1/*
2 * A type which wraps a semaphore
3 *
4 * semaphore.c
5 *
6 * Copyright (c) 2006-2008, R Oudkerk
7 * Licensed to PSF under a Contributor Agreement.
8 */
9
10#include "multiprocessing.h"
11
12enum { RECURSIVE_MUTEX, SEMAPHORE };
13
14typedef struct {
15 PyObject_HEAD
16 SEM_HANDLE handle;
17 unsigned long last_tid;
18 int count;
19 int maxvalue;
20 int kind;
21 char *name;
22} SemLockObject;
23
24/*[python input]
25class SEM_HANDLE_converter(CConverter):
26 type = "SEM_HANDLE"
27 format_unit = '"F_SEM_HANDLE"'
28
29[python start generated code]*/
30/*[python end generated code: output=da39a3ee5e6b4b0d input=3e0ad43e482d8716]*/
31
32/*[clinic input]
33module _multiprocessing
34class _multiprocessing.SemLock "SemLockObject *" "&_PyMp_SemLockType"
35[clinic start generated code]*/
36/*[clinic end generated code: output=da39a3ee5e6b4b0d input=935fb41b7d032599]*/
37
38#include "clinic/semaphore.c.h"
39
40#define ISMINE(o) (o->count > 0 && PyThread_get_thread_ident() == o->last_tid)
41
42
43#ifdef MS_WINDOWS
44
45/*
46 * Windows definitions
47 */
48
49#define SEM_FAILED NULL
50
51#define SEM_CLEAR_ERROR() SetLastError(0)
52#define SEM_GET_LAST_ERROR() GetLastError()
53#define SEM_CREATE(name, val, max) CreateSemaphore(NULL, val, max, NULL)
54#define SEM_CLOSE(sem) (CloseHandle(sem) ? 0 : -1)
55#define SEM_GETVALUE(sem, pval) _GetSemaphoreValue(sem, pval)
56#define SEM_UNLINK(name) 0
57
58static int
59_GetSemaphoreValue(HANDLE handle, long *value)
60{
61 long previous;
62
63 switch (WaitForSingleObjectEx(handle, 0, FALSE)) {
64 case WAIT_OBJECT_0:
65 if (!ReleaseSemaphore(handle, 1, &previous))
66 return MP_STANDARD_ERROR;
67 *value = previous + 1;
68 return 0;
69 case WAIT_TIMEOUT:
70 *value = 0;
71 return 0;
72 default:
73 return MP_STANDARD_ERROR;
74 }
75}
76
77/*[clinic input]
78_multiprocessing.SemLock.acquire
79
80 block as blocking: bool(accept={int}) = True
81 timeout as timeout_obj: object = None
82
83Acquire the semaphore/lock.
84[clinic start generated code]*/
85
86static PyObject *
87_multiprocessing_SemLock_acquire_impl(SemLockObject *self, int blocking,
88 PyObject *timeout_obj)
89/*[clinic end generated code: output=f9998f0b6b0b0872 input=86f05662cf753eb4]*/
90{
91 double timeout;
92 DWORD res, full_msecs, nhandles;
93 HANDLE handles[2], sigint_event;
94
95 /* calculate timeout */
96 if (!blocking) {
97 full_msecs = 0;
98 } else if (timeout_obj == Py_None) {
99 full_msecs = INFINITE;
100 } else {
101 timeout = PyFloat_AsDouble(timeout_obj);
102 if (PyErr_Occurred())
103 return NULL;
104 timeout *= 1000.0; /* convert to millisecs */
105 if (timeout < 0.0) {
106 timeout = 0.0;
107 } else if (timeout >= 0.5 * INFINITE) { /* 25 days */
108 PyErr_SetString(PyExc_OverflowError,
109 "timeout is too large");
110 return NULL;
111 }
112 full_msecs = (DWORD)(timeout + 0.5);
113 }
114
115 /* check whether we already own the lock */
116 if (self->kind == RECURSIVE_MUTEX && ISMINE(self)) {
