[Python-checkins] cpython: Issue #23715: signal.sigwaitinfo() and signal.sigtimedwait() are now retried
victor.stinner
python-checkins at python.org
Fri Mar 20 13:01:58 CET 2015
https://hg.python.org/cpython/rev/33a6e2587aad
changeset: 95092:33a6e2587aad
user: Victor Stinner <victor.stinner at gmail.com>
date: Fri Mar 20 12:54:28 2015 +0100
summary:
Issue #23715: signal.sigwaitinfo() and signal.sigtimedwait() are now retried
when interrupted by a signal not in the *sigset* parameter, if the signal
handler does not raise an exception. signal.sigtimedwait() recomputes the
timeout with a monotonic clock when it is retried.
Remove test_signal.test_sigwaitinfo_interrupted() because sigwaitinfo() doesn't
raise InterruptedError anymore if it is interrupted by a signal not in its
sigset parameter.
files:
Doc/library/signal.rst | 10 ++
Lib/test/eintrdata/eintr_tester.py | 38 +++++++++-
Lib/test/test_signal.py | 29 -------
Misc/NEWS | 5 +
Modules/signalmodule.c | 73 +++++++++++------
5 files changed, 99 insertions(+), 56 deletions(-)
diff --git a/Doc/library/signal.rst b/Doc/library/signal.rst
--- a/Doc/library/signal.rst
+++ b/Doc/library/signal.rst
@@ -408,6 +408,11 @@
.. versionadded:: 3.3
+ .. versionchanged:: 3.5
+ The function is now retried if interrupted by a signal not in *sigset*
+ and the signal handler does not raise an exception (see :pep:`475` for
+ the rationale).
+
.. function:: sigtimedwait(sigset, timeout)
@@ -422,6 +427,11 @@
.. versionadded:: 3.3
+ .. versionchanged:: 3.5
+ The function is now retried with the recomputed timeout if interrupted by
+ a signal not in *sigset* and the signal handler does not raise an
+ exception (see :pep:`475` for the rationale).
+
.. _signal-example:
diff --git a/Lib/test/eintrdata/eintr_tester.py b/Lib/test/eintrdata/eintr_tester.py
--- a/Lib/test/eintrdata/eintr_tester.py
+++ b/Lib/test/eintrdata/eintr_tester.py
@@ -264,11 +264,47 @@
self.assertGreaterEqual(dt, self.sleep_time)
+ at unittest.skipUnless(hasattr(signal, "setitimer"), "requires setitimer()")
+class SignalEINTRTest(EINTRBaseTest):
+ """ EINTR tests for the signal module. """
+
+ def test_sigtimedwait(self):
+ t0 = time.monotonic()
+ signal.sigtimedwait([], self.sleep_time)
+ dt = time.monotonic() - t0
+ self.assertGreaterEqual(dt, self.sleep_time)
+
+ def test_sigwaitinfo(self):
+ signum = signal.SIGUSR1
+ pid = os.getpid()
+
+ old_handler = signal.signal(signum, lambda *args: None)
+ self.addCleanup(signal.signal, signum, old_handler)
+
+ t0 = time.monotonic()
+ child_pid = os.fork()
+ if child_pid == 0:
+ # child
+ try:
+ self._sleep()
+ os.kill(pid, signum)
+ finally:
+ os._exit(0)
+ else:
+ # parent
+ signal.sigwaitinfo([signum])
+ dt = time.monotonic() - t0
+ os.waitpid(child_pid, 0)
+
+ self.assertGreaterEqual(dt, self.sleep_time)
+
+
def test_main():
support.run_unittest(
OSEINTRTest,
SocketEINTRTest,
- TimeEINTRTest)
+ TimeEINTRTest,
+ SignalEINTRTest)
if __name__ == "__main__":
diff --git a/Lib/test/test_signal.py b/Lib/test/test_signal.py
--- a/Lib/test/test_signal.py
+++ b/Lib/test/test_signal.py
@@ -936,35 +936,6 @@
signum = signal.SIGALRM
self.assertRaises(ValueError, signal.sigtimedwait, [signum], -1.0)
- @unittest.skipUnless(hasattr(signal, 'sigwaitinfo'),
- 'need signal.sigwaitinfo()')
- # Issue #18238: sigwaitinfo() can be interrupted on Linux (raises
- # InterruptedError), but not on AIX
- @unittest.skipIf(sys.platform.startswith("aix"),
- 'signal.sigwaitinfo() cannot be interrupted on AIX')
- def test_sigwaitinfo_interrupted(self):
- self.wait_helper(signal.SIGUSR1, '''
- def test(signum):
- import errno
-
- hndl_called = True
- def alarm_handler(signum, frame):
- hndl_called = False
-
- signal.signal(signal.SIGALRM, alarm_handler)
- signal.alarm(1)
- try:
- signal.sigwaitinfo([signal.SIGUSR1])
- except OSError as e:
- if e.errno == errno.EINTR:
- if not hndl_called:
- raise Exception("SIGALRM handler not called")
- else:
- raise Exception("Expected EINTR to be raised by sigwaitinfo")
- else:
- raise Exception("Expected EINTR to be raised by sigwaitinfo")
- ''')
-
@unittest.skipUnless(hasattr(signal, 'sigwait'),
'need signal.sigwait()')
@unittest.skipUnless(hasattr(signal, 'pthread_sigmask'),
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -21,6 +21,11 @@
Library
-------
+- Issue #23715: :func:`signal.sigwaitinfo` and :func:`signal.sigtimedwait` are
+ now retried when interrupted by a signal not in the *sigset* parameter, if
+ the signal handler does not raise an exception. signal.sigtimedwait()
+ recomputes the timeout with a monotonic clock when it is retried.
