This file is indexed.

/usr/share/pyshared/buildslave/runprocess.py is in buildbot-slave 0.8.8-1.

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
# This file is part of Buildbot.  Buildbot 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, version 2.
#
# 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, write to the Free Software Foundation, Inc., 51
# Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
#
# Copyright Buildbot Team Members

"""
Support for running 'shell commands'
"""

import sys
import os
import signal
import types
import re
import subprocess
import traceback
import stat
from collections import deque
from tempfile import NamedTemporaryFile

from twisted.python import runtime, log
from twisted.python.win32 import quoteArguments
from twisted.internet import reactor, defer, protocol, task, error

from buildslave import util
from buildslave.exceptions import AbandonChain

if runtime.platformType == 'posix':
    from twisted.internet.process import Process

def shell_quote(cmd_list):
    # attempt to quote cmd_list such that a shell will properly re-interpret
    # it.  The pipes module is only available on UNIX, and Windows "shell"
    # quoting is indescribably convoluted - so much so that it's not clear it's
    # reversible.  Also, the quote function is undocumented (although it looks
    # like it will be documentd soon: http://bugs.python.org/issue9723).
    # Finally, it has a nasty bug in some versions where an empty string is not
    # quoted.
    #
    # So:
    #  - use pipes.quote on UNIX, handling '' as a special case
    #  - use Python's repr() on Windows, as a best effort
    if runtime.platformType == 'win32':
        return " ".join([ `e` for e in cmd_list ])
    else:
        import pipes
        def quote(e):
            if not e:
                return '""'
            return pipes.quote(e)
        return " ".join([ quote(e) for e in cmd_list ])

class LogFileWatcher:
    POLL_INTERVAL = 2

    def __init__(self, command, name, logfile, follow=False):
        self.command = command
        self.name = name
        self.logfile = logfile

        log.msg("LogFileWatcher created to watch %s" % logfile)
        # we are created before the ShellCommand starts. If the logfile we're
        # supposed to be watching already exists, record its size and
        # ctime/mtime so we can tell when it starts to change.
        self.old_logfile_stats = self.statFile()
        self.started = False

        # follow the file, only sending back lines
        # added since we started watching
        self.follow = follow

        # every 2 seconds we check on the file again
        self.poller = task.LoopingCall(self.poll)

    def start(self):
        self.poller.start(self.POLL_INTERVAL).addErrback(self._cleanupPoll)

    def _cleanupPoll(self, err):
        log.err(err, msg="Polling error")
        self.poller = None

    def stop(self):
        self.poll()
        if self.poller is not None:
            self.poller.stop()
        if self.started:
            self.f.close()

    def statFile(self):
        if os.path.exists(self.logfile):
            s = os.stat(self.logfile)
            return (s[stat.ST_CTIME], s[stat.ST_MTIME], s[stat.ST_SIZE])
        return None

    def poll(self):
        if not self.started:
            s = self.statFile()
            if s == self.old_logfile_stats:
                return # not started yet
            if not s:
                # the file was there, but now it's deleted. Forget about the
                # initial state, clearly the process has deleted the logfile
                # in preparation for creating a new one.
                self.old_logfile_stats = None
                return # no file to work with
            self.f = open(self.logfile, "rb")
            # if we only want new lines, seek to
            # where we stat'd so we only find new
            # lines
            if self.follow:
                self.f.seek(s[2], 0)
            self.started = True
        self.f.seek(self.f.tell(), 0)
        while True:
            data = self.f.read(10000)
            if not data:
                return
            self.command.addLogfile(self.name, data)


if runtime.platformType == 'posix':
    class ProcGroupProcess(Process):
        """Simple subclass of Process to also make the spawned process a process
        group leader, so we can kill all members of the process group."""

        def _setupChild(self, *args, **kwargs):
            Process._setupChild(self, *args, **kwargs)

