_005fthreads-_002d_002d-Size-of-the-active-team"></a>
<h3 class="section">2.13 <code>omp_get_num_threads</code> – Size of the active team</h3>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>Returns the number of threads in the current team. In a sequential section of
the program <code>omp_get_num_threads</code> returns 1.
</p>
<p>The default team size may be initialized at startup by the
<code>OMP_NUM_THREADS</code> environment variable. At runtime, the size
of the current team may be set either by the <code>NUM_THREADS</code>
clause or by <code>omp_set_num_threads</code>. If none of the above were
used to define a specific value and <code>OMP_DYNAMIC</code> is disabled,
one thread per CPU online is used.
</p>
</dd>
<dt><em>C/C++</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Prototype</em>:</td><td width="80%"><code>int omp_get_num_threads(void);</code></td></tr>
</table>
</dd>
<dt><em>Fortran</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Interface</em>:</td><td width="80%"><code>integer function omp_get_num_threads()</code></td></tr>
</table>
</dd>
<dt><em>See also</em>:</dt>
<dd><p><a href="#omp_005fget_005fmax_005fthreads">omp_get_max_threads</a>, <a href="#omp_005fset_005fnum_005fthreads">omp_set_num_threads</a>, <a href="#OMP_005fNUM_005fTHREADS">OMP_NUM_THREADS</a>
</p>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 3.2.2.
</p></dd>
</dl>
<hr>
<a name="omp_005fget_005fproc_005fbind"></a>
<div class="header">
<p>
Next: <a href="#omp_005fget_005fschedule" accesskey="n" rel="next">omp_get_schedule</a>, Previous: <a href="#omp_005fget_005fnum_005fthreads" accesskey="p" rel="prev">omp_get_num_threads</a>, Up: <a href="#Runtime-Library-Routines" accesskey="u" rel="up">Runtime Library Routines</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="omp_005fget_005fproc_005fbind-_002d_002d-Whether-theads-may-be-moved-between-CPUs"></a>
<h3 class="section">2.14 <code>omp_get_proc_bind</code> – Whether theads may be moved between CPUs</h3>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>This functions returns the currently active thread affinity policy, which is
set via <code>OMP_PROC_BIND</code>. Possible values are <code>omp_proc_bind_false</code>,
<code>omp_proc_bind_true</code>, <code>omp_proc_bind_master</code>,
<code>omp_proc_bind_close</code> and <code>omp_proc_bind_spread</code>.
</p>
</dd>
<dt><em>C/C++</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Prototype</em>:</td><td width="80%"><code>omp_proc_bind_t omp_get_proc_bind(void);</code></td></tr>
</table>
</dd>
<dt><em>Fortran</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Interface</em>:</td><td width="80%"><code>integer(kind=omp_proc_bind_kind) function omp_get_proc_bind()</code></td></tr>
</table>
</dd>
<dt><em>See also</em>:</dt>
<dd><p><a href="#OMP_005fPROC_005fBIND">OMP_PROC_BIND</a>, <a href="#OMP_005fPLACES">OMP_PLACES</a>, <a href="#GOMP_005fCPU_005fAFFINITY">GOMP_CPU_AFFINITY</a>,
</p>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 3.2.22.
</p></dd>
</dl>
<hr>
<a name="omp_005fget_005fschedule"></a>
<div class="header">
<p>
Next: <a href="#omp_005fget_005fteam_005fnum" accesskey="n" rel="next">omp_get_team_num</a>, Previous: <a href="#omp_005fget_005fproc_005fbind" accesskey="p" rel="prev">omp_get_proc_bind</a>, Up: <a href="#Runtime-Library-Routines" accesskey="u" rel="up">Runtime Library Routines</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="omp_005fget_005fschedule-_002d_002d-Obtain-the-runtime-scheduling-method"></a>
<h3 class="section">2.15 <code>omp_get_schedule</code> – Obtain the runtime scheduling method</h3>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>Obtain the runtime scheduling method. The <var>kind</var> argument will be
set to the value <code>omp_sched_static</code>, <code>omp_sched_dynamic</code>,
<code>omp_sched_guided</code> or <code>omp_sched_auto</code>. The second argument,
<var>modifier</var>, is set to the chunk size.
</p>
</dd>
<dt><em>C/C++</em></dt>
<dd><table>
<tr><td width="20%"><em>Prototype</em>:</td><td width="80%"><code>void omp_get_schedule(omp_sched_t *kind, int *modifier);</code></td></tr>
</table>
</dd>
<dt><em>Fortran</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Interface</em>:</td><td width="80%"><code>subroutine omp_get_schedule(kind, modifier)</code></td></tr>
<tr><td width="20%"></td><td width="80%"><code>integer(kind=omp_sched_kind) kind</code></td></tr>
<tr><td width="20%"></td><td width="80%"><code>integer modifier</code></td></tr>
</table>
</dd>
<dt><em>See also</em>:</dt>
<dd><p><a href="#omp_005fset_005fschedule">omp_set_schedule</a>, <a href="#OMP_005fSCHEDULE">OMP_SCHEDULE</a>
</p>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 3.2.13.
</p></dd>
</dl>
<hr>
<a name="omp_005fget_005fteam_005fnum"></a>
<div class="header">
<p>
Next: <a href="#omp_005fget_005fteam_005fsize" accesskey="n" rel="next">omp_get_team_size</a>, Previous: <a href="#omp_005fget_005fschedule" accesskey="p" rel="prev">omp_get_schedule</a>, Up: <a href="#Runtime-Library-Routines" accesskey="u" rel="up">Runtime Library Routines</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="omp_005fget_005fteam_005fnum-_002d_002d-Get-team-number"></a>
<h3 class="section">2.16 <code>omp_get_team_num</code> – Get team number</h3>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>Returns the team number of the calling thread.
</p>
</dd>
<dt><em>C/C++</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Prototype</em>:</td><td width="80%"><code>int omp_get_team_num(void);</code></td></tr>
</table>
</dd>
<dt><em>Fortran</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Interface</em>:</td><td width="80%"><code>integer function omp_get_team_num()</code></td></tr>
</table>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 3.2.27.
</p></dd>
</dl>
<hr>
<a name="omp_005fget_005fteam_005fsize"></a>
<div class="header">
<p>
Next: <a href="#omp_005fget_005fthread_005flimit" accesskey="n" rel="next">omp_get_thread_limit</a>, Previous: <a href="#omp_005fget_005fteam_005fnum" accesskey="p" rel="prev">omp_get_team_num</a>, Up: <a href="#Runtime-Library-Routines" accesskey="u" rel="up">Runtime Library Routines</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="omp_005fget_005fteam_005fsize-_002d_002d-Number-of-threads-in-a-team"></a>
<h3 class="section">2.17 <code>omp_get_team_size</code> – Number of threads in a team</h3>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>This function returns the number of threads in a thread team to which
either the current thread or its ancestor belongs. For values of <var>level</var>
outside zero to <code>omp_get_level</code>, -1 is returned; if <var>level</var> is zero,
1 is returned, and for <code>omp_get_level</code>, the result is identical
to <code>omp_get_num_threads</code>.
</p>
</dd>
<dt><em>C/C++</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Prototype</em>:</td><td width="80%"><code>int omp_get_team_size(int level);</code></td></tr>
</table>
</dd>
<dt><em>Fortran</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Interface</em>:</td><td width="80%"><code>integer function omp_get_team_size(level)</code></td></tr>
<tr><td width="20%"></td><td width="80%"><code>integer level</code></td></tr>
</table>
</dd>
<dt><em>See also</em>:</dt>
<dd><p><a href="#omp_005fget_005fnum_005fthreads">omp_get_num_threads</a>, <a href="#omp_005fget_005flevel">omp_get_level</a>, <a href="#omp_005fget_005fancestor_005fthread_005fnum">omp_get_ancestor_thread_num</a>
</p>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 3.2.19.
</p></dd>
</dl>
<hr>
<a name="omp_005fget_005fthread_005flimit"></a>
<div class="header">
<p>
Next: <a href="#omp_005fget_005fthread_005fnum" accesskey="n" rel="next">omp_get_thread_num</a>, Previous: <a href="#omp_005fget_005fteam_005fsize" accesskey="p" rel="prev">omp_get_team_size</a>, Up: <a href="#Runtime-Library-Routines" accesskey="u" rel="up">Runtime Library Routines</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="omp_005fget_005fthread_005flimit-_002d_002d-Maximum-number-of-threads"></a>
<h3 class="section">2.18 <code>omp_get_thread_limit</code> – Maximum number of threads</h3>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>Return the maximum number of threads of the program.
</p>
</dd>
<dt><em>C/C++</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Prototype</em>:</td><td width="80%"><code>int omp_get_thread_limit(void);</code></td></tr>
</table>
</dd>
<dt><em>Fortran</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Interface</em>:</td><td width="80%"><code>integer function omp_get_thread_limit()</code></td></tr>
</table>
</dd>
<dt><em>See also</em>:</dt>
<dd><p><a href="#omp_005fget_005fmax_005fthreads">omp_get_max_threads</a>, <a href="#OMP_005fTHREAD_005fLIMIT">OMP_THREAD_LIMIT</a>
</p>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 3.2.14.
</p></dd>
</dl>
<hr>
<a name="omp_005fget_005fthread_005fnum"></a>
<div class="header">
<p>
Next: <a href="#omp_005fin_005fparallel" accesskey="n" rel="next">omp_in_parallel</a>, Previous: <a href="#omp_005fget_005fthread_005flimit" accesskey="p" rel="prev">omp_get_thread_limit</a>, Up: <a href="#Runtime-Library-Routines" accesskey="u" rel="up">Runtime Library Routines</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="omp_005fget_005fthread_005fnum-_002d_002d-Current-thread-ID"></a>
<h3 class="section">2.19 <code>omp_get_thread_num</code> – Current thread ID</h3>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>Returns a unique thread identification number within the current team.
In a sequential parts of the program, <code>omp_get_thread_num</code>
always returns 0. In parallel regions the return value varies
from 0 to <code>omp_get_num_threads</code>-1 inclusive. The return
value of the master thread of a team is always 0.
</p>
</dd>
<dt><em>C/C++</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Prototype</em>:</td><td width="80%"><code>int omp_get_thread_num(void);</code></td></tr>
</table>
</dd>
<dt><em>Fortran</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Interface</em>:</td><td width="80%"><code>integer function omp_get_thread_num()</code></td></tr>
</table>
</dd>
<dt><em>See also</em>:</dt>
<dd><p><a href="#omp_005fget_005fnum_005fthreads">omp_get_num_threads</a>, <a href="#omp_005fget_005fancestor_005fthread_005fnum">omp_get_ancestor_thread_num</a>
</p>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 3.2.4.
</p></dd>
</dl>
<hr>
<a name="omp_005fin_005fparallel"></a>
<div class="header">
<p>
Next: <a href="#omp_005fin_005ffinal" accesskey="n" rel="next">omp_in_final</a>, Previous: <a href="#omp_005fget_005fthread_005fnum" accesskey="p" rel="prev">omp_get_thread_num</a>, Up: <a href="#Runtime-Library-Routines" accesskey="u" rel="up">Runtime Library Routines</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="omp_005fin_005fparallel-_002d_002d-Whether-a-parallel-region-is-active"></a>
<h3 class="section">2.20 <code>omp_in_parallel</code> – Whether a parallel region is active</h3>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>This function returns <code>true</code> if currently running in parallel,
<code>false</code> otherwise. Here, <code>true</code> and <code>false</code> represent
their language-specific counterparts.
</p>
</dd>
<dt><em>C/C++</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Prototype</em>:</td><td width="80%"><code>int omp_in_parallel(void);</code></td></tr>
</table>
</dd>
<dt><em>Fortran</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Interface</em>:</td><td width="80%"><code>logical function omp_in_parallel()</code></td></tr>
</table>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 3.2.6.
</p></dd>
</dl>
<hr>
<a name="omp_005fin_005ffinal"></a>
<div class="header">
<p>
Next: <a href="#omp_005fis_005finitial_005fdevice" accesskey="n" rel="next">omp_is_initial_device</a>, Previous: <a href="#omp_005fin_005fparallel" accesskey="p" rel="prev">omp_in_parallel</a>, Up: <a href="#Runtime-Library-Routines" accesskey="u" rel="up">Runtime Library Routines</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="omp_005fin_005ffinal-_002d_002d-Whether-in-final-or-included-task-region"></a>
<h3 class="section">2.21 <code>omp_in_final</code> – Whether in final or included task region</h3>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>This function returns <code>true</code> if currently running in a final
or included task region, <code>false</code> otherwise. Here, <code>true</code>
and <code>false</code> represent their language-specific counterparts.
</p>
</dd>
<dt><em>C/C++</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Prototype</em>:</td><td width="80%"><code>int omp_in_final(void);</code></td></tr>
</table>
</dd>
<dt><em>Fortran</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Interface</em>:</td><td width="80%"><code>logical function omp_in_final()</code></td></tr>
</table>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 3.2.21.
</p></dd>
</dl>
<hr>
<a name="omp_005fis_005finitial_005fdevice"></a>
<div class="header">
<p>
Next: <a href="#omp_005fset_005fdefault_005fdevice" accesskey="n" rel="next">omp_set_default_device</a>, Previous: <a href="#omp_005fin_005ffinal" accesskey="p" rel="prev">omp_in_final</a>, Up: <a href="#Runtime-Library-Routines" accesskey="u" rel="up">Runtime Library Routines</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="omp_005fis_005finitial_005fdevice-_002d_002d-Whether-executing-on-the-host-device"></a>
<h3 class="section">2.22 <code>omp_is_initial_device</code> – Whether executing on the host device</h3>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>This function returns <code>true</code> if currently running on the host device,
<code>false</code> otherwise. Here, <code>true</code> and <code>false</code> represent
their language-specific counterparts.
</p>
</dd>
<dt><em>C/C++</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Prototype</em>:</td><td width="80%"><code>int omp_is_initial_device(void);</code></td></tr>
</table>
</dd>
<dt><em>Fortran</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Interface</em>:</td><td width="80%"><code>logical function omp_is_initial_device()</code></td></tr>
</table>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 3.2.28.
</p></dd>
</dl>
<hr>
<a name="omp_005fset_005fdefault_005fdevice"></a>
<div class="header">
<p>
Next: <a href="#omp_005fset_005fdynamic" accesskey="n" rel="next">omp_set_dynamic</a>, Previous: <a href="#omp_005fis_005finitial_005fdevice" accesskey="p" rel="prev">omp_is_initial_device</a>, Up: <a href="#Runtime-Library-Routines" accesskey="u" rel="up">Runtime Library Routines</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="omp_005fset_005fdefault_005fdevice-_002d_002d-Set-the-default-device-for-target-regions"></a>
<h3 class="section">2.23 <code>omp_set_default_device</code> – Set the default device for target regions</h3>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>Set the default device for target regions without device clause. The argument
shall be a nonnegative device number.
</p>
</dd>
<dt><em>C/C++</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Prototype</em>:</td><td width="80%"><code>void omp_set_default_device(int device_num);</code></td></tr>
</table>
</dd>
<dt><em>Fortran</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Interface</em>:</td><td width="80%"><code>subroutine omp_set_default_device(device_num)</code></td></tr>
<tr><td width="20%"></td><td width="80%"><code>integer device_num</code></td></tr>
</table>
</dd>
<dt><em>See also</em>:</dt>
<dd><p><a href="#OMP_005fDEFAULT_005fDEVICE">OMP_DEFAULT_DEVICE</a>, <a href="#omp_005fget_005fdefault_005fdevice">omp_get_default_device</a>
</p>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 3.2.23.
</p></dd>
</dl>
<hr>
<a name="omp_005fset_005fdynamic"></a>
<div class="header">
<p>
Next: <a href="#omp_005fset_005fmax_005factive_005flevels" accesskey="n" rel="next">omp_set_max_active_levels</a>, Previous: <a href="#omp_005fset_005fdefault_005fdevice" accesskey="p" rel="prev">omp_set_default_device</a>, Up: <a href="#Runtime-Library-Routines" accesskey="u" rel="up">Runtime Library Routines</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="omp_005fset_005fdynamic-_002d_002d-Enable_002fdisable-dynamic-teams"></a>
<h3 class="section">2.24 <code>omp_set_dynamic</code> – Enable/disable dynamic teams</h3>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>Enable or disable the dynamic adjustment of the number of threads
within a team. The function takes the language-specific equivalent
of <code>true</code> and <code>false</code>, where <code>true</code> enables dynamic
adjustment of team sizes and <code>false</code> disables it.
</p>
</dd>
<dt><em>C/C++</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Prototype</em>:</td><td width="80%"><code>void omp_set_dynamic(int dynamic_threads);</code></td></tr>
</table>
</dd>
<dt><em>Fortran</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Interface</em>:</td><td width="80%"><code>subroutine omp_set_dynamic(dynamic_threads)</code></td></tr>
<tr><td width="20%"></td><td width="80%"><code>logical, intent(in) :: dynamic_threads</code></td></tr>
</table>
</dd>
<dt><em>See also</em>:</dt>
<dd><p><a href="#OMP_005fDYNAMIC">OMP_DYNAMIC</a>, <a href="#omp_005fget_005fdynamic">omp_get_dynamic</a>
</p>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 3.2.7.
</p></dd>
</dl>
<hr>
<a name="omp_005fset_005fmax_005factive_005flevels"></a>
<div class="header">
<p>
Next: <a href="#omp_005fset_005fnested" accesskey="n" rel="next">omp_set_nested</a>, Previous: <a href="#omp_005fset_005fdynamic" accesskey="p" rel="prev">omp_set_dynamic</a>, Up: <a href="#Runtime-Library-Routines" accesskey="u" rel="up">Runtime Library Routines</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="omp_005fset_005fmax_005factive_005flevels-_002d_002d-Limits-the-number-of-active-parallel-regions"></a>
<h3 class="section">2.25 <code>omp_set_max_active_levels</code> – Limits the number of active parallel regions</h3>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>This function limits the maximum allowed number of nested, active
parallel regions.