117 ++self->count;
118 Py_RETURN_TRUE;
119 }
120
121 /* check whether we can acquire without releasing the GIL and blocking */
122 if (WaitForSingleObjectEx(self->handle, 0, FALSE) == WAIT_OBJECT_0) {
123 self->last_tid = GetCurrentThreadId();
124 ++self->count;
125 Py_RETURN_TRUE;
126 }
127
128 /* prepare list of handles */
129 nhandles = 0;
130 handles[nhandles++] = self->handle;
131 if (_PyOS_IsMainThread()) {
132 sigint_event = _PyOS_SigintEvent();
133 assert(sigint_event != NULL);
134 handles[nhandles++] = sigint_event;
135 }
136 else {
137 sigint_event = NULL;
138 }
139
140 /* do the wait */
141 Py_BEGIN_ALLOW_THREADS
142 if (sigint_event != NULL)
143 ResetEvent(sigint_event);
144 res = WaitForMultipleObjectsEx(nhandles, handles, FALSE, full_msecs, FALSE);
145 Py_END_ALLOW_THREADS
146
147 /* handle result */
148 switch (res) {
149 case WAIT_TIMEOUT:
150 Py_RETURN_FALSE;
151 case WAIT_OBJECT_0 + 0:
152 self->last_tid = GetCurrentThreadId();
153 ++self->count;
154 Py_RETURN_TRUE;
155 case WAIT_OBJECT_0 + 1:
156 errno = EINTR;
157 return PyErr_SetFromErrno(PyExc_OSError);
158 case WAIT_FAILED:
159 return PyErr_SetFromWindowsErr(0);
160 default:
161 PyErr_Format(PyExc_RuntimeError, "WaitForSingleObject() or "
162 "WaitForMultipleObjects() gave unrecognized "
163 "value %u", res);
164 return NULL;
165 }
166}
167
168/*[clinic input]
169_multiprocessing.SemLock.release
170
171Release the semaphore/lock.
172[clinic start generated code]*/
173
174static PyObject *
175_multiprocessing_SemLock_release_impl(SemLockObject *self)
176/*[clinic end generated code: output=b22f53ba96b0d1db input=ba7e63a961885d3d]*/
177{
178 if (self->kind == RECURSIVE_MUTEX) {
179 if (!ISMINE(self)) {
180 PyErr_SetString(PyExc_AssertionError, "attempt to "
181 "release recursive lock not owned "
182 "by thread");
183 return NULL;
184 }
185 if (self->count > 1) {
186 --self->count;
187 Py_RETURN_NONE;
188 }
189 assert(self->count == 1);
190 }
191
192 if (!ReleaseSemaphore(self->handle, 1, NULL)) {
193 if (GetLastError() == ERROR_TOO_MANY_POSTS) {
194 PyErr_SetString(PyExc_ValueError, "semaphore or lock "
195 "released too many times");
196 return NULL;
197 } else {
198 return PyErr_SetFromWindowsErr(0);
199 }
200 }
201
202 --self->count;
203 Py_RETURN_NONE;
204}
205
206#else /* !MS_WINDOWS */
207
208/*
209 * Unix definitions
210 */
211
212#define SEM_CLEAR_ERROR()
213#define SEM_GET_LAST_ERROR() 0
214#define SEM_CREATE(name, val, max) sem_open(name, O_CREAT | O_EXCL, 0600, val)
215#define SEM_CLOSE(sem) sem_close(sem)
216#define SEM_GETVALUE(sem, pval) sem_getvalue(sem, pval)
217#define SEM_UNLINK(name) sem_unlink(name)
218
219/* OS X 10.4 defines SEM_FAILED as -1 instead of (sem_t *)-1; this gives
220 compiler warnings, and (potentially) undefined behaviour. */
221#ifdef __APPLE__
222# undef SEM_FAILED
223# define SEM_FAILED ((sem_t *)-1)
224#endif
225
226#ifndef HAVE_SEM_UNLINK
227# define sem_unlink(name) 0
228#endif
229