            # this will cause the child to be the leader of its own process group;
            # it's also spelled setpgrp() on BSD, but this spelling seems to work
            # everywhere
            os.setpgid(0, 0)


class RunProcessPP(protocol.ProcessProtocol):
    debug = False

    def __init__(self, command):
        self.command = command
        self.pending_stdin = ""
        self.stdin_finished = False
        self.killed = False

    def setStdin(self, data):
        assert not self.connected
        self.pending_stdin = data

    def connectionMade(self):
        if self.debug:
            log.msg("RunProcessPP.connectionMade")

        if self.command.useProcGroup:
            if self.debug:
                log.msg(" recording pid %d as subprocess pgid"
                        % (self.transport.pid,))
            self.transport.pgid = self.transport.pid

        if self.pending_stdin:
            if self.debug: log.msg(" writing to stdin")
            self.transport.write(self.pending_stdin)
        if self.debug: log.msg(" closing stdin")
        self.transport.closeStdin()

    def outReceived(self, data):
        if self.debug:
            log.msg("RunProcessPP.outReceived")
        self.command.addStdout(data)

    def errReceived(self, data):
        if self.debug:
            log.msg("RunProcessPP.errReceived")
        self.command.addStderr(data)

    def processEnded(self, status_object):
        if self.debug:
            log.msg("RunProcessPP.processEnded", status_object)
        # status_object is a Failure wrapped around an
        # error.ProcessTerminated or and error.ProcessDone.
        # requires twisted >= 1.0.4 to overcome a bug in process.py
        sig = status_object.value.signal
        rc = status_object.value.exitCode

        # sometimes, even when we kill a process, GetExitCodeProcess will still return
        # a zero exit status.  So we force it.  See
        # http://stackoverflow.com/questions/2061735/42-passed-to-terminateprocess-sometimes-getexitcodeprocess-returns-0
        if self.killed and rc == 0:
            log.msg("process was killed, but exited with status 0; faking a failure")
            # windows returns '1' even for signalled failures, while POSIX returns -1
            if runtime.platformType == 'win32':
                rc = 1
            else:
                rc = -1
        self.command.finished(sig, rc)


class RunProcess:
    """
    This is a helper class, used by slave commands to run programs in a child
    shell.
    """

    notreally = False
    BACKUP_TIMEOUT = 5
    interruptSignal = "KILL"
    CHUNK_LIMIT = 128*1024

    # Don't send any data until at least BUFFER_SIZE bytes have been collected
    # or BUFFER_TIMEOUT elapsed
    BUFFER_SIZE = 64*1024
    BUFFER_TIMEOUT = 5

    # For sending elapsed time:
    startTime = None
    elapsedTime = None

    # For scheduling future events
    _reactor = reactor

    # I wish we had easy access to CLOCK_MONOTONIC in Python:
    # http://www.opengroup.org/onlinepubs/000095399/functions/clock_getres.html
    # Then changes to the system clock during a run wouldn't effect the "elapsed
    # time" results.

    def __init__(self, builder, command,
                 workdir, environ=None,
                 sendStdout=True, sendStderr=True, sendRC=True,
                 timeout=None, maxTime=None, initialStdin=None,
                 keepStdout=False, keepStderr=False,
                 logEnviron=True, logfiles={}, usePTY="slave-config",
                 useProcGroup=True):
        """

        @param keepStdout: if True, we keep a copy of all the stdout text
                           that we've seen. This copy is available in
                           self.stdout, which can be read after the command
                           has finished.
        @param keepStderr: same, for stderr

        @param usePTY: "slave-config" -> use the SlaveBuilder's usePTY;
            otherwise, true to use a PTY, false to not use a PTY.

