Lib/test/threaded_import_hangers.py

   1 # This is a helper module for test_threaded_import.  The test imports this
   2 # module, and this module tries to run various Python library functions in
   3 # their own thread, as a side effect of being imported.  If the spawned
   4 # thread doesn't complete in TIMEOUT seconds, an "appeared to hang" message
   5 # is appended to the module-global `errors` list.  That list remains empty
   6 # if (and only if) all functions tested complete.
   7
   8 TIMEOUT = 10
   9
  10 import threading
  11
  12 import tempfile
  13 import os.path
  14
  15 errors = []
  16
  17 # This class merely runs a function in its own thread T.  The thread importing
  18 # this module holds the import lock, so if the function called by T tries
  19 # to do its own imports it will block waiting for this module's import
  20 # to complete.
  21 class Worker(threading.Thread):
  22     def __init__(self, function, args):
  23         threading.Thread.__init__(self)
  24         self.function = function
  25         self.args = args
  26
  27     def run(self):
  28         self.function(*self.args)
  29
  30 for name, func, args in [
  31         # Bug 147376:  TemporaryFile hung on Windows, starting in Python 2.4.
  32         ("tempfile.TemporaryFile", tempfile.TemporaryFile, ()),
  33
  34         # The real cause for bug 147376:  ntpath.abspath() caused the hang.
  35         ("os.path.abspath", os.path.abspath, ('.',)),
  36         ]:
  37
  38     t = Worker(func, args)
  39     t.start()
  40     t.join(TIMEOUT)
  41     if t.is_alive():
  42         errors.append("%s appeared to hang" % name)