230#ifndef HAVE_SEM_TIMEDWAIT
231# define sem_timedwait(sem,deadline) sem_timedwait_save(sem,deadline,_save)
232
233static int
234sem_timedwait_save(sem_t *sem, struct timespec *deadline, PyThreadState *_save)
235{
236 int res;
237 unsigned long delay, difference;
238 struct timeval now, tvdeadline, tvdelay;
239
240 errno = 0;
241 tvdeadline.tv_sec = deadline->tv_sec;
242 tvdeadline.tv_usec = deadline->tv_nsec / 1000;
243
244 for (delay = 0 ; ; delay += 1000) {
245 /* poll */
246 if (sem_trywait(sem) == 0)
247 return 0;
248 else if (errno != EAGAIN)
249 return MP_STANDARD_ERROR;
250
251 /* get current time */
252 if (gettimeofday(&now, NULL) < 0)
253 return MP_STANDARD_ERROR;
254
255 /* check for timeout */
256 if (tvdeadline.tv_sec < now.tv_sec ||
257 (tvdeadline.tv_sec == now.tv_sec &&
258 tvdeadline.tv_usec <= now.tv_usec)) {
259 errno = ETIMEDOUT;
260 return MP_STANDARD_ERROR;
261 }
262
263 /* calculate how much time is left */
264 difference = (tvdeadline.tv_sec - now.tv_sec) * 1000000 +
265 (tvdeadline.tv_usec - now.tv_usec);
266
267 /* check delay not too long -- maximum is 20 msecs */
268 if (delay > 20000)
269 delay = 20000;
270 if (delay > difference)
271 delay = difference;
272
273 /* sleep */
274 tvdelay.tv_sec = delay / 1000000;
275 tvdelay.tv_usec = delay % 1000000;
276 if (select(0, NULL, NULL, NULL, &tvdelay) < 0)
277 return MP_STANDARD_ERROR;
278
279 /* check for signals */
280 Py_BLOCK_THREADS
281 res = PyErr_CheckSignals();
282 Py_UNBLOCK_THREADS
283
284 if (res) {
285 errno = EINTR;
286 return MP_EXCEPTION_HAS_BEEN_SET;
287 }
288 }
289}
290
291#endif /* !HAVE_SEM_TIMEDWAIT */
292
293/*[clinic input]
294_multiprocessing.SemLock.acquire
295
296 block as blocking: bool(accept={int}) = True
297 timeout as timeout_obj: object = None
298
299Acquire the semaphore/lock.
300[clinic start generated code]*/
301
302static PyObject *
303_multiprocessing_SemLock_acquire_impl(SemLockObject *self, int blocking,
304 PyObject *timeout_obj)
305/*[clinic end generated code: output=f9998f0b6b0b0872 input=86f05662cf753eb4]*/
306{
307 int res, err = 0;
308 struct timespec deadline = {0};
309
310 if (self->kind == RECURSIVE_MUTEX && ISMINE(self)) {
311 ++self->count;
312 Py_RETURN_TRUE;
313 }
314
315 int use_deadline = (timeout_obj != Py_None);
316 if (use_deadline) {
317 double timeout = PyFloat_AsDouble(timeout_obj);
318 if (PyErr_Occurred()) {
319 return NULL;
320 }
321 if (timeout < 0.0) {
322 timeout = 0.0;
323 }
324
325 struct timeval now;
326 if (gettimeofday(&now, NULL) < 0) {
327 PyErr_SetFromErrno(PyExc_OSError);
328 return NULL;
329 }
330 long sec = (long) timeout;
331 long nsec = (long) (1e9 * (timeout - sec) + 0.5);
332 deadline.tv_sec = now.tv_sec + sec;
333 deadline.tv_nsec = now.tv_usec * 1000 + nsec;
334 deadline.tv_sec += (deadline.tv_nsec / 1000000000);
335 deadline.tv_nsec %= 1000000000;
336 }
337
338 /* Check whether we can acquire without releasing the GIL and blocking */
339 do {
