import enum import errno import functools import inspect 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 import ( is_apple, is_apple_mobile, os_helper, threading_helper ) 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") CheckedSignals = enum._old_convert_( enum.IntEnum, 'Signals', 'signal', lambda name: name.isupper() and (name.startswith('SIG') and not name.startswith('SIG_')) or name.startswith('CTRL_'), source=signal, ) enum._test_simple_enum(CheckedSignals, signal.Signals) CheckedHandlers = enum._old_convert_( enum.IntEnum, 'Handlers', 'signal', lambda name: name in ('SIG_DFL', 'SIG_IGN'), source=signal, ) enum._test_simple_enum(CheckedHandlers, signal.Handlers) Sigmasks = getattr(signal, 'Sigmasks', None) if Sigmasks is not None: CheckedSigmasks = enum._old_convert_( enum.IntEnum, 'Sigmasks', 'signal', lambda name: name in ('SIG_BLOCK', 'SIG_UNBLOCK', 'SIG_SETMASK'), source=signal, ) enum._test_simple_enum(CheckedSigmasks, Sigmasks) def test_functions_module_attr(self): # Issue #27718: If __all__ is not defined all non-builtin functions # should have correct __module__ to be displayed by pydoc. for name in dir(signal): value = getattr(signal, name) if inspect.isroutine(value) and not inspect.isbuiltin(value): self.assertEqual(value.__module__, 'signal') @unittest.skipIf(sys.platform == "win32", "Not valid on Windows") class PosixTests(unittest.TestCase): def trivial_signal_handler(self, *args): pass def create_handler_with_partial(self, argument): return functools.partial(self.trivial_signal_handler, argument) 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) self.assertRaises(ValueError, signal.strsignal, 4242) 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) def test_no_repr_is_called_on_signal_handler(self): # See https://github.com/python/cpython/issues/112559. class MyArgument: def __init__(self): self.repr_count = 0 def __repr__(self): self.repr_count += 1 return super().__repr__() argument = MyArgument() self.assertEqual(0, argument.repr_count) handler = self.create_handler_with_partial(argument) hup = signal.signal(signal.SIGHUP, handler) self.assertIsInstance(hup, signal.Handlers) self.assertEqual(signal.getsignal(signal.SIGHUP), handler) signal.signal(signal.SIGHUP, hup) self.assertEqual(signal.getsignal(signal.SIGHUP), hup) self.assertEqual(0, argument.repr_count) def test_strsignal(self): self.assertIn("Interrupt", signal.strsignal(signal.SIGINT)) self.assertIn("Terminated", signal.strsignal(signal.SIGTERM)) self.assertIn("Hangup", signal.strsignal(signal.SIGHUP)) # 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( hasattr(signal, "valid_signals"), "requires signal.valid_signals" ) def test_valid_signals(self): s = signal.valid_signals() self.assertIsInstance(s, set) self.assertIn(signal.Signals.SIGINT, s) self.assertIn(signal.Signals.SIGALRM, s) self.assertNotIn(0, s) self.assertNotIn(signal.NSIG, s) self.assertLess(len(s), signal.NSIG) # gh-91145: Make sure that all SIGxxx constants exposed by the Python # signal module have a number in the [0; signal.NSIG-1] range. for name in dir(signal): if not name.startswith("SIG"): continue if name in {"SIG_IGN", "SIG_DFL"}: # SIG_IGN and SIG_DFL are pointers continue with self.subTest(name=name): signum = getattr(signal, name) self.assertGreaterEqual(signum, 0) self.assertLess(signum, signal.NSIG) @unittest.skipUnless(sys.executable, "sys.executable required.") @support.requires_subprocess() def test_keyboard_interrupt_exit_code(self): """KeyboardInterrupt triggers exit via SIGINT.""" process = subprocess.run( [sys.executable, "-c", "import os, signal, time\n" "os.kill(os.getpid(), signal.SIGINT)\n" "for _ in range(999): time.sleep(0.01)"], stderr=subprocess.PIPE) self.assertIn(b"KeyboardInterrupt", process.stderr) self.assertEqual(process.returncode, -signal.SIGINT) # Caveat: The exit code is insufficient to guarantee we actually died # via a signal. POSIX shells do more than look at the 8 bit value. # Writing an automation friendly test of an interactive shell # to confirm that our process died via a SIGINT proved too complex. @unittest.skipUnless(sys.platform == "win32", "Windows specific") class WindowsSignalTests(unittest.TestCase): def test_valid_signals(self): s = signal.valid_signals() self.assertIsInstance(s, set) self.assertGreaterEqual(len(s), 6) self.assertIn(signal.Signals.SIGINT, s) self.assertNotIn(0, s) self.assertNotIn(signal.NSIG, s) self.assertLess(len(s), signal.NSIG) 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) @unittest.skipUnless(sys.executable, "sys.executable required.") @support.requires_subprocess() def test_keyboard_interrupt_exit_code(self): """KeyboardInterrupt triggers an exit using STATUS_CONTROL_C_EXIT.""" # We