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") if os.name not in ("nt", "os2", "posix"): return tss_supported = True try: thread.stack_size(4096) except ValueError: verbose_print("caught expected ValueError setting " "stack_size(4096)") except thread.error: tss_supported = False verbose_print("platform does not support changing thread stack " "size") if tss_supported: 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: pass 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()