import os import random import signal import socket import statistics import subprocess import sys import threading import time import unittest from test import support from test.support.script_helper import assert_python_ok, spawn_python try: import _testcapi except ImportError: _testcapi = None class GenericTests(unittest.TestCase): def test_enums(self): for name in dir(signal): sig = getattr(signal, name) if name in {'SIG_DFL', 'SIG_IGN'}: self.assertIsInstance(sig, signal.Handlers) elif name in {'SIG_BLOCK', 'SIG_UNBLOCK', 'SIG_SETMASK'}: self.assertIsInstance(sig, signal.Sigmasks) elif name.startswith('SIG') and not name.startswith('SIG_'): self.assertIsInstance(sig, signal.Signals) elif name.startswith('CTRL_'): self.assertIsInstance(sig, signal.Signals) self.assertEqual(sys.platform, "win32") @unittest.skipIf(sys.platform == "win32", "Not valid on Windows") class PosixTests(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.assertIsInstance(hup, signal.Handlers) self.assertEqual(signal.getsignal(signal.SIGHUP), self.trivial_signal_handler) signal.signal(signal.SIGHUP, hup) self.assertEqual(signal.getsignal(signal.SIGHUP), hup) # Issue 3864, unknown if this affects earlier versions of freebsd also def test_interprocess_signal(self): dirname = os.path.dirname(__file__) script = os.path.join(dirname, 'signalinterproctester.py') assert_python_ok(script) @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 checked = set() 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. # Issue #18396, only for signals without a C-level handler. if signal.getsignal(sig) is not None: signal.signal(sig, signal.signal(sig, handler)) checked.add(sig) # Issue #18396: Ensure the above loop at least tested *something* self.assertTrue(checked) with self.assertRaises(ValueError): signal.signal(-1, handler) with self.assertRaises(ValueError): signal.signal(7, handler) class WakeupFDTests(unittest.TestCase): def test_invalid_call(self): # First parameter is positional-only with self.assertRaises(TypeError): signal.set_wakeup_fd(signum=signal.SIGINT) # warn_on_full_buffer is a keyword-only parameter with self.assertRaises(TypeError): signal.set_wakeup_fd(signal.SIGINT, False) def test_invalid_fd(self): fd = support.make_bad_fd() self.assertRaises((ValueError, OSError), signal.set_wakeup_fd, fd) def test_invalid_socket(self): sock = socket.socket() fd = sock.fileno() sock.close() self.assertRaises((ValueError, OSError), signal.set_wakeup_fd, fd) def test_set_wakeup_fd_result(self): r1, w1 = os.pipe() self.addCleanup(os.close, r1) self.addCleanup(os.close, w1) r2, w2 = os.pipe() self.addCleanup(os.close, r2) self.addCleanup(os.close, w2) if hasattr(os, 'set_blocking'): os.set_blocking(w1, False) os.set_blocking(w2, False) signal.set_wakeup_fd(w1) self.assertEqual(signal.set_wakeup_fd(w2), w1) self.assertEqual(signal.set_wakeup_fd(-1), w2) self.assertEqual(signal.set_wakeup_fd(-1), -1) def test_set_wakeup_fd_socket_result(self): sock1 = socket.socket() self.addCleanup(sock1.close) sock1.setblocking(False) fd1 = sock1.fileno() sock2 = socket.socket() self.addCleanup(sock2.close) sock2.setblocking(False) fd2 = sock2.fileno() signal.set_wakeup_fd(fd1) self.assertEqual(signal.set_wakeup_fd(fd2), fd1) self.assertEqual(signal.set_wakeup_fd(-1), fd2) self.assertEqual(signal.set_wakeup_fd(-1), -1) # On Windows, files are always blocking and Windows does not provide a # function to test if a socket is in non-blocking mode. @unittest.skipIf(sys.platform == "win32", "tests specific to POSIX") def test_set_wakeup_fd_blocking(self): rfd, wfd = os.pipe() self.addCleanup(os.close, rfd) self.addCleanup(os.close, wfd) # fd must be non-blocking os.set_blocking(wfd, True) with self.assertRaises(ValueError) as cm: signal.set_wakeup_fd(wfd) self.assertEqual(str(cm.exception), "the