+
- Issue #23001: Few functions in modules mmap, ossaudiodev, socket, ssl, and
codecs, that accepted only read-only bytes-like object now accept writable
bytes-like object too.
diff --git a/Modules/signalmodule.c b/Modules/signalmodule.c
--- a/Modules/signalmodule.c
+++ b/Modules/signalmodule.c
@@ -934,6 +934,7 @@
sigset_t set;
siginfo_t si;
int err;
+ int async_err = 0;
if (!PyArg_ParseTuple(args, "O:sigwaitinfo", &signals))
return NULL;
@@ -941,11 +942,14 @@
if (iterable_to_sigset(signals, &set))
return NULL;
- Py_BEGIN_ALLOW_THREADS
- err = sigwaitinfo(&set, &si);
- Py_END_ALLOW_THREADS
+ do {
+ Py_BEGIN_ALLOW_THREADS
+ err = sigwaitinfo(&set, &si);
+ Py_END_ALLOW_THREADS
+ } while (err == -1
+ && errno == EINTR && !(async_err = PyErr_CheckSignals()));
if (err == -1)
- return PyErr_SetFromErrno(PyExc_OSError);
+ return (!async_err) ? PyErr_SetFromErrno(PyExc_OSError) : NULL;
return fill_siginfo(&si);
}
@@ -962,25 +966,19 @@
static PyObject *
signal_sigtimedwait(PyObject *self, PyObject *args)
{
- PyObject *signals, *timeout;
- struct timespec buf;
+ PyObject *signals;
+ double timeout, frac;
+ struct timespec ts;
sigset_t set;
siginfo_t si;
- time_t tv_sec;
- long tv_nsec;
- int err;
+ int res;
+ _PyTime_timeval deadline, monotonic;
- if (!PyArg_ParseTuple(args, "OO:sigtimedwait",
+ if (!PyArg_ParseTuple(args, "Od:sigtimedwait",
&signals, &timeout))
return NULL;
- if (_PyTime_ObjectToTimespec(timeout, &tv_sec, &tv_nsec,
- _PyTime_ROUND_DOWN) == -1)
- return NULL;
- buf.tv_sec = tv_sec;
- buf.tv_nsec = tv_nsec;
-
- if (buf.tv_sec < 0 || buf.tv_nsec < 0) {
+ if (timeout < 0) {
PyErr_SetString(PyExc_ValueError, "timeout must be non-negative");
return NULL;
}
@@ -988,15 +986,38 @@
if (iterable_to_sigset(signals, &set))
return NULL;
- Py_BEGIN_ALLOW_THREADS
- err = sigtimedwait(&set, &si, &buf);
- Py_END_ALLOW_THREADS
- if (err == -1) {
- if (errno == EAGAIN)
- Py_RETURN_NONE;
- else
- return PyErr_SetFromErrno(PyExc_OSError);
- }
+ _PyTime_monotonic(&deadline);
+ _PyTime_AddDouble(&deadline, timeout, _PyTime_ROUND_UP);
+
+ do {
+ frac = fmod(timeout, 1.0);
+ timeout = floor(timeout);
+ ts.tv_sec = (long)timeout;
+ ts.tv_nsec = (long)(frac*1e9);
+
+ Py_BEGIN_ALLOW_THREADS
+ res = sigtimedwait(&set, &si, &ts);
+ Py_END_ALLOW_THREADS
+
+ if (res != -1)
+ break;
+
+ if (errno != EINTR) {
+ if (errno == EAGAIN)
+ Py_RETURN_NONE;
+ else
+ return PyErr_SetFromErrno(PyExc_OSError);
+ }
+
+ /* sigtimedwait() was interrupted by a signal (EINTR) */
+ if (PyErr_CheckSignals())
+ return NULL;
+
+ _PyTime_monotonic(&monotonic);
+ timeout = _PyTime_INTERVAL(monotonic, deadline);
+ if (timeout <= 0.0)
+ break;
+ } while (1);
return fill_siginfo(&si);
}
--
Repository URL: https://hg.python.org/cpython
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