        @param useProcGroup: (default True) use a process group for non-PTY
            process invocations
        """

        self.builder = builder

        # We need to take unicode commands and arguments and encode them using
        # the appropriate encoding for the slave.  This is mostly platform
        # specific, but can be overridden in the slave's buildbot.tac file.
        #
        # Encoding the command line here ensures that the called executables
        # receive arguments as bytestrings encoded with an appropriate
        # platform-specific encoding.  It also plays nicely with twisted's
        # spawnProcess which checks that arguments are regular strings or
        # unicode strings that can be encoded as ascii (which generates a
        # warning).
        def to_str(cmd):
            if isinstance(cmd, (tuple, list)):
                for i, a in enumerate(cmd):
                    if isinstance(a, unicode):
                        cmd[i] = a.encode(self.builder.unicode_encoding)
            elif isinstance(cmd, unicode):
                cmd = cmd.encode(self.builder.unicode_encoding)
            return cmd

        self.command = to_str(util.Obfuscated.get_real(command))
        self.fake_command = to_str(util.Obfuscated.get_fake(command))

        self.sendStdout = sendStdout
        self.sendStderr = sendStderr
        self.sendRC = sendRC
        self.logfiles = logfiles
        self.workdir = workdir
        self.process = None
        if not os.path.exists(workdir):
            os.makedirs(workdir)
        if environ:
            for key, v in environ.iteritems():
                if isinstance(v, list):
                    # Need to do os.pathsep translation.  We could either do that
                    # by replacing all incoming ':'s with os.pathsep, or by
                    # accepting lists.  I like lists better.
                    # If it's not a string, treat it as a sequence to be
                    # turned in to a string.
                    environ[key] = os.pathsep.join(environ[key])

            if environ.has_key('PYTHONPATH'):
                environ['PYTHONPATH'] += os.pathsep + "${PYTHONPATH}"

            # do substitution on variable values matching pattern: ${name}
            p = re.compile('\${([0-9a-zA-Z_]*)}')
            def subst(match):
                return os.environ.get(match.group(1), "")
            newenv = {}
            for key in os.environ.keys():
                # setting a key to None will delete it from the slave environment
                if key not in environ or environ[key] is not None:
                    newenv[key] = os.environ[key]
            for key, v in environ.iteritems():
                if v is not None:
                    if not isinstance(v, basestring):
                        raise RuntimeError("'env' values must be strings or "
                                "lists; key '%s' is incorrect" % (key,))
                    newenv[key] = p.sub(subst, v)

            self.environ = newenv
        else: # not environ
            self.environ = os.environ.copy()
        self.initialStdin = initialStdin
        self.logEnviron = logEnviron
        self.timeout = timeout
        self.timer = None
        self.maxTime = maxTime
        self.maxTimer = None
        self.keepStdout = keepStdout
        self.keepStderr = keepStderr

        self.buffered = deque()
        self.buflen = 0
        self.buftimer = None

        if usePTY == "slave-config":
            self.usePTY = self.builder.usePTY
        else:
            self.usePTY = usePTY

        # usePTY=True is a convenience for cleaning up all children and
        # grandchildren of a hung command. Fall back to usePTY=False on systems
        # and in situations where ptys cause problems.  PTYs are posix-only,
        # and for .closeStdin to matter, we must use a pipe, not a PTY
        if runtime.platformType != "posix" or initialStdin is not None:
            if self.usePTY and usePTY != "slave-config":
                self.sendStatus({'header': "WARNING: disabling usePTY for this command"})
            self.usePTY = False

        # use an explicit process group on POSIX, noting that usePTY always implies
        # a process group.
        if runtime.platformType != 'posix':
            useProcGroup = False
        elif self.usePTY:
            useProcGroup = True
        self.useProcGroup = useProcGroup

        self.logFileWatchers = []
        for name,filevalue in self.logfiles.items():
            filename = filevalue
            follow = False