fd %s must be in non-blocking mode" % wfd) # non-blocking is ok os.set_blocking(wfd, False) signal.set_wakeup_fd(wfd) signal.set_wakeup_fd(-1) @unittest.skipIf(sys.platform == "win32", "Not valid on Windows") class WakeupSignalTests(unittest.TestCase): @unittest.skipIf(_testcapi is None, 'need _testcapi') def check_wakeup(self, test_body, *signals, ordered=True): # use a subprocess to have only one thread code = """if 1: import _testcapi import os import signal import struct signals = {!r} def handler(signum, frame): pass def check_signum(signals): data = os.read(read, len(signals)+1) raised = struct.unpack('%uB' % len(data), data) if not {!r}: raised = set(raised) signals = set(signals) if raised != signals: raise Exception("%r != %r" % (raised, signals)) {} signal.signal(signal.SIGALRM, handler) read, write = os.pipe() os.set_blocking(write, False) signal.set_wakeup_fd(write) test() check_signum(signals) os.close(read) os.close(write) """.format(tuple(map(int, signals)), ordered, test_body) assert_python_ok('-c', code) @unittest.skipIf(_testcapi is None, 'need _testcapi') def test_wakeup_write_error(self): # Issue #16105: write() errors in the C signal handler should not # pass silently. # Use a subprocess to have only one thread. code = """if 1: import _testcapi import errno import os import signal import sys from test.support import captured_stderr def handler(signum, frame): 1/0 signal.signal(signal.SIGALRM, handler) r, w = os.pipe() os.set_blocking(r, False) # Set wakeup_fd a read-only file descriptor to trigger the error signal.set_wakeup_fd(r) try: with captured_stderr() as err: _testcapi.raise_signal(signal.SIGALRM) except ZeroDivisionError: # An ignored exception should have been printed out on stderr err = err.getvalue() if ('Exception ignored when trying to write to the signal wakeup fd' not in err): raise AssertionError(err) if ('OSError: [Errno %d]' % errno.EBADF) not in err: raise AssertionError(err) else: raise AssertionError("ZeroDivisionError not raised") os.close(r) os.close(w) """ r, w = os.pipe() try: os.write(r, b'x') except OSError: pass else: self.skipTest("OS doesn't report write() error on the read end of a pipe") finally: os.close(r) os.close(w) 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 class InterruptSelect(Exception): pass def handler(signum, frame): raise InterruptSelect signal.signal(signal.SIGALRM, handler) signal.alarm(1) # We attempt to get a signal during the sleep, # before select is called try: select.select([], [], [], TIMEOUT_FULL) except InterruptSelect: pass else: raise Exception("select() was not interrupted") before_time = time.monotonic() select.select([read], [], [], TIMEOUT_FULL) after_time = time.monotonic() dt = after_time - before_time if dt >= TIMEOUT_HALF: raise Exception("%s >= %s" % (dt, TIMEOUT_HALF)) """, signal.SIGALRM) def test_wakeup_fd_during(self): self.check_wakeup("""def test(): import select import time TIMEOUT_FULL = 10 TIMEOUT_HALF = 5 class InterruptSelect(Exception): pass def handler(signum, frame): raise InterruptSelect signal.signal(signal.SIGALRM, handler) signal.alarm(1) before_time = time.monotonic() # We attempt to get a signal during the select call try: select.select([read], [], [], TIMEOUT_FULL) except InterruptSelect: pass else: raise Exception("select() was not interrupted") after_time = time.monotonic() dt = after_time - before_time if dt >= TIMEOUT_HALF: raise Exception("%s >= %s" % (dt, TIMEOUT_HALF)) """, signal.SIGALRM) def test_signum(self): self.check_wakeup("""def test(): import _testcapi signal.signal(signal.SIGUSR1, handler) _testcapi.raise_signal(signal.SIGUSR1) _testcapi.raise_signal(signal.SIGALRM) """, signal.SIGUSR1, signal.SIGALRM) @unittest.skipUnless(hasattr(signal, 'pthread_sigmask'), 'need