| import errno |
| import gc |
| import os |
| import pickle |
| import select |
| import signal |
| import subprocess |
| import sys |
| import time |
| import traceback |
| import unittest |
| from test import support |
| from contextlib import closing |
| from test.script_helper import assert_python_ok, spawn_python |
| |
| if sys.platform in ('os2', 'riscos'): |
| raise unittest.SkipTest("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) |
| |
| |
| def ignoring_eintr(__func, *args, **kwargs): |
| try: |
| return __func(*args, **kwargs) |
| except EnvironmentError as e: |
| if e.errno != errno.EINTR: |
| raise |
| return None |
| |
| |
| @unittest.skipIf(sys.platform == "win32", "Not valid on Windows") |
| class InterProcessSignalTests(unittest.TestCase): |
| MAX_DURATION = 20 # Entire test should last at most 20 sec. |
| |
| def setUp(self): |
| self.using_gc = gc.isenabled() |
| gc.disable() |
| |
| def tearDown(self): |
| if self.using_gc: |
| gc.enable() |
| |
| def format_frame(self, frame, limit=None): |
| return ''.join(traceback.format_stack(frame, limit=limit)) |
| |
| def handlerA(self, signum, frame): |
| self.a_called = True |
| if support.verbose: |
| print("handlerA invoked from signal %s at:\n%s" % ( |
| signum, self.format_frame(frame, limit=1))) |
| |
| def handlerB(self, signum, frame): |
| self.b_called = True |
| if support.verbose: |
| print ("handlerB invoked from signal %s at:\n%s" % ( |
| signum, self.format_frame(frame, limit=1))) |
| raise HandlerBCalled(signum, self.format_frame(frame)) |
| |
| 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 support.verbose: |
| print("test runner's pid is", pid) |
| |
| child = ignoring_eintr(subprocess.Popen, ['kill', '-HUP', str(pid)]) |
| if child: |
| self.wait(child) |
| if not self.a_called: |
| time.sleep(1) # Give the signal time to be delivered. |
| self.assertTrue(self.a_called) |
| self.assertFalse(self.b_called) |
| self.a_called = False |
| |
| # Make sure the signal isn't delivered while the previous |
| # Popen object is being destroyed, because __del__ swallows |
| # exceptions. |
| del child |
| try: |
| child = subprocess.Popen(['kill', '-USR1', str(pid)]) |
| # This wait should be interrupted by the signal's exception. |
| self.wait(child) |
| time.sleep(1) # Give the signal time to be delivered. |
| self.fail('HandlerBCalled exception not raised') |
| except HandlerBCalled: |
| self.assertTrue(self.b_called) |
| self.assertFalse(self.a_called) |
| if support.verbose: |
| print("HandlerBCalled exception caught") |
| |
| child = ignoring_eintr(subprocess.Popen, ['kill', '-USR2', str(pid)]) |
| if child: |
| 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() |
| # But if another signal arrives before the alarm, pause |
| # may return early. |
| time.sleep(1) |
| except KeyboardInterrupt: |
| if 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, and the signal" |
| " didn't arrive after another second.") |
| |
| # Issue 3864, unknown if this affects earlier versions of freebsd also |
| @unittest.skipIf(sys.platform=='freebsd6', |
| 'inter process signals not reliable (do not mix well with threading) ' |
| 'on freebsd6') |
| 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 |
| # raises. The real work happens in self.run_test(). |
| os_done_r, os_done_w = os.pipe() |
| with closing(os.fdopen(os_done_r, 'rb')) as done_r, \ |
| closing(os.fdopen(os_done_w, 'wb')) as 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) |
| |
| |
| @unittest.skipIf(sys.platform == "win32", "Not valid on Windows") |
| 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.assertEqual(signal.getsignal(signal.SIGHUP), |
| self.trivial_signal_handler) |
| signal.signal(signal.SIGHUP, hup) |
| self.assertEqual(signal.getsignal(signal.SIGHUP), hup) |
| |
| |
| @unittest.skipUnless(sys.platform == "win32", "Windows specific") |
| class WindowsSignalTests(unittest.TestCase): |
| def test_issue9324(self): |
| # Updated for issue #10003, adding SIGBREAK |
| handler = lambda x, y: None |
| for sig in (signal.SIGABRT, signal.SIGBREAK, signal.SIGFPE, |
| signal.SIGILL, signal.SIGINT, signal.SIGSEGV, |
| signal.SIGTERM): |
| # Set and then reset a handler for signals that work on windows |
| signal.signal(sig, signal.signal(sig, handler)) |
| |
| with self.assertRaises(ValueError): |
| signal.signal(-1, handler) |
| |
| with self.assertRaises(ValueError): |
| signal.signal(7, handler) |
| |
| |
