This file is indexed.

/usr/include/libreoffice/rtl/instance.hxx is in libreoffice-dev 1:3.5.7-0ubuntu13.

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
/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*************************************************************************
 *
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * Copyright 2000, 2010 Oracle and/or its affiliates.
 *
 * OpenOffice.org - a multi-platform office productivity suite
 *
 * This file is part of OpenOffice.org.
 *
 * OpenOffice.org is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License version 3
 * only, as published by the Free Software Foundation.
 *
 * OpenOffice.org 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 Lesser General Public License version 3 for more details
 * (a copy is included in the LICENSE file that accompanied this code).
 *
 * You should have received a copy of the GNU Lesser General Public License
 * version 3 along with OpenOffice.org.  If not, see
 * <http://www.openoffice.org/license.html>
 * for a copy of the LGPLv3 License.
 *
 ************************************************************************/

#if !defined INCLUDED_RTL_INSTANCE_HXX
#define INCLUDED_RTL_INSTANCE_HXX

#include "osl/doublecheckedlocking.h"
#include "osl/getglobalmutex.hxx"

namespace {

/** A non-broken version of the double-checked locking pattern.

    See
    <http://www.cs.umd.edu/~pugh/java/memoryModel/DoubleCheckedLocking.html>
    for a description of double-checked locking, why it is broken, and how it
    can be fixed.  Always use this template instead of spelling out the
    double-checked locking pattern explicitly, and only in those rare cases
    where that is not possible and you have to spell it out explicitly, at
    least call OSL_DOUBLE_CHECKED_LOCKING_MEMORY_BARRIER() at the right
    places.  That way, all platform-dependent code to make double-checked
    locking work can be kept in one place.

    Usage scenarios:

    1  Static instance (most common case)

    Pattern:

      T * getInstance()
      {
          static T * pInstance = 0;
          if (!pInstance)
          {
              ::osl::MutexGuard aGuard(::osl::Mutex::getGlobalMutex());
              if (!pInstance)
              {
                  static T aInstance;
                  pInstance = &aInstance;
              }
          }
          return pInstance;
      }

    Code:

      #include "rtl/instance.hxx"
      #include "osl/getglobalmutex.hxx"

      namespace {
          struct Init
          {
              T * operator()()
              {
                  static T aInstance;
                  return &aInstance;
              }
          };
      }

      T * getInstance()
      {
          return rtl_Instance< T, Init, ::osl::MutexGuard,
                               ::osl::GetGlobalMutex >::create(
              Init(), ::osl::GetGlobalMutex());
      }

    2  Dynamic instance

    Pattern:

      T * getInstance()
      {
          static T * pInstance = 0;
          if (!pInstance)
          {
              ::osl::MutexGuard aGuard(::osl::Mutex::getGlobalMutex());
              if (!pInstance)
                  pInstance = new T;
          }
          return pInstance;
      }

    Code:

      #include "rtl/instance.hxx"
      #include "osl/getglobalmutex.hxx"

      namespace {
          struct Init
          {
              T * operator()()
              {
                  return new T;
              }
          };
      }

      T * getInstance()
      {
          return rtl_Instance< T, Init, ::osl::MutexGuard,
                               ::osl::GetGlobalMutex >::create(
              Init(), ::osl::GetGlobalMutex());
      }

    3  Other guard/mutex

    Pattern:

      T * getInstance()
      {
          static T * pInstance = 0;
          if (!pInstance)
          {
              SomeGuard aGuard(pSomeMutex);
              if (!pInstance)
              {
                  static T aInstance;
                  pInstance = &aInstance;
              }
          }
          return pInstance;
      }

    Code:

      #include "rtl/instance.hxx"

      namespace {
          struct InitInstance
          {
              T * operator()()
              {
                  static T aInstance;
                  return &aInstance;
              }
          };

          struct InitGuard
          {
              SomeMutex * operator()()
              {
                  return pSomeMutex;
              }
          };
      }

      T * getInstance()
      {
          return rtl_Instance< T, InitInstance,
                               SomeGuard, InitGuard >::create(
              InitInstance(), InitMutex());
      }

