| import unittest |
| from test import test_support |
| from contextlib import closing, nested |
| import pickle |
| import select |
| import signal |
| import subprocess |
| import traceback |
| import sys, os, time, errno |
| |
| if sys.platform[:3] in ('win', 'os2') or sys.platform == 'riscos': |
| raise test_support.TestSkipped("Can't test signal on %s" % \ |
| sys.platform) |
| |
| |
| class HandlerBCalled(Exception): |
| pass |
| |
| |
| def exit_subprocess(): |
| """Use os._exit(0) to exit the current subprocess. |
| |
| Otherwise, the test catches the SystemExit and continues executing |
| in parallel with the original test, so you wind up with an |
| exponential number of tests running concurrently. |
| """ |
| os._exit(0) |
| |
| |
| class InterProcessSignalTests(unittest.TestCase): |
| MAX_DURATION = 20 # Entire test should last at most 20 sec. |
| |
| def handlerA(self, *args): |
| self.a_called = True |
| if test_support.verbose: |
| print("handlerA invoked", args) |
| |
| def handlerB(self, *args): |
| self.b_called = True |
| if test_support.verbose: |
| print("handlerB invoked", args) |
| raise HandlerBCalled(*args) |
| |
| def wait(self, child): |
| """Wait for child to finish, ignoring EINTR.""" |
| while True: |
| try: |
| child.wait() |
| return |
| except OSError as e: |
| if e.errno != errno.EINTR: |
| raise |
| |
| def run_test(self): |
| # Install handlers. This function runs in a sub-process, so we |
| # don't worry about re-setting the default handlers. |
| signal.signal(signal.SIGHUP, self.handlerA) |
| signal.signal(signal.SIGUSR1, self.handlerB) |
| signal.signal(signal.SIGUSR2, signal.SIG_IGN) |
| signal.signal(signal.SIGALRM, signal.default_int_handler) |
| |
| # Variables the signals will modify: |
| self.a_called = False |
| self.b_called = False |
| |
| # Let the sub-processes know who to send signals to. |
| pid = os.getpid() |
| if test_support.verbose: |
| print("test runner's pid is", pid) |
| |
| child = subprocess.Popen(['kill', '-HUP', str(pid)]) |
| self.wait(child) |
| self.assertTrue(self.a_called) |
| self.assertFalse(self.b_called) |
| self.a_called = False |
| |
| try: |
| child = subprocess.Popen(['kill', '-USR1', str(pid)]) |
| # This wait should be interrupted by the signal's exception. |
| self.wait(child) |
| self.fail('HandlerBCalled exception not thrown') |
| except HandlerBCalled: |
| self.assertTrue(self.b_called) |
| self.assertFalse(self.a_called) |
| if test_support.verbose: |
| print("HandlerBCalled exception caught") |
| |
| child = subprocess.Popen(['kill', '-USR2', str(pid)]) |
| self.wait(child) # Nothing should happen. |
| |
| try: |
| signal.alarm(1) |
| # The race condition in pause doesn't matter in this case, |
| # since alarm is going to raise a KeyboardException, which |
| # will skip the call. |
| signal.pause() |
| except KeyboardInterrupt: |
| if test_support.verbose: |
| print("KeyboardInterrupt (the alarm() went off)") |
| except: |
| self.fail('Some other exception woke us from pause: %s' % |
| traceback.format_exc()) |
| else: |
| self.fail('pause returned of its own accord') |
| |
| def test_main(self): |
| # This function spawns a child process to insulate the main |
| # test-running process from all the signals. It then |
| # communicates with that child process over a pipe and |
| # re-raises information about any exceptions the child |
| # throws. The real work happens in self.run_test(). |
| os_done_r, os_done_w = os.pipe() |
| with nested(closing(os.fdopen(os_done_r, 'rb')), |
| closing(os.fdopen(os_done_w, 'wb'))) as (done_r, done_w): |
| child = os.fork() |
| if child == 0: |
| # In the child process; run the test and report results |
| # through the pipe. |
| try: |
| done_r.close() |
| # Have to close done_w again here because |
| # exit_subprocess() will skip the enclosing with block. |
| with closing(done_w): |
| try: |
| self.run_test() |
| except: |
| pickle.dump(traceback.format_exc(), done_w) |
| else: |
| pickle.dump(None, done_w) |