signal.pthread_sigmask()') def test_pending(self): self.check_wakeup("""def test(): signum1 = signal.SIGUSR1 signum2 = signal.SIGUSR2 signal.signal(signum1, handler) signal.signal(signum2, handler) signal.pthread_sigmask(signal.SIG_BLOCK, (signum1, signum2)) _testcapi.raise_signal(signum1) _testcapi.raise_signal(signum2) # Unblocking the 2 signals calls the C signal handler twice signal.pthread_sigmask(signal.SIG_UNBLOCK, (signum1, signum2)) """, signal.SIGUSR1, signal.SIGUSR2, ordered=False) @unittest.skipUnless(hasattr(socket, 'socketpair'), 'need socket.socketpair') class WakeupSocketSignalTests(unittest.TestCase): @unittest.skipIf(_testcapi is None, 'need _testcapi') def test_socket(self): # use a subprocess to have only one thread code = """if 1: import signal import socket import struct import _testcapi signum = signal.SIGINT signals = (signum,) def handler(signum, frame): pass signal.signal(signum, handler) read, write = socket.socketpair() write.setblocking(False) signal.set_wakeup_fd(write.fileno()) _testcapi.raise_signal(signum) data = read.recv(1) if not data: raise Exception("no signum written") raised = struct.unpack('B', data) if raised != signals: raise Exception("%r != %r" % (raised, signals)) read.close() write.close() """ assert_python_ok('-c', code) @unittest.skipIf(_testcapi is None, 'need _testcapi') def test_send_error(self): # Use a subprocess to have only one thread. if os.name == 'nt': action = 'send' else: action = 'write' code = """if 1: import errno import signal import socket import sys import time import _testcapi from test.support import captured_stderr signum = signal.SIGINT def handler(signum, frame): pass signal.signal(signum, handler) read, write = socket.socketpair() read.setblocking(False) write.setblocking(False) signal.set_wakeup_fd(write.fileno()) # Close sockets: send() will fail read.close() write.close() with captured_stderr() as err: _testcapi.raise_signal(signum) err = err.getvalue() if ('Exception ignored when trying to {action} to the signal wakeup fd' not in err): raise AssertionError(err) """.format(action=action) assert_python_ok('-c', code) @unittest.skipIf(_testcapi is None, 'need _testcapi') def test_warn_on_full_buffer(self): # Use a subprocess to have only one thread. if os.name == 'nt': action = 'send' else: action = 'write' code = """if 1: import errno import signal import socket import sys import time import _testcapi from test.support import captured_stderr signum = signal.SIGINT # This handler will be called, but we intentionally won't read from # the wakeup fd. def handler(signum, frame): pass signal.signal(signum, handler) read, write = socket.socketpair() # Fill the socketpair buffer if sys.platform == 'win32': # bpo-34130: On Windows, sometimes non-blocking send fails to fill # the full socketpair buffer, so use a timeout of 50 ms instead. write.settimeout(0.050) else: write.setblocking(False) # Start with large chunk size to reduce the # number of send needed to fill the buffer. written = 0 for chunk_size in (2 ** 16, 2 ** 8, 1): chunk = b"x" * chunk_size try: while True: write.send(chunk) written += chunk_size except (BlockingIOError, socket.timeout): pass print(f"%s bytes written into the socketpair" % written, flush=True) write.setblocking(False) try: write.send(b"x") except BlockingIOError: # The socketpair buffer seems full pass else: raise AssertionError("%s bytes failed to fill the socketpair " "buffer" % written) # By default, we get a warning when a signal arrives msg = ('Exception ignored when trying to {action} ' 'to the signal wakeup fd') signal.set_wakeup_fd(write.fileno()) with captured_stderr() as err: _testcapi.raise_signal(signum) err = err.getvalue() if msg not in err: raise AssertionError("first set_wakeup_fd() test failed, " "stderr: %r" % err) # And