# complains several times about module random having no attribute
# randrange, and then Python hangs.
-import _thread as thread
-from test.support import verbose, TestFailed
+import imp
+import sys
+import unittest
+from test.support import verbose, TestFailed, import_module, run_unittest
+thread = import_module('_thread')
-critical_section = thread.allocate_lock()
-done = thread.allocate_lock()
-
-def task():
- global N, critical_section, done
- import random
- x = random.randrange(1, 3)
- critical_section.acquire()
- N -= 1
- # Must release critical_section before releasing done, else the main
- # thread can exit and set critical_section to None as part of global
- # teardown; then critical_section.release() raises AttributeError.
- finished = N == 0
- critical_section.release()
- if finished:
- done.release()
-
-def test_import_hangers():
- import sys
- if verbose:
- print("testing import hangers ...", end=' ')
-
- import test.threaded_import_hangers
+def task(N, done, done_tasks, errors):
try:
- if test.threaded_import_hangers.errors:
- raise TestFailed(test.threaded_import_hangers.errors)
- elif verbose:
- print("OK.")
+ import random
+ # This will fail if random is not completely initialized
+ x = random.randrange(1, 3)
+ except Exception as e:
+ errors.append(e.with_traceback(None))
finally:
- # In case this test is run again, make sure the helper module
- # gets loaded from scratch again.
- del sys.modules['test.threaded_import_hangers']
+ done_tasks.append(thread.get_ident())
+ finished = len(done_tasks) == N
+ if finished:
+ done.release()
-# Tricky: When regrtest imports this module, the thread running regrtest
-# grabs the import lock and won't let go of it until this module returns.
-# All other threads attempting an import hang for the duration. Since
-# this test spawns threads that do little *but* import, we can't do that
-# successfully until after this module finishes importing and regrtest
-# regains control. To make this work, a special case was added to
-# regrtest to invoke a module's "test_main" function (if any) after
-# importing it.
-def test_main(): # magic name! see above
- global N, done
+class ThreadedImportTests(unittest.TestCase):
- import imp
- if imp.lock_held():
- # This triggers on, e.g., from test import autotest.
- raise unittest.SkipTest("can't run when import lock is held")
+ def test_parallel_module_init(self):
+ if imp.lock_held():
+ # This triggers on, e.g., from test import autotest.
+ raise unittest.SkipTest("can't run when import lock is held")
- done.acquire()
- for N in (20, 50) * 3:
- if verbose:
- print("Trying", N, "threads ...", end=' ')
- for i in range(N):
- thread.start_new_thread(task, ())
+ done = thread.allocate_lock()
done.acquire()
- if verbose:
- print("OK.")
- done.release()
+ for N in (20, 50) * 3:
+ if verbose:
+ print("Trying", N, "threads ...", end=' ')
+ # Make sure that random gets reimported freshly
+ try:
+ del sys.modules['random']
+ except KeyError:
+ pass
+ errors = []
+ done_tasks = []
+ for i in range(N):
+ thread.start_new_thread(task, (N, done, done_tasks, errors,))
+ done.acquire()
+ self.assertFalse(errors)
+ if verbose:
+ print("OK.")
+ done.release()
+
+ def test_import_hangers(self):
+ # In case this test is run again, make sure the helper module
+ # gets loaded from scratch again.
+ try:
+ del sys.modules['test.threaded_import_hangers']
+ except KeyError:
+ pass
+ import test.threaded_import_hangers
+ self.assertFalse(test.threaded_import_hangers.errors)
+
+
+def test_main():
+ run_unittest(ThreadedImportTests)
- test_import_hangers()
if __name__ == "__main__":
test_main()