| except: |
| print('Uh oh, raised from pickle.') |
| traceback.print_exc() |
| finally: |
| exit_subprocess() |
| |
| done_w.close() |
| # Block for up to MAX_DURATION seconds for the test to finish. |
| r, w, x = select.select([done_r], [], [], self.MAX_DURATION) |
| if done_r in r: |
| tb = pickle.load(done_r) |
| if tb: |
| self.fail(tb) |
| else: |
| os.kill(child, signal.SIGKILL) |
| self.fail('Test deadlocked after %d seconds.' % |
| self.MAX_DURATION) |
| |
| |
| class BasicSignalTests(unittest.TestCase): |
| def trivial_signal_handler(self, *args): |
| pass |
| |
| def test_out_of_range_signal_number_raises_error(self): |
| self.assertRaises(ValueError, signal.getsignal, 4242) |
| |
| self.assertRaises(ValueError, signal.signal, 4242, |
| self.trivial_signal_handler) |
| |
| def test_setting_signal_handler_to_none_raises_error(self): |
| self.assertRaises(TypeError, signal.signal, |
| signal.SIGUSR1, None) |
| |
| def test_getsignal(self): |
| hup = signal.signal(signal.SIGHUP, self.trivial_signal_handler) |
| self.assertEquals(signal.getsignal(signal.SIGHUP), |
| self.trivial_signal_handler) |
| signal.signal(signal.SIGHUP, hup) |
| self.assertEquals(signal.getsignal(signal.SIGHUP), hup) |
| |
| |
| class WakeupSignalTests(unittest.TestCase): |
| TIMEOUT_FULL = 10 |
| TIMEOUT_HALF = 5 |
| |
| def test_wakeup_fd_early(self): |
| import select |
| |
| signal.alarm(1) |
| before_time = time.time() |
| # We attempt to get a signal during the sleep, |
| # before select is called |
| time.sleep(self.TIMEOUT_FULL) |
| mid_time = time.time() |
| self.assert_(mid_time - before_time < self.TIMEOUT_HALF) |
| select.select([self.read], [], [], self.TIMEOUT_FULL) |
| after_time = time.time() |
| self.assert_(after_time - mid_time < self.TIMEOUT_HALF) |
| |
| def test_wakeup_fd_during(self): |
| import select |
| |
| signal.alarm(1) |
| before_time = time.time() |
| # We attempt to get a signal during the select call |
| self.assertRaises(select.error, select.select, |
| [self.read], [], [], self.TIMEOUT_FULL) |
| after_time = time.time() |
| self.assert_(after_time - before_time < self.TIMEOUT_HALF) |
| |
| def setUp(self): |
| import fcntl |
| |
| self.alrm = signal.signal(signal.SIGALRM, lambda x,y:None) |
| self.read, self.write = os.pipe() |
| flags = fcntl.fcntl(self.write, fcntl.F_GETFL, 0) |
| flags = flags | os.O_NONBLOCK |
| fcntl.fcntl(self.write, fcntl.F_SETFL, flags) |
| self.old_wakeup = signal.set_wakeup_fd(self.write) |
| |
| def tearDown(self): |
| signal.set_wakeup_fd(self.old_wakeup) |
| os.close(self.read) |
| os.close(self.write) |
| signal.signal(signal.SIGALRM, self.alrm) |
| |
| class SiginterruptTest(unittest.TestCase): |
| signum = signal.SIGUSR1 |
| def readpipe_interrupted(self, cb): |
| r, w = os.pipe() |
| ppid = os.getpid() |
| pid = os.fork() |
| |
| oldhandler = signal.signal(self.signum, lambda x,y: None) |
| cb() |
| if pid==0: |
| # child code: sleep, kill, sleep. and then exit, |
| # which closes the pipe from which the parent process reads |
| try: |
| time.sleep(0.2) |
| os.kill(ppid, self.signum) |
| time.sleep(0.2) |
| finally: |
| exit_subprocess() |
| |
| try: |
| os.close(w) |
| |
| try: |
| d=os.read(r, 1) |
| return False |
| except OSError as err: |
| if err.errno != errno.EINTR: |
| raise |
| return True |
| finally: |
| signal.signal(self.signum, oldhandler) |
| os.waitpid(pid, 0) |
| |
| def test_without_siginterrupt(self): |
| i=self.readpipe_interrupted(lambda: None) |
| self.assertEquals(i, True) |
| |
| def test_siginterrupt_on(self): |
| i=self.readpipe_interrupted(lambda: signal.siginterrupt(self.signum, 1)) |
| self.assertEquals(i, True) |
| |
| def test_siginterrupt_off(self): |
| i=self.readpipe_interrupted(lambda: signal.siginterrupt(self.signum, 0)) |
| self.assertEquals(i, False) |
| |
| def test_main(): |
| test_support.run_unittest(BasicSignalTests, InterProcessSignalTests, |
| WakeupSignalTests, SiginterruptTest) |
| |
| |
| if __name__ == "__main__": |
| test_main() |