also if warn_on_full_buffer=True signal.set_wakeup_fd(write.fileno(), warn_on_full_buffer=True) with captured_stderr() as err: _testcapi.raise_signal(signum) err = err.getvalue() if msg not in err: raise AssertionError("set_wakeup_fd(warn_on_full_buffer=True) " "test failed, stderr: %r" % err) # But not if warn_on_full_buffer=False signal.set_wakeup_fd(write.fileno(), warn_on_full_buffer=False) with captured_stderr() as err: _testcapi.raise_signal(signum) err = err.getvalue() if err != "": raise AssertionError("set_wakeup_fd(warn_on_full_buffer=False) " "test failed, stderr: %r" % err) # And then check the default again, to make sure warn_on_full_buffer # settings don't leak across calls. signal.set_wakeup_fd(write.fileno()) with captured_stderr() as err: _testcapi.raise_signal(signum) err = err.getvalue() if msg not in err: raise AssertionError("second set_wakeup_fd() test failed, " "stderr: %r" % err) """.format(action=action) assert_python_ok('-c', code) @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. """ # 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): 1 / 0 signal.signal(signal.SIGALRM, handler) if interrupt is not None: signal.siginterrupt(signal.SIGALRM, interrupt) print("ready") sys.stdout.flush() # run the test twice try: 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 ZeroDivisionError: pass else: sys.exit(2) sys.exit(3) finally: os.close(r) os.close(w) """ % (interrupt,) with spawn_python('-c', code) as process: try: # wait until the child process is loaded and has started first_line = process.stdout.readline() stdout, stderr = process.communicate(timeout=5.0) except subprocess.TimeoutExpired: 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): %r" % (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 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) self.hndl_count += 1 def sig_prof(self, *args): self.hndl_called = True signal.setitimer(signal.ITIMER_PROF, 0) 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) signal.pause() self.assertEqual(self.hndl_called, True) # Issue 3864, unknown if this affects earlier versions of freebsd also @unittest.skipIf(sys.platform in ('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.monotonic() while time.monotonic() - 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) 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.monotonic() while time.monotonic() - 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_setitimer_tiny(self): # bpo-30807: C setitimer() takes a microsecond-resolution interval. # Check that float -> timeval conversion doesn't round # the interval down to zero, which would disable the timer. self.itimer = signal.ITIMER_REAL signal.setitimer(self.itimer, 1e-6) time.sleep(1) self.assertEqual(self.hndl_called, True) class PendingSignalsTests(unittest.TestCase): """ Test pthread_sigmask(), pthread_kill(), sigpending() and sigwait() functions. """ @unittest.skipUnless(hasattr(signal, 'sigpending'), 'need signal.sigpending()') def test_sigpending_empty(self): self.assertEqual(signal.sigpending(), set()) @unittest.skipUnless(hasattr(signal, 'pthread_sigmask'), 'need signal.pthread_sigmask()') @unittest.skipUnless(hasattr(signal, 'sigpending'), 'need signal.sigpending()') def test_sigpending(self): code = """if 1: import os import signal def handler(signum, frame): 1/0 signum = signal.SIGUSR1 signal.signal(signum, handler) signal.pthread_sigmask(signal.SIG_BLOCK, [signum]) os.kill(os.getpid(), signum) pending = signal.sigpending() for sig in pending: assert isinstance(sig, signal.Signals), repr(pending) if pending != {signum}: raise Exception('%s != {%s}' % (pending, signum)) try: signal.pthread_sigmask(signal.SIG_UNBLOCK, [signum]) except ZeroDivisionError: pass else: raise Exception("ZeroDivisionError not raised") """ assert_python_ok('-c', code) @unittest.skipUnless(hasattr(signal, 'pthread_kill'), 'need signal.pthread_kill()') def test_pthread_kill(self): code = """if 1: import signal import threading import sys signum = signal.SIGUSR1 def handler(signum, frame): 1/0 signal.signal(signum, handler) tid = threading.get_ident() try: signal.pthread_kill(tid, signum) except ZeroDivisionError: pass else: raise Exception("ZeroDivisionError not raised") """ assert_python_ok('-c', code) @unittest.skipUnless(hasattr(signal, 'pthread_sigmask'), 'need signal.pthread_sigmask()') def wait_helper(self, blocked, test): """ test: body of the "def test(signum):" function. blocked: number of the blocked signal """ code = '''if 1: import signal import sys from signal import Signals def handler(signum, frame): 1/0 %s blocked = %s signum = signal.SIGALRM # child: block and wait the signal try: signal.signal(signum, handler) signal.pthread_sigmask(signal.SIG_BLOCK, [blocked]) # Do the tests test(signum) # The handler must not be called on unblock try: signal.pthread_sigmask(signal.SIG_UNBLOCK, [blocked]) except ZeroDivisionError: print("the signal handler has been called", file=sys.stderr) sys.exit(1) except BaseException as err: print("error: {}".format(err), file=sys.stderr) sys.stderr.flush() sys.exit(1) ''' % (test.strip(), blocked) # sig*wait* must be called with the signal blocked: since the current # process might have several threads running, use a subprocess to have # a single thread. assert_python_ok('-c', code) @unittest.skipUnless(hasattr(signal, 'sigwait'), 'need signal.sigwait()') def test_sigwait(self): self.wait_helper(signal.SIGALRM, ''' def test(signum): signal.alarm(1) received = signal.sigwait([signum]) assert isinstance(received, signal.Signals), received if received != signum: raise Exception('received %s, not %s' % (received, signum)) ''') @unittest.skipUnless(hasattr(signal, 'sigwaitinfo'), 'need signal.sigwaitinfo()') def test_sigwaitinfo(self): self.wait_helper(signal.SIGALRM, ''' def test(signum): signal.alarm(1) info = signal.sigwaitinfo([signum]) if info.si_signo != signum: raise Exception("info.si_signo != %s" % signum) ''') @unittest.skipUnless(hasattr(signal, 'sigtimedwait'), 'need signal.sigtimedwait()') def test_sigtimedwait(self): self.wait_helper(signal.SIGALRM, ''' def test(signum): signal.alarm(1) info = signal.sigtimedwait([signum], 10.1000) if info.si_signo != signum: raise Exception('info.si_signo != %s' % signum) ''') @unittest.skipUnless(hasattr(signal, 'sigtimedwait'), 'need signal.sigtimedwait()') def test_sigtimedwait_poll(self): # check that polling with sigtimedwait works self.wait_helper(signal.SIGALRM, ''' def test(signum): import os os.kill(os.getpid(), signum) info = signal.sigtimedwait([signum], 0) if info.si_signo != signum: raise Exception('info.si_signo != %s' % signum) ''') @unittest.skipUnless(hasattr(signal, 'sigtimedwait'), 'need signal.sigtimedwait()') def test_sigtimedwait_timeout(self): self.wait_helper(signal.SIGALRM, ''' def test(signum): received = signal.sigtimedwait([signum], 1.0) if received is not None: raise Exception("received=%r" % (received,)) ''') @unittest.skipUnless(hasattr(signal, 'sigtimedwait'), 'need signal.sigtimedwait()') def test_sigtimedwait_negative_timeout(self): signum = signal.SIGALRM self.assertRaises(ValueError, signal.sigtimedwait, [signum], -1.0) @unittest.skipUnless(hasattr(signal, 'sigwait'), 'need signal.sigwait()') @unittest.skipUnless(hasattr(signal, 'pthread_sigmask'), 'need signal.pthread_sigmask()') def test_sigwait_thread(self): # Check that calling sigwait() from a thread doesn't suspend the whole # process. A new interpreter is spawned to avoid problems when mixing # threads and fork(): only async-safe functions are allowed between # fork() and