</p>
</dd>
<dt><em>C/C++</em></dt>
<dd><table>
<tr><td width="20%"><em>Prototype</em>:</td><td width="80%"><code>void omp_set_max_active_levels(int max_levels);</code></td></tr>
</table>
</dd>
<dt><em>Fortran</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Interface</em>:</td><td width="80%"><code>subroutine omp_set_max_active_levels(max_levels)</code></td></tr>
<tr><td width="20%"></td><td width="80%"><code>integer max_levels</code></td></tr>
</table>
</dd>
<dt><em>See also</em>:</dt>
<dd><p><a href="#omp_005fget_005fmax_005factive_005flevels">omp_get_max_active_levels</a>, <a href="#omp_005fget_005factive_005flevel">omp_get_active_level</a>
</p>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 3.2.15.
</p></dd>
</dl>
<hr>
<a name="omp_005fset_005fnested"></a>
<div class="header">
<p>
Next: <a href="#omp_005fset_005fnum_005fthreads" accesskey="n" rel="next">omp_set_num_threads</a>, Previous: <a href="#omp_005fset_005fmax_005factive_005flevels" accesskey="p" rel="prev">omp_set_max_active_levels</a>, Up: <a href="#Runtime-Library-Routines" accesskey="u" rel="up">Runtime Library Routines</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="omp_005fset_005fnested-_002d_002d-Enable_002fdisable-nested-parallel-regions"></a>
<h3 class="section">2.26 <code>omp_set_nested</code> – Enable/disable nested parallel regions</h3>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>Enable or disable nested parallel regions, i.e., whether team members
are allowed to create new teams. The function takes the language-specific
equivalent of <code>true</code> and <code>false</code>, where <code>true</code> enables
dynamic adjustment of team sizes and <code>false</code> disables it.
</p>
</dd>
<dt><em>C/C++</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Prototype</em>:</td><td width="80%"><code>void omp_set_nested(int nested);</code></td></tr>
</table>
</dd>
<dt><em>Fortran</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Interface</em>:</td><td width="80%"><code>subroutine omp_set_nested(nested)</code></td></tr>
<tr><td width="20%"></td><td width="80%"><code>logical, intent(in) :: nested</code></td></tr>
</table>
</dd>
<dt><em>See also</em>:</dt>
<dd><p><a href="#OMP_005fNESTED">OMP_NESTED</a>, <a href="#omp_005fget_005fnested">omp_get_nested</a>
</p>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 3.2.10.
</p></dd>
</dl>
<hr>
<a name="omp_005fset_005fnum_005fthreads"></a>
<div class="header">
<p>
Next: <a href="#omp_005fset_005fschedule" accesskey="n" rel="next">omp_set_schedule</a>, Previous: <a href="#omp_005fset_005fnested" accesskey="p" rel="prev">omp_set_nested</a>, Up: <a href="#Runtime-Library-Routines" accesskey="u" rel="up">Runtime Library Routines</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="omp_005fset_005fnum_005fthreads-_002d_002d-Set-upper-team-size-limit"></a>
<h3 class="section">2.27 <code>omp_set_num_threads</code> – Set upper team size limit</h3>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>Specifies the number of threads used by default in subsequent parallel
sections, if those do not specify a <code>num_threads</code> clause. The
argument of <code>omp_set_num_threads</code> shall be a positive integer.
</p>
</dd>
<dt><em>C/C++</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Prototype</em>:</td><td width="80%"><code>void omp_set_num_threads(int num_threads);</code></td></tr>
</table>
</dd>
<dt><em>Fortran</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Interface</em>:</td><td width="80%"><code>subroutine omp_set_num_threads(num_threads)</code></td></tr>
<tr><td width="20%"></td><td width="80%"><code>integer, intent(in) :: num_threads</code></td></tr>
</table>
</dd>
<dt><em>See also</em>:</dt>
<dd><p><a href="#OMP_005fNUM_005fTHREADS">OMP_NUM_THREADS</a>, <a href="#omp_005fget_005fnum_005fthreads">omp_get_num_threads</a>, <a href="#omp_005fget_005fmax_005fthreads">omp_get_max_threads</a>
</p>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 3.2.1.
</p></dd>
</dl>
<hr>
<a name="omp_005fset_005fschedule"></a>
<div class="header">
<p>
Next: <a href="#omp_005finit_005flock" accesskey="n" rel="next">omp_init_lock</a>, Previous: <a href="#omp_005fset_005fnum_005fthreads" accesskey="p" rel="prev">omp_set_num_threads</a>, Up: <a href="#Runtime-Library-Routines" accesskey="u" rel="up">Runtime Library Routines</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="omp_005fset_005fschedule-_002d_002d-Set-the-runtime-scheduling-method"></a>
<h3 class="section">2.28 <code>omp_set_schedule</code> – Set the runtime scheduling method</h3>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>Sets the runtime scheduling method. The <var>kind</var> argument can have the
value <code>omp_sched_static</code>, <code>omp_sched_dynamic</code>,
<code>omp_sched_guided</code> or <code>omp_sched_auto</code>. Except for
<code>omp_sched_auto</code>, the chunk size is set to the value of
<var>modifier</var> if positive, or to the default value if zero or negative.
For <code>omp_sched_auto</code> the <var>modifier</var> argument is ignored.
</p>
</dd>
<dt><em>C/C++</em></dt>
<dd><table>
<tr><td width="20%"><em>Prototype</em>:</td><td width="80%"><code>void omp_set_schedule(omp_sched_t kind, int modifier);</code></td></tr>
</table>
</dd>
<dt><em>Fortran</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Interface</em>:</td><td width="80%"><code>subroutine omp_set_schedule(kind, modifier)</code></td></tr>
<tr><td width="20%"></td><td width="80%"><code>integer(kind=omp_sched_kind) kind</code></td></tr>
<tr><td width="20%"></td><td width="80%"><code>integer modifier</code></td></tr>
</table>
</dd>
<dt><em>See also</em>:</dt>
<dd><p><a href="#omp_005fget_005fschedule">omp_get_schedule</a>
<a href="#OMP_005fSCHEDULE">OMP_SCHEDULE</a>
</p>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 3.2.12.
</p></dd>
</dl>
<hr>
<a name="omp_005finit_005flock"></a>
<div class="header">
<p>
Next: <a href="#omp_005fset_005flock" accesskey="n" rel="next">omp_set_lock</a>, Previous: <a href="#omp_005fset_005fschedule" accesskey="p" rel="prev">omp_set_schedule</a>, Up: <a href="#Runtime-Library-Routines" accesskey="u" rel="up">Runtime Library Routines</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="omp_005finit_005flock-_002d_002d-Initialize-simple-lock"></a>
<h3 class="section">2.29 <code>omp_init_lock</code> – Initialize simple lock</h3>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>Initialize a simple lock. After initialization, the lock is in
an unlocked state.
</p>
</dd>
<dt><em>C/C++</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Prototype</em>:</td><td width="80%"><code>void omp_init_lock(omp_lock_t *lock);</code></td></tr>
</table>
</dd>
<dt><em>Fortran</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Interface</em>:</td><td width="80%"><code>subroutine omp_init_lock(svar)</code></td></tr>
<tr><td width="20%"></td><td width="80%"><code>integer(omp_lock_kind), intent(out) :: svar</code></td></tr>
</table>
</dd>
<dt><em>See also</em>:</dt>
<dd><p><a href="#omp_005fdestroy_005flock">omp_destroy_lock</a>
</p>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 3.3.1.
</p></dd>
</dl>
<hr>
<a name="omp_005fset_005flock"></a>
<div class="header">
<p>
Next: <a href="#omp_005ftest_005flock" accesskey="n" rel="next">omp_test_lock</a>, Previous: <a href="#omp_005finit_005flock" accesskey="p" rel="prev">omp_init_lock</a>, Up: <a href="#Runtime-Library-Routines" accesskey="u" rel="up">Runtime Library Routines</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="omp_005fset_005flock-_002d_002d-Wait-for-and-set-simple-lock"></a>
<h3 class="section">2.30 <code>omp_set_lock</code> – Wait for and set simple lock</h3>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>Before setting a simple lock, the lock variable must be initialized by
<code>omp_init_lock</code>. The calling thread is blocked until the lock
is available. If the lock is already held by the current thread,
a deadlock occurs.
</p>
</dd>
<dt><em>C/C++</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Prototype</em>:</td><td width="80%"><code>void omp_set_lock(omp_lock_t *lock);</code></td></tr>
</table>
</dd>
<dt><em>Fortran</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Interface</em>:</td><td width="80%"><code>subroutine omp_set_lock(svar)</code></td></tr>
<tr><td width="20%"></td><td width="80%"><code>integer(omp_lock_kind), intent(inout) :: svar</code></td></tr>
</table>
</dd>
<dt><em>See also</em>:</dt>
<dd><p><a href="#omp_005finit_005flock">omp_init_lock</a>, <a href="#omp_005ftest_005flock">omp_test_lock</a>, <a href="#omp_005funset_005flock">omp_unset_lock</a>
</p>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 3.3.3.
</p></dd>
</dl>
<hr>
<a name="omp_005ftest_005flock"></a>
<div class="header">
<p>
Next: <a href="#omp_005funset_005flock" accesskey="n" rel="next">omp_unset_lock</a>, Previous: <a href="#omp_005fset_005flock" accesskey="p" rel="prev">omp_set_lock</a>, Up: <a href="#Runtime-Library-Routines" accesskey="u" rel="up">Runtime Library Routines</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="omp_005ftest_005flock-_002d_002d-Test-and-set-simple-lock-if-available"></a>
<h3 class="section">2.31 <code>omp_test_lock</code> – Test and set simple lock if available</h3>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>Before setting a simple lock, the lock variable must be initialized by
<code>omp_init_lock</code>. Contrary to <code>omp_set_lock</code>, <code>omp_test_lock</code>
does not block if the lock is not available. This function returns
<code>true</code> upon success, <code>false</code> otherwise. Here, <code>true</code> and
<code>false</code> represent their language-specific counterparts.
</p>
</dd>
<dt><em>C/C++</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Prototype</em>:</td><td width="80%"><code>int omp_test_lock(omp_lock_t *lock);</code></td></tr>
</table>
</dd>
<dt><em>Fortran</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Interface</em>:</td><td width="80%"><code>logical function omp_test_lock(svar)</code></td></tr>
<tr><td width="20%"></td><td width="80%"><code>integer(omp_lock_kind), intent(inout) :: svar</code></td></tr>
</table>
</dd>
<dt><em>See also</em>:</dt>
<dd><p><a href="#omp_005finit_005flock">omp_init_lock</a>, <a href="#omp_005fset_005flock">omp_set_lock</a>, <a href="#omp_005fset_005flock">omp_set_lock</a>
</p>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 3.3.5.
</p></dd>
</dl>
<hr>
<a name="omp_005funset_005flock"></a>
<div class="header">
<p>
Next: <a href="#omp_005fdestroy_005flock" accesskey="n" rel="next">omp_destroy_lock</a>, Previous: <a href="#omp_005ftest_005flock" accesskey="p" rel="prev">omp_test_lock</a>, Up: <a href="#Runtime-Library-Routines" accesskey="u" rel="up">Runtime Library Routines</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="omp_005funset_005flock-_002d_002d-Unset-simple-lock"></a>
<h3 class="section">2.32 <code>omp_unset_lock</code> – Unset simple lock</h3>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>A simple lock about to be unset must have been locked by <code>omp_set_lock</code>
or <code>omp_test_lock</code> before. In addition, the lock must be held by the
thread calling <code>omp_unset_lock</code>. Then, the lock becomes unlocked. If one
or more threads attempted to set the lock before, one of them is chosen to,
again, set the lock to itself.
</p>
</dd>
<dt><em>C/C++</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Prototype</em>:</td><td width="80%"><code>void omp_unset_lock(omp_lock_t *lock);</code></td></tr>
</table>
</dd>
<dt><em>Fortran</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Interface</em>:</td><td width="80%"><code>subroutine omp_unset_lock(svar)</code></td></tr>
<tr><td width="20%"></td><td width="80%"><code>integer(omp_lock_kind), intent(inout) :: svar</code></td></tr>
</table>
</dd>
<dt><em>See also</em>:</dt>
<dd><p><a href="#omp_005fset_005flock">omp_set_lock</a>, <a href="#omp_005ftest_005flock">omp_test_lock</a>
</p>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 3.3.4.
</p></dd>
</dl>
<hr>
<a name="omp_005fdestroy_005flock"></a>
<div class="header">
<p>
Next: <a href="#omp_005finit_005fnest_005flock" accesskey="n" rel="next">omp_init_nest_lock</a>, Previous: <a href="#omp_005funset_005flock" accesskey="p" rel="prev">omp_unset_lock</a>, Up: <a href="#Runtime-Library-Routines" accesskey="u" rel="up">Runtime Library Routines</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="omp_005fdestroy_005flock-_002d_002d-Destroy-simple-lock"></a>
<h3 class="section">2.33 <code>omp_destroy_lock</code> – Destroy simple lock</h3>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>Destroy a simple lock. In order to be destroyed, a simple lock must be
in the unlocked state.
</p>
</dd>
<dt><em>C/C++</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Prototype</em>:</td><td width="80%"><code>void omp_destroy_lock(omp_lock_t *lock);</code></td></tr>
</table>
</dd>
<dt><em>Fortran</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Interface</em>:</td><td width="80%"><code>subroutine omp_destroy_lock(svar)</code></td></tr>
<tr><td width="20%"></td><td width="80%"><code>integer(omp_lock_kind), intent(inout) :: svar</code></td></tr>
</table>
</dd>
<dt><em>See also</em>:</dt>
<dd><p><a href="#omp_005finit_005flock">omp_init_lock</a>
</p>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 3.3.2.
</p></dd>
</dl>
<hr>
<a name="omp_005finit_005fnest_005flock"></a>
<div class="header">
<p>
Next: <a href="#omp_005fset_005fnest_005flock" accesskey="n" rel="next">omp_set_nest_lock</a>, Previous: <a href="#omp_005fdestroy_005flock" accesskey="p" rel="prev">omp_destroy_lock</a>, Up: <a href="#Runtime-Library-Routines" accesskey="u" rel="up">Runtime Library Routines</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="omp_005finit_005fnest_005flock-_002d_002d-Initialize-nested-lock"></a>
<h3 class="section">2.34 <code>omp_init_nest_lock</code> – Initialize nested lock</h3>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>Initialize a nested lock. After initialization, the lock is in
an unlocked state and the nesting count is set to zero.
</p>
</dd>
<dt><em>C/C++</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Prototype</em>:</td><td width="80%"><code>void omp_init_nest_lock(omp_nest_lock_t *lock);</code></td></tr>
</table>
</dd>
<dt><em>Fortran</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Interface</em>:</td><td width="80%"><code>subroutine omp_init_nest_lock(nvar)</code></td></tr>
<tr><td width="20%"></td><td width="80%"><code>integer(omp_nest_lock_kind), intent(out) :: nvar</code></td></tr>
</table>
</dd>
<dt><em>See also</em>:</dt>
<dd><p><a href="#omp_005fdestroy_005fnest_005flock">omp_destroy_nest_lock</a>
</p>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 3.3.1.
</p></dd>
</dl>
<hr>
<a name="omp_005fset_005fnest_005flock"></a>
<div class="header">
<p>
Next: <a href="#omp_005ftest_005fnest_005flock" accesskey="n" rel="next">omp_test_nest_lock</a>, Previous: <a href="#omp_005finit_005fnest_005flock" accesskey="p" rel="prev">omp_init_nest_lock</a>, Up: <a href="#Runtime-Library-Routines" accesskey="u" rel="up">Runtime Library Routines</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="omp_005fset_005fnest_005flock-_002d_002d-Wait-for-and-set-nested-lock"></a>
<h3 class="section">2.35 <code>omp_set_nest_lock</code> – Wait for and set nested lock</h3>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>Before setting a nested lock, the lock variable must be initialized by
<code>omp_init_nest_lock</code>. The calling thread is blocked until the lock
is available. If the lock is already held by the current thread, the
nesting count for the lock is incremented.
</p>
</dd>
<dt><em>C/C++</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Prototype</em>:</td><td width="80%"><code>void omp_set_nest_lock(omp_nest_lock_t *lock);</code></td></tr>
</table>
</dd>
<dt><em>Fortran</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Interface</em>:</td><td width="80%"><code>subroutine omp_set_nest_lock(nvar)</code></td></tr>
<tr><td width="20%"></td><td width="80%"><code>integer(omp_nest_lock_kind), intent(inout) :: nvar</code></td></tr>
</table>
</dd>
<dt><em>See also</em>:</dt>
<dd><p><a href="#omp_005finit_005fnest_005flock">omp_init_nest_lock</a>, <a href="#omp_005funset_005fnest_005flock">omp_unset_nest_lock</a>
</p>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 3.3.3.
</p></dd>
</dl>
<hr>
<a name="omp_005ftest_005fnest_005flock"></a>
<div class="header">
<p>
Next: <a href="#omp_005funset_005fnest_005flock" accesskey="n" rel="next">omp_unset_nest_lock</a>, Previous: <a href="#omp_005fset_005fnest_005flock" accesskey="p" rel="prev">omp_set_nest_lock</a>, Up: <a href="#Runtime-Library-Routines" accesskey="u" rel="up">Runtime Library Routines</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="omp_005ftest_005fnest_005flock-_002d_002d-Test-and-set-nested-lock-if-available"></a>
<h3 class="section">2.36 <code>omp_test_nest_lock</code> – Test and set nested lock if available</h3>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>Before setting a nested lock, the lock variable must be initialized by
<code>omp_init_nest_lock</code>. Contrary to <code>omp_set_nest_lock</code>,
<code>omp_test_nest_lock</code> does not block if the lock is not available.
If the lock is already held by the current thread, the new nesting count
is returned. Otherwise, the return value equals zero.
</p>
</dd>
<dt><em>C/C++</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Prototype</em>:</td><td width="80%"><code>int omp_test_nest_lock(omp_nest_lock_t *lock);</code></td></tr>
</table>
</dd>
<dt><em>Fortran</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Interface</em>:</td><td width="80%"><code>logical function omp_test_nest_lock(nvar)</code></td></tr>
<tr><td width="20%"></td><td width="80%"><code>integer(omp_nest_lock_kind), intent(inout) :: nvar</code></td></tr>
</table>
</dd>
<dt><em>See also</em>:</dt>
<dd><p><a href="#omp_005finit_005flock">omp_init_lock</a>, <a href="#omp_005fset_005flock">omp_set_lock</a>, <a href="#omp_005fset_005flock">omp_set_lock</a>
</p>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 3.3.5.