| @unittest.skipIf(sys.platform == "win32", "Not valid on Windows") |
| class WakeupSignalTests(unittest.TestCase): |
| def check_wakeup(self, test_body): |
| # use a subprocess to have only one thread and to not change signal |
| # handling of the parent process |
| code = """if 1: |
| import fcntl |
| import os |
| import signal |
| |
| def handler(signum, frame): |
| pass |
| |
| {} |
| |
| signal.signal(signal.SIGALRM, handler) |
| read, write = os.pipe() |
| flags = fcntl.fcntl(write, fcntl.F_GETFL, 0) |
| flags = flags | os.O_NONBLOCK |
| fcntl.fcntl(write, fcntl.F_SETFL, flags) |
| signal.set_wakeup_fd(write) |
| |
| test() |
| |
| os.close(read) |
| os.close(write) |
| """.format(test_body) |
| |
| assert_python_ok('-c', code) |
| |
| def test_wakeup_fd_early(self): |
| self.check_wakeup("""def test(): |
| import select |
| import time |
| |
| TIMEOUT_FULL = 10 |
| TIMEOUT_HALF = 5 |
| |
| signal.alarm(1) |
| before_time = time.time() |
| # We attempt to get a signal during the sleep, |
| # before select is called |
| time.sleep(TIMEOUT_FULL) |
| mid_time = time.time() |
| dt = mid_time - before_time |
| if dt >= TIMEOUT_HALF: |
| raise Exception("%s >= %s" % (dt, TIMEOUT_HALF)) |
| select.select([read], [], [], TIMEOUT_FULL) |
| after_time = time.time() |
| dt = after_time - mid_time |
| if dt >= TIMEOUT_HALF: |
| raise Exception("%s >= %s" % (dt, TIMEOUT_HALF)) |
| """) |
| |
| def test_wakeup_fd_during(self): |
| self.check_wakeup("""def test(): |
| import select |
| import time |
| |
| TIMEOUT_FULL = 10 |
| TIMEOUT_HALF = 5 |
| |
| signal.alarm(1) |
| before_time = time.time() |
| # We attempt to get a signal during the select call |
| try: |
| select.select([read], [], [], TIMEOUT_FULL) |
| except select.error: |
| pass |
| else: |
| raise Exception("select.error not raised") |
| after_time = time.time() |
| dt = after_time - before_time |
| if dt >= TIMEOUT_HALF: |
| raise Exception("%s >= %s" % (dt, TIMEOUT_HALF)) |
| """) |
| |
| @unittest.skipIf(sys.platform == "win32", "Not valid on Windows") |
| class SiginterruptTest(unittest.TestCase): |
| |
| def readpipe_interrupted(self, interrupt): |
| """Perform a read during which a signal will arrive. Return True if the |
| read is interrupted by the signal and raises an exception. Return False |
| if it returns normally. |
| """ |
| class Timeout(Exception): |
| pass |
| |
| # use a subprocess to have only one thread, to have a timeout on the |
| # blocking read and to not touch signal handling in this process |
| code = """if 1: |
| import errno |
| import os |
| import signal |
| import sys |
| |
| interrupt = %r |
| r, w = os.pipe() |
| |
| def handler(signum, frame): |
| pass |
| |
| signal.signal(signal.SIGALRM, handler) |
| if interrupt is not None: |
| signal.siginterrupt(signal.SIGALRM, interrupt) |
| |
| print("ready") |
| sys.stdout.flush() |
| |
| # run the test twice |
| for loop in range(2): |
| # send a SIGALRM in a second (during the read) |
| signal.alarm(1) |
| try: |
| # blocking call: read from a pipe without data |
| os.read(r, 1) |
| except OSError as err: |
| if err.errno != errno.EINTR: |
| raise |
| else: |
| sys.exit(2) |
| sys.exit(3) |
| """ % (interrupt,) |
| with spawn_python('-c', code) as process: |
| try: |
| # wait until the child process is loaded and has started |
| first_line = process.stdout.readline() |
| |
| # Wait the process with a timeout of 5 seconds |
| timeout = time.time() + 5.0 |
| while True: |
| if timeout < time.time(): |
| raise Timeout() |
| status = process.poll() |
| if status is not None: |
| break |
| time.sleep(0.1) |
| |
| stdout, stderr = process.communicate() |
| except Timeout: |
| process.kill() |
| return False |
| else: |
| stdout = first_line + stdout |
| exitcode = process.wait() |
| if exitcode not in (2, 3): |
| raise Exception("Child error (exit code %s): %s" |
| % (exitcode, stdout)) |
| return (exitcode == 3) |
| |
| def test_without_siginterrupt(self): |
| # If a signal handler is installed and siginterrupt is not called |
| # at all, when that signal arrives, it interrupts a syscall that's in |
| # progress. |
| interrupted = self.readpipe_interrupted(None) |
| self.assertTrue(interrupted) |
| |
| def test_siginterrupt_on(self): |
| # If a signal handler is installed and siginterrupt is called with |
| # a true value for the second argument, when that signal arrives, it |
| # interrupts a syscall that's in progress. |
| interrupted = self.readpipe_interrupted(True) |