exec(). assert_python_ok("-c", """if True: import os, threading, sys, time, signal # the default handler terminates the process signum = signal.SIGUSR1 def kill_later(): # wait until the main thread is waiting in sigwait() time.sleep(1) os.kill(os.getpid(), signum) # the signal must be blocked by all the threads signal.pthread_sigmask(signal.SIG_BLOCK, [signum]) killer = threading.Thread(target=kill_later) killer.start() received = signal.sigwait([signum]) if received != signum: print("sigwait() received %s, not %s" % (received, signum), file=sys.stderr) sys.exit(1) killer.join() # unblock the signal, which should have been cleared by sigwait() signal.pthread_sigmask(signal.SIG_UNBLOCK, [signum]) """) @unittest.skipUnless(hasattr(signal, 'pthread_sigmask'), 'need signal.pthread_sigmask()') def test_pthread_sigmask_arguments(self): self.assertRaises(TypeError, signal.pthread_sigmask) self.assertRaises(TypeError, signal.pthread_sigmask, 1) self.assertRaises(TypeError, signal.pthread_sigmask, 1, 2, 3) self.assertRaises(OSError, signal.pthread_sigmask, 1700, []) @unittest.skipUnless(hasattr(signal, 'pthread_sigmask'), 'need signal.pthread_sigmask()') def test_pthread_sigmask(self): code = """if 1: import signal import os; import threading def handler(signum, frame): 1/0 def kill(signum): os.kill(os.getpid(), signum) def check_mask(mask): for sig in mask: assert isinstance(sig, signal.Signals), repr(sig) def read_sigmask(): sigmask = signal.pthread_sigmask(signal.SIG_BLOCK, []) check_mask(sigmask) return sigmask signum = signal.SIGUSR1 # Install our signal handler old_handler = signal.signal(signum, handler) # Unblock SIGUSR1 (and copy the old mask) to test our signal handler old_mask = signal.pthread_sigmask(signal.SIG_UNBLOCK, [signum]) check_mask(old_mask) try: kill(signum) except ZeroDivisionError: pass else: raise Exception("ZeroDivisionError not raised") # Block and then raise SIGUSR1. The signal is blocked: the signal # handler is not called, and the signal is now pending mask = signal.pthread_sigmask(signal.SIG_BLOCK, [signum]) check_mask(mask) kill(signum) # Check the new mask blocked = read_sigmask() check_mask(blocked) if signum not in blocked: raise Exception("%s not in %s" % (signum, blocked)) if old_mask ^ blocked != {signum}: raise Exception("%s ^ %s != {%s}" % (old_mask, blocked, signum)) # Unblock SIGUSR1 try: # unblock the pending signal calls immediately the signal handler signal.pthread_sigmask(signal.SIG_UNBLOCK, [signum]) except ZeroDivisionError: pass else: raise Exception("ZeroDivisionError not raised") try: kill(signum) except ZeroDivisionError: pass else: raise Exception("ZeroDivisionError not raised") # Check the new mask unblocked = read_sigmask() if signum in unblocked: raise Exception("%s in %s" % (signum, unblocked)) if blocked ^ unblocked != {signum}: raise Exception("%s ^ %s != {%s}" % (blocked, unblocked, signum)) if old_mask != unblocked: raise Exception("%s != %s" % (old_mask, unblocked)) """ assert_python_ok('-c', code) @unittest.skipUnless(hasattr(signal, 'pthread_kill'), 'need signal.pthread_kill()') def test_pthread_kill_main_thread(self): # Test that a signal can be sent to the main thread with pthread_kill() # before any other thread has been created (see issue #12392). code = """if True: import threading import signal import sys def handler(signum, frame): sys.exit(3) signal.signal(signal.SIGUSR1, handler) signal.pthread_kill(threading.get_ident(), signal.SIGUSR1) sys.exit(2) """ with spawn_python('-c', code) as process: stdout, stderr = process.communicate() exitcode = process.wait() if exitcode != 3: raise Exception("Child error (exit code %s): %s" % (exitcode, stdout)) class StressTest(unittest.TestCase): """ Stress signal delivery, especially when a signal arrives in the middle of recomputing