import os
import unittest
import random
from test import support
thread = support.import_module('_thread')
import time
import sys
import weakref
from test import lock_tests
NUMTASKS = 10
NUMTRIPS = 3
_print_mutex = thread.allocate_lock()
def verbose_print(arg):
"""Helper function for printing out debugging output."""
if support.verbose:
with _print_mutex:
print(arg)
class BasicThreadTest(unittest.TestCase):
def setUp(self):
self.done_mutex = thread.allocate_lock()
self.done_mutex.acquire()
self.running_mutex = thread.allocate_lock()
self.random_mutex = thread.allocate_lock()
self.created = 0
self.running = 0
self.next_ident = 0
class ThreadRunningTests(BasicThreadTest):
def newtask(self):
with self.running_mutex:
self.next_ident += 1
verbose_print("creating task %s" % self.next_ident)
thread.start_new_thread(self.task, (self.next_ident,))
self.created += 1
self.running += 1
def task(self, ident):
with self.random_mutex:
delay = random.random() / 10000.0
verbose_print("task %s will run for %sus" % (ident, round(delay*1e6)))
time.sleep(delay)
verbose_print("task %s done" % ident)
with self.running_mutex:
self.running -= 1
if self.created == NUMTASKS and self.running == 0:
self.done_mutex.release()
def test_starting_threads(self):
# Basic test for thread creation.
for i in range(NUMTASKS):
self.newtask()
verbose_print("waiting for tasks to complete...")
self.done_mutex.acquire()
verbose_print("all tasks done")
def test_stack_size(self):
# Various stack size tests.
self.assertEqual(thread.stack_size(), 0, "initial stack size is not 0")
thread.stack_size(0)
self.assertEqual(thread.stack_size(), 0, "stack_size not reset to default")
@unittest.skipIf(os.name not in ("nt", "posix"), 'test meant for nt and posix')
def test_nt_and_posix_stack_size(self):
try:
thread.stack_size(4096)
except ValueError:
verbose_print("caught expected ValueError setting "
"stack_size(4096)")
except thread.error:
self.skipTest("platform does not support changing thread stack "
"size")
fail_msg = "stack_size(%d) failed - should succeed"
for tss in (262144, 0x100000, 0):
thread.stack_size(tss)
self.assertEqual(thread.stack_size(), tss, fail_msg % tss)
verbose_print("successfully set stack_size(%d)" % tss)
for tss in (262144, 0x100000):
verbose_print("trying stack_size = (%d)" % tss)
self.next_ident = 0
self.created = 0
for i in range(NUMTASKS):
self.newtask()
verbose_print("waiting for all tasks to complete")
self.done_mutex.acquire()
verbose_print("all tasks done")
thread.stack_size(0)
def test__count(self):
# Test the _count() function.
orig = thread._count()
mut = thread.allocate_lock()
mut.acquire()
started = []
def task():
started.append(None)
mut.acquire()
mut.release()
thread.start_new_thread(task, ())
while not started:
time.sleep(0.01)
self.assertEqual(thread._count(), orig + 1)
# Allow the task to finish.
mut.release()
# The only reliable way to be sure that the thread ended from the
# interpreter's point of view is to wait for the function object to be
# destroyed.
done = []
wr = weakref.ref(task, lambda _: done.append(None))
del task
while not done:
time.sleep(0.01)
self.assertEqual(thread._count(), orig)
def test_save_exception_state_on_error(self):
# See issue #14474
def task():
started.release()
raise SyntaxError
def mywrite(self, *args):
try:
raise ValueError
except ValueError:
pass
real_write(self, *args)
c = thread._count()
started = thread.allocate_lock()
with support.captured_output("stderr") as stderr:
real_write = stderr.write
stderr.write = mywrite
started.acquire()
thread.start_new_thread(task, ())
started.acquire()
while thread._count() > c:
time.sleep(0.01)
self.assertIn("Traceback", stderr.getvalue())
class Barrier:
def __init__(self, num_threads):
self.num_threads = num_threads
self.waiting = 0
self.checkin_mutex = thread.allocate_lock()
self.checkout_mutex = thread.allocate_lock()
self.checkout_mutex.acquire()
def enter(self):
self.checkin_mutex.acquire()
self.waiting = self.waiting + 1
if self.waiting == self.num_threads:
self.waiting = self.num_threads - 1
self.checkout_mutex.release()
return
self.checkin_mutex.release()
self.checkout_mutex.acquire()
self.waiting = self.waiting - 1
if self.waiting == 0:
self.checkin_mutex.release()
return
self.checkout_mutex.release()
class BarrierTest(BasicThreadTest):
def test_barrier(self):
self.bar = Barrier(NUMTASKS)
self.running = NUMTASKS
for i in range(NUMTASKS):
thread.start_new_thread(self.task2, (i,))
verbose_print("waiting for tasks to end")
self.done_mutex.acquire()
verbose_print("tasks done")
def task2(self, ident):
for i in range(NUMTRIPS):
if ident == 0:
# give it a good chance to enter the next
# barrier before the others are all out
# of the current one
delay = 0
else:
with self.random_mutex:
delay = random.random() / 10000.0
verbose_print("task %s will run for %sus" %
(ident, round(delay * 1e6)))
time.sleep(delay)
verbose_print("task %s entering %s" % (ident, i))
self.bar.enter()
verbose_print("task %s leaving barrier" % ident)
with self.running_mutex:
self.running -= 1
# Must release mutex before releasing done, else the main thread can
# exit and set mutex to None as part of global teardown; then
# mutex.release() raises AttributeError.
finished = self.running == 0
if finished:
self.done_mutex.release()
class LockTests(lock_tests.LockTests):
locktype = thread.allocate_lock
class TestForkInThread(unittest.TestCase):
def setUp(self):
self.read_fd, self.write_fd = os.pipe()
@unittest.skipIf(sys.platform.startswith('win'),
"This test is only appropriate for POSIX-like systems.")
@support.reap_threads
def test_forkinthread(self):
def thread1():
try:
pid = os.fork() # fork in a thread
except RuntimeError:
os._exit(1) # exit the child
if pid == 0: # child
try:
os.close(self.read_fd)
os.write(self.write_fd, b"OK")
finally:
os._exit(0)
else: # parent
os.close(self.write_fd)
thread.start_new_thread(thread1, ())
self.assertEqual(os.read(self.read_fd, 2), b"OK",
"Unable to fork() in thread")
def tearDown(self):
try:
os.close(self.read_fd)
except OSError:
pass
try:
os.close(self.write_fd)
except OSError:
pass
def test_main():
support.run_unittest(ThreadRunningTests, BarrierTest, LockTests,
TestForkInThread)
if __name__ == "__main__":
test_main()