    4  Calculate extra data

    Pattern:

      T * getInstance()
      {
          static T * pInstance = 0;
          if (!pInstance)
          {
              Data aData(...);
              ::osl::MutexGuard aGuard(::osl::Mutex::getGlobalMutex());
              if (!pInstance)
              {
                  static T aInstance(aData);
                  pInstance = &aInstance;
              }
          }
          return pInstance;
      }

    Code:

      #include "rtl/instance.hxx"
      #include "osl/getglobalmutex.hxx"

      namespace {
          struct InitInstance
          {
              T * operator()()
              {
                  static T aInstance;
                  return &aInstance;
              }
          }

          struct InitData
          {
              Data const & operator()()
              {
                  return ...;
              }
          }
      }

      T * getInstance()
      {
          return rtl_Instance< T, InitInstance,
                               ::osl::Mutex, ::osl::GetGlobalMutex,
                               Data, InitData >::create(
              InitInstance(), ::osl::GetGlobalMutex(), InitData());
      }

    Some comments:

    For any instantiation of rtl_Instance, at most one call to a create method
    may occur in the program code:  Each occurrence of a create method within
    the program code is supposed to return a fresh object instance on the
    first call, and that same object instance on subsequent calls; but
    independent occurrences of create methods are supposed to return
    independent object instances.  Since there is a one-to-one correspondence
    between object instances and instantiations of rtl_Instance, the
    requirement should be clear.  One measure to enforce the requirement is
    that rtl_Instance lives in an unnamed namespace, so that instantiations of
    rtl_Instance in different translation units will definitely be different
    instantiations.  A drawback of that measure is that the name of the class
    needs a funny "hand coded" prefix "rtl_" instead of a proper namespace
    prefix like "::rtl::".

    A known problem with this template is when two occurrences of calls to
    create methods with identical template arguments appear in one translation
    unit.  Those two places will share a single object instance.  This can be
    avoided by using different Init structs (see the above code samples) in
    the two places.

    There is no need to make m_pInstance volatile, in order to avoid usage of
    stale copies of m_pInstance:  At the first check, a thread will see that
    m_pInstance contains either 0 or a valid pointer.  If it contains a valid
    pointer, it cannot be stale, and that pointer is used.  If it contains 0,
    acquiring the mutex will ensure that the second check sees a non-stale
    value in all cases.

    On some compilers, the create methods would not be inlined if they
    contained any static variables, so m_pInstance is made a class member
    instead (and the create methods are inlined).  But on MSC, the definition
    of the class member m_pInstance would cause compilation to fail with an
    internal compiler error.  Since MSC is able to inline methods containing
    static variables, m_pInstance is moved into the methods there.  Note that
    this only works well because for any instantiation of rtl_Instance at most
    one call to a create method should be present, anyway.
 */
template< typename Inst, typename InstCtor,
          typename Guard, typename GuardCtor,
          typename Data = int, typename DataCtor = int >
class rtl_Instance
{
public:
    static inline Inst * create(InstCtor aInstCtor, GuardCtor aGuardCtor)
    {
#if defined _MSC_VER
        static Inst * m_pInstance = 0;
#endif // _MSC_VER
        Inst * p = m_pInstance;
        if (!p)
        {
            Guard aGuard(aGuardCtor());
            p = m_pInstance;
            if (!p)
            {
                p = aInstCtor();
                OSL_DOUBLE_CHECKED_LOCKING_MEMORY_BARRIER();
                m_pInstance = p;
            }
        }
        else
        {
            OSL_DOUBLE_CHECKED_LOCKING_MEMORY_BARRIER();
        }
        return p;
    }

    static inline Inst * create(InstCtor aInstCtor, GuardCtor aGuardCtor,
                                DataCtor aDataCtor)
    {
#if defined _MSC_VER
        static Inst * m_pInstance = 0;
#endif // _MSC_VER
        Inst * p = m_pInstance;
        if (!p)
        {
            Data aData(aDataCtor());
            Guard aGuard(aGuardCtor());
            p = m_pInstance;
            if (!p)
            {
                p = aInstCtor(aData);
                OSL_DOUBLE_CHECKED_LOCKING_MEMORY_BARRIER();
                m_pInstance = p;
            }
        }
        else
        {
            OSL_DOUBLE_CHECKED_LOCKING_MEMORY_BARRIER();
        }
        return p;
    }