            # check for a dictionary of options
            # filename is required, others are optional
            if type(filevalue) == dict:
                filename = filevalue['filename']
                follow = filevalue.get('follow', False)

            w = LogFileWatcher(self, name,
                               os.path.join(self.workdir, filename),
                               follow=follow)
            self.logFileWatchers.append(w)

    def __repr__(self):
        return "<%s '%s'>" % (self.__class__.__name__, self.fake_command)

    def sendStatus(self, status):
        self.builder.sendUpdate(status)

    def start(self):
        # return a Deferred which fires (with the exit code) when the command
        # completes
        if self.keepStdout:
            self.stdout = ""
        if self.keepStderr:
            self.stderr = ""
        self.deferred = defer.Deferred()
        try:
            self._startCommand()
        except:
            log.msg("error in RunProcess._startCommand")
            log.err()
            self._addToBuffers('stderr', "error in RunProcess._startCommand\n")
            self._addToBuffers('stderr', traceback.format_exc())
            self._sendBuffers()
            # pretend it was a shell error
            self.deferred.errback(AbandonChain(-1))
        return self.deferred

    def _startCommand(self):
        # ensure workdir exists
        if not os.path.isdir(self.workdir):
            os.makedirs(self.workdir)
        log.msg("RunProcess._startCommand")
        if self.notreally:
            self._addToBuffers('header', "command '%s' in dir %s" % \
                             (self.fake_command, self.workdir))
            self._addToBuffers('header', "(not really)\n")
            self.finished(None, 0)
            return

        self.pp = RunProcessPP(self)

        self.using_comspec = False
        if type(self.command) in types.StringTypes:
            if runtime.platformType  == 'win32':
                argv = os.environ['COMSPEC'].split() # allow %COMSPEC% to have args
                if '/c' not in argv: argv += ['/c']
                argv += [self.command]
                self.using_comspec = True
            else:
                # for posix, use /bin/sh. for other non-posix, well, doesn't
                # hurt to try
                argv = ['/bin/sh', '-c', self.command]
            display = self.fake_command
        else:
            # On windows, CreateProcess requires an absolute path to the executable.
            # When we call spawnProcess below, we pass argv[0] as the executable.
            # So, for .exe's that we have absolute paths to, we can call directly
            # Otherwise, we should run under COMSPEC (usually cmd.exe) to
            # handle path searching, etc.
            if runtime.platformType == 'win32' and not \
                    (self.command[0].lower().endswith(".exe") and os.path.isabs(self.command[0])):
                argv = os.environ['COMSPEC'].split() # allow %COMSPEC% to have args
                if '/c' not in argv: argv += ['/c']
                argv += list(self.command)
                self.using_comspec = True
            else:
                argv = self.command
            # Attempt to format this for use by a shell, although the process isn't perfect
            display = shell_quote(self.fake_command)

        # $PWD usually indicates the current directory; spawnProcess may not
        # update this value, though, so we set it explicitly here.  This causes
        # weird problems (bug #456) on msys, though..
        if not self.environ.get('MACHTYPE', None) == 'i686-pc-msys':
            self.environ['PWD'] = os.path.abspath(self.workdir)

        # self.stdin is handled in RunProcessPP.connectionMade

        log.msg(" " + display)
        self._addToBuffers('header', display+"\n")

        # then comes the secondary information
        msg = " in dir %s" % (self.workdir,)
        if self.timeout:
            if self.timeout == 1:
                unit = "sec"
            else:
                unit = "secs"
            msg += " (timeout %d %s)" % (self.timeout, unit)
        if self.maxTime:
            if self.maxTime == 1:
                unit = "sec"
            else:
                unit = "secs"
            msg += " (maxTime %d %s)" % (self.maxTime, unit)
        log.msg(" " + msg)
        self._addToBuffers('header', msg+"\n")

        msg = " watching logfiles %s" % (self.logfiles,)
        log.msg(" " + msg)
        self._addToBuffers('header', msg+"\n")

        # then the obfuscated command array for resolving unambiguity
        msg = " argv: %s" % (self.fake_command,)
        log.msg(" " + msg)
        self._addToBuffers('header', msg+"\n")

        # then the environment, since it sometimes causes problems
        if self.logEnviron:
            msg = " environment:\n"
            env_names = self.environ.keys()
            env_names.sort()
            for name in env_names:
                msg += "  %s=%s\n" % (name, self.environ[name])
            log.msg(" environment: %s" % (self.environ,))
            self._addToBuffers('header', msg)

        if self.initialStdin:
            msg = " writing %d bytes to stdin" % len(self.initialStdin)
            log.msg(" " + msg)
            self._addToBuffers('header', msg+"\n")

        msg = " using PTY: %s" % bool(self.usePTY)
        log.msg(" " + msg)
        self._addToBuffers('header', msg+"\n")

