diff --git a/Doc/c-api/exceptions.rst b/Doc/c-api/exceptions.rst index 33b44390d24..46033ca7389 100644 --- a/Doc/c-api/exceptions.rst +++ b/Doc/c-api/exceptions.rst @@ -443,13 +443,20 @@ in various ways. There is a separate error indicator for each thread. .. c:function:: int PySignal_SetWakeupFd(int fd) - This utility function specifies a file descriptor to which a ``'\0'`` byte will - be written whenever a signal is received. It returns the previous such file - descriptor. The value ``-1`` disables the feature; this is the initial state. + This utility function specifies a file descriptor to which the signal number + is written as a single byte whenever a signal is received. *fd* must be + non-blocking. It returns the previous such file descriptor. + + On Windows, the function only supports socket handles. + + The value ``-1`` disables the feature; this is the initial state. This is equivalent to :func:`signal.set_wakeup_fd` in Python, but without any error checking. *fd* should be a valid file descriptor. The function should only be called from the main thread. + .. versionchanged:: 3.5 + On Windows, the function now only supports socket handles. + .. c:function:: PyObject* PyErr_NewException(char *name, PyObject *base, PyObject *dict) diff --git a/Doc/library/signal.rst b/Doc/library/signal.rst index a97ce66ef52..cda228bdc95 100644 --- a/Doc/library/signal.rst +++ b/Doc/library/signal.rst @@ -308,6 +308,8 @@ The :mod:`signal` module defines the following functions: a library to wakeup a poll or select call, allowing the signal to be fully processed. + On Windows, the function only supports socket handles. + The old wakeup fd is returned. *fd* must be non-blocking. It is up to the library to remove any bytes before calling poll or select again. @@ -318,6 +320,9 @@ The :mod:`signal` module defines the following functions: attempting to call it from other threads will cause a :exc:`ValueError` exception to be raised. + .. versionchanged:: 3.5 + On Windows, the function now only supports socket handles. + .. function:: siginterrupt(signalnum, flag) diff --git a/Lib/test/test_signal.py b/Lib/test/test_signal.py index 56ab6316b61..28bb4d6e23f 100644 --- a/Lib/test/test_signal.py +++ b/Lib/test/test_signal.py @@ -6,6 +6,7 @@ import gc import pickle import select import signal +import socket import struct import subprocess import traceback @@ -251,21 +252,43 @@ class WindowsSignalTests(unittest.TestCase): class WakeupFDTests(unittest.TestCase): def test_invalid_fd(self): - fd = support.make_bad_fd() + if sys.platform == "win32": + sock = socket.socket() + fd = sock.fileno() + sock.close() + else: + fd = support.make_bad_fd() self.assertRaises((ValueError, OSError), signal.set_wakeup_fd, fd) - def test_set_wakeup_fd_result(self): - r1, w1 = os.pipe() - self.addCleanup(os.close, r1) - self.addCleanup(os.close, w1) - r2, w2 = os.pipe() - self.addCleanup(os.close, r2) - self.addCleanup(os.close, w2) + @unittest.skipUnless(sys.platform == "win32", 'test specific to Windows') + def test_only_socket(self): + # set_wakeup_fd() expects a socket on Windows + with open(support.TESTFN, 'wb') as fp: + self.addCleanup(support.unlink, support.TESTFN) + self.assertRaises(ValueError, + signal.set_wakeup_fd, fp.fileno()) - signal.set_wakeup_fd(w1) - self.assertIs(signal.set_wakeup_fd(w2), w1) - self.assertIs(signal.set_wakeup_fd(-1), w2) + def test_set_wakeup_fd_result(self): + if sys.platform == 'win32': + sock1 = socket.socket() + self.addCleanup(sock1.close) + fd1 = sock1.fileno() + + sock2 = socket.socket() + self.addCleanup(sock2.close) + fd2 = sock2.fileno() + else: + r1, fd1 = os.pipe() + self.addCleanup(os.close, r1) + self.addCleanup(os.close, fd1) + r2, fd2 = os.pipe() + self.addCleanup(os.close, r2) + self.addCleanup(os.close, fd2) + + signal.set_wakeup_fd(fd1) + self.assertIs(signal.set_wakeup_fd(fd2), fd1) + self.assertIs(signal.set_wakeup_fd(-1), fd2) self.assertIs(signal.set_wakeup_fd(-1), -1) @@ -441,6 +464,90 @@ class WakeupSignalTests(unittest.TestCase): """, signal.SIGUSR1, signal.SIGUSR2, ordered=False) +@unittest.skipUnless(hasattr(socket, 'socketpair'), 'need socket.socketpair') +class WakeupSocketSignalTests(unittest.TestCase): + + @unittest.skipIf(_testcapi is None, 'need _testcapi') + def test_socket(self): + # use a subprocess to have only one thread + code = """if 1: + import signal + import socket + import struct + import _testcapi + + signum = signal.SIGINT + signals = (signum,) + + def handler(signum, frame): + pass + + signal.signal(signum, handler) + + read, write = socket.socketpair() + read.setblocking(False) + write.setblocking(False) + signal.set_wakeup_fd(write.fileno()) + + _testcapi.raise_signal(signum) + + data = read.recv(1) + if not data: + raise Exception("no signum written") + raised = struct.unpack('B', data) + if raised != signals: + raise Exception("%r != %r" % (raised, signals)) + + read.close() + write.close() + """ + + assert_python_ok('-c', code) + + @unittest.skipIf(_testcapi is None, 'need _testcapi') + def test_send_error(self): + # Use a subprocess to have only one thread. + if os.name == 'nt': + action = 'send' + else: + action = 'write' + code = """if 1: + import errno + import signal + import socket + import sys + import time + import _testcapi + from test.support import captured_stderr + + signum = signal.SIGINT + + def handler(signum, frame): + pass + + signal.signal(signum, handler) + + read, write = socket.socketpair() + read.setblocking(False) + write.setblocking(False) + + signal.set_wakeup_fd(write.fileno()) + + # Close sockets: send() will fail + read.close() + write.close() + + with captured_stderr() as err: + _testcapi.raise_signal(signum) + + err = err.getvalue() + if ('Exception ignored when trying to {action} to the signal wakeup fd' + not in err): + raise AssertionError(err) + """.format(action=action) + assert_python_ok('-c', code) + + @unittest.skipIf(sys.platform == "win32", "Not valid on Windows") class SiginterruptTest(unittest.TestCase): @@ -990,6 +1097,7 @@ def test_main(): try: support.run_unittest(GenericTests, PosixTests, InterProcessSignalTests, WakeupFDTests, WakeupSignalTests, + WakeupSocketSignalTests, SiginterruptTest, ItimerTest, WindowsSignalTests, PendingSignalsTests) finally: diff --git a/Modules/signalmodule.c b/Modules/signalmodule.c index c4f01216444..a315f23a038 100644 --- a/Modules/signalmodule.c +++ b/Modules/signalmodule.c @@ -4,6 +4,9 @@ /* XXX Signals should be recorded per thread, now we have thread state. */ #include "Python.h" +#ifdef MS_WINDOWS +#include "socketmodule.h" /* needed for SOCKET_T */ +#endif #ifndef MS_WINDOWS #include "posixmodule.h" #endif @@ -87,7 +90,18 @@ static volatile struct { PyObject *func; } Handlers[NSIG]; +#ifdef MS_WINDOWS +#define INVALID_SOCKET ((SOCKET_T)-1) + +static volatile struct { + SOCKET_T fd; + int send_err_set; + int send_errno; + int send_win_error; +} wakeup = {INVALID_SOCKET, 0, 0}; +#else static volatile sig_atomic_t wakeup_fd = -1; +#endif /* Speed up sigcheck() when none tripped */ static volatile sig_atomic_t is_tripped = 