    static inline Inst * create(InstCtor aInstCtor, GuardCtor aGuardCtor,
                                const Data &rData)
    {
#if defined _MSC_VER
        static Inst * m_pInstance = 0;
#endif // _MSC_VER
        Inst * p = m_pInstance;
        if (!p)
        {
            Guard aGuard(aGuardCtor());
            p = m_pInstance;
            if (!p)
            {
                p = aInstCtor(rData);
                OSL_DOUBLE_CHECKED_LOCKING_MEMORY_BARRIER();
                m_pInstance = p;
            }
        }
        else
        {
            OSL_DOUBLE_CHECKED_LOCKING_MEMORY_BARRIER();
        }
        return p;
    }

private:
#if !defined _MSC_VER
    static Inst * m_pInstance;
#endif // _MSC_VER
};

#if !defined _MSC_VER
template< typename Inst, typename InstCtor,
          typename Guard, typename GuardCtor,
          typename Data, typename DataCtor >
Inst *
rtl_Instance< Inst, InstCtor, Guard, GuardCtor, Data, DataCtor >::m_pInstance
= 0;
#endif // _MSC_VER

}

namespace rtl {

/** Helper base class for a late-initialized (default-constructed)
    static variable, implementing the double-checked locking pattern correctly.

    @derive
    Derive from this class (common practice), e.g.
    <pre>
    struct MyStatic : public rtl::Static<MyType, MyStatic> {};
    ...
    MyType & rStatic = MyStatic::get();
    ...
    </pre>

    @tplparam T
              variable's type
    @tplparam Unique
              Implementation trick to make the inner static holder unique,
              using the outer class
              (the one that derives from this base class)
*/
#if defined HAVE_THREADSAFE_STATICS
template<typename T, typename Unique>
class Static {
public:
    /** Gets the static.  Mutual exclusion is implied by a functional
        -fthreadsafe-statics

        @return
                static variable
    */
    static T & get() {
        static T instance;
        return instance;
    }
};
#else
template<typename T, typename Unique>
class Static {
public:
    /** Gets the static.  Mutual exclusion is performed using the
        osl global mutex.

        @return
                static variable
    */
    static T & get() {
        return *rtl_Instance<
            T, StaticInstance,
            ::osl::MutexGuard, ::osl::GetGlobalMutex >::create(
                StaticInstance(), ::osl::GetGlobalMutex() );
    }
private:
    struct StaticInstance {
        T * operator () () {
            static T instance;
            return &instance;
        }
    };
};
#endif

/** Helper base class for a late-initialized (default-constructed)
    static variable, implementing the double-checked locking pattern correctly.

    @derive
    Derive from this class (common practice), e.g.
    <pre>
    struct MyStatic : public rtl::Static<MyType, MyStatic> {};
    ...
    MyType & rStatic = MyStatic::get();
    ...
    </pre>

    @tplparam T
              variable's type
    @tplparam Unique
              Implementation trick to make the inner static holder unique,
              using the outer class
              (the one that derives from this base class)
*/
#if (__GNUC__ >= 4)
template<typename T, typename Data, typename Unique>
class StaticWithArg {
public:
    /** Gets the static.  Mutual exclusion is implied by a functional
        -fthreadsafe-statics

        @return
                static variable
    */
    static T & get(const Data& rData) {
        static T instance(rData);
        return instance;
    }

    /** Gets the static.  Mutual exclusion is implied by a functional
        -fthreadsafe-statics

        @return
                static variable
    */
    static T & get(Data& rData) {
        static T instance(rData);
        return instance;
    }
};
#else
template<typename T, typename Data, typename Unique>
class StaticWithArg {
public:
    /** Gets the static.  Mutual exclusion is performed using the
        osl global mutex.

