| """This test case provides support for checking forking and wait behavior. |
| |
| To test different wait behavior, override the wait_impl method. |
| |
| We want fork1() semantics -- only the forking thread survives in the |
| child after a fork(). |
| |
| On some systems (e.g. Solaris without posix threads) we find that all |
| active threads survive in the child after a fork(); this is an error. |
| """ |
| |
| import os, sys, time, unittest |
| import test.support as support |
| _thread = support.import_module('_thread') |
| |
| LONGSLEEP = 2 |
| SHORTSLEEP = 0.5 |
| NUM_THREADS = 4 |
| |
| class ForkWait(unittest.TestCase): |
| |
| def setUp(self): |
| self.alive = {} |
| self.stop = 0 |
| |
| def f(self, id): |
| while not self.stop: |
| self.alive[id] = os.getpid() |
| try: |
| time.sleep(SHORTSLEEP) |
| except OSError: |
| pass |
| |
| def wait_impl(self, cpid): |
| for i in range(10): |
| # waitpid() shouldn't hang, but some of the buildbots seem to hang |
| # in the forking tests. This is an attempt to fix the problem. |
| spid, status = os.waitpid(cpid, os.WNOHANG) |
| if spid == cpid: |
| break |
| time.sleep(2 * SHORTSLEEP) |
| |
| self.assertEqual(spid, cpid) |
| self.assertEqual(status, 0, "cause = %d, exit = %d" % (status&0xff, status>>8)) |
| |
| @support.reap_threads |
| def test_wait(self): |
| for i in range(NUM_THREADS): |
| _thread.start_new(self.f, (i,)) |
| |
| # busy-loop to wait for threads |
| deadline = time.monotonic() + 10.0 |
| while len(self.alive) < NUM_THREADS: |
| time.sleep(0.1) |
| if time.monotonic() <= deadline: |
| break |
| |
| a = sorted(self.alive.keys()) |
| self.assertEqual(a, list(range(NUM_THREADS))) |
| |
| prefork_lives = self.alive.copy() |
| |
| if sys.platform in ['unixware7']: |
| cpid = os.fork1() |
| else: |
| cpid = os.fork() |
| |
| if cpid == 0: |
| # Child |
| time.sleep(LONGSLEEP) |
| n = 0 |
| for key in self.alive: |
| if self.alive[key] != prefork_lives[key]: |
| n += 1 |
| os._exit(n) |
| else: |
| # Parent |
| try: |
| self.wait_impl(cpid) |
| finally: |
| # Tell threads to die |
| self.stop = 1 |