[Python-checkins] cpython: Issue #12303: Add sigwaitinfo() and sigtimedwait() to the signal module.

Sat Jun 25 12:15:08 CEST 2011

http://hg.python.org/cpython/rev/1137f7021b95
changeset: 70964:1137f7021b95
user: Ross Lagerwall <rosslagerwall at gmail.com>
date: Sat Jun 25 12:13:40 2011 +0200
summary:
 Issue #12303: Add sigwaitinfo() and sigtimedwait() to the signal module.
files:
 Doc/library/signal.rst | 45 +++++++-
 Doc/whatsnew/3.3.rst | 4 +
 Lib/test/test_signal.py | 99 +++++++++++++++--
 Misc/NEWS | 2 +
 Modules/signalmodule.c | 154 +++++++++++++++++++++++++++-
 configure | 4 +-
 configure.in | 4 +-
 pyconfig.h.in | 6 +
 8 files changed, 295 insertions(+), 23 deletions(-)

diff --git a/Doc/library/signal.rst b/Doc/library/signal.rst
--- a/Doc/library/signal.rst
+++ b/Doc/library/signal.rst
@@ -179,7 +179,8 @@
 will then be called. Returns nothing. Not on Windows. (See the Unix man page
 :manpage:`signal(2)`.)
 
- See also :func:`sigwait` and :func:`sigpending`.
+ See also :func:`sigwait`, :func:`sigwaitinfo`, :func:`sigtimedwait` and
+ :func:`sigpending`.
 
 
 .. function:: pthread_kill(thread_id, signum)
@@ -334,7 +335,47 @@
 Availability: Unix (see the man page :manpage:`sigwait(3)` for further
 information).
 
- See also :func:`pause`, :func:`pthread_sigmask` and :func:`sigpending`.
+ See also :func:`pause`, :func:`pthread_sigmask`, :func:`sigpending`,
+ :func:`sigwaitinfo` and :func:`sigtimedwait`.
+
+ .. versionadded:: 3.3
+
+
+.. function:: sigwaitinfo(sigset)
+
+ Suspend execution of the calling thread until the delivery of one of the
+ signals specified in the signal set *sigset*. The function accepts the
+ signal and removes it from the pending list of signals. If one of the
+ signals in *sigset* is already pending for the calling thread, the function
+ will return immediately with information about that signal. The signal
+ handler is not called for the delivered signal. The function raises an
+ :exc:`OSError` with error number set to :const:`errno.EINTR` if it is
+ interrupted by a signal that is not in *sigset*.
+
+ The return value is an object representing the data contained in the
+ :c:type:`siginfo_t` structure, namely: :attr:`si_signo`, :attr:`si_code`,
+ :attr:`si_errno`, :attr:`si_pid`, :attr:`si_uid`, :attr:`si_status`,
+ :attr:`si_band`.
+
+ Availability: Unix (see the man page :manpage:`sigwaitinfo(2)` for further
+ information).
+
+ See also :func:`pause`, :func:`sigwait` and :func:`sigtimedwait`.
+
+ .. versionadded:: 3.3
+
+
+.. function:: sigtimedwait(sigset, (timeout_sec, timeout_nsec))
+
+ Like :func:`sigtimedwait`, but takes a tuple of ``(seconds, nanoseconds)``
+ as an additional argument specifying a timeout. If both *timeout_sec* and
+ *timeout_nsec* are specified as :const:`0`, a poll is performed. Returns
+ :const:`None` if a timeout occurs.
+
+ Availability: Unix (see the man page :manpage:`sigtimedwait(2)` for further
+ information).
+
+ See also :func:`pause`, :func:`sigwait` and :func:`sigwaitinfo`.
 