340 res = sem_trywait(self->handle);
341 err = errno;
342 } while (res < 0 && errno == EINTR && !PyErr_CheckSignals());
343 errno = err;
344
345 if (res < 0 && errno == EAGAIN && blocking) {
346 /* Couldn't acquire immediately, need to block */
347 do {
348 Py_BEGIN_ALLOW_THREADS
349 if (!use_deadline) {
350 res = sem_wait(self->handle);
351 }
352 else {
353 res = sem_timedwait(self->handle, &deadline);
354 }
355 Py_END_ALLOW_THREADS
356 err = errno;
357 if (res == MP_EXCEPTION_HAS_BEEN_SET)
358 break;
359 } while (res < 0 && errno == EINTR && !PyErr_CheckSignals());
360 }
361
362 if (res < 0) {
363 errno = err;
364 if (errno == EAGAIN || errno == ETIMEDOUT)
365 Py_RETURN_FALSE;
366 else if (errno == EINTR)
367 return NULL;
368 else
369 return PyErr_SetFromErrno(PyExc_OSError);
370 }
371
372 ++self->count;
373 self->last_tid = PyThread_get_thread_ident();
374
375 Py_RETURN_TRUE;
376}
377
378/*[clinic input]
379_multiprocessing.SemLock.release
380
381Release the semaphore/lock.
382[clinic start generated code]*/
383
384static PyObject *
385_multiprocessing_SemLock_release_impl(SemLockObject *self)
386/*[clinic end generated code: output=b22f53ba96b0d1db input=ba7e63a961885d3d]*/
387{
388 if (self->kind == RECURSIVE_MUTEX) {
389 if (!ISMINE(self)) {
390 PyErr_SetString(PyExc_AssertionError, "attempt to "
391 "release recursive lock not owned "
392 "by thread");
393 return NULL;
394 }
395 if (self->count > 1) {
396 --self->count;
397 Py_RETURN_NONE;
398 }
399 assert(self->count == 1);
400 } else {
401#ifdef HAVE_BROKEN_SEM_GETVALUE
402 /* We will only check properly the maxvalue == 1 case */
403 if (self->maxvalue == 1) {
404 /* make sure that already locked */
405 if (sem_trywait(self->handle) < 0) {
406 if (errno != EAGAIN) {
407 PyErr_SetFromErrno(PyExc_OSError);
408 return NULL;
409 }
410 /* it is already locked as expected */
411 } else {
412 /* it was not locked so undo wait and raise */
413 if (sem_post(self->handle) < 0) {
414 PyErr_SetFromErrno(PyExc_OSError);
415 return NULL;
416 }
417 PyErr_SetString(PyExc_ValueError, "semaphore "
418 "or lock released too many "
419 "times");
420 return NULL;
421 }
422 }
423#else
424 int sval;
425
426 /* This check is not an absolute guarantee that the semaphore
427 does not rise above maxvalue. */
428 if (sem_getvalue(self->handle, &sval) < 0) {
429 return PyErr_SetFromErrno(PyExc_OSError);
430 } else if (sval >= self->maxvalue) {
431 PyErr_SetString(PyExc_ValueError, "semaphore or lock "
432 "released too many times");
433 return NULL;
434 }
435#endif
436 }
437
438 if (sem_post(self->handle) < 0)
439 return PyErr_SetFromErrno(PyExc_OSError);
440
441 --self->count;
442 Py_RETURN_NONE;
443}
444
445#endif /* !MS_WINDOWS */
446
447/*
448 * All platforms
449 */
450
451static PyObject *
452newsemlockobject(PyTypeObject *type, SEM_HANDLE handle, int kind, int maxvalue,
453 char *name)
454{
455 SemLockObject *self;
456
457 self = PyObject_New(SemLockObject, type);
