cosmopolitan/libc/thread/pthread_detach.c
2022-09-05 08:27:15 -07:00

51 lines
2.8 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2022 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/intrin/atomic.h"
#include "libc/intrin/pthread.h"
#include "libc/macros.internal.h"
#include "libc/mem/mem.h"
#include "libc/thread/posixthread.internal.h"
#include "libc/thread/spawn.h"
/**
* Asks POSIX thread to free itself automatically on termination.
*
* @return 0 on success, or errno with error
*/
int pthread_detach(pthread_t thread) {
enum PosixThreadStatus status;
struct PosixThread *pt = thread;
for (;;) {
status = atomic_load_explicit(&pt->status, memory_order_relaxed);
if (status == kPosixThreadDetached || status == kPosixThreadZombie) {
break;
} else if (status == kPosixThreadTerminated) {
_join(&pt->spawn);
free(pt);
break;
} else if (status == kPosixThreadStarted &&
atomic_compare_exchange_weak_explicit(
&pt->status, &status, kPosixThreadDetached,
memory_order_acquire, memory_order_relaxed)) {
pthread_zombies_add(pt);
break;
}
}
return 0;
}