        # put data into stdin and close it, if necessary.  This will be
        # buffered until connectionMade is called
        if self.initialStdin:
            self.pp.setStdin(self.initialStdin)

        self.startTime = util.now(self._reactor)

        # start the process

        self.process = self._spawnProcess(
                                 self.pp, argv[0], argv,
                                 self.environ,
                                 self.workdir,
                                 usePTY=self.usePTY)

        # set up timeouts

        if self.timeout:
            self.timer = self._reactor.callLater(self.timeout, self.doTimeout)

        if self.maxTime:
            self.maxTimer = self._reactor.callLater(self.maxTime, self.doMaxTimeout)

        for w in self.logFileWatchers:
            w.start()

    def _spawnProcess(self, processProtocol, executable, args=(), env={},
            path=None, uid=None, gid=None, usePTY=False, childFDs=None):
        """private implementation of reactor.spawnProcess, to allow use of
        L{ProcGroupProcess}"""

        # use the ProcGroupProcess class, if available
        if runtime.platformType == 'posix':
            if self.useProcGroup and not usePTY:
                return ProcGroupProcess(reactor, executable, args, env, path,
                                    processProtocol, uid, gid, childFDs)

        # fall back
        if self.using_comspec:
            return self._spawnAsBatch(processProtocol, executable, args, env,
                                      path, usePTY=usePTY)
        else:
            return reactor.spawnProcess(processProtocol, executable, args, env,
                                        path, usePTY=usePTY)

    def _spawnAsBatch(self, processProtocol, executable, args, env,
            path, usePTY):
        """A cheat that routes around the impedance mismatch between
        twisted and cmd.exe with respect to escaping quotes"""

        tf = NamedTemporaryFile(dir='.',suffix=".bat",delete=False)
        #echo off hides this cheat from the log files.
        tf.write( "@echo off\n" )
        if type(self.command) in types.StringTypes:
            tf.write( self.command )
        else:
            def maybe_escape_pipes(arg):
                if arg != '|':
                    return arg.replace('|','^|')
                else:
                    return '|'
            cmd = [maybe_escape_pipes(arg) for arg in self.command]
            tf.write( quoteArguments(cmd) )
        tf.close()

        argv = os.environ['COMSPEC'].split() # allow %COMSPEC% to have args
        if '/c' not in argv: argv += ['/c']
        argv += [tf.name]

        def unlink_temp(result):
            os.unlink(tf.name)
            return result
        self.deferred.addBoth(unlink_temp)

        return reactor.spawnProcess(processProtocol, executable, argv, env,
                                    path, usePTY=usePTY)

    def _chunkForSend(self, data):
        """
        limit the chunks that we send over PB to 128k, since it has a hardwired
        string-size limit of 640k.
        """
        LIMIT = self.CHUNK_LIMIT
        for i in range(0, len(data), LIMIT):
            yield data[i:i+LIMIT]

    def _collapseMsg(self, msg):
        """
        Take msg, which is a dictionary of lists of output chunks, and
        concatentate all the chunks into a single string
        """
        retval = {}
        for log in msg:
            data = "".join(msg[log])
            if isinstance(log, tuple) and log[0] == 'log':
                retval['log'] = (log[1], data)
            else:
                retval[log] = data
        return retval

    def _sendMessage(self, msg):
        """
        Collapse and send msg to the master
        """
        if not msg:
            return
        msg = self._collapseMsg(msg)
        self.sendStatus(msg)

    def _bufferTimeout(self):
        self.buftimer = None
        self._sendBuffers()

    def _sendBuffers(self):
        """
        Send all the content in our buffers.
        """
        msg = {}
        msg_size = 0
        lastlog = None
        logdata = []
        while self.buffered:
            # Grab the next bits from the buffer
            logname, data = self.buffered.popleft()