</p></dd>
</dl>
<hr>
<a name="omp_005funset_005fnest_005flock"></a>
<div class="header">
<p>
Next: <a href="#omp_005fdestroy_005fnest_005flock" accesskey="n" rel="next">omp_destroy_nest_lock</a>, Previous: <a href="#omp_005ftest_005fnest_005flock" accesskey="p" rel="prev">omp_test_nest_lock</a>, Up: <a href="#Runtime-Library-Routines" accesskey="u" rel="up">Runtime Library Routines</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="omp_005funset_005fnest_005flock-_002d_002d-Unset-nested-lock"></a>
<h3 class="section">2.37 <code>omp_unset_nest_lock</code> – Unset nested lock</h3>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>A nested lock about to be unset must have been locked by <code>omp_set_nested_lock</code>
or <code>omp_test_nested_lock</code> before. In addition, the lock must be held by the
thread calling <code>omp_unset_nested_lock</code>. If the nesting count drops to zero, the
lock becomes unlocked. If one ore more threads attempted to set the lock before,
one of them is chosen to, again, set the lock to itself.
</p>
</dd>
<dt><em>C/C++</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Prototype</em>:</td><td width="80%"><code>void omp_unset_nest_lock(omp_nest_lock_t *lock);</code></td></tr>
</table>
</dd>
<dt><em>Fortran</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Interface</em>:</td><td width="80%"><code>subroutine omp_unset_nest_lock(nvar)</code></td></tr>
<tr><td width="20%"></td><td width="80%"><code>integer(omp_nest_lock_kind), intent(inout) :: nvar</code></td></tr>
</table>
</dd>
<dt><em>See also</em>:</dt>
<dd><p><a href="#omp_005fset_005fnest_005flock">omp_set_nest_lock</a>
</p>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 3.3.4.
</p></dd>
</dl>
<hr>
<a name="omp_005fdestroy_005fnest_005flock"></a>
<div class="header">
<p>
Next: <a href="#omp_005fget_005fwtick" accesskey="n" rel="next">omp_get_wtick</a>, Previous: <a href="#omp_005funset_005fnest_005flock" accesskey="p" rel="prev">omp_unset_nest_lock</a>, Up: <a href="#Runtime-Library-Routines" accesskey="u" rel="up">Runtime Library Routines</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="omp_005fdestroy_005fnest_005flock-_002d_002d-Destroy-nested-lock"></a>
<h3 class="section">2.38 <code>omp_destroy_nest_lock</code> – Destroy nested lock</h3>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>Destroy a nested lock. In order to be destroyed, a nested lock must be
in the unlocked state and its nesting count must equal zero.
</p>
</dd>
<dt><em>C/C++</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Prototype</em>:</td><td width="80%"><code>void omp_destroy_nest_lock(omp_nest_lock_t *);</code></td></tr>
</table>
</dd>
<dt><em>Fortran</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Interface</em>:</td><td width="80%"><code>subroutine omp_destroy_nest_lock(nvar)</code></td></tr>
<tr><td width="20%"></td><td width="80%"><code>integer(omp_nest_lock_kind), intent(inout) :: nvar</code></td></tr>
</table>
</dd>
<dt><em>See also</em>:</dt>
<dd><p><a href="#omp_005finit_005flock">omp_init_lock</a>
</p>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 3.3.2.
</p></dd>
</dl>
<hr>
<a name="omp_005fget_005fwtick"></a>
<div class="header">
<p>
Next: <a href="#omp_005fget_005fwtime" accesskey="n" rel="next">omp_get_wtime</a>, Previous: <a href="#omp_005fdestroy_005fnest_005flock" accesskey="p" rel="prev">omp_destroy_nest_lock</a>, Up: <a href="#Runtime-Library-Routines" accesskey="u" rel="up">Runtime Library Routines</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="omp_005fget_005fwtick-_002d_002d-Get-timer-precision"></a>
<h3 class="section">2.39 <code>omp_get_wtick</code> – Get timer precision</h3>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>Gets the timer precision, i.e., the number of seconds between two
successive clock ticks.
</p>
</dd>
<dt><em>C/C++</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Prototype</em>:</td><td width="80%"><code>double omp_get_wtick(void);</code></td></tr>
</table>
</dd>
<dt><em>Fortran</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Interface</em>:</td><td width="80%"><code>double precision function omp_get_wtick()</code></td></tr>
</table>
</dd>
<dt><em>See also</em>:</dt>
<dd><p><a href="#omp_005fget_005fwtime">omp_get_wtime</a>
</p>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 3.4.2.
</p></dd>
</dl>
<hr>
<a name="omp_005fget_005fwtime"></a>
<div class="header">
<p>
Previous: <a href="#omp_005fget_005fwtick" accesskey="p" rel="prev">omp_get_wtick</a>, Up: <a href="#Runtime-Library-Routines" accesskey="u" rel="up">Runtime Library Routines</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="omp_005fget_005fwtime-_002d_002d-Elapsed-wall-clock-time"></a>
<h3 class="section">2.40 <code>omp_get_wtime</code> – Elapsed wall clock time</h3>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>Elapsed wall clock time in seconds. The time is measured per thread, no
guarantee can be made that two distinct threads measure the same time.
Time is measured from some "time in the past", which is an arbitrary time
guaranteed not to change during the execution of the program.
</p>
</dd>
<dt><em>C/C++</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Prototype</em>:</td><td width="80%"><code>double omp_get_wtime(void);</code></td></tr>
</table>
</dd>
<dt><em>Fortran</em>:</dt>
<dd><table>
<tr><td width="20%"><em>Interface</em>:</td><td width="80%"><code>double precision function omp_get_wtime()</code></td></tr>
</table>
</dd>
<dt><em>See also</em>:</dt>
<dd><p><a href="#omp_005fget_005fwtick">omp_get_wtick</a>
</p>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 3.4.1.
</p></dd>
</dl>
<hr>
<a name="Environment-Variables"></a>
<div class="header">
<p>
Next: <a href="#The-libgomp-ABI" accesskey="n" rel="next">The libgomp ABI</a>, Previous: <a href="#Runtime-Library-Routines" accesskey="p" rel="prev">Runtime Library Routines</a>, Up: <a href="#Top" accesskey="u" rel="up">Top</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="Environment-Variables-1"></a>
<h2 class="chapter">3 Environment Variables</h2>
<p>The environment variables which beginning with <code>OMP_</code> are defined by
section 4 of the OpenMP specification in version 4.0, while those
beginning with <code>GOMP_</code> are GNU extensions.
</p>
<table class="menu" border="0" cellspacing="0">
<tr><td align="left" valign="top">• <a href="#OMP_005fCANCELLATION" accesskey="1">OMP_CANCELLATION</a>:</td><td> </td><td align="left" valign="top">Set whether cancellation is activated
</td></tr>
<tr><td align="left" valign="top">• <a href="#OMP_005fDISPLAY_005fENV" accesskey="2">OMP_DISPLAY_ENV</a>:</td><td> </td><td align="left" valign="top">Show OpenMP version and environment variables
</td></tr>
<tr><td align="left" valign="top">• <a href="#OMP_005fDEFAULT_005fDEVICE" accesskey="3">OMP_DEFAULT_DEVICE</a>:</td><td> </td><td align="left" valign="top">Set the device used in target regions
</td></tr>
<tr><td align="left" valign="top">• <a href="#OMP_005fDYNAMIC" accesskey="4">OMP_DYNAMIC</a>:</td><td> </td><td align="left" valign="top">Dynamic adjustment of threads
</td></tr>
<tr><td align="left" valign="top">• <a href="#OMP_005fMAX_005fACTIVE_005fLEVELS" accesskey="5">OMP_MAX_ACTIVE_LEVELS</a>:</td><td> </td><td align="left" valign="top">Set the maximum number of nested parallel regions
</td></tr>
<tr><td align="left" valign="top">• <a href="#OMP_005fNESTED" accesskey="6">OMP_NESTED</a>:</td><td> </td><td align="left" valign="top">Nested parallel regions
</td></tr>
<tr><td align="left" valign="top">• <a href="#OMP_005fNUM_005fTHREADS" accesskey="7">OMP_NUM_THREADS</a>:</td><td> </td><td align="left" valign="top">Specifies the number of threads to use
</td></tr>
<tr><td align="left" valign="top">• <a href="#OMP_005fPROC_005fBIND" accesskey="8">OMP_PROC_BIND</a>:</td><td> </td><td align="left" valign="top">Whether theads may be moved between CPUs
</td></tr>
<tr><td align="left" valign="top">• <a href="#OMP_005fPLACES" accesskey="9">OMP_PLACES</a>:</td><td> </td><td align="left" valign="top">Specifies on which CPUs the theads should be placed
</td></tr>
<tr><td align="left" valign="top">• <a href="#OMP_005fSTACKSIZE">OMP_STACKSIZE</a>:</td><td> </td><td align="left" valign="top">Set default thread stack size
</td></tr>
<tr><td align="left" valign="top">• <a href="#OMP_005fSCHEDULE">OMP_SCHEDULE</a>:</td><td> </td><td align="left" valign="top">How threads are scheduled
</td></tr>
<tr><td align="left" valign="top">• <a href="#OMP_005fTHREAD_005fLIMIT">OMP_THREAD_LIMIT</a>:</td><td> </td><td align="left" valign="top">Set the maximum number of threads
</td></tr>
<tr><td align="left" valign="top">• <a href="#OMP_005fWAIT_005fPOLICY">OMP_WAIT_POLICY</a>:</td><td> </td><td align="left" valign="top">How waiting threads are handled
</td></tr>
<tr><td align="left" valign="top">• <a href="#GOMP_005fCPU_005fAFFINITY">GOMP_CPU_AFFINITY</a>:</td><td> </td><td align="left" valign="top">Bind threads to specific CPUs
</td></tr>
<tr><td align="left" valign="top">• <a href="#GOMP_005fSTACKSIZE">GOMP_STACKSIZE</a>:</td><td> </td><td align="left" valign="top">Set default thread stack size
</td></tr>
<tr><td align="left" valign="top">• <a href="#GOMP_005fSPINCOUNT">GOMP_SPINCOUNT</a>:</td><td> </td><td align="left" valign="top">Set the busy-wait spin count
</td></tr>
</table>
<hr>
<a name="OMP_005fCANCELLATION"></a>
<div class="header">
<p>
Next: <a href="#OMP_005fDISPLAY_005fENV" accesskey="n" rel="next">OMP_DISPLAY_ENV</a>, Up: <a href="#Environment-Variables" accesskey="u" rel="up">Environment Variables</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="OMP_005fCANCELLATION-_002d_002d-Set-whether-cancellation-is-activated"></a>
<h3 class="section">3.1 <code>OMP_CANCELLATION</code> – Set whether cancellation is activated</h3>
<a name="index-Environment-Variable"></a>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>If set to <code>TRUE</code>, the cancellation is activated. If set to <code>FALSE</code> or
if unset, cancellation is disabled and the <code>cancel</code> construct is ignored.
</p>
</dd>
<dt><em>See also</em>:</dt>
<dd><p><a href="#omp_005fget_005fcancellation">omp_get_cancellation</a>
</p>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 4.11
</p></dd>
</dl>
<hr>
<a name="OMP_005fDISPLAY_005fENV"></a>
<div class="header">
<p>
Next: <a href="#OMP_005fDEFAULT_005fDEVICE" accesskey="n" rel="next">OMP_DEFAULT_DEVICE</a>, Previous: <a href="#OMP_005fCANCELLATION" accesskey="p" rel="prev">OMP_CANCELLATION</a>, Up: <a href="#Environment-Variables" accesskey="u" rel="up">Environment Variables</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="OMP_005fDISPLAY_005fENV-_002d_002d-Show-OpenMP-version-and-environment-variables"></a>
<h3 class="section">3.2 <code>OMP_DISPLAY_ENV</code> – Show OpenMP version and environment variables</h3>
<a name="index-Environment-Variable-1"></a>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>If set to <code>TRUE</code>, the OpenMP version number and the values
associated with the OpenMP environment variables are printed to <code>stderr</code>.
If set to <code>VERBOSE</code>, it additionally shows the value of the environment
variables which are GNU extensions. If undefined or set to <code>FALSE</code>,
this information will not be shown.
</p>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 4.12
</p></dd>
</dl>
<hr>
<a name="OMP_005fDEFAULT_005fDEVICE"></a>
<div class="header">
<p>
Next: <a href="#OMP_005fDYNAMIC" accesskey="n" rel="next">OMP_DYNAMIC</a>, Previous: <a href="#OMP_005fDISPLAY_005fENV" accesskey="p" rel="prev">OMP_DISPLAY_ENV</a>, Up: <a href="#Environment-Variables" accesskey="u" rel="up">Environment Variables</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="OMP_005fDEFAULT_005fDEVICE-_002d_002d-Set-the-device-used-in-target-regions"></a>
<h3 class="section">3.3 <code>OMP_DEFAULT_DEVICE</code> – Set the device used in target regions</h3>
<a name="index-Environment-Variable-2"></a>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>Set to choose the device which is used in a <code>target</code> region, unless the
value is overridden by <code>omp_set_default_device</code> or by a <code>device</code>
clause. The value shall be the nonnegative device number. If no device with
the given device number exists, the code is executed on the host. If unset,
device number 0 will be used.
</p>
</dd>
<dt><em>See also</em>:</dt>
<dd><p><a href="#omp_005fget_005fdefault_005fdevice">omp_get_default_device</a>, <a href="#omp_005fset_005fdefault_005fdevice">omp_set_default_device</a>,
</p>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 4.11
</p></dd>
</dl>
<hr>
<a name="OMP_005fDYNAMIC"></a>
<div class="header">
<p>
Next: <a href="#OMP_005fMAX_005fACTIVE_005fLEVELS" accesskey="n" rel="next">OMP_MAX_ACTIVE_LEVELS</a>, Previous: <a href="#OMP_005fDEFAULT_005fDEVICE" accesskey="p" rel="prev">OMP_DEFAULT_DEVICE</a>, Up: <a href="#Environment-Variables" accesskey="u" rel="up">Environment Variables</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="OMP_005fDYNAMIC-_002d_002d-Dynamic-adjustment-of-threads"></a>
<h3 class="section">3.4 <code>OMP_DYNAMIC</code> – Dynamic adjustment of threads</h3>
<a name="index-Environment-Variable-3"></a>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>Enable or disable the dynamic adjustment of the number of threads
within a team. The value of this environment variable shall be
<code>TRUE</code> or <code>FALSE</code>. If undefined, dynamic adjustment is
disabled by default.
</p>
</dd>
<dt><em>See also</em>:</dt>
<dd><p><a href="#omp_005fset_005fdynamic">omp_set_dynamic</a>
</p>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 4.3
</p></dd>
</dl>
<hr>
<a name="OMP_005fMAX_005fACTIVE_005fLEVELS"></a>
<div class="header">
<p>
Next: <a href="#OMP_005fNESTED" accesskey="n" rel="next">OMP_NESTED</a>, Previous: <a href="#OMP_005fDYNAMIC" accesskey="p" rel="prev">OMP_DYNAMIC</a>, Up: <a href="#Environment-Variables" accesskey="u" rel="up">Environment Variables</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="OMP_005fMAX_005fACTIVE_005fLEVELS-_002d_002d-Set-the-maximum-number-of-nested-parallel-regions"></a>
<h3 class="section">3.5 <code>OMP_MAX_ACTIVE_LEVELS</code> – Set the maximum number of nested parallel regions</h3>
<a name="index-Environment-Variable-4"></a>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>Specifies the initial value for the maximum number of nested parallel
regions. The value of this variable shall be a positive integer.
If undefined, the number of active levels is unlimited.
</p>
</dd>
<dt><em>See also</em>:</dt>
<dd><p><a href="#omp_005fset_005fmax_005factive_005flevels">omp_set_max_active_levels</a>
</p>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 4.9
</p></dd>
</dl>
<hr>
<a name="OMP_005fNESTED"></a>
<div class="header">
<p>
Next: <a href="#OMP_005fNUM_005fTHREADS" accesskey="n" rel="next">OMP_NUM_THREADS</a>, Previous: <a href="#OMP_005fMAX_005fACTIVE_005fLEVELS" accesskey="p" rel="prev">OMP_MAX_ACTIVE_LEVELS</a>, Up: <a href="#Environment-Variables" accesskey="u" rel="up">Environment Variables</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="OMP_005fNESTED-_002d_002d-Nested-parallel-regions"></a>
<h3 class="section">3.6 <code>OMP_NESTED</code> – Nested parallel regions</h3>
<a name="index-Environment-Variable-5"></a>
<a name="index-Implementation-specific-setting"></a>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>Enable or disable nested parallel regions, i.e., whether team members
are allowed to create new teams. The value of this environment variable
shall be <code>TRUE</code> or <code>FALSE</code>. If undefined, nested parallel
regions are disabled by default.
</p>
</dd>
<dt><em>See also</em>:</dt>
<dd><p><a href="#omp_005fset_005fnested">omp_set_nested</a>
</p>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 4.6
</p></dd>
</dl>
<hr>
<a name="OMP_005fNUM_005fTHREADS"></a>
<div class="header">
<p>
Next: <a href="#OMP_005fPROC_005fBIND" accesskey="n" rel="next">OMP_PROC_BIND</a>, Previous: <a href="#OMP_005fNESTED" accesskey="p" rel="prev">OMP_NESTED</a>, Up: <a href="#Environment-Variables" accesskey="u" rel="up">Environment Variables</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="OMP_005fNUM_005fTHREADS-_002d_002d-Specifies-the-number-of-threads-to-use"></a>
<h3 class="section">3.7 <code>OMP_NUM_THREADS</code> – Specifies the number of threads to use</h3>
<a name="index-Environment-Variable-6"></a>
<a name="index-Implementation-specific-setting-1"></a>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>Specifies the default number of threads to use in parallel regions. The
value of this variable shall be a comma-separated list of positive integers;
the value specified the number of threads to use for the corresponding nested
level. If undefined one thread per CPU is used.