don't test via os.kill(os.getpid(), signal.CTRL_C_EVENT) here # as that requires setting up a console control handler in a child # in its own process group. Doable, but quite complicated. (see # @eryksun on https://github.com/python/cpython/pull/11862) process = subprocess.run( [sys.executable, "-c", "raise KeyboardInterrupt"], stderr=subprocess.PIPE) self.assertIn(b"KeyboardInterrupt", process.stderr) STATUS_CONTROL_C_EXIT = 0xC000013A self.assertEqual(process.returncode, STATUS_CONTROL_C_EXIT) 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 = os_helper.make_bad_fd() self.assertRaises((ValueError, OSError), signal.set_wakeup_fd, fd) @unittest.skipUnless(support.has_socket_support, "needs working sockets.") def test_invalid_socket(self): sock = socket.socket() fd = sock.fileno() sock.close() self.assertRaises((ValueError, OSError), signal.set_wakeup_fd, fd) # Emscripten does not support fstat on pipes yet. # https://github.com/emscripten-core/emscripten/issues/16414 @unittest.skipIf(support.is_emscripten, "Emscripten cannot fstat pipes.") @unittest.skipUnless(hasattr(os, "pipe"), "requires os.pipe()") 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) @unittest.skipIf(support.is_emscripten, "Emscripten cannot fstat pipes.") @unittest.skipUnless(support.has_socket_support, "needs working sockets.") 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") @unittest.skipIf(support.is_emscripten, "Emscripten cannot fstat pipes.") @unittest.skipUnless(hasattr(os, "pipe"), "requires os.pipe()") 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') @unittest.skipUnless(hasattr(os, "pipe"), "requires os.pipe()") 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: signal.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(): signal.signal(signal.SIGUSR1, handler) signal.raise_signal(signal.SIGUSR1) signal.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)) signal.raise_signal(signum1) signal.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()) signal.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: signal.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) written = 0 if sys.platform == "vxworks": CHUNK_SIZES = (1,) else: # Start with large chunk size to reduce the # number of send needed to fill the buffer. CHUNK_SIZES = (2 ** 16, 2 ** 8, 1) for chunk_size in CHUNK_SIZES: chunk = b"x" * chunk_size try: while True: write.send(chunk) written += chunk_size except (BlockingIOError, TimeoutError): 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: signal.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: signal.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: signal.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: signal.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") @unittest.skipUnless(hasattr(signal, 'siginterrupt'), "needs signal.siginterrupt()") @support.requires_subprocess() @unittest.skipUnless(hasattr(os, "pipe"), "requires os.pipe()") class SiginterruptTest(unittest.TestCase): def readpipe_interrupted(self, interrupt, timeout=support.SHORT_TIMEOUT): """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=timeout) 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) @support.requires_resource('walltime') 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, timeout=2) self.assertFalse(interrupted) @unittest.skipIf(sys.platform == "win32", "Not valid on Windows") @unittest.skipUnless(hasattr(signal, 'getitimer') and hasattr(signal, 'setitimer'), "needs signal.getitimer() and signal.setitimer()") 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',) or is_apple_mobile, '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) for _ in support.busy_retry(support.LONG_TIMEOUT): # use up some virtual time by doing real work _ = pow(12345, 67890, 10000019) if signal.getitimer(self.itimer) == (0.0, 0.0): # sig_vtalrm handler stopped this itimer break # 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) for _ in support.busy_retry(support.LONG_TIMEOUT): # do some work _ = pow(12345, 67890, 10000019) if signal.getitimer(self.itimer) == (0.0, 0.0): # sig_prof handler stopped this itimer break # 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()') @threading_helper.requires_working_threading() 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()') @threading_helper.requires_working_threading() 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, []) with self.assertRaises(ValueError): signal.pthread_sigmask(signal.SIG_BLOCK, [signal.NSIG]) with self.assertRaises(ValueError): signal.pthread_sigmask(signal.SIG_BLOCK, [0]) with self.assertRaises(ValueError): signal.pthread_sigmask(signal.SIG_BLOCK, [1<<1000]) @unittest.skipUnless(hasattr(signal, 'pthread_sigmask'), 'need