            # If this log is different than the last one, then we have to send
            # out the message so far.  This is because the message is
            # transferred as a dictionary, which makes the ordering of keys
            # unspecified, and makes it impossible to interleave data from
            # different logs.  A future enhancement could be to change the
            # master to support a list of (logname, data) tuples instead of a
            # dictionary.
            # On our first pass through this loop lastlog is None
            if lastlog is None:
                lastlog = logname
            elif logname != lastlog:
                self._sendMessage(msg)
                msg = {}
                msg_size = 0
            lastlog = logname

            logdata = msg.setdefault(logname, [])

            # Chunkify the log data to make sure we're not sending more than
            # CHUNK_LIMIT at a time
            for chunk in self._chunkForSend(data):
                if len(chunk) == 0: continue
                logdata.append(chunk)
                msg_size += len(chunk)
                if msg_size >= self.CHUNK_LIMIT:
                    # We've gone beyond the chunk limit, so send out our
                    # message.  At worst this results in a message slightly
                    # larger than (2*CHUNK_LIMIT)-1
                    self._sendMessage(msg)
                    msg = {}
                    logdata = msg.setdefault(logname, [])
                    msg_size = 0
        self.buflen = 0
        if logdata:
            self._sendMessage(msg)
        if self.buftimer:
            if self.buftimer.active():
                self.buftimer.cancel()
            self.buftimer = None

    def _addToBuffers(self, logname, data):
        """
        Add data to the buffer for logname
        Start a timer to send the buffers if BUFFER_TIMEOUT elapses.
        If adding data causes the buffer size to grow beyond BUFFER_SIZE, then
        the buffers will be sent.
        """
        n = len(data)

        self.buflen += n
        self.buffered.append((logname, data))
        if self.buflen > self.BUFFER_SIZE:
            self._sendBuffers()
        elif not self.buftimer:
            self.buftimer = self._reactor.callLater(self.BUFFER_TIMEOUT, self._bufferTimeout)

    def addStdout(self, data):
        if self.sendStdout:
            self._addToBuffers('stdout', data)

        if self.keepStdout:
            self.stdout += data
        if self.timer:
            self.timer.reset(self.timeout)

    def addStderr(self, data):
        if self.sendStderr:
            self._addToBuffers('stderr', data)

        if self.keepStderr:
            self.stderr += data
        if self.timer:
            self.timer.reset(self.timeout)

    def addLogfile(self, name, data):
        self._addToBuffers( ('log', name), data)

        if self.timer:
            self.timer.reset(self.timeout)

    def finished(self, sig, rc):
        self.elapsedTime = util.now(self._reactor) - self.startTime
        log.msg("command finished with signal %s, exit code %s, elapsedTime: %0.6f" % (sig,rc,self.elapsedTime))
        for w in self.logFileWatchers:
            # this will send the final updates
            w.stop()
        self._sendBuffers()
        if sig is not None:
            rc = -1
        if self.sendRC:
            if sig is not None:
                self.sendStatus(
                    {'header': "process killed by signal %d\n" % sig})
            self.sendStatus({'rc': rc})
        self.sendStatus({'header': "elapsedTime=%0.6f\n" % self.elapsedTime})
        if self.timer:
            self.timer.cancel()
            self.timer = None
        if self.maxTimer:
            self.maxTimer.cancel()
            self.maxTimer = None
        if self.buftimer:
            self.buftimer.cancel()
            self.buftimer = None
        d = self.deferred
        self.deferred = None
        if d:
            d.callback(rc)
        else:
            log.msg("Hey, command %s finished twice" % self)

    def failed(self, why):
        self._sendBuffers()
        log.msg("RunProcess.failed: command failed: %s" % (why,))
        if self.timer:
            self.timer.cancel()
            self.timer = None
        if self.maxTimer:
            self.maxTimer.cancel()
            self.maxTimer = None
        if self.buftimer:
            self.buftimer.cancel()
            self.buftimer = None
        d = self.deferred
        self.deferred = None
        if d:
            d.errback(why)
        else:
            log.msg("Hey, command %s finished twice" % self)

