diff options
| -rw-r--r-- | Lib/tempfile.py | 47 | ||||
| -rw-r--r-- | Lib/test/output/test_threadedtempfile | 5 | ||||
| -rw-r--r-- | Lib/test/test_threadedtempfile.py | 85 |
3 files changed, 121 insertions, 16 deletions
diff --git a/Lib/tempfile.py b/Lib/tempfile.py index 3e1e08d..8ac707d 100644 --- a/Lib/tempfile.py +++ b/Lib/tempfile.py @@ -67,25 +67,40 @@ def gettempdir(): return tempdir -_pid = None +# template caches the result of gettempprefix, for speed, when possible. +# XXX unclear why this isn't "_template"; left it "template" for backward +# compatibility. +if os.name == "posix": + # We don't try to cache the template on posix: the pid may change on us + # between calls due to a fork, and on Linux the pid changes even for + # another thread in the same process. Since any attempt to keep the + # cache in synch would have to call os.getpid() anyway in order to make + # sure the pid hasn't changed between calls, a cache wouldn't save any + # time. In addition, a cache is difficult to keep correct with the pid + # changing willy-nilly, and earlier attempts proved buggy (races). + template = None + +# Else the pid never changes, so gettempprefix always returns the same +# string. +elif os.name == "nt": + template = '~' + `os.getpid()` + '-' +elif os.name == 'mac': + template = 'Python-Tmp-' +else: + template = 'tmp' # XXX might choose a better one def gettempprefix(): - """Function to calculate a prefix of the filename to use.""" - global template, _pid - if os.name == 'posix' and _pid and _pid != os.getpid(): - # Our pid changed; we must have forked -- zap the template - template = None + """Function to calculate a prefix of the filename to use. + + This incorporates the current process id on systems that support such a + notion, so that concurrent processes don't generate the same prefix. + """ + + global template if template is None: - if os.name == 'posix': - _pid = os.getpid() - template = '@' + `_pid` + '.' - elif os.name == 'nt': - template = '~' + `os.getpid()` + '-' - elif os.name == 'mac': - template = 'Python-Tmp-' - else: - template = 'tmp' # XXX might choose a better one - return template + return '@' + `os.getpid()` + '.' + else: + return template def mktemp(suffix=""): diff --git a/Lib/test/output/test_threadedtempfile b/Lib/test/output/test_threadedtempfile new file mode 100644 index 0000000..2552877 --- /dev/null +++ b/Lib/test/output/test_threadedtempfile @@ -0,0 +1,5 @@ +test_threadedtempfile +Creating +Starting +Reaping +Done: errors 0 ok 1000 diff --git a/Lib/test/test_threadedtempfile.py b/Lib/test/test_threadedtempfile.py new file mode 100644 index 0000000..a5ee12f --- /dev/null +++ b/Lib/test/test_threadedtempfile.py @@ -0,0 +1,85 @@ +""" +Create and delete FILES_PER_THREAD temp files (via tempfile.TemporaryFile) +in each of NUM_THREADS threads, recording the number of successes and +failures. A failure is a bug in tempfile, and may be due to: + ++ Trying to create more than one tempfile with the same name. ++ Trying to delete a tempfile that doesn't still exist. ++ Something we've never seen before. + +By default, NUM_THREADS == 20 and FILES_PER_THREAD == 50. This is enough to +create about 150 failures per run under Win98SE in 2.0, and runs pretty +quickly. Guido reports needing to boost FILES_PER_THREAD to 500 before +provoking a 2.0 failure under Linux. Run the test alone to boost either +via cmdline switches: + +-f FILES_PER_THREAD (int) +-t NUM_THREADS (int) +""" + +NUM_THREADS = 20 # change w/ -t option +FILES_PER_THREAD = 50 # change w/ -f option + +import threading +from test.test_support import TestFailed +import StringIO +from traceback import print_exc + +startEvent = threading.Event() + +import tempfile +tempfile.gettempdir() # Do this now, to avoid spurious races later + +class TempFileGreedy(threading.Thread): + error_count = 0 + ok_count = 0 + + def run(self): + self.errors = StringIO.StringIO() + startEvent.wait() + for i in range(FILES_PER_THREAD): + try: + f = tempfile.TemporaryFile("w+b") + f.close() + except: + self.error_count += 1 + print_exc(file=self.errors) + else: + self.ok_count += 1 + +def _test(): + threads = [] + + print "Creating" + for i in range(NUM_THREADS): + t = TempFileGreedy() + threads.append(t) + t.start() + + print "Starting" + startEvent.set() + + print "Reaping" + ok = errors = 0 + for t in threads: + t.join() + ok += t.ok_count + errors += t.error_count + if t.error_count: + print '%s errors:\n%s' % (t.getName(), t.errors.getvalue()) + + msg = "Done: errors %d ok %d" % (errors, ok) + print msg + if errors: + raise TestFailed(msg) + +if __name__ == "__main__": + import sys, getopt + opts, args = getopt.getopt(sys.argv[1:], "t:f:") + for o, v in opts: + if o == "-f": + FILES_PER_THREAD = int(v) + elif o == "-t": + NUM_THREADS = int(v) + +_test() |