</p>
</dd>
<dt><em>See also</em>:</dt>
<dd><p><a href="#omp_005fset_005fnum_005fthreads">omp_set_num_threads</a>
</p>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 4.2
</p></dd>
</dl>
<hr>
<a name="OMP_005fPROC_005fBIND"></a>
<div class="header">
<p>
Next: <a href="#OMP_005fPLACES" accesskey="n" rel="next">OMP_PLACES</a>, Previous: <a href="#OMP_005fNUM_005fTHREADS" accesskey="p" rel="prev">OMP_NUM_THREADS</a>, Up: <a href="#Environment-Variables" accesskey="u" rel="up">Environment Variables</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="OMP_005fPROC_005fBIND-_002d_002d-Whether-theads-may-be-moved-between-CPUs"></a>
<h3 class="section">3.8 <code>OMP_PROC_BIND</code> – Whether theads may be moved between CPUs</h3>
<a name="index-Environment-Variable-7"></a>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>Specifies whether threads may be moved between processors. If set to
<code>TRUE</code>, OpenMP theads should not be moved; if set to <code>FALSE</code>
they may be moved. Alternatively, a comma separated list with the
values <code>MASTER</code>, <code>CLOSE</code> and <code>SPREAD</code> can be used to specify
the thread affinity policy for the corresponding nesting level. With
<code>MASTER</code> the worker threads are in the same place partition as the
master thread. With <code>CLOSE</code> those are kept close to the master thread
in contiguous place partitions. And with <code>SPREAD</code> a sparse distribution
across the place partitions is used.
</p>
<p>When undefined, <code>OMP_PROC_BIND</code> defaults to <code>TRUE</code> when
<code>OMP_PLACES</code> or <code>GOMP_CPU_AFFINITY</code> is set and <code>FALSE</code> otherwise.
</p>
</dd>
<dt><em>See also</em>:</dt>
<dd><p><a href="#OMP_005fPLACES">OMP_PLACES</a>, <a href="#GOMP_005fCPU_005fAFFINITY">GOMP_CPU_AFFINITY</a>, <a href="#omp_005fget_005fproc_005fbind">omp_get_proc_bind</a>
</p>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 4.4
</p></dd>
</dl>
<hr>
<a name="OMP_005fPLACES"></a>
<div class="header">
<p>
Next: <a href="#OMP_005fSTACKSIZE" accesskey="n" rel="next">OMP_STACKSIZE</a>, Previous: <a href="#OMP_005fPROC_005fBIND" accesskey="p" rel="prev">OMP_PROC_BIND</a>, Up: <a href="#Environment-Variables" accesskey="u" rel="up">Environment Variables</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="OMP_005fPLACES-_002d_002d-Specifies-on-which-CPUs-the-theads-should-be-placed"></a>
<h3 class="section">3.9 <code>OMP_PLACES</code> – Specifies on which CPUs the theads should be placed</h3>
<a name="index-Environment-Variable-8"></a>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>The thread placement can be either specified using an abstract name or by an
explicit list of the places. The abstract names <code>threads</code>, <code>cores</code>
and <code>sockets</code> can be optionally followed by a positive number in
parentheses, which denotes the how many places shall be created. With
<code>threads</code> each place corresponds to a single hardware thread; <code>cores</code>
to a single core with the corresponding number of hardware threads; and with
<code>sockets</code> the place corresponds to a single socket. The resulting
placement can be shown by setting the <code>OMP_DISPLAY_ENV</code> environment
variable.
</p>
<p>Alternatively, the placement can be specified explicitly as comma-separated
list of places. A place is specified by set of nonnegative numbers in curly
braces, denoting the denoting the hardware threads. The hardware threads
belonging to a place can either be specified as comma-separated list of
nonnegative thread numbers or using an interval. Multiple places can also be
either specified by a comma-separated list of places or by an interval. To
specify an interval, a colon followed by the count is placed after after
the hardware thread number or the place. Optionally, the length can be
followed by a colon and the stride number – otherwise a unit stride is
assumed. For instance, the following specifies the same places list:
<code>"{0,1,2}, {3,4,6}, {7,8,9}, {10,11,12}"</code>;
<code>"{0:3}, {3:3}, {7:3}, {10:3}"</code>; and <code>"{0:2}:4:3"</code>.
</p>
<p>If <code>OMP_PLACES</code> and <code>GOMP_CPU_AFFINITY</code> are unset and
<code>OMP_PROC_BIND</code> is either unset or <code>false</code>, threads may be moved
between CPUs following no placement policy.
</p>
</dd>
<dt><em>See also</em>:</dt>
<dd><p><a href="#OMP_005fPROC_005fBIND">OMP_PROC_BIND</a>, <a href="#GOMP_005fCPU_005fAFFINITY">GOMP_CPU_AFFINITY</a>, <a href="#omp_005fget_005fproc_005fbind">omp_get_proc_bind</a>,
<a href="#OMP_005fDISPLAY_005fENV">OMP_DISPLAY_ENV</a>
</p>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 4.5
</p></dd>
</dl>
<hr>
<a name="OMP_005fSTACKSIZE"></a>
<div class="header">
<p>
Next: <a href="#OMP_005fSCHEDULE" accesskey="n" rel="next">OMP_SCHEDULE</a>, Previous: <a href="#OMP_005fPLACES" accesskey="p" rel="prev">OMP_PLACES</a>, Up: <a href="#Environment-Variables" accesskey="u" rel="up">Environment Variables</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="OMP_005fSTACKSIZE-_002d_002d-Set-default-thread-stack-size"></a>
<h3 class="section">3.10 <code>OMP_STACKSIZE</code> – Set default thread stack size</h3>
<a name="index-Environment-Variable-9"></a>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>Set the default thread stack size in kilobytes, unless the number
is suffixed by <code>B</code>, <code>K</code>, <code>M</code> or <code>G</code>, in which
case the size is, respectively, in bytes, kilobytes, megabytes
or gigabytes. This is different from <code>pthread_attr_setstacksize</code>
which gets the number of bytes as an argument. If the stack size cannot
be set due to system constraints, an error is reported and the initial
stack size is left unchanged. If undefined, the stack size is system
dependent.
</p>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 4.7
</p></dd>
</dl>
<hr>
<a name="OMP_005fSCHEDULE"></a>
<div class="header">
<p>
Next: <a href="#OMP_005fTHREAD_005fLIMIT" accesskey="n" rel="next">OMP_THREAD_LIMIT</a>, Previous: <a href="#OMP_005fSTACKSIZE" accesskey="p" rel="prev">OMP_STACKSIZE</a>, Up: <a href="#Environment-Variables" accesskey="u" rel="up">Environment Variables</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="OMP_005fSCHEDULE-_002d_002d-How-threads-are-scheduled"></a>
<h3 class="section">3.11 <code>OMP_SCHEDULE</code> – How threads are scheduled</h3>
<a name="index-Environment-Variable-10"></a>
<a name="index-Implementation-specific-setting-2"></a>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>Allows to specify <code>schedule type</code> and <code>chunk size</code>.
The value of the variable shall have the form: <code>type[,chunk]</code> where
<code>type</code> is one of <code>static</code>, <code>dynamic</code>, <code>guided</code> or <code>auto</code>
The optional <code>chunk</code> size shall be a positive integer. If undefined,
dynamic scheduling and a chunk size of 1 is used.
</p>
</dd>
<dt><em>See also</em>:</dt>
<dd><p><a href="#omp_005fset_005fschedule">omp_set_schedule</a>
</p>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Sections 2.7.1 and 4.1
</p></dd>
</dl>
<hr>
<a name="OMP_005fTHREAD_005fLIMIT"></a>
<div class="header">
<p>
Next: <a href="#OMP_005fWAIT_005fPOLICY" accesskey="n" rel="next">OMP_WAIT_POLICY</a>, Previous: <a href="#OMP_005fSCHEDULE" accesskey="p" rel="prev">OMP_SCHEDULE</a>, Up: <a href="#Environment-Variables" accesskey="u" rel="up">Environment Variables</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="OMP_005fTHREAD_005fLIMIT-_002d_002d-Set-the-maximum-number-of-threads"></a>
<h3 class="section">3.12 <code>OMP_THREAD_LIMIT</code> – Set the maximum number of threads</h3>
<a name="index-Environment-Variable-11"></a>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>Specifies the number of threads to use for the whole program. The
value of this variable shall be a positive integer. If undefined,
the number of threads is not limited.
</p>
</dd>
<dt><em>See also</em>:</dt>
<dd><p><a href="#OMP_005fNUM_005fTHREADS">OMP_NUM_THREADS</a>, <a href="#omp_005fget_005fthread_005flimit">omp_get_thread_limit</a>
</p>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 4.10
</p></dd>
</dl>
<hr>
<a name="OMP_005fWAIT_005fPOLICY"></a>
<div class="header">
<p>
Next: <a href="#GOMP_005fCPU_005fAFFINITY" accesskey="n" rel="next">GOMP_CPU_AFFINITY</a>, Previous: <a href="#OMP_005fTHREAD_005fLIMIT" accesskey="p" rel="prev">OMP_THREAD_LIMIT</a>, Up: <a href="#Environment-Variables" accesskey="u" rel="up">Environment Variables</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="OMP_005fWAIT_005fPOLICY-_002d_002d-How-waiting-threads-are-handled"></a>
<h3 class="section">3.13 <code>OMP_WAIT_POLICY</code> – How waiting threads are handled</h3>
<a name="index-Environment-Variable-12"></a>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>Specifies whether waiting threads should be active or passive. If
the value is <code>PASSIVE</code>, waiting threads should not consume CPU
power while waiting; while the value is <code>ACTIVE</code> specifies that
they should. If undefined, threads wait actively for a short time
before waiting passively.
</p>
</dd>
<dt><em>See also</em>:</dt>
<dd><p><a href="#GOMP_005fSPINCOUNT">GOMP_SPINCOUNT</a>
</p>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://www.openmp.org/">OpenMP specification v4.0</a>, Section 4.8
</p></dd>
</dl>
<hr>
<a name="GOMP_005fCPU_005fAFFINITY"></a>
<div class="header">
<p>
Next: <a href="#GOMP_005fSTACKSIZE" accesskey="n" rel="next">GOMP_STACKSIZE</a>, Previous: <a href="#OMP_005fWAIT_005fPOLICY" accesskey="p" rel="prev">OMP_WAIT_POLICY</a>, Up: <a href="#Environment-Variables" accesskey="u" rel="up">Environment Variables</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="GOMP_005fCPU_005fAFFINITY-_002d_002d-Bind-threads-to-specific-CPUs"></a>
<h3 class="section">3.14 <code>GOMP_CPU_AFFINITY</code> – Bind threads to specific CPUs</h3>
<a name="index-Environment-Variable-13"></a>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>Binds threads to specific CPUs. The variable should contain a space-separated
or comma-separated list of CPUs. This list may contain different kinds of
entries: either single CPU numbers in any order, a range of CPUs (M-N)
or a range with some stride (M-N:S). CPU numbers are zero based. For example,
<code>GOMP_CPU_AFFINITY="0 3 1-2 4-15:2"</code> will bind the initial thread
to CPU 0, the second to CPU 3, the third to CPU 1, the fourth to
CPU 2, the fifth to CPU 4, the sixth through tenth to CPUs 6, 8, 10, 12,
and 14 respectively and then start assigning back from the beginning of
the list. <code>GOMP_CPU_AFFINITY=0</code> binds all threads to CPU 0.
</p>
<p>There is no GNU OpenMP library routine to determine whether a CPU affinity
specification is in effect. As a workaround, language-specific library
functions, e.g., <code>getenv</code> in C or <code>GET_ENVIRONMENT_VARIABLE</code> in
Fortran, may be used to query the setting of the <code>GOMP_CPU_AFFINITY</code>
environment variable. A defined CPU affinity on startup cannot be changed
or disabled during the runtime of the application.
</p>
<p>If both <code>GOMP_CPU_AFFINITY</code> and <code>OMP_PROC_BIND</code> are set,
<code>OMP_PROC_BIND</code> has a higher precedence. If neither has been set and
<code>OMP_PROC_BIND</code> is unset, or when <code>OMP_PROC_BIND</code> is set to
<code>FALSE</code>, the host system will handle the assignment of threads to CPUs.
</p>
</dd>
<dt><em>See also</em>:</dt>
<dd><p><a href="#OMP_005fPLACES">OMP_PLACES</a>, <a href="#OMP_005fPROC_005fBIND">OMP_PROC_BIND</a>
</p></dd>
</dl>
<hr>
<a name="GOMP_005fSTACKSIZE"></a>
<div class="header">
<p>
Next: <a href="#GOMP_005fSPINCOUNT" accesskey="n" rel="next">GOMP_SPINCOUNT</a>, Previous: <a href="#GOMP_005fCPU_005fAFFINITY" accesskey="p" rel="prev">GOMP_CPU_AFFINITY</a>, Up: <a href="#Environment-Variables" accesskey="u" rel="up">Environment Variables</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="GOMP_005fSTACKSIZE-_002d_002d-Set-default-thread-stack-size"></a>
<h3 class="section">3.15 <code>GOMP_STACKSIZE</code> – Set default thread stack size</h3>
<a name="index-Environment-Variable-14"></a>
<a name="index-Implementation-specific-setting-3"></a>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>Set the default thread stack size in kilobytes. This is different from
<code>pthread_attr_setstacksize</code> which gets the number of bytes as an
argument. If the stack size cannot be set due to system constraints, an
error is reported and the initial stack size is left unchanged. If undefined,
the stack size is system dependent.
</p>
</dd>
<dt><em>See also</em>:</dt>
<dd><p><a href="#OMP_005fSTACKSIZE">OMP_STACKSIZE</a>
</p>
</dd>
<dt><em>Reference</em>:</dt>
<dd><p><a href="http://gcc.gnu.org/ml/gcc-patches/2006-06/msg00493.html">GCC Patches Mailinglist</a>,
<a href="http://gcc.gnu.org/ml/gcc-patches/2006-06/msg00496.html">GCC Patches Mailinglist</a>
</p></dd>
</dl>
<hr>
<a name="GOMP_005fSPINCOUNT"></a>
<div class="header">
<p>
Previous: <a href="#GOMP_005fSTACKSIZE" accesskey="p" rel="prev">GOMP_STACKSIZE</a>, Up: <a href="#Environment-Variables" accesskey="u" rel="up">Environment Variables</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="GOMP_005fSPINCOUNT-_002d_002d-Set-the-busy_002dwait-spin-count"></a>
<h3 class="section">3.16 <code>GOMP_SPINCOUNT</code> – Set the busy-wait spin count</h3>
<a name="index-Environment-Variable-15"></a>
<a name="index-Implementation-specific-setting-4"></a>
<dl compact="compact">
<dt><em>Description</em>:</dt>
<dd><p>Determines how long a threads waits actively with consuming CPU power
before waiting passively without consuming CPU power. The value may be
either <code>INFINITE</code>, <code>INFINITY</code> to always wait actively or an
integer which gives the number of spins of the busy-wait loop. The
integer may optionally be followed by the following suffixes acting
as multiplication factors: <code>k</code> (kilo, thousand), <code>M</code> (mega,
million), <code>G</code> (giga, billion), or <code>T</code> (tera, trillion).
If undefined, 0 is used when <code>OMP_WAIT_POLICY</code> is <code>PASSIVE</code>,
300,000 is used when <code>OMP_WAIT_POLICY</code> is undefined and
30 billion is used when <code>OMP_WAIT_POLICY</code> is <code>ACTIVE</code>.
If there are more OpenMP threads than available CPUs, 1000 and 100
spins are used for <code>OMP_WAIT_POLICY</code> being <code>ACTIVE</code> or
undefined, respectively; unless the <code>GOMP_SPINCOUNT</code> is lower
or <code>OMP_WAIT_POLICY</code> is <code>PASSIVE</code>.
</p>
</dd>
<dt><em>See also</em>:</dt>
<dd><p><a href="#OMP_005fWAIT_005fPOLICY">OMP_WAIT_POLICY</a>
</p></dd>
</dl>
<hr>
<a name="The-libgomp-ABI"></a>
<div class="header">
<p>
Next: <a href="#Reporting-Bugs" accesskey="n" rel="next">Reporting Bugs</a>, Previous: <a href="#Environment-Variables" accesskey="p" rel="prev">Environment Variables</a>, Up: <a href="#Top" accesskey="u" rel="up">Top</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="The-libgomp-ABI-1"></a>
<h2 class="chapter">4 The libgomp ABI</h2>
<p>The following sections present notes on the external ABI as
presented by libgomp. Only maintainers should need them.