    def doTimeout(self):
        self.timer = None
        msg = "command timed out: %d seconds without output" % self.timeout
        self.kill(msg)

    def doMaxTimeout(self):
        self.maxTimer = None
        msg = "command timed out: %d seconds elapsed" % self.maxTime
        self.kill(msg)

    def kill(self, msg):
        # This may be called by the timeout, or when the user has decided to
        # abort this build.
        self._sendBuffers()
        if self.timer:
            self.timer.cancel()
            self.timer = None
        if self.maxTimer:
            self.maxTimer.cancel()
            self.maxTimer = None
        if self.buftimer:
            self.buftimer.cancel()
            self.buftimer = None
        msg += ", attempting to kill"
        log.msg(msg)
        self.sendStatus({'header': "\n" + msg + "\n"})

        # let the PP know that we are killing it, so that it can ensure that
        # the exit status comes out right
        self.pp.killed = True

        # keep track of whether we believe we've successfully killed something
        hit = 0

        # try signalling the process group
        if not hit and self.useProcGroup and runtime.platformType == "posix":
            sig = getattr(signal, "SIG"+ self.interruptSignal, None)

            if sig is None:
                log.msg("signal module is missing SIG%s" % self.interruptSignal)
            elif not hasattr(os, "kill"):
                log.msg("os module is missing the 'kill' function")
            elif self.process.pgid is None:
                log.msg("self.process has no pgid")
            else:
                log.msg("trying to kill process group %d" %
                                                (self.process.pgid,))
                try:
                    os.kill(-self.process.pgid, sig)
                    log.msg(" signal %s sent successfully" % sig)
                    self.process.pgid = None
                    hit = 1
                except OSError:
                    log.msg('failed to kill process group (ignored): %s' %
                            (sys.exc_info()[1],))
                    # probably no-such-process, maybe because there is no process
                    # group
                    pass

        elif runtime.platformType == "win32":
            if self.interruptSignal == None:
                log.msg("self.interruptSignal==None, only pretending to kill child")
            elif self.process.pid is not None:
                log.msg("using TASKKILL /F PID /T to kill pid %s" % self.process.pid)
                subprocess.check_call("TASKKILL /F /PID %s /T" % self.process.pid)
                log.msg("taskkill'd pid %s" % self.process.pid)
                hit = 1

        # try signalling the process itself (works on Windows too, sorta)
        if not hit:
            try:
                log.msg("trying process.signalProcess('%s')" % (self.interruptSignal,))
                self.process.signalProcess(self.interruptSignal)
                log.msg(" signal %s sent successfully" % (self.interruptSignal,))
                hit = 1
            except OSError:
                log.err("from process.signalProcess:")
                # could be no-such-process, because they finished very recently
                pass
            except error.ProcessExitedAlready:
                log.msg("Process exited already - can't kill")
                # the process has already exited, and likely finished() has
                # been called already or will be called shortly
                pass

        if not hit:
            log.msg("signalProcess/os.kill failed both times")

        if runtime.platformType == "posix":
            # we only do this under posix because the win32eventreactor
            # blocks here until the process has terminated, while closing
            # stderr. This is weird.
            self.pp.transport.loseConnection()

        if self.deferred:
            # finished ought to be called momentarily. Just in case it doesn't,
            # set a timer which will abandon the command.
            self.timer = self._reactor.callLater(self.BACKUP_TIMEOUT,
                                       self.doBackupTimeout)

    def doBackupTimeout(self):
        log.msg("we tried to kill the process, and it wouldn't die.."
                " finish anyway")
        self.timer = None
        self.sendStatus({'header': "SIGKILL failed to kill process\n"})
        if self.sendRC:
            self.sendStatus({'header': "using fake rc=-1\n"})
            self.sendStatus({'rc': -1})
        self.failed(RuntimeError("SIGKILL failed to kill process"))