[Python-checkins] cpython: Issue #23485: select.poll.poll() is now retried when interrupted by a signal
victor.stinner
python-checkins at python.org
Mon Mar 30 22:15:59 CEST 2015
https://hg.python.org/cpython/rev/69b1683ee001
changeset: 95307:69b1683ee001
user: Victor Stinner <victor.stinner at gmail.com>
date: Mon Mar 30 21:38:00 2015 +0200
summary:
Issue #23485: select.poll.poll() is now retried when interrupted by a signal
files:
Doc/library/select.rst | 6 +
Doc/whatsnew/3.5.rst | 2 +-
Lib/asyncore.py | 6 +-
Lib/selectors.py | 7 +-
Lib/test/eintrdata/eintr_tester.py | 20 ++-
Modules/selectmodule.c | 131 ++++++++++------
6 files changed, 111 insertions(+), 61 deletions(-)
diff --git a/Doc/library/select.rst b/Doc/library/select.rst
--- a/Doc/library/select.rst
+++ b/Doc/library/select.rst
@@ -408,6 +408,12 @@
returning. If *timeout* is omitted, negative, or :const:`None`, the call will
block until there is an event for this poll object.
+ .. versionchanged:: 3.5
+ The function is now retried with a recomputed timeout when interrupted by
+ a signal, except if the signal handler raises an exception (see
+ :pep:`475` for the rationale), instead of raising
+ :exc:`InterruptedError`.
+
.. _kqueue-objects:
diff --git a/Doc/whatsnew/3.5.rst b/Doc/whatsnew/3.5.rst
--- a/Doc/whatsnew/3.5.rst
+++ b/Doc/whatsnew/3.5.rst
@@ -621,7 +621,7 @@
- :func:`os.open`, :func:`open`
- :func:`os.read`, :func:`os.write`
- - :func:`select.select`
+ - :func:`select.select`, :func:`select.poll.poll`
- :func:`time.sleep`
* Before Python 3.5, a :class:`datetime.time` object was considered to be false
diff --git a/Lib/asyncore.py b/Lib/asyncore.py
--- a/Lib/asyncore.py
+++ b/Lib/asyncore.py
@@ -179,10 +179,8 @@
flags |= select.POLLOUT
if flags:
pollster.register(fd, flags)
- try:
- r = pollster.poll(timeout)
- except InterruptedError:
- r = []
+
+ r = pollster.poll(timeout)
for fd, flags in r:
obj = map.get(fd)
if obj is None:
diff --git a/Lib/selectors.py b/Lib/selectors.py
--- a/Lib/selectors.py
+++ b/Lib/selectors.py
@@ -359,11 +359,10 @@
# poll() has a resolution of 1 millisecond, round away from
# zero to wait *at least* timeout seconds.
timeout = math.ceil(timeout * 1e3)
+
+ fd_event_list = self._poll.poll(timeout)
+
ready = []
- try:
- fd_event_list = self._poll.poll(timeout)
- except InterruptedError:
- return ready
for fd, event in fd_event_list:
events = 0
if event & ~select.POLLIN:
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
@@ -38,8 +38,12 @@
cls.signal_period)
@classmethod
+ def stop_alarm(cls):
+ signal.setitimer(signal.ITIMER_REAL, 0, 0)
+
+ @classmethod
def tearDownClass(cls):
- signal.setitimer(signal.ITIMER_REAL, 0, 0)
+ cls.stop_alarm()
signal.signal(signal.SIGALRM, cls.orig_handler)
@classmethod
@@ -260,7 +264,7 @@
def test_sleep(self):
t0 = time.monotonic()
time.sleep(self.sleep_time)
- signal.alarm(0)
+ self.stop_alarm()
dt = time.monotonic() - t0
self.assertGreaterEqual(dt, self.sleep_time)
@@ -311,7 +315,17 @@
def test_select(self):
t0 = time.monotonic()
select.select([], [], [], self.sleep_time)
- signal.alarm(0)
+ self.stop_alarm()
+ dt = time.monotonic() - t0
+ self.assertGreaterEqual(dt, self.sleep_time)
+
+ @unittest.skipUnless(hasattr(select, 'poll'), 'need select.poll')
+ def test_poll(self):
+ poller = select.poll()
+
+ t0 = time.monotonic()
+ poller.poll(self.sleep_time * 1e3)
+ self.stop_alarm()
dt = time.monotonic() - t0
self.assertGreaterEqual(dt, self.sleep_time)
diff --git a/Modules/selectmodule.c b/Modules/selectmodule.c
--- a/Modules/selectmodule.c
+++ b/Modules/selectmodule.c
@@ -279,6 +279,7 @@
break;
}
_PyTime_AsTimeval_noraise(timeout, &tv, _PyTime_ROUND_CEILING);
+ /* retry select() with the recomputed timeout */
}
} while (1);
@@ -520,30 +521,39 @@
static PyObject *
poll_poll(pollObject *self, PyObject *args)
{
- PyObject *result_list = NULL, *tout = NULL;
- int timeout = 0, poll_result, i, j;
+ PyObject *result_list = NULL, *timeout_obj = NULL;
+ int poll_result, i, j;
PyObject *value = NULL, *num = NULL;