| self.assertTrue(interrupted) |
| |
| def test_siginterrupt_off(self): |
| # If a signal handler is installed and siginterrupt is called with |
| # a false value for the second argument, when that signal arrives, it |
| # does not interrupt a syscall that's in progress. |
| interrupted = self.readpipe_interrupted(False) |
| self.assertFalse(interrupted) |
| |
| |
| @unittest.skipIf(sys.platform == "win32", "Not valid on Windows") |
| class ItimerTest(unittest.TestCase): |
| def setUp(self): |
| self.hndl_called = False |
| self.hndl_count = 0 |
| self.itimer = None |
| self.old_alarm = signal.signal(signal.SIGALRM, self.sig_alrm) |
| |
| def tearDown(self): |
| signal.signal(signal.SIGALRM, self.old_alarm) |
| if self.itimer is not None: # test_itimer_exc doesn't change this attr |
| # just ensure that itimer is stopped |
| signal.setitimer(self.itimer, 0) |
| |
| def sig_alrm(self, *args): |
| self.hndl_called = True |
| if support.verbose: |
| print("SIGALRM handler invoked", args) |
| |
| def sig_vtalrm(self, *args): |
| self.hndl_called = True |
| |
| if self.hndl_count > 3: |
| # it shouldn't be here, because it should have been disabled. |
| raise signal.ItimerError("setitimer didn't disable ITIMER_VIRTUAL " |
| "timer.") |
| elif self.hndl_count == 3: |
| # disable ITIMER_VIRTUAL, this function shouldn't be called anymore |
| signal.setitimer(signal.ITIMER_VIRTUAL, 0) |
| if support.verbose: |
| print("last SIGVTALRM handler call") |
| |
| self.hndl_count += 1 |
| |
| if support.verbose: |
| print("SIGVTALRM handler invoked", args) |
| |
| def sig_prof(self, *args): |
| self.hndl_called = True |
| signal.setitimer(signal.ITIMER_PROF, 0) |
| |
| if support.verbose: |
| print("SIGPROF handler invoked", args) |
| |
| def test_itimer_exc(self): |
| # XXX I'm assuming -1 is an invalid itimer, but maybe some platform |
| # defines it ? |
| self.assertRaises(signal.ItimerError, signal.setitimer, -1, 0) |
| # Negative times are treated as zero on some platforms. |
| if 0: |
| self.assertRaises(signal.ItimerError, |
| signal.setitimer, signal.ITIMER_REAL, -1) |
| |
| def test_itimer_real(self): |
| self.itimer = signal.ITIMER_REAL |
| signal.setitimer(self.itimer, 1.0) |
| if support.verbose: |
| print("\ncall pause()...") |
| signal.pause() |
| |
| self.assertEqual(self.hndl_called, True) |
| |
| # Issue 3864, unknown if this affects earlier versions of freebsd also |
| @unittest.skipIf(sys.platform in ('freebsd6', 'netbsd5'), |
| 'itimer not reliable (does not mix well with threading) on some BSDs.') |
| def test_itimer_virtual(self): |
| self.itimer = signal.ITIMER_VIRTUAL |
| signal.signal(signal.SIGVTALRM, self.sig_vtalrm) |
| signal.setitimer(self.itimer, 0.3, 0.2) |
| |
| start_time = time.time() |
| while time.time() - start_time < 60.0: |
| # use up some virtual time by doing real work |
| _ = pow(12345, 67890, 10000019) |
| if signal.getitimer(self.itimer) == (0.0, 0.0): |
| break # sig_vtalrm handler stopped this itimer |
| else: # Issue 8424 |
| self.skipTest("timeout: likely cause: machine too slow or load too " |
| "high") |
| |
| # virtual itimer should be (0.0, 0.0) now |
| self.assertEqual(signal.getitimer(self.itimer), (0.0, 0.0)) |
| # and the handler should have been called |
| self.assertEqual(self.hndl_called, True) |
| |
| # Issue 3864, unknown if this affects earlier versions of freebsd also |
| @unittest.skipIf(sys.platform=='freebsd6', |
| 'itimer not reliable (does not mix well with threading) on freebsd6') |
| def test_itimer_prof(self): |
| self.itimer = signal.ITIMER_PROF |
| signal.signal(signal.SIGPROF, self.sig_prof) |
| signal.setitimer(self.itimer, 0.2, 0.2) |
| |
| start_time = time.time() |
| while time.time() - start_time < 60.0: |
| # do some work |
| _ = pow(12345, 67890, 10000019) |
| if signal.getitimer(self.itimer) == (0.0, 0.0): |
| break # sig_prof handler stopped this itimer |
| else: # Issue 8424 |
| self.skipTest("timeout: likely cause: machine too slow or load too " |
| "high") |
| |
| # profiling itimer should be (0.0, 0.0) now |
| self.assertEqual(signal.getitimer(self.itimer), (0.0, 0.0)) |
| # and the handler should have been called |
| self.assertEqual(self.hndl_called, True) |
| |
| def test_main(): |
| try: |
| support.run_unittest(BasicSignalTests, InterProcessSignalTests, |
| WakeupSignalTests, SiginterruptTest, |
| ItimerTest, WindowsSignalTests) |
| finally: |
| support.reap_children() |
| |
| |
| if __name__ == "__main__": |
| test_main() |