Issue #23485: select.epoll.poll() is now retried when interrupted by a signal

This commit is contained in:
Victor Stinner 2015-03-30 21:59:21 +02:00
parent 3c7d6e0693
commit 41eba224de
5 changed files with 71 additions and 23 deletions

View File

@ -329,6 +329,12 @@ Edge and Level Trigger Polling (epoll) Objects
Wait for events. timeout in seconds (float)
.. 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`.
.. _poll-objects:

View File

@ -621,7 +621,7 @@ Changes in the Python API
- :func:`os.open`, :func:`open`
- :func:`os.read`, :func:`os.write`
- :func:`select.select`, :func:`select.poll.poll`
- :func:`select.select`, :func:`select.poll.poll`, :func:`select.epoll.poll`
- :func:`time.sleep`
* Before Python 3.5, a :class:`datetime.time` object was considered to be false

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@ -423,11 +423,9 @@ if hasattr(select, 'epoll'):
# FD is registered.
max_ev = max(len(self._fd_to_key), 1)
fd_event_list = self._epoll.poll(timeout, max_ev)
ready = []
try:
fd_event_list = self._epoll.poll(timeout, max_ev)
except InterruptedError:
return ready
for fd, event in fd_event_list:
events = 0
if event & ~select.EPOLLIN:

View File

@ -329,6 +329,17 @@ class SelectEINTRTest(EINTRBaseTest):
dt = time.monotonic() - t0
self.assertGreaterEqual(dt, self.sleep_time)
@unittest.skipUnless(hasattr(select, 'epoll'), 'need select.epoll')
def test_epoll(self):
poller = select.epoll()
self.addCleanup(poller.close)
t0 = time.monotonic()
poller.poll(self.sleep_time)
self.stop_alarm()
dt = time.monotonic() - t0
self.assertGreaterEqual(dt, self.sleep_time)
def test_main():
support.run_unittest(

View File

@ -535,7 +535,7 @@ poll_poll(pollObject *self, PyObject *args)
if (timeout_obj == NULL || timeout_obj == Py_None) {
timeout = -1;
ms = -1;
deadline = 0;
deadline = 0; /* initialize to prevent gcc warning */
}
else {
if (_PyTime_FromMillisecondsObject(&timeout, timeout_obj,
@ -1465,34 +1465,46 @@ fd is the target file descriptor of the operation.");
static PyObject *
pyepoll_poll(pyEpoll_Object *self, PyObject *args, PyObject *kwds)
{
double dtimeout = -1.;
int timeout;
static char *kwlist[] = {"timeout", "maxevents", NULL};
PyObject *timeout_obj = NULL;
int maxevents = -1;
int nfds, i;
PyObject *elist = NULL, *etuple = NULL;
struct epoll_event *evs = NULL;
static char *kwlist[] = {"timeout", "maxevents", NULL};
_PyTime_t timeout, ms, deadline;
if (self->epfd < 0)
return pyepoll_err_closed();
if (!PyArg_ParseTupleAndKeywords(args, kwds, "|di:poll", kwlist,
&dtimeout, &maxevents)) {
if (!PyArg_ParseTupleAndKeywords(args, kwds, "|Oi:poll", kwlist,
&timeout_obj, &maxevents)) {
return NULL;
}
if (dtimeout < 0) {
if (timeout_obj == NULL || timeout_obj == Py_None) {
timeout = -1;
}
else if (dtimeout * 1000.0 > INT_MAX) {
PyErr_SetString(PyExc_OverflowError,
"timeout is too large");
return NULL;
ms = -1;
deadline = 0; /* initialize to prevent gcc warning */
}
else {
/* epoll_wait() has a resolution of 1 millisecond, round away from zero
to wait *at least* dtimeout seconds. */
timeout = (int)ceil(dtimeout * 1000.0);
/* epoll_wait() has a resolution of 1 millisecond, round towards
infinity to wait at least timeout seconds. */
if (_PyTime_FromSecondsObject(&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;
}
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;
}
if (maxevents == -1) {
@ -1511,9 +1523,30 @@ pyepoll_poll(pyEpoll_Object *self, PyObject *args, PyObject *kwds)
return NULL;
}
Py_BEGIN_ALLOW_THREADS
nfds = epoll_wait(self->epfd, evs, maxevents, timeout);
Py_END_ALLOW_THREADS
do {
Py_BEGIN_ALLOW_THREADS
errno = 0;
nfds = epoll_wait(self->epfd, evs, maxevents, (int)ms);
Py_END_ALLOW_THREADS
if (errno != EINTR)
break;
/* poll() was interrupted by a signal */
if (PyErr_CheckSignals())
goto error;
if (timeout >= 0) {
timeout = deadline - _PyTime_GetMonotonicClock();
if (timeout < 0) {
nfds = 0;
break;
}
ms = _PyTime_AsMilliseconds(timeout, _PyTime_ROUND_CEILING);
/* retry epoll_wait() with the recomputed timeout */
}
} while(1);
if (nfds < 0) {
PyErr_SetFromErrno(PyExc_OSError);
goto error;