cosmopolitan/libc/thread/pthread_mutex_consistent.c
2024-12-23 21:57:52 -08:00

41 lines
2.5 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│ vi: set et ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi │
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2024 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/cosmo.h"
#include "libc/dce.h"
#include "libc/intrin/atomic.h"
#include "libc/thread/lock.h"
#include "libc/thread/thread.h"
/**
* Recovers mutex whose owner died.
*
* @return 0 on success, or errno on error
*/
int pthread_mutex_consistent(pthread_mutex_t *mutex) {
// The POSIX concept of robust mutexes is a bit cray. So let's change
// things up a bit. Rather than implementing all those goofy behaviors
// we shall simply use this function to weasel around the ownership
// check in pthread_mutex_unlock().
uint64_t word = atomic_load_explicit(&mutex->_word, memory_order_relaxed);
if (IsModeDbg() || MUTEX_TYPE(word) == PTHREAD_MUTEX_ERRORCHECK)
__deadlock_track(mutex, 0);
return 0;
}