diff options
| -rw-r--r-- | Doc/library/errno.rst | 5 | ||||
| -rw-r--r-- | Doc/library/exceptions.rst | 7 | ||||
| -rw-r--r-- | Doc/library/select.rst | 7 | ||||
| -rw-r--r-- | Doc/whatsnew/3.5.rst | 14 | ||||
| -rw-r--r-- | Lib/asyncore.py | 5 | ||||
| -rw-r--r-- | Lib/selectors.py | 5 | ||||
| -rw-r--r-- | Lib/test/eintrdata/eintr_tester.py | 16 | ||||
| -rw-r--r-- | Misc/NEWS | 4 | ||||
| -rw-r--r-- | Modules/selectmodule.c | 53 |
9 files changed, 85 insertions, 31 deletions
diff --git a/Doc/library/errno.rst b/Doc/library/errno.rst index d2163b6..22a5cbc 100644 --- a/Doc/library/errno.rst +++ b/Doc/library/errno.rst @@ -41,7 +41,10 @@ defined by the module. The specific list of defined symbols is available as .. data:: EINTR - Interrupted system call + Interrupted system call. + + .. seealso:: + This error is mapped to the exception :exc:`InterruptedError`. .. data:: EIO diff --git a/Doc/library/exceptions.rst b/Doc/library/exceptions.rst index 271a5c8..bddd0ed 100644 --- a/Doc/library/exceptions.rst +++ b/Doc/library/exceptions.rst @@ -536,7 +536,12 @@ depending on the system error code. .. exception:: InterruptedError Raised when a system call is interrupted by an incoming signal. - Corresponds to :c:data:`errno` ``EINTR``. + Corresponds to :c:data:`errno` :py:data:`~errno.EINTR`. + + .. versionchanged:: 3.5 + Python now retries system calls when a syscall is interrupted by a + signal, except if the signal handler raises an exception (see :pep:`475` + for the rationale), instead of raising :exc:`InterruptedError`. .. exception:: IsADirectoryError diff --git a/Doc/library/select.rst b/Doc/library/select.rst index 5334af8..7fe09cb 100644 --- a/Doc/library/select.rst +++ b/Doc/library/select.rst @@ -145,6 +145,13 @@ The module defines the following: library, and does not handle file descriptors that don't originate from WinSock. + .. 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`. + + .. attribute:: PIPE_BUF The minimum number of bytes which can be written without blocking to a pipe diff --git a/Doc/whatsnew/3.5.rst b/Doc/whatsnew/3.5.rst index d33dfe8..3f70a94 100644 --- a/Doc/whatsnew/3.5.rst +++ b/Doc/whatsnew/3.5.rst @@ -173,9 +173,10 @@ PEP and implementation written by Ben Hoyt with the help of Victor Stinner. PEP 475: Retry system calls failing with EINTR ---------------------------------------------- -:pep:`475` adds support for automatic retry of system calls failing with EINTR: -this means that user code doesn't have to deal with EINTR or InterruptedError -manually, and should make it more robust against asynchronous signal reception. +:pep:`475` adds support for automatic retry of system calls failing with +:py:data:`~errno.EINTR`: this means that user code doesn't have to deal with +EINTR or :exc:`InterruptedError` manually, and should make it more robust +against asynchronous signal reception. .. seealso:: @@ -614,12 +615,13 @@ that may require changes to your code. Changes in the Python API ------------------------- -* :pep:`475`: the following functions are now retried when interrupted instead - of raising :exc:`InterruptedError` if the signal handler does not raise - an exception: +* :pep:`475`: Examples of functions which are now retried when interrupted + instead of raising :exc:`InterruptedError` if the signal handler does not + raise an exception: - :func:`os.open`, :func:`open` - :func:`os.read`, :func:`os.write` + - :func:`select.select` - :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 index 68efd45..5578dda 100644 --- a/Lib/asyncore.py +++ b/Lib/asyncore.py @@ -141,10 +141,7 @@ def poll(timeout=0.0, map=None): time.sleep(timeout) return - try: - r, w, e = select.select(r, w, e, timeout) - except InterruptedError: - return + r, w, e = select.select(r, w, e, timeout) for fd in r: obj = map.get(fd) diff --git a/Lib/selectors.py b/Lib/selectors.py index 6d569c3..4f2a377 100644 --- a/Lib/selectors.py +++ b/Lib/selectors.py @@ -310,10 +310,7 @@ class SelectSelector(_BaseSelectorImpl): def select(self, timeout=None): timeout = None if timeout is None else max(timeout, 0) ready = [] - try: - r, w, _ = self._select(self._readers, self._writers, [], timeout) - except InterruptedError: - return