cpython/Lib/test/test_signal.py

1181 lines
40 KiB
Python

import os
import random
import signal
import socket
import statistics
import subprocess
import sys
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()