the signal state or executing previously tripped signal handlers. """ def setsig(self, signum, handler): old_handler = signal.signal(signum, handler) self.addCleanup(signal.signal, signum, old_handler) def measure_itimer_resolution(self): N = 20 times = [] def handler(signum=None, frame=None): if len(times) < N: times.append(time.perf_counter()) # 1 µs is the smallest possible timer interval, # we want to measure what the concrete duration # will be on this platform signal.setitimer(signal.ITIMER_REAL, 1e-6) self.addCleanup(signal.setitimer, signal.ITIMER_REAL, 0) self.setsig(signal.SIGALRM, handler) handler() while len(times) < N: time.sleep(1e-3) durations = [times[i+1] - times[i] for i in range(len(times) - 1)] med = statistics.median(durations) if support.verbose: print("detected median itimer() resolution: %.6f s." % (med,)) return med def decide_itimer_count(self): # Some systems have poor setitimer() resolution (for example # measured around 20 ms. on FreeBSD 9), so decide on a reasonable # number of sequential timers based on that. reso = self.measure_itimer_resolution() if reso <= 1e-4: return 10000 elif reso <= 1e-2: return 100 else: self.skipTest("detected itimer resolution (%.3f s.) too high " "(> 10 ms.) on this platform (or system too busy)" % (reso,)) @unittest.skipUnless(hasattr(signal, "setitimer"), "test needs setitimer()") def test_stress_delivery_dependent(self): """ This test uses dependent signal handlers. """ N = self.decide_itimer_count() sigs = [] def first_handler(signum, frame): # 1e-6 is the minimum non-zero value for `setitimer()`. # Choose a random delay so as to improve chances of # triggering a race condition. Ideally the signal is received # when inside critical signal-handling routines such as # Py_MakePendingCalls(). signal.setitimer(signal.ITIMER_REAL, 1e-6 + random.random() * 1e-5) def second_handler(signum=None, frame=None): sigs.append(signum) # Here on Linux, SIGPROF > SIGALRM > SIGUSR1. By using both # ascending and descending sequences (SIGUSR1 then SIGALRM, # SIGPROF then SIGALRM), we maximize chances of hitting a bug. self.setsig(signal.SIGPROF, first_handler) self.setsig(signal.SIGUSR1, first_handler) self.setsig(signal.SIGALRM, second_handler) # for ITIMER_REAL expected_sigs = 0 deadline = time.monotonic() + 15.0 while expected_sigs < N: os.kill(os.getpid(), signal.SIGPROF) expected_sigs += 1 # Wait for handlers to run to avoid signal coalescing while len(sigs) < expected_sigs and time.monotonic() < deadline: time.sleep(1e-5) os.kill(os.getpid(), signal.SIGUSR1) expected_sigs += 1 while len(sigs) < expected_sigs and time.monotonic() < deadline: time.sleep(1e-5) # All ITIMER_REAL signals should have been delivered to the # Python handler self.assertEqual(len(sigs), N, "Some signals were lost") @unittest.skipUnless(hasattr(signal, "setitimer"), "test needs setitimer()") def test_stress_delivery_simultaneous(self): """ This test uses simultaneous signal handlers. """ N = self.decide_itimer_count() sigs = [] def handler(signum, frame): sigs.append(signum) self.setsig(signal.SIGUSR1, handler) self.setsig(signal.SIGALRM, handler) # for ITIMER_REAL expected_sigs = 0 deadline = time.monotonic() + 15.0 while expected_sigs < N: # Hopefully the SIGALRM will be received somewhere during # initial processing of SIGUSR1. signal.setitimer(signal.ITIMER_REAL, 1e-6 + random.random() * 1e-5) os.kill(os.getpid(), signal.SIGUSR1) expected_sigs += 2 # Wait for handlers to run to avoid signal coalescing while len(sigs) < expected_sigs and time.monotonic() < deadline: time.sleep(1e-5) # All ITIMER_REAL signals should have been delivered to the # Python handler self.assertEqual(len(sigs), N, "Some signals were lost") def tearDownModule(): support.reap_children() if __name__ == "__main__": unittest.main()