 .. versionadded:: 3.3
 
diff --git a/Doc/whatsnew/3.3.rst b/Doc/whatsnew/3.3.rst
--- a/Doc/whatsnew/3.3.rst
+++ b/Doc/whatsnew/3.3.rst
@@ -169,6 +169,10 @@
 * :func:`~signal.pthread_kill`: send a signal to a thread ;
 * :func:`~signal.sigpending`: examine pending functions ;
 * :func:`~signal.sigwait`: wait a signal.
+ * :func:`~signal.sigwaitinfo`: wait for a signal, returning detailed
+ information about it.
+ * :func:`~signal.sigtimedwait`: like :func:`~signal.sigwaitinfo` but with a
+ timeout.
 
 * The signal handler writes the signal number as a single byte instead of
 a nul byte into the wakeup file descriptor. So it is possible to wait more
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
@@ -520,6 +520,7 @@
 functions.
 """
 def setUp(self):
+ self.hndl_called = False
 self.has_pthread_kill = hasattr(signal, 'pthread_kill')
 
 def handler(self, signum, frame):
@@ -607,45 +608,35 @@
 with self.assertRaises(ZeroDivisionError):
 signal.pthread_kill(current, signum)
 
- @unittest.skipUnless(hasattr(signal, 'sigwait'),
- 'need signal.sigwait()')
 @unittest.skipUnless(hasattr(signal, 'pthread_sigmask'),
 'need signal.pthread_sigmask()')
 @unittest.skipUnless(hasattr(os, 'fork'), 'need os.fork()')
- def test_sigwait(self):
- def test(signum):
- signal.alarm(1)
- received = signal.sigwait([signum])
- if received != signum:
- print("sigwait() received %s, not %s"
- % (received, signum),
- file=sys.stderr)
- os._exit(1)
-
+ def wait_helper(self, test, handler, blocked=signal.SIGALRM):
 signum = signal.SIGALRM
 
- # sigwait must be called with the signal blocked: since the current
+ # sig*wait* must be called with the signal blocked: since the current
 # process might have several threads running, we fork() a child process
 # to have a single thread.
 pid = os.fork()
 if pid == 0:
 # child: block and wait the signal
 try:
- signal.signal(signum, self.handler)
- signal.pthread_sigmask(signal.SIG_BLOCK, [signum])
+ 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, [signum])
+ signal.pthread_sigmask(signal.SIG_UNBLOCK, [blocked])
 except ZeroDivisionError:
 print("the signal handler has been called",
 file=sys.stderr)
 os._exit(1)
 except BaseException as err:
 print("error: {}".format(err), file=sys.stderr)
+ sys.stderr.flush()
 os._exit(1)
 else:
 os._exit(0)
@@ -655,6 +646,82 @@
 