458 if (!self)
459 return NULL;
460 self->handle = handle;
461 self->kind = kind;
462 self->count = 0;
463 self->last_tid = 0;
464 self->maxvalue = maxvalue;
465 self->name = name;
466 return (PyObject*)self;
467}
468
469/*[clinic input]
470@classmethod
471_multiprocessing.SemLock.__new__
472
473 kind: int
474 value: int
475 maxvalue: int
476 name: str
477 unlink: bool(accept={int})
478
479[clinic start generated code]*/
480
481static PyObject *
482_multiprocessing_SemLock_impl(PyTypeObject *type, int kind, int value,
483 int maxvalue, const char *name, int unlink)
484/*[clinic end generated code: output=30727e38f5f7577a input=b378c3ee27d3a0fa]*/
485{
486 SEM_HANDLE handle = SEM_FAILED;
487 PyObject *result;
488 char *name_copy = NULL;
489
490 if (kind != RECURSIVE_MUTEX && kind != SEMAPHORE) {
491 PyErr_SetString(PyExc_ValueError, "unrecognized kind");
492 return NULL;
493 }
494
495 if (!unlink) {
496 name_copy = PyMem_Malloc(strlen(name) + 1);
497 if (name_copy == NULL) {
498 return PyErr_NoMemory();
499 }
500 strcpy(name_copy, name);
501 }
502
503 SEM_CLEAR_ERROR();
504 handle = SEM_CREATE(name, value, maxvalue);
505 /* On Windows we should fail if GetLastError()==ERROR_ALREADY_EXISTS */
506 if (handle == SEM_FAILED || SEM_GET_LAST_ERROR() != 0)
507 goto failure;
508
509 if (unlink && SEM_UNLINK(name) < 0)
510 goto failure;
511
512 result = newsemlockobject(type, handle, kind, maxvalue, name_copy);
513 if (!result)
514 goto failure;
515
516 return result;
517
518 failure:
519 if (handle != SEM_FAILED)
520 SEM_CLOSE(handle);
521 PyMem_Free(name_copy);
522 if (!PyErr_Occurred()) {
523 _PyMp_SetError(NULL, MP_STANDARD_ERROR);
524 }
525 return NULL;
526}
527
528/*[clinic input]
529@classmethod
530_multiprocessing.SemLock._rebuild
531
532 handle: SEM_HANDLE
533 kind: int
534 maxvalue: int
535 name: str(accept={str, NoneType})
536 /
537
538[clinic start generated code]*/
539
540static PyObject *
541_multiprocessing_SemLock__rebuild_impl(PyTypeObject *type, SEM_HANDLE handle,
542 int kind, int maxvalue,
543 const char *name)
544/*[clinic end generated code: output=2aaee14f063f3bd9 input=f7040492ac6d9962]*/
545{
546 char *name_copy = NULL;
547
548 if (name != NULL) {
549 name_copy = PyMem_Malloc(strlen(name) + 1);
550 if (name_copy == NULL)
551 return PyErr_NoMemory();
552 strcpy(name_copy, name);
553 }
554
555#ifndef MS_WINDOWS
556 if (name != NULL) {
557 handle = sem_open(name, 0);
558 if (handle == SEM_FAILED) {
559 PyMem_Free(name_copy);
560 return PyErr_SetFromErrno(PyExc_OSError);
561 }
562 }
563#endif
564
565 return newsemlockobject(type, handle, kind, maxvalue, name_copy);
566}
567
568static void
569semlock_dealloc(SemLockObject* self)
570{
571 if (self->handle != SEM_FAILED)
572 SEM_CLOSE(self->handle);
573 PyMem_Free(self->name);
574 PyObject_Free(self);
575}
576
577/*[clinic input]
578_multiprocessing.SemLock._count
579
580Num of `acquire()`s minus num of `release()`s for this process.