</p>
<table class="menu" border="0" cellspacing="0">
<tr><td align="left" valign="top">• <a href="#Implementing-MASTER-construct" accesskey="1">Implementing MASTER construct</a>:</td><td> </td><td align="left" valign="top">
</td></tr>
<tr><td align="left" valign="top">• <a href="#Implementing-CRITICAL-construct" accesskey="2">Implementing CRITICAL construct</a>:</td><td> </td><td align="left" valign="top">
</td></tr>
<tr><td align="left" valign="top">• <a href="#Implementing-ATOMIC-construct" accesskey="3">Implementing ATOMIC construct</a>:</td><td> </td><td align="left" valign="top">
</td></tr>
<tr><td align="left" valign="top">• <a href="#Implementing-FLUSH-construct" accesskey="4">Implementing FLUSH construct</a>:</td><td> </td><td align="left" valign="top">
</td></tr>
<tr><td align="left" valign="top">• <a href="#Implementing-BARRIER-construct" accesskey="5">Implementing BARRIER construct</a>:</td><td> </td><td align="left" valign="top">
</td></tr>
<tr><td align="left" valign="top">• <a href="#Implementing-THREADPRIVATE-construct" accesskey="6">Implementing THREADPRIVATE construct</a>:</td><td> </td><td align="left" valign="top">
</td></tr>
<tr><td align="left" valign="top">• <a href="#Implementing-PRIVATE-clause" accesskey="7">Implementing PRIVATE clause</a>:</td><td> </td><td align="left" valign="top">
</td></tr>
<tr><td align="left" valign="top">• <a href="#Implementing-FIRSTPRIVATE-LASTPRIVATE-COPYIN-and-COPYPRIVATE-clauses" accesskey="8">Implementing FIRSTPRIVATE LASTPRIVATE COPYIN and COPYPRIVATE clauses</a>:</td><td> </td><td align="left" valign="top">
</td></tr>
<tr><td align="left" valign="top">• <a href="#Implementing-REDUCTION-clause" accesskey="9">Implementing REDUCTION clause</a>:</td><td> </td><td align="left" valign="top">
</td></tr>
<tr><td align="left" valign="top">• <a href="#Implementing-PARALLEL-construct">Implementing PARALLEL construct</a>:</td><td> </td><td align="left" valign="top">
</td></tr>
<tr><td align="left" valign="top">• <a href="#Implementing-FOR-construct">Implementing FOR construct</a>:</td><td> </td><td align="left" valign="top">
</td></tr>
<tr><td align="left" valign="top">• <a href="#Implementing-ORDERED-construct">Implementing ORDERED construct</a>:</td><td> </td><td align="left" valign="top">
</td></tr>
<tr><td align="left" valign="top">• <a href="#Implementing-SECTIONS-construct">Implementing SECTIONS construct</a>:</td><td> </td><td align="left" valign="top">
</td></tr>
<tr><td align="left" valign="top">• <a href="#Implementing-SINGLE-construct">Implementing SINGLE construct</a>:</td><td> </td><td align="left" valign="top">
</td></tr>
</table>
<hr>
<a name="Implementing-MASTER-construct"></a>
<div class="header">
<p>
Next: <a href="#Implementing-CRITICAL-construct" accesskey="n" rel="next">Implementing CRITICAL construct</a>, Up: <a href="#The-libgomp-ABI" accesskey="u" rel="up">The libgomp ABI</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="Implementing-MASTER-construct-1"></a>
<h3 class="section">4.1 Implementing MASTER construct</h3>
<div class="smallexample">
<pre class="smallexample">if (omp_get_thread_num () == 0)
block
</pre></div>
<p>Alternately, we generate two copies of the parallel subfunction
and only include this in the version run by the master thread.
Surely this is not worthwhile though...
</p>
<hr>
<a name="Implementing-CRITICAL-construct"></a>
<div class="header">
<p>
Next: <a href="#Implementing-ATOMIC-construct" accesskey="n" rel="next">Implementing ATOMIC construct</a>, Previous: <a href="#Implementing-MASTER-construct" accesskey="p" rel="prev">Implementing MASTER construct</a>, Up: <a href="#The-libgomp-ABI" accesskey="u" rel="up">The libgomp ABI</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="Implementing-CRITICAL-construct-1"></a>
<h3 class="section">4.2 Implementing CRITICAL construct</h3>
<p>Without a specified name,
</p>
<div class="smallexample">
<pre class="smallexample"> void GOMP_critical_start (void);
void GOMP_critical_end (void);
</pre></div>
<p>so that we don’t get COPY relocations from libgomp to the main
application.
</p>
<p>With a specified name, use omp_set_lock and omp_unset_lock with
name being transformed into a variable declared like
</p>
<div class="smallexample">
<pre class="smallexample"> omp_lock_t gomp_critical_user_<name> __attribute__((common))
</pre></div>
<p>Ideally the ABI would specify that all zero is a valid unlocked
state, and so we wouldn’t need to initialize this at
startup.
</p>
<hr>
<a name="Implementing-ATOMIC-construct"></a>
<div class="header">
<p>
Next: <a href="#Implementing-FLUSH-construct" accesskey="n" rel="next">Implementing FLUSH construct</a>, Previous: <a href="#Implementing-CRITICAL-construct" accesskey="p" rel="prev">Implementing CRITICAL construct</a>, Up: <a href="#The-libgomp-ABI" accesskey="u" rel="up">The libgomp ABI</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="Implementing-ATOMIC-construct-1"></a>
<h3 class="section">4.3 Implementing ATOMIC construct</h3>
<p>The target should implement the <code>__sync</code> builtins.
</p>
<p>Failing that we could add
</p>
<div class="smallexample">
<pre class="smallexample"> void GOMP_atomic_enter (void)
void GOMP_atomic_exit (void)
</pre></div>
<p>which reuses the regular lock code, but with yet another lock
object private to the library.
</p>
<hr>
<a name="Implementing-FLUSH-construct"></a>
<div class="header">
<p>
Next: <a href="#Implementing-BARRIER-construct" accesskey="n" rel="next">Implementing BARRIER construct</a>, Previous: <a href="#Implementing-ATOMIC-construct" accesskey="p" rel="prev">Implementing ATOMIC construct</a>, Up: <a href="#The-libgomp-ABI" accesskey="u" rel="up">The libgomp ABI</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="Implementing-FLUSH-construct-1"></a>
<h3 class="section">4.4 Implementing FLUSH construct</h3>
<p>Expands to the <code>__sync_synchronize</code> builtin.
</p>
<hr>
<a name="Implementing-BARRIER-construct"></a>
<div class="header">
<p>
Next: <a href="#Implementing-THREADPRIVATE-construct" accesskey="n" rel="next">Implementing THREADPRIVATE construct</a>, Previous: <a href="#Implementing-FLUSH-construct" accesskey="p" rel="prev">Implementing FLUSH construct</a>, Up: <a href="#The-libgomp-ABI" accesskey="u" rel="up">The libgomp ABI</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="Implementing-BARRIER-construct-1"></a>
<h3 class="section">4.5 Implementing BARRIER construct</h3>
<div class="smallexample">
<pre class="smallexample"> void GOMP_barrier (void)
</pre></div>
<hr>
<a name="Implementing-THREADPRIVATE-construct"></a>
<div class="header">
<p>
Next: <a href="#Implementing-PRIVATE-clause" accesskey="n" rel="next">Implementing PRIVATE clause</a>, Previous: <a href="#Implementing-BARRIER-construct" accesskey="p" rel="prev">Implementing BARRIER construct</a>, Up: <a href="#The-libgomp-ABI" accesskey="u" rel="up">The libgomp ABI</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="Implementing-THREADPRIVATE-construct-1"></a>
<h3 class="section">4.6 Implementing THREADPRIVATE construct</h3>
<p>In _most_ cases we can map this directly to <code>__thread</code>. Except
that OMP allows constructors for C++ objects. We can either
refuse to support this (how often is it used?) or we can
implement something akin to .ctors.
</p>
<p>Even more ideally, this ctor feature is handled by extensions
to the main pthreads library. Failing that, we can have a set
of entry points to register ctor functions to be called.
</p>
<hr>
<a name="Implementing-PRIVATE-clause"></a>
<div class="header">
<p>
Next: <a href="#Implementing-FIRSTPRIVATE-LASTPRIVATE-COPYIN-and-COPYPRIVATE-clauses" accesskey="n" rel="next">Implementing FIRSTPRIVATE LASTPRIVATE COPYIN and COPYPRIVATE clauses</a>, Previous: <a href="#Implementing-THREADPRIVATE-construct" accesskey="p" rel="prev">Implementing THREADPRIVATE construct</a>, Up: <a href="#The-libgomp-ABI" accesskey="u" rel="up">The libgomp ABI</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="Implementing-PRIVATE-clause-1"></a>
<h3 class="section">4.7 Implementing PRIVATE clause</h3>
<p>In association with a PARALLEL, or within the lexical extent
of a PARALLEL block, the variable becomes a local variable in
the parallel subfunction.
</p>
<p>In association with FOR or SECTIONS blocks, create a new
automatic variable within the current function. This preserves
the semantic of new variable creation.
</p>
<hr>
<a name="Implementing-FIRSTPRIVATE-LASTPRIVATE-COPYIN-and-COPYPRIVATE-clauses"></a>
<div class="header">
<p>
Next: <a href="#Implementing-REDUCTION-clause" accesskey="n" rel="next">Implementing REDUCTION clause</a>, Previous: <a href="#Implementing-PRIVATE-clause" accesskey="p" rel="prev">Implementing PRIVATE clause</a>, Up: <a href="#The-libgomp-ABI" accesskey="u" rel="up">The libgomp ABI</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="Implementing-FIRSTPRIVATE-LASTPRIVATE-COPYIN-and-COPYPRIVATE-clauses-1"></a>
<h3 class="section">4.8 Implementing FIRSTPRIVATE LASTPRIVATE COPYIN and COPYPRIVATE clauses</h3>
<p>This seems simple enough for PARALLEL blocks. Create a private
struct for communicating between the parent and subfunction.
In the parent, copy in values for scalar and "small" structs;
copy in addresses for others TREE_ADDRESSABLE types. In the
subfunction, copy the value into the local variable.
</p>
<p>It is not clear what to do with bare FOR or SECTION blocks.
The only thing I can figure is that we do something like:
</p>
<div class="smallexample">
<pre class="smallexample">#pragma omp for firstprivate(x) lastprivate(y)
for (int i = 0; i < n; ++i)
body;
</pre></div>
<p>which becomes
</p>
<div class="smallexample">
<pre class="smallexample">{
int x = x, y;
// for stuff
if (i == n)
y = y;
}
</pre></div>
<p>where the "x=x" and "y=y" assignments actually have different
uids for the two variables, i.e. not something you could write
directly in C. Presumably this only makes sense if the "outer"
x and y are global variables.
</p>
<p>COPYPRIVATE would work the same way, except the structure
broadcast would have to happen via SINGLE machinery instead.
</p>
<hr>
<a name="Implementing-REDUCTION-clause"></a>
<div class="header">
<p>
Next: <a href="#Implementing-PARALLEL-construct" accesskey="n" rel="next">Implementing PARALLEL construct</a>, Previous: <a href="#Implementing-FIRSTPRIVATE-LASTPRIVATE-COPYIN-and-COPYPRIVATE-clauses" accesskey="p" rel="prev">Implementing FIRSTPRIVATE LASTPRIVATE COPYIN and COPYPRIVATE clauses</a>, Up: <a href="#The-libgomp-ABI" accesskey="u" rel="up">The libgomp ABI</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="Implementing-REDUCTION-clause-1"></a>
<h3 class="section">4.9 Implementing REDUCTION clause</h3>
<p>The private struct mentioned in the previous section should have
a pointer to an array of the type of the variable, indexed by the
thread’s <var>team_id</var>. The thread stores its final value into the
array, and after the barrier, the master thread iterates over the
array to collect the values.
</p>
<hr>
<a name="Implementing-PARALLEL-construct"></a>
<div class="header">
<p>
Next: <a href="#Implementing-FOR-construct" accesskey="n" rel="next">Implementing FOR construct</a>, Previous: <a href="#Implementing-REDUCTION-clause" accesskey="p" rel="prev">Implementing REDUCTION clause</a>, Up: <a href="#The-libgomp-ABI" accesskey="u" rel="up">The libgomp ABI</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="Implementing-PARALLEL-construct-1"></a>
<h3 class="section">4.10 Implementing PARALLEL construct</h3>
<div class="smallexample">
<pre class="smallexample"> #pragma omp parallel
{
body;
}
</pre></div>
<p>becomes
</p>
<div class="smallexample">
<pre class="smallexample"> void subfunction (void *data)
{
use data;
body;
}
setup data;
GOMP_parallel_start (subfunction, &data, num_threads);
subfunction (&data);
GOMP_parallel_end ();
</pre></div>
<div class="smallexample">
<pre class="smallexample"> void GOMP_parallel_start (void (*fn)(void *), void *data, unsigned num_threads)
</pre></div>
<p>The <var>FN</var> argument is the subfunction to be run in parallel.
</p>
<p>The <var>DATA</var> argument is a pointer to a structure used to
communicate data in and out of the subfunction, as discussed
above with respect to FIRSTPRIVATE et al.
</p>
<p>The <var>NUM_THREADS</var> argument is 1 if an IF clause is present
and false, or the value of the NUM_THREADS clause, if
present, or 0.
</p>
<p>The function needs to create the appropriate number of
threads and/or launch them from the dock. It needs to
create the team structure and assign team ids.
</p>
<div class="smallexample">
<pre class="smallexample"> void GOMP_parallel_end (void)
</pre></div>
<p>Tears down the team and returns us to the previous <code>omp_in_parallel()</code> state.
</p>
<hr>
<a name="Implementing-FOR-construct"></a>
<div class="header">
<p>
Next: <a href="#Implementing-ORDERED-construct" accesskey="n" rel="next">Implementing ORDERED construct</a>, Previous: <a href="#Implementing-PARALLEL-construct" accesskey="p" rel="prev">Implementing PARALLEL construct</a>, Up: <a href="#The-libgomp-ABI" accesskey="u" rel="up">The libgomp ABI</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="Implementing-FOR-construct-1"></a>
<h3 class="section">4.11 Implementing FOR construct</h3>
<div class="smallexample">
<pre class="smallexample"> #pragma omp parallel for
for (i = lb; i <= ub; i++)
body;
</pre></div>
<p>becomes
</p>
<div class="smallexample">
<pre class="smallexample"> void subfunction (void *data)
{
long _s0, _e0;
while (GOMP_loop_static_next (&_s0, &_e0))
{
long _e1 = _e0, i;
for (i = _s0; i < _e1; i++)
body;
}
GOMP_loop_end_nowait ();
}
GOMP_parallel_loop_static (subfunction, NULL, 0, lb, ub+1, 1, 0);
subfunction (NULL);
GOMP_parallel_end ();
</pre></div>
<div class="smallexample">
<pre class="smallexample"> #pragma omp for schedule(runtime)
for (i = 0; i < n; i++)
body;
</pre></div>
<p>becomes
</p>
<div class="smallexample">
<pre class="smallexample"> {
long i, _s0, _e0;
if (GOMP_loop_runtime_start (0, n, 1, &_s0, &_e0))
do {
long _e1 = _e0;
for (i = _s0, i < _e0; i++)
body;
} while (GOMP_loop_runtime_next (&_s0, _&e0));
GOMP_loop_end ();
}
</pre></div>
<p>Note that while it looks like there is trickiness to propagating
a non-constant STEP, there isn’t really. We’re explicitly allowed
to evaluate it as many times as we want, and any variables involved
should automatically be handled as PRIVATE or SHARED like any other
variables. So the expression should remain evaluable in the
subfunction. We can also pull it into a local variable if we like,
but since its supposed to remain unchanged, we can also not if we like.
</p>
<p>If we have SCHEDULE(STATIC), and no ORDERED, then we ought to be
able to get away with no work-sharing context at all, since we can
simply perform the arithmetic directly in each thread to divide up
the iterations. Which would mean that we wouldn’t need to call any
of these routines.
</p>
<p>There are separate routines for handling loops with an ORDERED
clause. Bookkeeping for that is non-trivial...
</p>
<hr>
<a name="Implementing-ORDERED-construct"></a>
<div class="header">
<p>
Next: <a href="#Implementing-SECTIONS-construct" accesskey="n" rel="next">Implementing SECTIONS construct</a>, Previous: <a href="#Implementing-FOR-construct" accesskey="p" rel="prev">Implementing FOR construct</a>, Up: <a href="#The-libgomp-ABI" accesskey="u" rel="up">The libgomp ABI</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="Implementing-ORDERED-construct-1"></a>
<h3 class="section">4.12 Implementing ORDERED construct</h3>
<div class="smallexample">
<pre class="smallexample"> void GOMP_ordered_start (void)
void GOMP_ordered_end (void)
</pre></div>
<hr>
<a name="Implementing-SECTIONS-construct"></a>
<div class="header">
<p>
Next: <a href="#Implementing-SINGLE-construct" accesskey="n" rel="next">Implementing SINGLE construct</a>, Previous: <a href="#Implementing-ORDERED-construct" accesskey="p" rel="prev">Implementing ORDERED construct</a>, Up: <a href="#The-libgomp-ABI" accesskey="u" rel="up">The libgomp ABI</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="Implementing-SECTIONS-construct-1"></a>
<h3 class="section">4.13 Implementing SECTIONS construct</h3>
<p>A block as
</p>
<div class="smallexample">
<pre class="smallexample"> #pragma omp sections
{
#pragma omp section
stmt1;
#pragma omp section
stmt2;
#pragma omp section
stmt3;
}
</pre></div>
<p>becomes
</p>
<div class="smallexample">
<pre class="smallexample"> for (i = GOMP_sections_start (3); i != 0; i = GOMP_sections_next ())
switch (i)
{
case 1:
stmt1;
break;
case 2:
stmt2;
break;
case 3:
stmt3;
break;
}
GOMP_barrier ();
</pre></div>
<hr>
<a name="Implementing-SINGLE-construct"></a>
<div class="header">
<p>
Previous: <a href="#Implementing-SECTIONS-construct" accesskey="p" rel="prev">Implementing SECTIONS construct</a>, Up: <a href="#The-libgomp-ABI" accesskey="u" rel="up">The libgomp ABI</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="Implementing-SINGLE-construct-1"></a>
<h3 class="section">4.14 Implementing SINGLE construct</h3>
<p>A block like
</p>
<div class="smallexample">
<pre class="smallexample"> #pragma omp single
{
body;
}
</pre></div>
<p>becomes
</p>
<div class="smallexample">
<pre class="smallexample"> if (GOMP_single_start ())
body;
GOMP_barrier ();
</pre></div>
<p>while
</p>
<div class="smallexample">
<pre class="smallexample"> #pragma omp single copyprivate(x)
body;
</pre></div>
<p>becomes
</p>
<div class="smallexample">
<pre class="smallexample"> datap = GOMP_single_copy_start ();
if (datap == NULL)
{
body;
data.x = x;
GOMP_single_copy_end (&data);
}
else
x = datap->x;
GOMP_barrier ();
</pre></div>
<hr>
<a name="Reporting-Bugs"></a>
<div class="header">
<p>
Next: <a href="#Copying" accesskey="n" rel="next">Copying</a>, Previous: <a href="#The-libgomp-ABI" accesskey="p" rel="prev">The libgomp ABI</a>, Up: <a href="#Top" accesskey="u" rel="up">Top</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="Reporting-Bugs-1"></a>
<h2 class="chapter">5 Reporting Bugs</h2>
<p>Bugs in the GNU OpenMP implementation should be reported via
<a href="http://gcc.gnu.org/bugzilla/">Bugzilla</a>. For all cases, please add
"openmp" to the keywords field in the bug report.