 @unittest.skipUnless(hasattr(signal, 'sigwait'),
 'need signal.sigwait()')
+ def test_sigwait(self):
+ def test(signum):
+ signal.alarm(1)
+ self.assertEqual(signum, signal.sigwait([signum]))
+
+ self.wait_helper(test, self.handler)
+
+ @unittest.skipUnless(hasattr(signal, 'sigwaitinfo'),
+ 'need signal.sigwaitinfo()')
+ def test_sigwaitinfo(self):
+ def test(signum):
+ signal.alarm(1)
+ info = signal.sigwaitinfo([signum])
+ self.assertEqual(signum, info.si_signo)
+
+ self.wait_helper(test, self.handler)
+
+ @unittest.skipUnless(hasattr(signal, 'sigtimedwait'),
+ 'need signal.sigtimedwait()')
+ def test_sigtimedwait(self):
+ def test(signum):
+ signal.alarm(1)
+ info = signal.sigtimedwait([signum], (10, 1000))
+ self.assertEqual(signum, info.si_signo)
+
+ self.wait_helper(test, self.handler)
+
+ # check that polling with sigtimedwait works
+ @unittest.skipUnless(hasattr(signal, 'sigtimedwait'),
+ 'need signal.sigtimedwait()')
+ def test_sigtimedwait_poll(self):
+ def test(signum):
+ self.kill(signum)
+ info = signal.sigtimedwait([signum], (0, 0))
+ self.assertEqual(signum, info.si_signo)
+
+ self.wait_helper(test, self.handler)
+
+ @unittest.skipUnless(hasattr(signal, 'sigtimedwait'),
+ 'need signal.sigtimedwait()')
+ def test_sigtimedwait_timeout(self):
+ def test(signum):
+ self.assertEqual(None, signal.sigtimedwait([signum], (1, 35500)))
+
+ self.wait_helper(test, self.handler)
+
+ @unittest.skipUnless(hasattr(signal, 'sigtimedwait'),
+ 'need signal.sigtimedwait()')
+ def test_sigtimedwait_negative_timeout(self):
+ signum = signal.SIGALRM
+ self.assertRaises(ValueError, signal.sigtimedwait, [signum], (-1, -1))
+ self.assertRaises(ValueError, signal.sigtimedwait, [signum], (0, -1))
+ self.assertRaises(ValueError, signal.sigtimedwait, [signum], (-1, 0))
+
+ def alarm_handler(self, signum, frame):
+ self.hndl_called = True
+
+ @unittest.skipUnless(hasattr(signal, 'sigwaitinfo'),
+ 'need signal.sigwaitinfo()')
+ def test_sigwaitinfo_interrupted(self):
+ def test(signum):
+ signal.alarm(1)
+ try:
+ signal.sigwaitinfo([signal.SIGUSR1])
+ except OSError as e:
+ if e.errno == errno.EINTR:
+ self.assertTrue(self.hndl_called)
+ else:
+ self.fail("Expected EINTR to be raised by sigwaitinfo")
+ else:
+ self.fail("Expected EINTR to be raised by sigwaitinfo")
+
+ self.wait_helper(test, self.alarm_handler, signal.SIGUSR1)
+
+ @unittest.skipUnless(hasattr(signal, 'sigwait'),
+ 'need signal.sigwait()')
 @unittest.skipUnless(hasattr(signal, 'pthread_sigmask'),
 'need signal.pthread_sigmask()')
 @unittest.skipIf(threading is None, "test needs threading module")
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -200,6 +200,8 @@
 Library
 -------
 
+- Issue #12303: Add sigwaitinfo() and sigtimedwait() to the signal module.
+
 - Issue #12404: Remove C89 incompatible code from mmap module. Patch by Akira
 Kitada.
 
diff --git a/Modules/signalmodule.c b/Modules/signalmodule.c
--- a/Modules/signalmodule.c
+++ b/Modules/signalmodule.c
@@ -507,7 +507,8 @@
 Returns current value of given itimer.");
 #endif
 
-#if defined(PYPTHREAD_SIGMASK) || defined(HAVE_SIGWAIT)
+#if defined(PYPTHREAD_SIGMASK) || defined(HAVE_SIGWAIT) || \
+ defined(HAVE_SIGWAITINFO) || defined(HAVE_SIGTIMEDWAIT)
 /* Convert an iterable to a sigset.
 Return 0 on success, return -1 and raise an exception on error. */
 