581[clinic start generated code]*/
582
583static PyObject *
584_multiprocessing_SemLock__count_impl(SemLockObject *self)
585/*[clinic end generated code: output=5ba8213900e517bb input=36fc59b1cd1025ab]*/
586{
587 return PyLong_FromLong((long)self->count);
588}
589
590/*[clinic input]
591_multiprocessing.SemLock._is_mine
592
593Whether the lock is owned by this thread.
594[clinic start generated code]*/
595
596static PyObject *
597_multiprocessing_SemLock__is_mine_impl(SemLockObject *self)
598/*[clinic end generated code: output=92dc98863f4303be input=a96664cb2f0093ba]*/
599{
600 /* only makes sense for a lock */
601 return PyBool_FromLong(ISMINE(self));
602}
603
604/*[clinic input]
605_multiprocessing.SemLock._get_value
606
607Get the value of the semaphore.
608[clinic start generated code]*/
609
610static PyObject *
611_multiprocessing_SemLock__get_value_impl(SemLockObject *self)
612/*[clinic end generated code: output=64bc1b89bda05e36 input=cb10f9a769836203]*/
613{
614#ifdef HAVE_BROKEN_SEM_GETVALUE
615 PyErr_SetNone(PyExc_NotImplementedError);
616 return NULL;
617#else
618 int sval;
619 if (SEM_GETVALUE(self->handle, &sval) < 0)
620 return _PyMp_SetError(NULL, MP_STANDARD_ERROR);
621 /* some posix implementations use negative numbers to indicate
622 the number of waiting threads */
623 if (sval < 0)
624 sval = 0;
625 return PyLong_FromLong((long)sval);
626#endif
627}
628
629/*[clinic input]
630_multiprocessing.SemLock._is_zero
631
632Return whether semaphore has value zero.
633[clinic start generated code]*/
634
635static PyObject *
636_multiprocessing_SemLock__is_zero_impl(SemLockObject *self)
637/*[clinic end generated code: output=815d4c878c806ed7 input=294a446418d31347]*/
638{
639#ifdef HAVE_BROKEN_SEM_GETVALUE
640 if (sem_trywait(self->handle) < 0) {
641 if (errno == EAGAIN)
642 Py_RETURN_TRUE;
643 return _PyMp_SetError(NULL, MP_STANDARD_ERROR);
644 } else {
645 if (sem_post(self->handle) < 0)
646 return _PyMp_SetError(NULL, MP_STANDARD_ERROR);
647 Py_RETURN_FALSE;
648 }
649#else
650 int sval;
651 if (SEM_GETVALUE(self->handle, &sval) < 0)
652 return _PyMp_SetError(NULL, MP_STANDARD_ERROR);
653 return PyBool_FromLong((long)sval == 0);
654#endif
655}
656
657/*[clinic input]
658_multiprocessing.SemLock._after_fork
659
660Rezero the net acquisition count after fork().
661[clinic start generated code]*/
662
663static PyObject *
664_multiprocessing_SemLock__after_fork_impl(SemLockObject *self)
665/*[clinic end generated code: output=718bb27914c6a6c1 input=190991008a76621e]*/
666{
667 self->count = 0;
668 Py_RETURN_NONE;
669}
670
671/*[clinic input]
672_multiprocessing.SemLock.__enter__
673
674Enter the semaphore/lock.
675[clinic start generated code]*/
676
677static PyObject *
678_multiprocessing_SemLock___enter___impl(SemLockObject *self)
679/*[clinic end generated code: output=beeb2f07c858511f input=c5e27d594284690b]*/
680{
681 return _multiprocessing_SemLock_acquire_impl(self, 1, Py_None);
682}
683
684/*[clinic input]
685_multiprocessing.SemLock.__exit__
686
687 exc_type: object = None
688 exc_value: object = None
689 exc_tb: object = None
690 /
691
692Exit the semaphore/lock.