0; @@ -171,6 +185,33 @@ checksignals_witharg(void * unused) return PyErr_CheckSignals(); } +#ifdef MS_WINDOWS +static int +report_wakeup_error(void* Py_UNUSED(data)) +{ + PyObject *res; + + if (wakeup.send_win_error) { + /* PyErr_SetExcFromWindowsErr() invokes FormatMessage() which + recognizes the error codes used by both GetLastError() and + WSAGetLastError */ + res = PyErr_SetExcFromWindowsErr(PyExc_OSError, wakeup.send_win_error); + } + else { + errno = wakeup.send_errno; + res = PyErr_SetFromErrno(PyExc_OSError); + } + + assert(res == NULL); + wakeup.send_err_set = 0; + + PySys_WriteStderr("Exception ignored when trying to send to the " + "signal wakeup fd:\n"); + PyErr_WriteUnraisable(NULL); + + return 0; +} +#else static int report_wakeup_error(void *data) { @@ -183,26 +224,51 @@ report_wakeup_error(void *data) errno = save_errno; return 0; } +#endif static void trip_signal(int sig_num) { unsigned char byte; - int rc = 0; + Py_ssize_t rc; Handlers[sig_num].tripped = 1; + +#ifdef MS_WINDOWS + if (wakeup.fd != INVALID_SOCKET) { + byte = (unsigned char)sig_num; + do { + rc = send(wakeup.fd, &byte, 1, 0); + } while (rc < 0 && errno == EINTR); + + /* we only have a storage for one error in the wakeup structure */ + if (rc < 0 && !wakeup.send_err_set) { + wakeup.send_err_set = 1; + wakeup.send_errno = errno; + wakeup.send_win_error = GetLastError(); + Py_AddPendingCall(report_wakeup_error, NULL); + } + } +#else if (wakeup_fd != -1) { byte = (unsigned char)sig_num; - while ((rc = write(wakeup_fd, &byte, 1)) == -1 && errno == EINTR); - if (rc == -1) - Py_AddPendingCall(report_wakeup_error, (void *) (Py_intptr_t) errno); + do { + rc = write(wakeup_fd, &byte, 1); + } while (rc < 0 && errno == EINTR); + + if (rc < 0) { + Py_AddPendingCall(report_wakeup_error, + (void *)(Py_intptr_t)errno); + } + } +#endif + + if (!is_tripped) { + /* Set is_tripped after setting .tripped, as it gets + cleared in PyErr_CheckSignals() before .tripped. */ + is_tripped = 1; + Py_AddPendingCall(checksignals_witharg, NULL); } - if (is_tripped) - return; - /* Set is_tripped after setting .tripped, as it gets - cleared in PyErr_CheckSignals() before .tripped. */ - is_tripped = 1; - Py_AddPendingCall(checksignals_witharg, NULL); } static void @@ -426,10 +492,28 @@ signal_siginterrupt(PyObject *self, PyObject *args) static PyObject * signal_set_wakeup_fd(PyObject *self, PyObject *args) { - struct stat buf; +#ifdef MS_WINDOWS + PyObject *fdobj; + SOCKET_T fd, old_fd; + int res; + int res_size = sizeof res; + PyObject *mod; + struct stat st; + + if (!PyArg_ParseTuple(args, "O:set_wakeup_fd", &fdobj)) + return NULL; + + fd = PyLong_AsSocket_t(fdobj); + if (fd == (SOCKET_T)(-1) && PyErr_Occurred()) + return NULL; +#else int fd, old_fd; + struct stat st; + if (!PyArg_ParseTuple(args, "i:set_wakeup_fd", &fd)) return NULL; +#endif + #ifdef WITH_THREAD if (PyThread_get_thread_ident() != main_thread) { PyErr_SetString(PyExc_ValueError, @@ -438,28 +522,54 @@ signal_set_wakeup_fd(PyObject *self, PyObject *args) } #endif - if (fd != -1) { - if (!