@@ -679,6 +680,140 @@
 Wait a signal.");
 #endif /* #ifdef HAVE_SIGPENDING */
 
+#if defined(HAVE_SIGWAITINFO) || defined(HAVE_SIGTIMEDWAIT)
+static int initialized;
+static PyStructSequence_Field struct_siginfo_fields[] = {
+ {"si_signo", "signal number"},
+ {"si_code", "signal code"},
+ {"si_errno", "errno associated with this signal"},
+ {"si_pid", "sending process ID"},
+ {"si_uid", "real user ID of sending process"},
+ {"si_status", "exit value or signal"},
+ {"si_band", "band event for SIGPOLL"},
+ {0}
+};
+
+PyDoc_STRVAR(struct_siginfo__doc__,
+"struct_siginfo: Result from sigwaitinfo or sigtimedwait.\n\n\
+This object may be accessed either as a tuple of\n\
+(si_signo, si_code, si_errno, si_pid, si_uid, si_status, si_band),\n\
+or via the attributes si_signo, si_code, and so on.");
+
+static PyStructSequence_Desc struct_siginfo_desc = {
+ "signal.struct_siginfo", /* name */
+ struct_siginfo__doc__, /* doc */
+ struct_siginfo_fields, /* fields */
+ 7 /* n_in_sequence */
+};
+
+static PyTypeObject SiginfoType;
+
+static PyObject *
+fill_siginfo(siginfo_t *si)
+{
+ PyObject *result = PyStructSequence_New(&SiginfoType);
+ if (!result)
+ return NULL;
+
+ PyStructSequence_SET_ITEM(result, 0, PyLong_FromLong((long)(si->si_signo)));
+ PyStructSequence_SET_ITEM(result, 1, PyLong_FromLong((long)(si->si_code)));
+ PyStructSequence_SET_ITEM(result, 2, PyLong_FromLong((long)(si->si_errno)));
+ PyStructSequence_SET_ITEM(result, 3, PyLong_FromPid(si->si_pid));
+ PyStructSequence_SET_ITEM(result, 4, PyLong_FromLong((long)(si->si_uid)));
+ PyStructSequence_SET_ITEM(result, 5,
+ PyLong_FromLong((long)(si->si_status)));
+ PyStructSequence_SET_ITEM(result, 6, PyLong_FromLong(si->si_band));
+ if (PyErr_Occurred()) {
+ Py_DECREF(result);
+ return NULL;
+ }
+
+ return result;
+}
+#endif
+
+#ifdef HAVE_SIGWAITINFO
+static PyObject *
+signal_sigwaitinfo(PyObject *self, PyObject *args)
+{
+ PyObject *signals;
+ sigset_t set;
+ siginfo_t si;
+ int err;
+
+ if (!PyArg_ParseTuple(args, "O:sigwaitinfo", &signals))
+ return NULL;
+
+ if (iterable_to_sigset(signals, &set))
+ return NULL;
+
+ Py_BEGIN_ALLOW_THREADS
+ err = sigwaitinfo(&set, &si);
+ Py_END_ALLOW_THREADS
+ if (err == -1)
+ return PyErr_SetFromErrno(PyExc_OSError);
+
+ return fill_siginfo(&si);
+}
+
+PyDoc_STRVAR(signal_sigwaitinfo_doc,
+"sigwaitinfo(sigset) -> struct_siginfo\n\
+\n\
+Wait synchronously for a signal until one of the signals in *sigset* is\n\
+delivered.\n\
+Returns a struct_siginfo containing information about the signal.");
+#endif /* #ifdef HAVE_SIGWAITINFO */
+
+#ifdef HAVE_SIGTIMEDWAIT
+static PyObject *
+signal_sigtimedwait(PyObject *self, PyObject *args)
+{
+ PyObject *signals, *timeout;
+ struct timespec buf;
+ sigset_t set;
+ siginfo_t si;
+ int err;
+
+ if (!PyArg_ParseTuple(args, "OO:sigtimedwait", &signals, &timeout))
+ return NULL;
+
+ if (!PyTuple_Check(timeout) || PyTuple_Size(timeout) != 2) {
+ PyErr_SetString(PyExc_TypeError,
+ "sigtimedwait() arg 2 must be a tuple "
+ "(timeout_sec, timeout_nsec)");
+ return NULL;
+ } else if (!PyArg_ParseTuple(timeout, "ll:sigtimedwait",
+ &(buf.tv_sec), &(buf.tv_nsec)))
+ return NULL;
+
+ if (buf.tv_sec < 0 || buf.tv_nsec < 0) {
+ PyErr_SetString(PyExc_ValueError, "timeout must be non-negative");
+ return NULL;
+ }
+
+ 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);
+ }
+
+ return fill_siginfo(&si);
+}
+
+PyDoc_STRVAR(signal_sigtimedwait_doc,
+"sigtimedwait(sigset, (timeout_sec, timeout_nsec)) -> struct_siginfo\n\
+\n\
+Like sigwaitinfo(), but with a timeout specified as a tuple of (seconds,\n\
+nanoseconds).");
+#endif /* #ifdef HAVE_SIGTIMEDWAIT */
+
 