693[clinic start generated code]*/
694
695static PyObject *
696_multiprocessing_SemLock___exit___impl(SemLockObject *self,
697 PyObject *exc_type,
698 PyObject *exc_value, PyObject *exc_tb)
699/*[clinic end generated code: output=3b37c1a9f8b91a03 input=7d644b64a89903f8]*/
700{
701 return _multiprocessing_SemLock_release_impl(self);
702}
703
704/*
705 * Semaphore methods
706 */
707
708static PyMethodDef semlock_methods[] = {
709 _MULTIPROCESSING_SEMLOCK_ACQUIRE_METHODDEF
710 _MULTIPROCESSING_SEMLOCK_RELEASE_METHODDEF
711 _MULTIPROCESSING_SEMLOCK___ENTER___METHODDEF
712 _MULTIPROCESSING_SEMLOCK___EXIT___METHODDEF
713 _MULTIPROCESSING_SEMLOCK__COUNT_METHODDEF
714 _MULTIPROCESSING_SEMLOCK__IS_MINE_METHODDEF
715 _MULTIPROCESSING_SEMLOCK__GET_VALUE_METHODDEF
716 _MULTIPROCESSING_SEMLOCK__IS_ZERO_METHODDEF
717 _MULTIPROCESSING_SEMLOCK__REBUILD_METHODDEF
718 _MULTIPROCESSING_SEMLOCK__AFTER_FORK_METHODDEF
719 {NULL}
720};
721
722/*
723 * Member table
724 */
725
726static PyMemberDef semlock_members[] = {
727 {"handle", T_SEM_HANDLE, offsetof(SemLockObject, handle), READONLY,
728 ""},
729 {"kind", T_INT, offsetof(SemLockObject, kind), READONLY,
730 ""},
731 {"maxvalue", T_INT, offsetof(SemLockObject, maxvalue), READONLY,
732 ""},
733 {"name", T_STRING, offsetof(SemLockObject, name), READONLY,
734 ""},
735 {NULL}
736};
737
738/*
739 * Semaphore type
740 */
741
742PyTypeObject _PyMp_SemLockType = {
743 PyVarObject_HEAD_INIT(NULL, 0)
744 /* tp_name */ "_multiprocessing.SemLock",
745 /* tp_basicsize */ sizeof(SemLockObject),
746 /* tp_itemsize */ 0,
747 /* tp_dealloc */ (destructor)semlock_dealloc,
748 /* tp_vectorcall_offset */ 0,
749 /* tp_getattr */ 0,
750 /* tp_setattr */ 0,
751 /* tp_as_async */ 0,
752 /* tp_repr */ 0,
753 /* tp_as_number */ 0,
754 /* tp_as_sequence */ 0,
755 /* tp_as_mapping */ 0,
756 /* tp_hash */ 0,
757 /* tp_call */ 0,
758 /* tp_str */ 0,
759 /* tp_getattro */ 0,
760 /* tp_setattro */ 0,
761 /* tp_as_buffer */ 0,
762 /* tp_flags */ Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,
763 /* tp_doc */ "Semaphore/Mutex type",
764 /* tp_traverse */ 0,
765 /* tp_clear */ 0,
766 /* tp_richcompare */ 0,
767 /* tp_weaklistoffset */ 0,
768 /* tp_iter */ 0,
769 /* tp_iternext */ 0,
770 /* tp_methods */ semlock_methods,
771 /* tp_members */ semlock_members,
772 /* tp_getset */ 0,
773 /* tp_base */ 0,
774 /* tp_dict */ 0,
775 /* tp_descr_get */ 0,
776 /* tp_descr_set */ 0,
777 /* tp_dictoffset */ 0,
778 /* tp_init */ 0,
779 /* tp_alloc */ 0,
780 /* tp_new */ _multiprocessing_SemLock,
781};
782
783/*
784 * Function to unlink semaphore names
785 */
786
787PyObject *
788_PyMp_sem_unlink(const char *name)
789{
790 if (SEM_UNLINK(name) < 0) {
791 _PyMp_SetError(NULL, MP_STANDARD_ERROR);
792 return NULL;
793 }
794
795 Py_RETURN_NONE;
796}
797