</p>
<hr>
<a name="Copying"></a>
<div class="header">
<p>
Next: <a href="#GNU-Free-Documentation-License" accesskey="n" rel="next">GNU Free Documentation License</a>, Previous: <a href="#Reporting-Bugs" accesskey="p" rel="prev">Reporting Bugs</a>, Up: <a href="#Top" accesskey="u" rel="up">Top</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="GNU-General-Public-License"></a>
<h2 class="unnumbered">GNU General Public License</h2>
<div align="center">Version 3, 29 June 2007
</div>
<div class="display">
<pre class="display">Copyright © 2007 Free Software Foundation, Inc. <a href="http://fsf.org/">http://fsf.org/</a>
Everyone is permitted to copy and distribute verbatim copies of this
license document, but changing it is not allowed.
</pre></div>
<a name="Preamble"></a>
<h3 class="heading">Preamble</h3>
<p>The GNU General Public License is a free, copyleft license for
software and other kinds of works.
</p>
<p>The licenses for most software and other practical works are designed
to take away your freedom to share and change the works. By contrast,
the GNU General Public License is intended to guarantee your freedom
to share and change all versions of a program–to make sure it remains
free software for all its users. We, the Free Software Foundation,
use the GNU General Public License for most of our software; it
applies also to any other work released this way by its authors. You
can apply it to your programs, too.
</p>
<p>When we speak of free software, we are referring to freedom, not
price. Our General Public Licenses are designed to make sure that you
have the freedom to distribute copies of free software (and charge for
them if you wish), that you receive source code or can get it if you
want it, that you can change the software or use pieces of it in new
free programs, and that you know you can do these things.
</p>
<p>To protect your rights, we need to prevent others from denying you
these rights or asking you to surrender the rights. Therefore, you
have certain responsibilities if you distribute copies of the
software, or if you modify it: responsibilities to respect the freedom
of others.
</p>
<p>For example, if you distribute copies of such a program, whether
gratis or for a fee, you must pass on to the recipients the same
freedoms that you received. You must make sure that they, too,
receive or can get the source code. And you must show them these
terms so they know their rights.
</p>
<p>Developers that use the GNU GPL protect your rights with two steps:
(1) assert copyright on the software, and (2) offer you this License
giving you legal permission to copy, distribute and/or modify it.
</p>
<p>For the developers’ and authors’ protection, the GPL clearly explains
that there is no warranty for this free software. For both users’ and
authors’ sake, the GPL requires that modified versions be marked as
changed, so that their problems will not be attributed erroneously to
authors of previous versions.
</p>
<p>Some devices are designed to deny users access to install or run
modified versions of the software inside them, although the
manufacturer can do so. This is fundamentally incompatible with the
aim of protecting users’ freedom to change the software. The
systematic pattern of such abuse occurs in the area of products for
individuals to use, which is precisely where it is most unacceptable.
Therefore, we have designed this version of the GPL to prohibit the
practice for those products. If such problems arise substantially in
other domains, we stand ready to extend this provision to those
domains in future versions of the GPL, as needed to protect the
freedom of users.
</p>
<p>Finally, every program is threatened constantly by software patents.
States should not allow patents to restrict development and use of
software on general-purpose computers, but in those that do, we wish
to avoid the special danger that patents applied to a free program
could make it effectively proprietary. To prevent this, the GPL
assures that patents cannot be used to render the program non-free.
</p>
<p>The precise terms and conditions for copying, distribution and
modification follow.
</p>
<a name="TERMS-AND-CONDITIONS"></a>
<h3 class="heading">TERMS AND CONDITIONS</h3>
<ol>
<li> Definitions.
<p>“This License” refers to version 3 of the GNU General Public License.
</p>
<p>“Copyright” also means copyright-like laws that apply to other kinds
of works, such as semiconductor masks.
</p>
<p>“The Program” refers to any copyrightable work licensed under this
License. Each licensee is addressed as “you”. “Licensees” and
“recipients” may be individuals or organizations.
</p>
<p>To “modify” a work means to copy from or adapt all or part of the work
in a fashion requiring copyright permission, other than the making of
an exact copy. The resulting work is called a “modified version” of
the earlier work or a work “based on” the earlier work.
</p>
<p>A “covered work” means either the unmodified Program or a work based
on the Program.
</p>
<p>To “propagate” a work means to do anything with it that, without
permission, would make you directly or secondarily liable for
infringement under applicable copyright law, except executing it on a
computer or modifying a private copy. Propagation includes copying,
distribution (with or without modification), making available to the
public, and in some countries other activities as well.
</p>
<p>To “convey” a work means any kind of propagation that enables other
parties to make or receive copies. Mere interaction with a user
through a computer network, with no transfer of a copy, is not
conveying.
</p>
<p>An interactive user interface displays “Appropriate Legal Notices” to
the extent that it includes a convenient and prominently visible
feature that (1) displays an appropriate copyright notice, and (2)
tells the user that there is no warranty for the work (except to the
extent that warranties are provided), that licensees may convey the
work under this License, and how to view a copy of this License. If
the interface presents a list of user commands or options, such as a
menu, a prominent item in the list meets this criterion.
</p>
</li><li> Source Code.
<p>The “source code” for a work means the preferred form of the work for
making modifications to it. “Object code” means any non-source form
of a work.
</p>
<p>A “Standard Interface” means an interface that either is an official
standard defined by a recognized standards body, or, in the case of
interfaces specified for a particular programming language, one that
is widely used among developers working in that language.
</p>
<p>The “System Libraries” of an executable work include anything, other
than the work as a whole, that (a) is included in the normal form of
packaging a Major Component, but which is not part of that Major
Component, and (b) serves only to enable use of the work with that
Major Component, or to implement a Standard Interface for which an
implementation is available to the public in source code form. A
“Major Component”, in this context, means a major essential component
(kernel, window system, and so on) of the specific operating system
(if any) on which the executable work runs, or a compiler used to
produce the work, or an object code interpreter used to run it.
</p>
<p>The “Corresponding Source” for a work in object code form means all
the source code needed to generate, install, and (for an executable
work) run the object code and to modify the work, including scripts to
control those activities. However, it does not include the work’s
System Libraries, or general-purpose tools or generally available free
programs which are used unmodified in performing those activities but
which are not part of the work. For example, Corresponding Source
includes interface definition files associated with source files for
the work, and the source code for shared libraries and dynamically
linked subprograms that the work is specifically designed to require,
such as by intimate data communication or control flow between those
subprograms and other parts of the work.
</p>
<p>The Corresponding Source need not include anything that users can
regenerate automatically from other parts of the Corresponding Source.
</p>
<p>The Corresponding Source for a work in source code form is that same
work.
</p>
</li><li> Basic Permissions.
<p>All rights granted under this License are granted for the term of
copyright on the Program, and are irrevocable provided the stated
conditions are met. This License explicitly affirms your unlimited
permission to run the unmodified Program. The output from running a
covered work is covered by this License only if the output, given its
content, constitutes a covered work. This License acknowledges your
rights of fair use or other equivalent, as provided by copyright law.
</p>
<p>You may make, run and propagate covered works that you do not convey,
without conditions so long as your license otherwise remains in force.
You may convey covered works to others for the sole purpose of having
them make modifications exclusively for you, or provide you with
facilities for running those works, provided that you comply with the
terms of this License in conveying all material for which you do not
control copyright. Those thus making or running the covered works for
you must do so exclusively on your behalf, under your direction and
control, on terms that prohibit them from making any copies of your
copyrighted material outside their relationship with you.
</p>
<p>Conveying under any other circumstances is permitted solely under the
conditions stated below. Sublicensing is not allowed; section 10
makes it unnecessary.
</p>
</li><li> Protecting Users’ Legal Rights From Anti-Circumvention Law.
<p>No covered work shall be deemed part of an effective technological
measure under any applicable law fulfilling obligations under article
11 of the WIPO copyright treaty adopted on 20 December 1996, or
similar laws prohibiting or restricting circumvention of such
measures.
</p>
<p>When you convey a covered work, you waive any legal power to forbid
circumvention of technological measures to the extent such
circumvention is effected by exercising rights under this License with
respect to the covered work, and you disclaim any intention to limit
operation or modification of the work as a means of enforcing, against
the work’s users, your or third parties’ legal rights to forbid
circumvention of technological measures.
</p>
</li><li> Conveying Verbatim Copies.
<p>You may convey verbatim copies of the Program’s source code as you
receive it, in any medium, provided that you conspicuously and
appropriately publish on each copy an appropriate copyright notice;
keep intact all notices stating that this License and any
non-permissive terms added in accord with section 7 apply to the code;
keep intact all notices of the absence of any warranty; and give all
recipients a copy of this License along with the Program.
</p>
<p>You may charge any price or no price for each copy that you convey,
and you may offer support or warranty protection for a fee.
</p>
</li><li> Conveying Modified Source Versions.
<p>You may convey a work based on the Program, or the modifications to
produce it from the Program, in the form of source code under the
terms of section 4, provided that you also meet all of these
conditions:
</p>
<ol>
<li> The work must carry prominent notices stating that you modified it,
and giving a relevant date.
</li><li> The work must carry prominent notices stating that it is released
under this License and any conditions added under section 7. This
requirement modifies the requirement in section 4 to “keep intact all
notices”.
</li><li> You must license the entire work, as a whole, under this License to
anyone who comes into possession of a copy. This License will
therefore apply, along with any applicable section 7 additional terms,
to the whole of the work, and all its parts, regardless of how they
are packaged. This License gives no permission to license the work in
any other way, but it does not invalidate such permission if you have
separately received it.
</li><li> If the work has interactive user interfaces, each must display
Appropriate Legal Notices; however, if the Program has interactive
interfaces that do not display Appropriate Legal Notices, your work
need not make them do so.
</li></ol>
<p>A compilation of a covered work with other separate and independent
works, which are not by their nature extensions of the covered work,
and which are not combined with it such as to form a larger program,
in or on a volume of a storage or distribution medium, is called an
“aggregate” if the compilation and its resulting copyright are not
used to limit the access or legal rights of the compilation’s users
beyond what the individual works permit. Inclusion of a covered work
in an aggregate does not cause this License to apply to the other
parts of the aggregate.
</p>
</li><li> Conveying Non-Source Forms.
<p>You may convey a covered work in object code form under the terms of
sections 4 and 5, provided that you also convey the machine-readable
Corresponding Source under the terms of this License, in one of these
ways:
</p>
<ol>
<li> Convey the object code in, or embodied in, a physical product
(including a physical distribution medium), accompanied by the
Corresponding Source fixed on a durable physical medium customarily
used for software interchange.
</li><li> Convey the object code in, or embodied in, a physical product
(including a physical distribution medium), accompanied by a written
offer, valid for at least three years and valid for as long as you
offer spare parts or customer support for that product model, to give
anyone who possesses the object code either (1) a copy of the
Corresponding Source for all the software in the product that is
covered by this License, on a durable physical medium customarily used
for software interchange, for a price no more than your reasonable
cost of physically performing this conveying of source, or (2) access
to copy the Corresponding Source from a network server at no charge.
</li><li> Convey individual copies of the object code with a copy of the written
offer to provide the Corresponding Source. This alternative is
allowed only occasionally and noncommercially, and only if you
received the object code with such an offer, in accord with subsection
6b.
</li><li> Convey the object code by offering access from a designated place
(gratis or for a charge), and offer equivalent access to the
Corresponding Source in the same way through the same place at no
further charge. You need not require recipients to copy the
Corresponding Source along with the object code. If the place to copy
the object code is a network server, the Corresponding Source may be
on a different server (operated by you or a third party) that supports
equivalent copying facilities, provided you maintain clear directions
next to the object code saying where to find the Corresponding Source.
Regardless of what server hosts the Corresponding Source, you remain
obligated to ensure that it is available for as long as needed to
satisfy these requirements.
</li><li> Convey the object code using peer-to-peer transmission, provided you
inform other peers where the object code and Corresponding Source of
the work are being offered to the general public at no charge under
subsection 6d.
</li></ol>
<p>A separable portion of the object code, whose source code is excluded
from the Corresponding Source as a System Library, need not be
included in conveying the object code work.
</p>
<p>A “User Product” is either (1) a “consumer product”, which means any
tangible personal property which is normally used for personal,
family, or household purposes, or (2) anything designed or sold for
incorporation into a dwelling. In determining whether a product is a
consumer product, doubtful cases shall be resolved in favor of
coverage. For a particular product received by a particular user,
“normally used” refers to a typical or common use of that class of
product, regardless of the status of the particular user or of the way
in which the particular user actually uses, or expects or is expected
to use, the product. A product is a consumer product regardless of
whether the product has substantial commercial, industrial or
non-consumer uses, unless such uses represent the only significant
mode of use of the product.
</p>
<p>“Installation Information” for a User Product means any methods,
procedures, authorization keys, or other information required to
install and execute modified versions of a covered work in that User
Product from a modified version of its Corresponding Source. The
information must suffice to ensure that the continued functioning of
the modified object code is in no case prevented or interfered with
solely because modification has been made.
</p>
<p>If you convey an object code work under this section in, or with, or
specifically for use in, a User Product, and the conveying occurs as
part of a transaction in which the right of possession and use of the
User Product is transferred to the recipient in perpetuity or for a
fixed term (regardless of how the transaction is characterized), the
Corresponding Source conveyed under this section must be accompanied
by the Installation Information. But this requirement does not apply
if neither you nor any third party retains the ability to install
modified object code on the User Product (for example, the work has
been installed in ROM).
</p>
<p>The requirement to provide Installation Information does not include a
requirement to continue to provide support service, warranty, or
updates for a work that has been modified or installed by the
recipient, or for the User Product in which it has been modified or
installed. Access to a network may be denied when the modification
itself materially and adversely affects the operation of the network
or violates the rules and protocols for communication across the
network.
</p>
<p>Corresponding Source conveyed, and Installation Information provided,
in accord with this section must be in a format that is publicly
documented (and with an implementation available to the public in
source code form), and must require no special password or key for
unpacking, reading or copying.
</p>
</li><li> Additional Terms.
<p>“Additional permissions” are terms that supplement the terms of this
License by making exceptions from one or more of its conditions.
Additional permissions that are applicable to the entire Program shall
be treated as though they were included in this License, to the extent
that they are valid under applicable law. If additional permissions
apply only to part of the Program, that part may be used separately
under those permissions, but the entire Program remains governed by
this License without regard to the additional permissions.
</p>
<p>When you convey a copy of a covered work, you may at your option
remove any additional permissions from that copy, or from any part of
it. (Additional permissions may be written to require their own
removal in certain cases when you modify the work.) You may place
additional permissions on material, added by you to a covered work,
for which you have or can give appropriate copyright permission.
</p>
<p>Notwithstanding any other provision of this License, for material you
add to a covered work, you may (if authorized by the copyright holders
of that material) supplement the terms of this License with terms:
</p>
<ol>
<li> Disclaiming warranty or limiting liability differently from the terms
of sections 15 and 16 of this License; or
</li><li> Requiring preservation of specified reasonable legal notices or author
attributions in that material or in the Appropriate Legal Notices
displayed by works containing it; or
</li><li> Prohibiting misrepresentation of the origin of that material, or
requiring that modified versions of such material be marked in
reasonable ways as different from the original version; or
</li><li> Limiting the use for publicity purposes of names of licensors or
authors of the material; or
</li><li> Declining to grant rights under trademark law for use of some trade
names, trademarks, or service marks; or
</li><li> Requiring indemnification of licensors and authors of that material by
anyone who conveys the material (or modified versions of it) with
contractual assumptions of liability to the recipient, for any
liability that these contractual assumptions directly impose on those
licensors and authors.
</li></ol>
<p>All other non-permissive additional terms are considered “further
restrictions” within the meaning of section 10. If the Program as you
received it, or any part of it, contains a notice stating that it is
governed by this License along with a term that is a further
restriction, you may remove that term. If a license document contains
a further restriction but permits relicensing or conveying under this
License, you may add to a covered work material governed by the terms
of that license document, provided that the further restriction does
not survive such relicensing or conveying.
</p>
<p>If you add terms to a covered work in accord with this section, you
must place, in the relevant source files, a statement of the
additional terms that apply to those files, or a notice indicating
where to find the applicable terms.
</p>
<p>Additional terms, permissive or non-permissive, may be stated in the
form of a separately written license, or stated as exceptions; the
above requirements apply either way.
</p>
</li><li> Termination.
<p>You may not propagate or modify a covered work except as expressly
provided under this License. Any attempt otherwise to propagate or
modify it is void, and will automatically terminate your rights under
this License (including any patent licenses granted under the third
paragraph of section 11).
</p>
<p>However, if you cease all violation of this License, then your license
from a particular copyright holder is reinstated (a) provisionally,
unless and until the copyright holder explicitly and finally
terminates your license, and (b) permanently, if the copyright holder
fails to notify you of the violation by some reasonable means prior to
60 days after the cessation.
</p>
<p>Moreover, your license from a particular copyright holder is
reinstated permanently if the copyright holder notifies you of the
violation by some reasonable means, this is the first time you have
received notice of violation of this License (for any work) from that
copyright holder, and you cure the violation prior to 30 days after
your receipt of the notice.
</p>
<p>Termination of your rights under this section does not terminate the
licenses of parties who have received copies or rights from you under
this License. If your rights have been terminated and not permanently
reinstated, you do not qualify to receive new licenses for the same
material under section 10.
</p>
</li><li> Acceptance Not Required for Having Copies.
<p>You are not required to accept this License in order to receive or run
a copy of the Program. Ancillary propagation of a covered work
occurring solely as a consequence of using peer-to-peer transmission
to receive a copy likewise does not require acceptance. However,
nothing other than this License grants you permission to propagate or
modify any covered work. These actions infringe copyright if you do
not accept this License. Therefore, by modifying or propagating a
covered work, you indicate your acceptance of this License to do so.
</p>
</li><li> Automatic Licensing of Downstream Recipients.
<p>Each time you convey a covered work, the recipient automatically
receives a license from the original licensors, to run, modify and
propagate that work, subject to this License. You are not responsible
for enforcing compliance by third parties with this License.