 #if defined(HAVE_PTHREAD_KILL) && defined(WITH_THREAD)
 static PyObject *
@@ -752,6 +887,14 @@
 {"sigwait", (PyCFunction)signal_sigwait,
 METH_VARARGS, signal_sigwait_doc},
 #endif
+#ifdef HAVE_SIGWAITINFO
+ {"sigwaitinfo", (PyCFunction)signal_sigwaitinfo,
+ METH_VARARGS, signal_sigwaitinfo_doc},
+#endif
+#ifdef HAVE_SIGTIMEDWAIT
+ {"sigtimedwait", (PyCFunction)signal_sigtimedwait,
+ METH_VARARGS, signal_sigtimedwait_doc},
+#endif
 {NULL, NULL} /* sentinel */
 };
 
@@ -820,6 +963,15 @@
 if (m == NULL)
 return NULL;
 
+#if defined(HAVE_SIGWAITINFO) || defined(HAVE_SIGTIMEDWAIT)
+ if (!initialized)
+ PyStructSequence_InitType(&SiginfoType, &struct_siginfo_desc);
+
+ Py_INCREF((PyObject*) &SiginfoType);
+ PyModule_AddObject(m, "struct_siginfo", (PyObject*) &SiginfoType);
+ initialized = 1;
+#endif
+
 /* Add some symbolic constants to the module */
 d = PyModule_GetDict(m);
 
diff --git a/configure b/configure
--- a/configure
+++ b/configure
@@ -9367,8 +9367,8 @@
 select sem_open sem_timedwait sem_getvalue sem_unlink sendfile setegid seteuid \
 setgid sethostname \
 setlocale setregid setreuid setresuid setresgid setsid setpgid setpgrp setpriority setuid setvbuf \
- sigaction sigaltstack siginterrupt sigpending \
- sigrelse sigwait snprintf strftime strlcpy symlinkat sync \
+ sigaction sigaltstack siginterrupt sigpending sigrelse \
+ sigtimedwait sigwait sigwaitinfo snprintf strftime strlcpy symlinkat sync \
 sysconf tcgetpgrp tcsetpgrp tempnam timegm times tmpfile tmpnam tmpnam_r \
 truncate uname unlinkat unsetenv utimensat utimes waitid waitpid wait3 wait4 \
 wcscoll wcsftime wcsxfrm writev _getpty
diff --git a/configure.in b/configure.in
--- a/configure.in
+++ b/configure.in
@@ -2552,8 +2552,8 @@
 select sem_open sem_timedwait sem_getvalue sem_unlink sendfile setegid seteuid \
 setgid sethostname \
 setlocale setregid setreuid setresuid setresgid setsid setpgid setpgrp setpriority setuid setvbuf \
- sigaction sigaltstack siginterrupt sigpending \
- sigrelse sigwait snprintf strftime strlcpy symlinkat sync \
+ sigaction sigaltstack siginterrupt sigpending sigrelse \
+ sigtimedwait sigwait sigwaitinfo snprintf strftime strlcpy symlinkat sync \
 sysconf tcgetpgrp tcsetpgrp tempnam timegm times tmpfile tmpnam tmpnam_r \
 truncate uname unlinkat unsetenv utimensat utimes waitid waitpid wait3 wait4 \
 wcscoll wcsftime wcsxfrm writev _getpty)
diff --git a/pyconfig.h.in b/pyconfig.h.in
--- a/pyconfig.h.in
+++ b/pyconfig.h.in
@@ -743,9 +743,15 @@
 /* Define to 1 if you have the `sigrelse' function. */
 #undef HAVE_SIGRELSE
 
+/* Define to 1 if you have the `sigtimedwait' function. */
+#undef HAVE_SIGTIMEDWAIT
+
 /* Define to 1 if you have the `sigwait' function. */
 #undef HAVE_SIGWAIT
 
+/* Define to 1 if you have the `sigwaitinfo' function. */
+#undef HAVE_SIGWAITINFO
+
 /* Define to 1 if you have the `snprintf' function. */
 #undef HAVE_SNPRINTF
 
-- 
Repository URL: http://hg.python.org/cpython