signal.pthread_sigmask()') def test_pthread_sigmask_valid_signals(self): s = signal.pthread_sigmask(signal.SIG_BLOCK, signal.valid_signals()) self.addCleanup(signal.pthread_sigmask, signal.SIG_SETMASK, s) # Get current blocked set s = signal.pthread_sigmask(signal.SIG_UNBLOCK, signal.valid_signals()) self.assertLessEqual(s, signal.valid_signals()) @unittest.skipUnless(hasattr(signal, 'pthread_sigmask'), 'need signal.pthread_sigmask()') @threading_helper.requires_working_threading() 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()') @threading_helper.requires_working_threading() 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() + support.SHORT_TIMEOUT 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 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 for _ in support.sleeping_retry(support.SHORT_TIMEOUT): if len(sigs) >= expected_sigs: break # All ITIMER_REAL signals should have been delivered to the # Python handler self.assertEqual(len(sigs), N, "Some signals were lost") @support.requires_gil_enabled("gh-121065: test is flaky on free-threaded build") @unittest.skipIf(is_apple, "crashes due to system bug (FB13453490)") @unittest.skipUnless(hasattr(signal, "SIGUSR1"), "test needs SIGUSR1") @threading_helper.requires_working_threading() def test_stress_modifying_handlers(self): # bpo-43406: race condition between trip_signal() and signal.signal signum = signal.SIGUSR1 num_sent_signals = 0 num_received_signals = 0 do_stop = False def custom_handler(signum, frame): nonlocal num_received_signals num_received_signals += 1 def set_interrupts(): nonlocal num_sent_signals while not do_stop: signal.raise_signal(signum) num_sent_signals += 1 def cycle_handlers(): while num_sent_signals < 100 or num_received_signals < 1: for i in range(20000): # Cycle between a Python-defined and a non-Python handler for handler in [custom_handler, signal.SIG_IGN]: signal.signal(signum, handler) old_handler = signal.signal(signum, custom_handler) self.addCleanup(signal.signal, signum, old_handler) t = threading.Thread(target=set_interrupts) try: ignored = False with support.catch_unraisable_exception() as cm: t.start() cycle_handlers() do_stop = True t.join() if cm.unraisable is not None: # An unraisable exception may be printed out when # a signal is ignored due to the aforementioned # race condition, check it. self.assertIsInstance(cm.unraisable.exc_value, OSError) self.assertIn( f"Signal {signum:d} ignored due to race condition", str(cm.unraisable.exc_value)) ignored = True # bpo-43406: Even if it is unlikely, it's technically possible that # all signals were ignored because of race conditions. if not ignored: # Sanity check that some signals were received, but not all self.assertGreater(num_received_signals, 0) self.assertLessEqual(num_received_signals, num_sent_signals) finally: do_stop = True t.join() class RaiseSignalTest(unittest.TestCase): def test_sigint(self): with self.assertRaises(KeyboardInterrupt): signal.raise_signal(signal.SIGINT) @unittest.skipIf(sys.platform != "win32", "Windows specific test") def test_invalid_argument(self): try: SIGHUP = 1 # not supported on win32 signal.raise_signal(SIGHUP) self.fail("OSError (Invalid argument) expected") except OSError as e: if e.errno == errno.EINVAL: pass else: raise def test_handler(self): is_ok = False def handler(a, b): nonlocal is_ok is_ok = True old_signal = signal.signal(signal.SIGINT, handler) self.addCleanup(signal.signal, signal.SIGINT, old_signal) signal.raise_signal(signal.SIGINT) self.assertTrue(is_ok) def test__thread_interrupt_main(self): # See https://github.com/python/cpython/issues/102397 code = """if 1: import _thread class Foo(): def __del__(self): _thread.interrupt_main() x = Foo() """ rc, out, err = assert_python_ok('-c', code) self.assertIn(b'OSError: Signal 2 ignored due to race condition', err) class PidfdSignalTest(unittest.TestCase): @unittest.skipUnless( hasattr(signal, "pidfd_send_signal"), "pidfd support not built in", ) def test_pidfd_send_signal(self): with self.assertRaises(OSError) as cm: signal.pidfd_send_signal(0, signal.SIGINT) if cm.exception.errno == errno.ENOSYS: self.skipTest("kernel does not support pidfds") elif cm.exception.errno == errno.EPERM: self.skipTest("Not enough privileges to use pidfs") self.assertEqual(cm.exception.errno, errno.EBADF) my_pidfd = os.open(f'/proc/{os.getpid()}', os.O_DIRECTORY) self.addCleanup(os.close, my_pidfd) with self.assertRaisesRegex(TypeError, "^siginfo must be None$"): signal.pidfd_send_signal(my_pidfd, signal.SIGINT, object(), 0) with self.assertRaises(KeyboardInterrupt): signal.pidfd_send_signal(my_pidfd, signal.SIGINT) def tearDownModule(): support.reap_children() if __name__ == "__main__": unittest.main()