_PyVerify_fd(fd)) { - PyErr_SetString(PyExc_ValueError, "invalid fd"); +#ifdef MS_WINDOWS + if (fd != INVALID_SOCKET) { + /* Import the _socket module to call WSAStartup() */ + mod = PyImport_ImportModuleNoBlock("_socket"); + if (mod == NULL) + return NULL; + Py_DECREF(mod); + + /* test the socket */ + if (getsockopt(fd, SOL_SOCKET, SO_ERROR, + (char *)&res, &res_size) != 0) { + int err = WSAGetLastError(); + if (err == WSAENOTSOCK) + PyErr_SetString(PyExc_ValueError, "fd is not a socket"); + else + PyErr_SetExcFromWindowsErr(PyExc_OSError, err); return NULL; } + } - if (fstat(fd, &buf) != 0) - return PyErr_SetFromErrno(PyExc_OSError); + old_fd = wakeup.fd; + wakeup.fd = fd; + + if (old_fd != INVALID_SOCKET) + return PyLong_FromSocket_t(old_fd); + else + return PyLong_FromLong(-1); +#else + if (fd != -1) { + if (fstat(fd, &st) != 0) { + PyErr_SetFromErrno(PyExc_OSError); + return NULL; + } } old_fd = wakeup_fd; wakeup_fd = fd; return PyLong_FromLong(old_fd); +#endif } PyDoc_STRVAR(set_wakeup_fd_doc, "set_wakeup_fd(fd) -> fd\n\ \n\ -Sets the fd to be written to (with '\\0') when a signal\n\ +Sets the fd to be written to (with the signal number) when a signal\n\ comes in. A library can use this to wakeup select or poll.\n\ -The previous fd is returned.\n\ +The previous fd or -1 is returned.\n\ \n\ The fd must be non-blocking."); @@ -467,10 +577,17 @@ The fd must be non-blocking."); int PySignal_SetWakeupFd(int fd) { - int old_fd = wakeup_fd; + int old_fd; if (fd < 0) fd = -1; + +#ifdef MS_WINDOWS + old_fd = Py_SAFE_DOWNCAST(wakeup.fd, SOCKET_T, int); + wakeup.fd = fd; +#else + old_fd = wakeup_fd; wakeup_fd = fd; +#endif return old_fd; } diff --git a/PCbuild/pythoncore.vcxproj b/PCbuild/pythoncore.vcxproj index 6021cd74cbf..1ad16fb8222 100644 --- a/PCbuild/pythoncore.vcxproj +++ b/PCbuild/pythoncore.vcxproj @@ -176,7 +176,7 @@ "$(SolutionDir)make_buildinfo.exe" Release "$(IntDir)\" - $(IntDir)getbuildinfo.o;%(AdditionalDependencies) + $(IntDir)getbuildinfo.o;ws2_32.lib;%(AdditionalDependencies) $(OutDir)$(PyDllName).dll libc;%(IgnoreSpecificDefaultLibraries) 0x1e000000 @@ -212,7 +212,7 @@ IF %ERRORLEVEL% NEQ 0 ( "$(SolutionDir)make_buildinfo.exe" Release "$(IntDir)\" - $(IntDir)getbuildinfo.o;%(AdditionalDependencies) + $(IntDir)getbuildinfo.o;ws2_32.lib;%(AdditionalDependencies) libc;%(IgnoreSpecificDefaultLibraries) 0x1e000000 @@ -247,7 +247,7 @@ IF %ERRORLEVEL% NEQ 0 ( "$(SolutionDir)make_buildinfo.exe" Debug "$(IntDir)" - $(IntDir)getbuildinfo.o;%(AdditionalDependencies) + $(IntDir)getbuildinfo.o;ws2_32.lib;%(AdditionalDependencies) libc;%(IgnoreSpecificDefaultLibraries) 0x1e000000 @@ -285,7 +285,7 @@ IF %ERRORLEVEL% NEQ 0 ( "$(SolutionDir)make_buildinfo.exe" Debug "$(IntDir)" - $(IntDir)getbuildinfo.o;%(AdditionalDependencies) + $(IntDir)getbuildinfo.o;ws2_32.lib;%(AdditionalDependencies) libc;%(IgnoreSpecificDefaultLibraries) 0x1e000000 @@ -317,7 +317,7 @@ IF %ERRORLEVEL% NEQ 0 ( "$(SolutionDir)make_buildinfo.exe" Release "$(IntDir)\" - $(IntDir)getbuildinfo.o;%(AdditionalDependencies) + $(IntDir)getbuildinfo.o;ws2_32.lib;%(AdditionalDependencies) $(OutDir)$(PyDllName).dll libc;%(IgnoreSpecificDefaultLibraries) 0x1e000000 @@ -353,7 +353,7 @@ IF %ERRORLEVEL% NEQ 0 ( "$(SolutionDir)make_buildinfo.exe" Release "$(IntDir)\" - $(IntDir)getbuildinfo.o;%(AdditionalDependencies) + $(IntDir)getbuildinfo.o;ws2_32.lib;%(AdditionalDependencies) libc;%(IgnoreSpecificDefaultLibraries) 0x1e000000 MachineX64 @@ -386,7 +386,7 @@ IF %ERRORLEVEL% NEQ 0 ( "$(SolutionDir)make_buildinfo.exe" Release "$(IntDir)\" - $(IntDir)getbuildinfo.o;%(AdditionalDependencies) + $(IntDir)getbuildinfo.o;ws2_32.lib;%(AdditionalDependencies) $(OutDir)$(PyDllName).dll libc;%(IgnoreSpecificDefaultLibraries) 0x1e000000 @@ -422,7 +422,7 @@ IF %ERRORLEVEL% NEQ 0 ( "$(SolutionDir)make_buildinfo.exe" Release "$(IntDir)\" - $(IntDir)getbuildinfo.o;%(AdditionalDependencies) + $(IntDir)getbuildinfo.o;ws2_32.lib;%(AdditionalDependencies) libc;%(IgnoreSpecificDefaultLibraries) 0x1e000000 MachineX64