</p>
<p>An “entity transaction” is a transaction transferring control of an
organization, or substantially all assets of one, or subdividing an
organization, or merging organizations. If propagation of a covered
work results from an entity transaction, each party to that
transaction who receives a copy of the work also receives whatever
licenses to the work the party’s predecessor in interest had or could
give under the previous paragraph, plus a right to possession of the
Corresponding Source of the work from the predecessor in interest, if
the predecessor has it or can get it with reasonable efforts.
</p>
<p>You may not impose any further restrictions on the exercise of the
rights granted or affirmed under this License. For example, you may
not impose a license fee, royalty, or other charge for exercise of
rights granted under this License, and you may not initiate litigation
(including a cross-claim or counterclaim in a lawsuit) alleging that
any patent claim is infringed by making, using, selling, offering for
sale, or importing the Program or any portion of it.
</p>
</li><li> Patents.
<p>A “contributor” is a copyright holder who authorizes use under this
License of the Program or a work on which the Program is based. The
work thus licensed is called the contributor’s “contributor version”.
</p>
<p>A contributor’s “essential patent claims” are all patent claims owned
or controlled by the contributor, whether already acquired or
hereafter acquired, that would be infringed by some manner, permitted
by this License, of making, using, or selling its contributor version,
but do not include claims that would be infringed only as a
consequence of further modification of the contributor version. For
purposes of this definition, “control” includes the right to grant
patent sublicenses in a manner consistent with the requirements of
this License.
</p>
<p>Each contributor grants you a non-exclusive, worldwide, royalty-free
patent license under the contributor’s essential patent claims, to
make, use, sell, offer for sale, import and otherwise run, modify and
propagate the contents of its contributor version.
</p>
<p>In the following three paragraphs, a “patent license” is any express
agreement or commitment, however denominated, not to enforce a patent
(such as an express permission to practice a patent or covenant not to
sue for patent infringement). To “grant” such a patent license to a
party means to make such an agreement or commitment not to enforce a
patent against the party.
</p>
<p>If you convey a covered work, knowingly relying on a patent license,
and the Corresponding Source of the work is not available for anyone
to copy, free of charge and under the terms of this License, through a
publicly available network server or other readily accessible means,
then you must either (1) cause the Corresponding Source to be so
available, or (2) arrange to deprive yourself of the benefit of the
patent license for this particular work, or (3) arrange, in a manner
consistent with the requirements of this License, to extend the patent
license to downstream recipients. “Knowingly relying” means you have
actual knowledge that, but for the patent license, your conveying the
covered work in a country, or your recipient’s use of the covered work
in a country, would infringe one or more identifiable patents in that
country that you have reason to believe are valid.
</p>
<p>If, pursuant to or in connection with a single transaction or
arrangement, you convey, or propagate by procuring conveyance of, a
covered work, and grant a patent license to some of the parties
receiving the covered work authorizing them to use, propagate, modify
or convey a specific copy of the covered work, then the patent license
you grant is automatically extended to all recipients of the covered
work and works based on it.
</p>
<p>A patent license is “discriminatory” if it does not include within the
scope of its coverage, prohibits the exercise of, or is conditioned on
the non-exercise of one or more of the rights that are specifically
granted under this License. You may not convey a covered work if you
are a party to an arrangement with a third party that is in the
business of distributing software, under which you make payment to the
third party based on the extent of your activity of conveying the
work, and under which the third party grants, to any of the parties
who would receive the covered work from you, a discriminatory patent
license (a) in connection with copies of the covered work conveyed by
you (or copies made from those copies), or (b) primarily for and in
connection with specific products or compilations that contain the
covered work, unless you entered into that arrangement, or that patent
license was granted, prior to 28 March 2007.
</p>
<p>Nothing in this License shall be construed as excluding or limiting
any implied license or other defenses to infringement that may
otherwise be available to you under applicable patent law.
</p>
</li><li> No Surrender of Others’ Freedom.
<p>If conditions are imposed on you (whether by court order, agreement or
otherwise) that contradict the conditions of this License, they do not
excuse you from the conditions of this License. If you cannot convey
a covered work so as to satisfy simultaneously your obligations under
this License and any other pertinent obligations, then as a
consequence you may not convey it at all. For example, if you agree
to terms that obligate you to collect a royalty for further conveying
from those to whom you convey the Program, the only way you could
satisfy both those terms and this License would be to refrain entirely
from conveying the Program.
</p>
</li><li> Use with the GNU Affero General Public License.
<p>Notwithstanding any other provision of this License, you have
permission to link or combine any covered work with a work licensed
under version 3 of the GNU Affero General Public License into a single
combined work, and to convey the resulting work. The terms of this
License will continue to apply to the part which is the covered work,
but the special requirements of the GNU Affero General Public License,
section 13, concerning interaction through a network will apply to the
combination as such.
</p>
</li><li> Revised Versions of this License.
<p>The Free Software Foundation may publish revised and/or new versions
of the GNU General Public License from time to time. Such new
versions will be similar in spirit to the present version, but may
differ in detail to address new problems or concerns.
</p>
<p>Each version is given a distinguishing version number. If the Program
specifies that a certain numbered version of the GNU General Public
License “or any later version” applies to it, you have the option of
following the terms and conditions either of that numbered version or
of any later version published by the Free Software Foundation. If
the Program does not specify a version number of the GNU General
Public License, you may choose any version ever published by the Free
Software Foundation.
</p>
<p>If the Program specifies that a proxy can decide which future versions
of the GNU General Public License can be used, that proxy’s public
statement of acceptance of a version permanently authorizes you to
choose that version for the Program.
</p>
<p>Later license versions may give you additional or different
permissions. However, no additional obligations are imposed on any
author or copyright holder as a result of your choosing to follow a
later version.
</p>
</li><li> Disclaimer of Warranty.
<p>THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM “AS IS” WITHOUT
WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND
PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE
DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR OR
CORRECTION.
</p>
</li><li> Limitation of Liability.
<p>IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR
CONVEYS THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES,
INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES
ARISING OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT
NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR
LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM
TO OPERATE WITH ANY OTHER PROGRAMS), EVEN IF SUCH HOLDER OR OTHER
PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
</p>
</li><li> Interpretation of Sections 15 and 16.
<p>If the disclaimer of warranty and limitation of liability provided
above cannot be given local legal effect according to their terms,
reviewing courts shall apply local law that most closely approximates
an absolute waiver of all civil liability in connection with the
Program, unless a warranty or assumption of liability accompanies a
copy of the Program in return for a fee.
</p>
</li></ol>
<a name="END-OF-TERMS-AND-CONDITIONS"></a>
<h3 class="heading">END OF TERMS AND CONDITIONS</h3>
<a name="How-to-Apply-These-Terms-to-Your-New-Programs"></a>
<h3 class="heading">How to Apply These Terms to Your New Programs</h3>
<p>If you develop a new program, and you want it to be of the greatest
possible use to the public, the best way to achieve this is to make it
free software which everyone can redistribute and change under these
terms.
</p>
<p>To do so, attach the following notices to the program. It is safest
to attach them to the start of each source file to most effectively
state the exclusion of warranty; and each file should have at least
the “copyright” line and a pointer to where the full notice is found.
</p>
<div class="smallexample">
<pre class="smallexample"><var>one line to give the program's name and a brief idea of what it does.</var>
Copyright (C) <var>year</var> <var>name of author</var>
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or (at
your option) any later version.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <a href="http://www.gnu.org/licenses/">http://www.gnu.org/licenses/</a>.
</pre></div>
<p>Also add information on how to contact you by electronic and paper mail.
</p>
<p>If the program does terminal interaction, make it output a short
notice like this when it starts in an interactive mode:
</p>
<div class="smallexample">
<pre class="smallexample"><var>program</var> Copyright (C) <var>year</var> <var>name of author</var>
This program comes with ABSOLUTELY NO WARRANTY; for details type ‘<samp>show w</samp>’.
This is free software, and you are welcome to redistribute it
under certain conditions; type ‘<samp>show c</samp>’ for details.
</pre></div>
<p>The hypothetical commands ‘<samp>show w</samp>’ and ‘<samp>show c</samp>’ should show
the appropriate parts of the General Public License. Of course, your
program’s commands might be different; for a GUI interface, you would
use an “about box”.
</p>
<p>You should also get your employer (if you work as a programmer) or school,
if any, to sign a “copyright disclaimer” for the program, if necessary.
For more information on this, and how to apply and follow the GNU GPL, see
<a href="http://www.gnu.org/licenses/">http://www.gnu.org/licenses/</a>.
</p>
<p>The GNU General Public License does not permit incorporating your
program into proprietary programs. If your program is a subroutine
library, you may consider it more useful to permit linking proprietary
applications with the library. If this is what you want to do, use
the GNU Lesser General Public License instead of this License. But
first, please read <a href="http://www.gnu.org/philosophy/why-not-lgpl.html">http://www.gnu.org/philosophy/why-not-lgpl.html</a>.
</p>
<hr>
<a name="GNU-Free-Documentation-License"></a>
<div class="header">
<p>
Next: <a href="#Funding" accesskey="n" rel="next">Funding</a>, Previous: <a href="#Copying" accesskey="p" rel="prev">Copying</a>, Up: <a href="#Top" accesskey="u" rel="up">Top</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="GNU-Free-Documentation-License-1"></a>
<h2 class="unnumbered">GNU Free Documentation License</h2>
<a name="index-FDL_002c-GNU-Free-Documentation-License"></a>
<div align="center">Version 1.3, 3 November 2008
</div>
<div class="display">
<pre class="display">Copyright © 2000, 2001, 2002, 2007, 2008 Free Software Foundation, Inc.
<a href="http://fsf.org/">http://fsf.org/</a>
Everyone is permitted to copy and distribute verbatim copies
of this license document, but changing it is not allowed.
</pre></div>
<ol>
<li> PREAMBLE
<p>The purpose of this License is to make a manual, textbook, or other
functional and useful document <em>free</em> in the sense of freedom: to
assure everyone the effective freedom to copy and redistribute it,
with or without modifying it, either commercially or noncommercially.
Secondarily, this License preserves for the author and publisher a way
to get credit for their work, while not being considered responsible
for modifications made by others.
</p>
<p>This License is a kind of “copyleft”, which means that derivative
works of the document must themselves be free in the same sense. It
complements the GNU General Public License, which is a copyleft
license designed for free software.
</p>
<p>We have designed this License in order to use it for manuals for free
software, because free software needs free documentation: a free
program should come with manuals providing the same freedoms that the
software does. But this License is not limited to software manuals;
it can be used for any textual work, regardless of subject matter or
whether it is published as a printed book. We recommend this License
principally for works whose purpose is instruction or reference.
</p>
</li><li> APPLICABILITY AND DEFINITIONS
<p>This License applies to any manual or other work, in any medium, that
contains a notice placed by the copyright holder saying it can be
distributed under the terms of this License. Such a notice grants a
world-wide, royalty-free license, unlimited in duration, to use that
work under the conditions stated herein. The “Document”, below,
refers to any such manual or work. Any member of the public is a
licensee, and is addressed as “you”. You accept the license if you
copy, modify or distribute the work in a way requiring permission
under copyright law.
</p>
<p>A “Modified Version” of the Document means any work containing the
Document or a portion of it, either copied verbatim, or with
modifications and/or translated into another language.
</p>
<p>A “Secondary Section” is a named appendix or a front-matter section
of the Document that deals exclusively with the relationship of the
publishers or authors of the Document to the Document’s overall
subject (or to related matters) and contains nothing that could fall
directly within that overall subject. (Thus, if the Document is in
part a textbook of mathematics, a Secondary Section may not explain
any mathematics.) The relationship could be a matter of historical
connection with the subject or with related matters, or of legal,
commercial, philosophical, ethical or political position regarding
them.
</p>
<p>The “Invariant Sections” are certain Secondary Sections whose titles
are designated, as being those of Invariant Sections, in the notice
that says that the Document is released under this License. If a
section does not fit the above definition of Secondary then it is not
allowed to be designated as Invariant. The Document may contain zero
Invariant Sections. If the Document does not identify any Invariant
Sections then there are none.
</p>
<p>The “Cover Texts” are certain short passages of text that are listed,
as Front-Cover Texts or Back-Cover Texts, in the notice that says that
the Document is released under this License. A Front-Cover Text may
be at most 5 words, and a Back-Cover Text may be at most 25 words.
</p>
<p>A “Transparent” copy of the Document means a machine-readable copy,
represented in a format whose specification is available to the
general public, that is suitable for revising the document
straightforwardly with generic text editors or (for images composed of
pixels) generic paint programs or (for drawings) some widely available
drawing editor, and that is suitable for input to text formatters or
for automatic translation to a variety of formats suitable for input
to text formatters. A copy made in an otherwise Transparent file
format whose markup, or absence of markup, has been arranged to thwart
or discourage subsequent modification by readers is not Transparent.
An image format is not Transparent if used for any substantial amount
of text. A copy that is not “Transparent” is called “Opaque”.
</p>
<p>Examples of suitable formats for Transparent copies include plain
<small>ASCII</small> without markup, Texinfo input format, LaTeX input
format, <acronym>SGML</acronym> or <acronym>XML</acronym> using a publicly available
<acronym>DTD</acronym>, and standard-conforming simple <acronym>HTML</acronym>,
PostScript or <acronym>PDF</acronym> designed for human modification. Examples
of transparent image formats include <acronym>PNG</acronym>, <acronym>XCF</acronym> and
<acronym>JPG</acronym>. Opaque formats include proprietary formats that can be
read and edited only by proprietary word processors, <acronym>SGML</acronym> or
<acronym>XML</acronym> for which the <acronym>DTD</acronym> and/or processing tools are
not generally available, and the machine-generated <acronym>HTML</acronym>,
PostScript or <acronym>PDF</acronym> produced by some word processors for
output purposes only.
</p>
<p>The “Title Page” means, for a printed book, the title page itself,
plus such following pages as are needed to hold, legibly, the material
this License requires to appear in the title page. For works in
formats which do not have any title page as such, “Title Page” means
the text near the most prominent appearance of the work’s title,
preceding the beginning of the body of the text.
</p>
<p>The “publisher” means any person or entity that distributes copies
of the Document to the public.
</p>
<p>A section “Entitled XYZ” means a named subunit of the Document whose
title either is precisely XYZ or contains XYZ in parentheses following
text that translates XYZ in another language. (Here XYZ stands for a
specific section name mentioned below, such as “Acknowledgements”,
“Dedications”, “Endorsements”, or “History”.) To “Preserve the Title”
of such a section when you modify the Document means that it remains a
section “Entitled XYZ” according to this definition.
</p>
<p>The Document may include Warranty Disclaimers next to the notice which
states that this License applies to the Document. These Warranty
Disclaimers are considered to be included by reference in this
License, but only as regards disclaiming warranties: any other
implication that these Warranty Disclaimers may have is void and has
no effect on the meaning of this License.
</p>
</li><li> VERBATIM COPYING
<p>You may copy and distribute the Document in any medium, either
commercially or noncommercially, provided that this License, the
copyright notices, and the license notice saying this License applies
to the Document are reproduced in all copies, and that you add no other
conditions whatsoever to those of this License. You may not use
technical measures to obstruct or control the reading or further
copying of the copies you make or distribute. However, you may accept
compensation in exchange for copies. If you distribute a large enough
number of copies you must also follow the conditions in section 3.
</p>
<p>You may also lend copies, under the same conditions stated above, and
you may publicly display copies.
</p>
</li><li> COPYING IN QUANTITY
<p>If you publish printed copies (or copies in media that commonly have
printed covers) of the Document, numbering more than 100, and the
Document’s license notice requires Cover Texts, you must enclose the
copies in covers that carry, clearly and legibly, all these Cover
Texts: Front-Cover Texts on the front cover, and Back-Cover Texts on
the back cover. Both covers must also clearly and legibly identify
you as the publisher of these copies. The front cover must present
the full title with all words of the title equally prominent and
visible. You may add other material on the covers in addition.
Copying with changes limited to the covers, as long as they preserve
the title of the Document and satisfy these conditions, can be treated
as verbatim copying in other respects.
</p>
<p>If the required texts for either cover are too voluminous to fit
legibly, you should put the first ones listed (as many as fit
reasonably) on the actual cover, and continue the rest onto adjacent
pages.
</p>
<p>If you publish or distribute Opaque copies of the Document numbering
more than 100, you must either include a machine-readable Transparent
copy along with each Opaque copy, or state in or with each Opaque copy
a computer-network location from which the general network-using
public has access to download using public-standard network protocols
a complete Transparent copy of the Document, free of added material.
If you use the latter option, you must take reasonably prudent steps,
when you begin distribution of Opaque copies in quantity, to ensure
that this Transparent copy will remain thus accessible at the stated
location until at least one year after the last time you distribute an
Opaque copy (directly or through your agents or retailers) of that
edition to the public.
</p>
<p>It is requested, but not required, that you contact the authors of the
Document well before redistributing any large number of copies, to give
them a chance to provide you with an updated version of the Document.
</p>
</li><li> MODIFICATIONS
<p>You may copy and distribute a Modified Version of the Document under
the conditions of sections 2 and 3 above, provided that you release
the Modified Version under precisely this License, with the Modified
Version filling the role of the Document, thus licensing distribution
and modification of the Modified Version to whoever possesses a copy
of it. In addition, you must do these things in the Modified Version:
</p>
<ol>
<li> Use in the Title Page (and on the covers, if any) a title distinct
from that of the Document, and from those of previous versions
(which should, if there were any, be listed in the History section
of the Document). You may use the same title as a previous version
if the original publisher of that version gives permission.
</li><li> List on the Title Page, as authors, one or more persons or entities
responsible for authorship of the modifications in the Modified
Version, together with at least five of the principal authors of the
Document (all of its principal authors, if it has fewer than five),
unless they release you from this requirement.
</li><li> State on the Title page the name of the publisher of the
Modified Version, as the publisher.
</li><li> Preserve all the copyright notices of the Document.
</li><li> Add an appropriate copyright notice for your modifications
adjacent to the other copyright notices.
</li><li> Include, immediately after the copyright notices, a license notice
giving the public permission to use the Modified Version under the
terms of this License, in the form shown in the Addendum below.
</li><li> Preserve in that license notice the full lists of Invariant Sections
and required Cover Texts given in the Document’s license notice.