+ _PyTime_t timeout, ms, deadline;
+ int async_err = 0;
- if (!PyArg_UnpackTuple(args, "poll", 0, 1, &tout)) {
+ if (!PyArg_ParseTuple(args, "|O:poll", &timeout_obj)) {
return NULL;
}
/* Check values for timeout */
- if (tout == NULL || tout == Py_None)
+ if (timeout_obj == NULL || timeout_obj == Py_None) {
timeout = -1;
- else if (!PyNumber_Check(tout)) {
- PyErr_SetString(PyExc_TypeError,
- "timeout must be an integer or None");
- return NULL;
+ ms = -1;
+ deadline = 0;
}
else {
- tout = PyNumber_Long(tout);
- if (!tout)
+ if (_PyTime_FromMillisecondsObject(&timeout, timeout_obj,
+ _PyTime_ROUND_CEILING) < 0) {
+ if (PyErr_ExceptionMatches(PyExc_TypeError)) {
+ PyErr_SetString(PyExc_TypeError,
+ "timeout must be an integer or None");
+ }
return NULL;
- timeout = _PyLong_AsInt(tout);
- Py_DECREF(tout);
- if (timeout == -1 && PyErr_Occurred())
+ }
+
+ ms = _PyTime_AsMilliseconds(timeout, _PyTime_ROUND_CEILING);
+ if (ms < INT_MIN || ms > INT_MAX) {
+ PyErr_SetString(PyExc_OverflowError, "timeout is too large");
return NULL;
+ }
+
+ deadline = _PyTime_GetMonotonicClock() + timeout;
}
/* Avoid concurrent poll() invocation, issue 8865 */
@@ -561,14 +571,38 @@
self->poll_running = 1;
/* call poll() */
- Py_BEGIN_ALLOW_THREADS
- poll_result = poll(self->ufds, self->ufd_len, timeout);
- Py_END_ALLOW_THREADS
+ async_err = 0;
+ do {
+ Py_BEGIN_ALLOW_THREADS
+ errno = 0;
+ poll_result = poll(self->ufds, self->ufd_len, (int)ms);
+ Py_END_ALLOW_THREADS
+
+ if (errno != EINTR)
+ break;
+
+ /* poll() was interrupted by a signal */
+ if (PyErr_CheckSignals()) {
+ async_err = 1;
+ break;
+ }
+
+ if (timeout >= 0) {
+ timeout = deadline - _PyTime_GetMonotonicClock();
+ if (timeout < 0) {
+ poll_result = 0;
+ break;
+ }
+ ms = _PyTime_AsMilliseconds(timeout, _PyTime_ROUND_CEILING);
+ /* retry poll() with the recomputed timeout */
+ }
+ } while (1);
self->poll_running = 0;
if (poll_result < 0) {
- PyErr_SetFromErrno(PyExc_OSError);
+ if (!async_err)
+ PyErr_SetFromErrno(PyExc_OSError);
return NULL;
}
@@ -577,41 +611,40 @@
result_list = PyList_New(poll_result);
if (!result_list)
return NULL;
- else {
- for (i = 0, j = 0; j < poll_result; j++) {
- /* skip to the next fired descriptor */
- while (!self->ufds[i].revents) {
- i++;
- }
- /* if we hit a NULL return, set value to NULL
- and break out of loop; code at end will
- clean up result_list */
- value = PyTuple_New(2);
- if (value == NULL)
- goto error;
- num = PyLong_FromLong(self->ufds[i].fd);
- if (num == NULL) {
- Py_DECREF(value);
- goto error;
- }
- PyTuple_SET_ITEM(value, 0, num);
- /* The &0xffff is a workaround for AIX. 'revents'
- is a 16-bit short, and IBM assigned POLLNVAL
- to be 0x8000, so the conversion to int results
- in a negative number. See SF bug #923315. */
- num = PyLong_FromLong(self->ufds[i].revents & 0xffff);
- if (num == NULL) {
- Py_DECREF(value);
- goto error;
- }
- PyTuple_SET_ITEM(value, 1, num);
- if ((PyList_SetItem(result_list, j, value)) == -1) {
- Py_DECREF(value);
- goto error;
- }
+ for (i = 0, j = 0; j < poll_result; j++) {
+ /* skip to the next fired descriptor */
+ while (!self->ufds[i].revents) {
i++;
}
+ /* if we hit a NULL return, set value to NULL
+ and break out of loop; code at end will
+ clean up result_list */
+ value = PyTuple_New(2);
+ if (value == NULL)
+ goto error;
+ num = PyLong_FromLong(self->ufds[i].fd);
+ if (num == NULL) {
+ Py_DECREF(value);
+ goto error;
+ }
+ PyTuple_SET_ITEM(value, 0, num);
+
+ /* The &0xffff is a workaround for AIX. 'revents'
+ is a 16-bit short, and IBM assigned POLLNVAL
+ to be 0x8000, so the conversion to int results
+ in a negative number. See SF bug #923315. */
+ num = PyLong_FromLong(self->ufds[i].revents & 0xffff);
+ if (num == NULL) {
+ Py_DECREF(value);
+ goto error;
+ }
+ PyTuple_SET_ITEM(value, 1, num);
+ if ((PyList_SetItem(result_list, j, value)) == -1) {
+ Py_DECREF(value);
+ goto error;
+ }
+ i++;
}
return result_list;
--
Repository URL: https://hg.python.org/cpython
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