ready + r, w, _ = self._select(self._readers, self._writers, [], timeout) r = set(r) w = set(w) for fd in r | w: diff --git a/Lib/test/eintrdata/eintr_tester.py b/Lib/test/eintrdata/eintr_tester.py index ba056fb..82cef83 100644 --- a/Lib/test/eintrdata/eintr_tester.py +++ b/Lib/test/eintrdata/eintr_tester.py @@ -10,6 +10,7 @@ sub-second periodicity (contrarily to signal()). import io import os +import select import signal import socket import time @@ -303,12 +304,25 @@ class SignalEINTRTest(EINTRBaseTest): self.assertGreaterEqual(dt, self.sleep_time) +@unittest.skipUnless(hasattr(signal, "setitimer"), "requires setitimer()") +class SelectEINTRTest(EINTRBaseTest): + """ EINTR tests for the select module. """ + + def test_select(self): + t0 = time.monotonic() + select.select([], [], [], self.sleep_time) + signal.alarm(0) + dt = time.monotonic() - t0 + self.assertGreaterEqual(dt, self.sleep_time) + + def test_main(): support.run_unittest( OSEINTRTest, SocketEINTRTest, TimeEINTRTest, - SignalEINTRTest) + SignalEINTRTest, + SelectEINTRTest) if __name__ == "__main__": @@ -13,6 +13,10 @@ Core and Builtins Library ------- +- Issue #23485: select.select() is now retried automatically with the + recomputed timeout when interrupted by a signal, except if the signal handler + raises an exception. This change is part of the PEP 475. + - Issue #23752: When built from an existing file descriptor, io.FileIO() now only calls fstat() once. Before fstat() was called twice, which was not necessary. diff --git a/Modules/selectmodule.c b/Modules/selectmodule.c index a852344..a6d6a83 100644 --- a/Modules/selectmodule.c +++ b/Modules/selectmodule.c @@ -193,29 +193,31 @@ select_select(PyObject *self, PyObject *args) #endif /* SELECT_USES_HEAP */ PyObject *ifdlist, *ofdlist, *efdlist; PyObject *ret = NULL; - PyObject *tout = Py_None; + PyObject *timeout_obj = Py_None; fd_set ifdset, ofdset, efdset; struct timeval tv, *tvp; int imax, omax, emax, max; int n; + _PyTime_t timeout, deadline = 0; /* convert arguments */ if (!PyArg_UnpackTuple(args, "select", 3, 4, - &ifdlist, &ofdlist, &efdlist, &tout)) + &ifdlist, &ofdlist, &efdlist, &timeout_obj)) return NULL; - if (tout == Py_None) - tvp = (struct timeval *)0; + if (timeout_obj == Py_None) + tvp = (struct timeval *)NULL; else { - _PyTime_t ts; - - if (_PyTime_FromSecondsObject(&ts, tout, _PyTime_ROUND_CEILING) < 0) { - PyErr_SetString(PyExc_TypeError, - "timeout must be a float or None"); + if (_PyTime_FromSecondsObject(&timeout, timeout_obj, + _PyTime_ROUND_CEILING) < 0) { + if (PyErr_ExceptionMatches(PyExc_TypeError)) { + PyErr_SetString(PyExc_TypeError, + "timeout must be a float or None"); + } return NULL; } - if (_PyTime_AsTimeval(ts, &tv, _PyTime_ROUND_CEILING) == -1) + if (_PyTime_AsTimeval(timeout, &tv, _PyTime_ROUND_CEILING) == -1) return NULL; if (tv.tv_sec < 0) { PyErr_SetString(PyExc_ValueError, "timeout must be non-negative"); @@ -224,7 +226,6 @@ select_select(PyObject *self, PyObject *args) tvp = &tv; } - #ifdef SELECT_USES_HEAP /* Allocate memory for the lists */ rfd2obj = PyMem_NEW(pylist, FD_SETSIZE + 1); @@ -237,6 +238,7 @@ select_select(PyObject *self, PyObject *args) return PyErr_NoMemory(); } #endif /* SELECT_USES_HEAP */ + /* Convert sequences to fd_sets, and get maximum fd number * propagates the Python exception set in seq2set() */ @@ -249,13 +251,36 @@ select_select(PyObject *self, PyObject *args) goto finally; if ((emax=seq2set(efdlist, &efdset, efd2obj)) < 0) goto finally; + max = imax; if (omax > max) max = omax; if (emax > max) max = emax; - Py_BEGIN_ALLOW_THREADS - n = select(max, &ifdset, &ofdset, &efdset, tvp); - Py_END_ALLOW_THREADS + if (tvp) + deadline = _PyTime_GetMonotonicClock() + timeout; + + do { + Py_BEGIN_ALLOW_THREADS + errno = 0; + n = select(max, &ifdset, &ofdset, &efdset, tvp); + Py_END_ALLOW_THREADS + + if (errno != EINTR) + break; + + /* select() was interrupted by a signal */ + if (PyErr_CheckSignals()) + goto finally; + + if (tvp) { + timeout = deadline - _PyTime_GetMonotonicClock(); + if (timeout < 0) { + n = 0; + break; + } + _PyTime_AsTimeval_noraise(timeout, &tv, _PyTime_ROUND_CEILING); + } + } while (1); #ifdef MS_WINDOWS if (n == SOCKET_ERROR) { |