</li><li> Include an unaltered copy of this License.
</li><li> Preserve the section Entitled “History”, Preserve its Title, and add
to it an item stating at least the title, year, new authors, and
publisher of the Modified Version as given on the Title Page. If
there is no section Entitled “History” in the Document, create one
stating the title, year, authors, and publisher of the Document as
given on its Title Page, then add an item describing the Modified
Version as stated in the previous sentence.
</li><li> Preserve the network location, if any, given in the Document for
public access to a Transparent copy of the Document, and likewise
the network locations given in the Document for previous versions
it was based on. These may be placed in the “History” section.
You may omit a network location for a work that was published at
least four years before the Document itself, or if the original
publisher of the version it refers to gives permission.
</li><li> For any section Entitled “Acknowledgements” or “Dedications”, Preserve
the Title of the section, and preserve in the section all the
substance and tone of each of the contributor acknowledgements and/or
dedications given therein.
</li><li> Preserve all the Invariant Sections of the Document,
unaltered in their text and in their titles. Section numbers
or the equivalent are not considered part of the section titles.
</li><li> Delete any section Entitled “Endorsements”. Such a section
may not be included in the Modified Version.
</li><li> Do not retitle any existing section to be Entitled “Endorsements” or
to conflict in title with any Invariant Section.
</li><li> Preserve any Warranty Disclaimers.
</li></ol>
<p>If the Modified Version includes new front-matter sections or
appendices that qualify as Secondary Sections and contain no material
copied from the Document, you may at your option designate some or all
of these sections as invariant. To do this, add their titles to the
list of Invariant Sections in the Modified Version’s license notice.
These titles must be distinct from any other section titles.
</p>
<p>You may add a section Entitled “Endorsements”, provided it contains
nothing but endorsements of your Modified Version by various
parties—for example, statements of peer review or that the text has
been approved by an organization as the authoritative definition of a
standard.
</p>
<p>You may add a passage of up to five words as a Front-Cover Text, and a
passage of up to 25 words as a Back-Cover Text, to the end of the list
of Cover Texts in the Modified Version. Only one passage of
Front-Cover Text and one of Back-Cover Text may be added by (or
through arrangements made by) any one entity. If the Document already
includes a cover text for the same cover, previously added by you or
by arrangement made by the same entity you are acting on behalf of,
you may not add another; but you may replace the old one, on explicit
permission from the previous publisher that added the old one.
</p>
<p>The author(s) and publisher(s) of the Document do not by this License
give permission to use their names for publicity for or to assert or
imply endorsement of any Modified Version.
</p>
</li><li> COMBINING DOCUMENTS
<p>You may combine the Document with other documents released under this
License, under the terms defined in section 4 above for modified
versions, provided that you include in the combination all of the
Invariant Sections of all of the original documents, unmodified, and
list them all as Invariant Sections of your combined work in its
license notice, and that you preserve all their Warranty Disclaimers.
</p>
<p>The combined work need only contain one copy of this License, and
multiple identical Invariant Sections may be replaced with a single
copy. If there are multiple Invariant Sections with the same name but
different contents, make the title of each such section unique by
adding at the end of it, in parentheses, the name of the original
author or publisher of that section if known, or else a unique number.
Make the same adjustment to the section titles in the list of
Invariant Sections in the license notice of the combined work.
</p>
<p>In the combination, you must combine any sections Entitled “History”
in the various original documents, forming one section Entitled
“History”; likewise combine any sections Entitled “Acknowledgements”,
and any sections Entitled “Dedications”. You must delete all
sections Entitled “Endorsements.”
</p>
</li><li> COLLECTIONS OF DOCUMENTS
<p>You may make a collection consisting of the Document and other documents
released under this License, and replace the individual copies of this
License in the various documents with a single copy that is included in
the collection, provided that you follow the rules of this License for
verbatim copying of each of the documents in all other respects.
</p>
<p>You may extract a single document from such a collection, and distribute
it individually under this License, provided you insert a copy of this
License into the extracted document, and follow this License in all
other respects regarding verbatim copying of that document.
</p>
</li><li> AGGREGATION WITH INDEPENDENT WORKS
<p>A compilation of the Document or its derivatives with other separate
and independent documents or works, in or on a volume of a storage or
distribution medium, is called an “aggregate” if the copyright
resulting from the compilation is not used to limit the legal rights
of the compilation’s users beyond what the individual works permit.
When the Document is included in an aggregate, this License does not
apply to the other works in the aggregate which are not themselves
derivative works of the Document.
</p>
<p>If the Cover Text requirement of section 3 is applicable to these
copies of the Document, then if the Document is less than one half of
the entire aggregate, the Document’s Cover Texts may be placed on
covers that bracket the Document within the aggregate, or the
electronic equivalent of covers if the Document is in electronic form.
Otherwise they must appear on printed covers that bracket the whole
aggregate.
</p>
</li><li> TRANSLATION
<p>Translation is considered a kind of modification, so you may
distribute translations of the Document under the terms of section 4.
Replacing Invariant Sections with translations requires special
permission from their copyright holders, but you may include
translations of some or all Invariant Sections in addition to the
original versions of these Invariant Sections. You may include a
translation of this License, and all the license notices in the
Document, and any Warranty Disclaimers, provided that you also include
the original English version of this License and the original versions
of those notices and disclaimers. In case of a disagreement between
the translation and the original version of this License or a notice
or disclaimer, the original version will prevail.
</p>
<p>If a section in the Document is Entitled “Acknowledgements”,
“Dedications”, or “History”, the requirement (section 4) to Preserve
its Title (section 1) will typically require changing the actual
title.
</p>
</li><li> TERMINATION
<p>You may not copy, modify, sublicense, or distribute the Document
except as expressly provided under this License. Any attempt
otherwise to copy, modify, sublicense, or distribute it is void, and
will automatically terminate your rights under this License.
</p>
<p>However, if you cease all violation of this License, then your license
from a particular copyright holder is reinstated (a) provisionally,
unless and until the copyright holder explicitly and finally
terminates your license, and (b) permanently, if the copyright holder
fails to notify you of the violation by some reasonable means prior to
60 days after the cessation.
</p>
<p>Moreover, your license from a particular copyright holder is
reinstated permanently if the copyright holder notifies you of the
violation by some reasonable means, this is the first time you have
received notice of violation of this License (for any work) from that
copyright holder, and you cure the violation prior to 30 days after
your receipt of the notice.
</p>
<p>Termination of your rights under this section does not terminate the
licenses of parties who have received copies or rights from you under
this License. If your rights have been terminated and not permanently
reinstated, receipt of a copy of some or all of the same material does
not give you any rights to use it.
</p>
</li><li> FUTURE REVISIONS OF THIS LICENSE
<p>The Free Software Foundation may publish new, revised versions
of the GNU Free Documentation License from time to time. Such new
versions will be similar in spirit to the present version, but may
differ in detail to address new problems or concerns. See
<a href="http://www.gnu.org/copyleft/">http://www.gnu.org/copyleft/</a>.
</p>
<p>Each version of the License is given a distinguishing version number.
If the Document specifies that a particular numbered version of this
License “or any later version” applies to it, you have the option of
following the terms and conditions either of that specified version or
of any later version that has been published (not as a draft) by the
Free Software Foundation. If the Document does not specify a version
number of this License, you may choose any version ever published (not
as a draft) by the Free Software Foundation. If the Document
specifies that a proxy can decide which future versions of this
License can be used, that proxy’s public statement of acceptance of a
version permanently authorizes you to choose that version for the
Document.
</p>
</li><li> RELICENSING
<p>“Massive Multiauthor Collaboration Site” (or “MMC Site”) means any
World Wide Web server that publishes copyrightable works and also
provides prominent facilities for anybody to edit those works. A
public wiki that anybody can edit is an example of such a server. A
“Massive Multiauthor Collaboration” (or “MMC”) contained in the
site means any set of copyrightable works thus published on the MMC
site.
</p>
<p>“CC-BY-SA” means the Creative Commons Attribution-Share Alike 3.0
license published by Creative Commons Corporation, a not-for-profit
corporation with a principal place of business in San Francisco,
California, as well as future copyleft versions of that license
published by that same organization.
</p>
<p>“Incorporate” means to publish or republish a Document, in whole or
in part, as part of another Document.
</p>
<p>An MMC is “eligible for relicensing” if it is licensed under this
License, and if all works that were first published under this License
somewhere other than this MMC, and subsequently incorporated in whole
or in part into the MMC, (1) had no cover texts or invariant sections,
and (2) were thus incorporated prior to November 1, 2008.
</p>
<p>The operator of an MMC Site may republish an MMC contained in the site
under CC-BY-SA on the same site at any time before August 1, 2009,
provided the MMC is eligible for relicensing.
</p>
</li></ol>
<a name="ADDENDUM_003a-How-to-use-this-License-for-your-documents"></a>
<h3 class="unnumberedsec">ADDENDUM: How to use this License for your documents</h3>
<p>To use this License in a document you have written, include a copy of
the License in the document and put the following copyright and
license notices just after the title page:
</p>
<div class="smallexample">
<pre class="smallexample"> Copyright (C) <var>year</var> <var>your name</var>.
Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.3
or any later version published by the Free Software Foundation;
with no Invariant Sections, no Front-Cover Texts, and no Back-Cover
Texts. A copy of the license is included in the section entitled ``GNU
Free Documentation License''.
</pre></div>
<p>If you have Invariant Sections, Front-Cover Texts and Back-Cover Texts,
replace the “with...Texts.” line with this:
</p>
<div class="smallexample">
<pre class="smallexample"> with the Invariant Sections being <var>list their titles</var>, with
the Front-Cover Texts being <var>list</var>, and with the Back-Cover Texts
being <var>list</var>.
</pre></div>
<p>If you have Invariant Sections without Cover Texts, or some other
combination of the three, merge those two alternatives to suit the
situation.
</p>
<p>If your document contains nontrivial examples of program code, we
recommend releasing these examples in parallel under your choice of
free software license, such as the GNU General Public License,
to permit their use in free software.
</p>
<hr>
<a name="Funding"></a>
<div class="header">
<p>
Next: <a href="#Library-Index" accesskey="n" rel="next">Library Index</a>, Previous: <a href="#GNU-Free-Documentation-License" accesskey="p" rel="prev">GNU Free Documentation License</a>, Up: <a href="#Top" accesskey="u" rel="up">Top</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="Funding-Free-Software"></a>
<h2 class="unnumbered">Funding Free Software</h2>
<p>If you want to have more free software a few years from now, it makes
sense for you to help encourage people to contribute funds for its
development. The most effective approach known is to encourage
commercial redistributors to donate.
</p>
<p>Users of free software systems can boost the pace of development by
encouraging for-a-fee distributors to donate part of their selling price
to free software developers—the Free Software Foundation, and others.
</p>
<p>The way to convince distributors to do this is to demand it and expect
it from them. So when you compare distributors, judge them partly by
how much they give to free software development. Show distributors
they must compete to be the one who gives the most.
</p>
<p>To make this approach work, you must insist on numbers that you can
compare, such as, “We will donate ten dollars to the Frobnitz project
for each disk sold.” Don’t be satisfied with a vague promise, such as
“A portion of the profits are donated,” since it doesn’t give a basis
for comparison.
</p>
<p>Even a precise fraction “of the profits from this disk” is not very
meaningful, since creative accounting and unrelated business decisions
can greatly alter what fraction of the sales price counts as profit.
If the price you pay is $50, ten percent of the profit is probably
less than a dollar; it might be a few cents, or nothing at all.
</p>
<p>Some redistributors do development work themselves. This is useful too;
but to keep everyone honest, you need to inquire how much they do, and
what kind. Some kinds of development make much more long-term
difference than others. For example, maintaining a separate version of
a program contributes very little; maintaining the standard version of a
program for the whole community contributes much. Easy new ports
contribute little, since someone else would surely do them; difficult
ports such as adding a new CPU to the GNU Compiler Collection contribute more;
major new features or packages contribute the most.
</p>
<p>By establishing the idea that supporting further development is “the
proper thing to do” when distributing free software for a fee, we can
assure a steady flow of resources into making more free software.
</p>
<div class="display">
<pre class="display">Copyright © 1994 Free Software Foundation, Inc.
Verbatim copying and redistribution of this section is permitted
without royalty; alteration is not permitted.
</pre></div>
<hr>
<a name="Library-Index"></a>
<div class="header">
<p>
Previous: <a href="#Funding" accesskey="p" rel="prev">Funding</a>, Up: <a href="#Top" accesskey="u" rel="up">Top</a> [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="#Library-Index" title="Index" rel="index">Index</a>]</p>
</div>
<a name="Library-Index-1"></a>
<h2 class="unnumbered">Library Index</h2>
<table><tr><th valign="top">Jump to: </th><td><a class="summary-letter" href="#Library-Index_cp_letter-E"><b>E</b></a>
<a class="summary-letter" href="#Library-Index_cp_letter-F"><b>F</b></a>
<a class="summary-letter" href="#Library-Index_cp_letter-I"><b>I</b></a>
</td></tr></table>
<table class="index-cp" border="0">
<tr><td></td><th align="left">Index Entry</th><td> </td><th align="left"> Section</th></tr>
<tr><td colspan="4"> <hr></td></tr>
<tr><th><a name="Library-Index_cp_letter-E">E</a></th><td></td><td></td></tr>
<tr><td></td><td valign="top"><a href="#index-Environment-Variable">Environment Variable</a>:</td><td> </td><td valign="top"><a href="#OMP_005fCANCELLATION">OMP_CANCELLATION</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-Environment-Variable-1">Environment Variable</a>:</td><td> </td><td valign="top"><a href="#OMP_005fDISPLAY_005fENV">OMP_DISPLAY_ENV</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-Environment-Variable-2">Environment Variable</a>:</td><td> </td><td valign="top"><a href="#OMP_005fDEFAULT_005fDEVICE">OMP_DEFAULT_DEVICE</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-Environment-Variable-3">Environment Variable</a>:</td><td> </td><td valign="top"><a href="#OMP_005fDYNAMIC">OMP_DYNAMIC</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-Environment-Variable-4">Environment Variable</a>:</td><td> </td><td valign="top"><a href="#OMP_005fMAX_005fACTIVE_005fLEVELS">OMP_MAX_ACTIVE_LEVELS</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-Environment-Variable-5">Environment Variable</a>:</td><td> </td><td valign="top"><a href="#OMP_005fNESTED">OMP_NESTED</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-Environment-Variable-6">Environment Variable</a>:</td><td> </td><td valign="top"><a href="#OMP_005fNUM_005fTHREADS">OMP_NUM_THREADS</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-Environment-Variable-7">Environment Variable</a>:</td><td> </td><td valign="top"><a href="#OMP_005fPROC_005fBIND">OMP_PROC_BIND</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-Environment-Variable-8">Environment Variable</a>:</td><td> </td><td valign="top"><a href="#OMP_005fPLACES">OMP_PLACES</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-Environment-Variable-9">Environment Variable</a>:</td><td> </td><td valign="top"><a href="#OMP_005fSTACKSIZE">OMP_STACKSIZE</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-Environment-Variable-10">Environment Variable</a>:</td><td> </td><td valign="top"><a href="#OMP_005fSCHEDULE">OMP_SCHEDULE</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-Environment-Variable-11">Environment Variable</a>:</td><td> </td><td valign="top"><a href="#OMP_005fTHREAD_005fLIMIT">OMP_THREAD_LIMIT</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-Environment-Variable-12">Environment Variable</a>:</td><td> </td><td valign="top"><a href="#OMP_005fWAIT_005fPOLICY">OMP_WAIT_POLICY</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-Environment-Variable-13">Environment Variable</a>:</td><td> </td><td valign="top"><a href="#GOMP_005fCPU_005fAFFINITY">GOMP_CPU_AFFINITY</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-Environment-Variable-14">Environment Variable</a>:</td><td> </td><td valign="top"><a href="#GOMP_005fSTACKSIZE">GOMP_STACKSIZE</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-Environment-Variable-15">Environment Variable</a>:</td><td> </td><td valign="top"><a href="#GOMP_005fSPINCOUNT">GOMP_SPINCOUNT</a></td></tr>
<tr><td colspan="4"> <hr></td></tr>
<tr><th><a name="Library-Index_cp_letter-F">F</a></th><td></td><td></td></tr>
<tr><td></td><td valign="top"><a href="#index-FDL_002c-GNU-Free-Documentation-License">FDL, GNU Free Documentation License</a>:</td><td> </td><td valign="top"><a href="#GNU-Free-Documentation-License">GNU Free Documentation License</a></td></tr>
<tr><td colspan="4"> <hr></td></tr>
<tr><th><a name="Library-Index_cp_letter-I">I</a></th><td></td><td></td></tr>
<tr><td></td><td valign="top"><a href="#index-Implementation-specific-setting">Implementation specific setting</a>:</td><td> </td><td valign="top"><a href="#OMP_005fNESTED">OMP_NESTED</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-Implementation-specific-setting-1">Implementation specific setting</a>:</td><td> </td><td valign="top"><a href="#OMP_005fNUM_005fTHREADS">OMP_NUM_THREADS</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-Implementation-specific-setting-2">Implementation specific setting</a>:</td><td> </td><td valign="top"><a href="#OMP_005fSCHEDULE">OMP_SCHEDULE</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-Implementation-specific-setting-3">Implementation specific setting</a>:</td><td> </td><td valign="top"><a href="#GOMP_005fSTACKSIZE">GOMP_STACKSIZE</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-Implementation-specific-setting-4">Implementation specific setting</a>:</td><td> </td><td valign="top"><a href="#GOMP_005fSPINCOUNT">GOMP_SPINCOUNT</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-Introduction">Introduction</a>:</td><td> </td><td valign="top"><a href="#Top">Top</a></td></tr>
<tr><td colspan="4"> <hr></td></tr>
</table>
<table><tr><th valign="top">Jump to: </th><td><a class="summary-letter" href="#Library-Index_cp_letter-E"><b>E</b></a>
<a class="summary-letter" href="#Library-Index_cp_letter-F"><b>F</b></a>
<a class="summary-letter" href="#Library-Index_cp_letter-I"><b>I</b></a>
</td></tr></table>
<hr>
</body>
</html>
|