        @return
                static variable
    */
    static T & get(const Data& rData) {
        return *rtl_Instance<
            T, StaticInstanceWithArg,
            ::osl::MutexGuard, ::osl::GetGlobalMutex,
            Data >::create( StaticInstanceWithArg(),
                                      ::osl::GetGlobalMutex(),
                                      rData );
    }

    /** Gets the static.  Mutual exclusion is performed using the
        osl global mutex.

        @return
                static variable
    */
    static T & get(Data& rData) {
        return *rtl_Instance<
            T, StaticInstanceWithArg,
            ::osl::MutexGuard, ::osl::GetGlobalMutex,
            Data >::create( StaticInstanceWithArg(),
                                      ::osl::GetGlobalMutex(),
                                      rData );
    }
private:
    struct StaticInstanceWithArg {
        T * operator () (const Data& rData) {
            static T instance(rData);
            return &instance;
        }

        T * operator () (Data& rData) {
            static T instance(rData);
            return &instance;
         }
    };
};
#endif

/** Helper class for a late-initialized static aggregate, e.g. an array,
    implementing the double-checked locking pattern correctly.

    @tplparam T
              aggregate's element type
    @tplparam InitAggregate
              initializer functor class
*/
#if (__GNUC__ >= 4)
template<typename T, typename InitAggregate>
class StaticAggregate {
public:
    /** Gets the static aggregate, late-initializing.
        Mutual exclusion is implied by a functional
        -fthreadsafe-statics

        @return
                aggregate
    */
    static T * get() {
        static T *instance = InitAggregate()();
        return instance;
    }
};
#else
template<typename T, typename InitAggregate>
class StaticAggregate {
public:
    /** Gets the static aggregate, late-initializing.
        Mutual exclusion is performed using the osl global mutex.

        @return
                aggregate
    */
    static T * get() {
        return rtl_Instance<
            T, InitAggregate,
            ::osl::MutexGuard, ::osl::GetGlobalMutex >::create(
                InitAggregate(), ::osl::GetGlobalMutex() );
    }
};
#endif
/** Helper base class for a late-initialized static variable,
    implementing the double-checked locking pattern correctly.

    @derive
    Derive from this class (common practice),
    providing an initializer functor class, e.g.
    <pre>
    struct MyStatic : public rtl::StaticWithInit<MyType, MyStatic> {
        MyType operator () () {
            ...
            return MyType( ... );
        }
    };
    ...
    MyType & rStatic = MyStatic::get();
    ...
    </pre>

    @tplparam T
              variable's type
    @tplparam InitData
              initializer functor class
    @tplparam Unique
              Implementation trick to make the inner static holder unique,
              using the outer class
              (the one that derives from this base class).
              Default is InitData (common practice).
    @tplparam Data
              Initializer functor's return type.
              Default is T (common practice).
*/
#if (__GNUC__ >= 4)
template<typename T, typename InitData,
         typename Unique = InitData, typename Data = T>
class StaticWithInit {
public:
    /** Gets the static.  Mutual exclusion is implied by a functional
        -fthreadsafe-statics

        @return
                static variable
    */
    static T & get() {
        static T instance = InitData()();
        return instance;
    }
};
#else
template<typename T, typename InitData,
         typename Unique = InitData, typename Data = T>
class StaticWithInit {
public:
    /** Gets the static.  Mutual exclusion is performed using the
        osl global mutex.

        @return
                static variable
    */
    static T & get() {
        return *rtl_Instance<
            T, StaticInstanceWithInit,
            ::osl::MutexGuard, ::osl::GetGlobalMutex,
            Data, InitData >::create( StaticInstanceWithInit(),
                                      ::osl::GetGlobalMutex(),
                                      InitData() );
    }
private:
    struct StaticInstanceWithInit {
        T * operator () ( Data d ) {
            static T instance(d);
            return &instance;
        }
    };
};
#endif
} // namespace rtl

#endif // INCLUDED_RTL_INSTANCE_HXX

/* vim:set shiftwidth=4 softtabstop=4 expandtab: */