mirror of
https://github.com/jart/cosmopolitan.git
synced 2025-01-31 11:37:35 +00:00
e16a7d8f3b
`et` means `expandtab`. ```sh rg 'vi: .* :vi' -l -0 | \ xargs -0 sed -i '' 's/vi: \(.*\) et\(.*\) :vi/vi: \1 xoet\2:vi/' rg 'vi: .* :vi' -l -0 | \ xargs -0 sed -i '' 's/vi: \(.*\)noet\(.*\):vi/vi: \1et\2 :vi/' rg 'vi: .* :vi' -l -0 | \ xargs -0 sed -i '' 's/vi: \(.*\)xoet\(.*\):vi/vi: \1noet\2:vi/' ```
51 lines
2.9 KiB
C
51 lines
2.9 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 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/assert.h"
|
|
#include "libc/intrin/atomic.h"
|
|
#include "libc/limits.h"
|
|
#include "libc/sysv/errfuns.h"
|
|
#include "libc/thread/semaphore.h"
|
|
|
|
/**
|
|
* Destroys unnamed semaphore.
|
|
*
|
|
* If `sem` was successfully initialized by sem_init() then
|
|
* sem_destroy() may be called multiple times, before it may be
|
|
* reinitialized again by calling sem_init().
|
|
*
|
|
* Calling sem_destroy() on a semaphore created by sem_open() has
|
|
* undefined behavior. Using `sem` after calling sem_destroy() is
|
|
* undefined behavior that will cause semaphore APIs to either crash or
|
|
* raise `EINVAL` until `sem` is passed to sem_init() again.
|
|
*
|
|
* @param sem was created by sem_init()
|
|
* @return 0 on success, or -1 w/ errno
|
|
* @raise EINVAL if `sem` wasn't valid
|
|
* @raise EBUSY if `sem` has waiters
|
|
*/
|
|
int sem_destroy(sem_t *sem) {
|
|
int waiters;
|
|
npassert(sem->sem_magic != SEM_MAGIC_NAMED);
|
|
if (sem->sem_magic != SEM_MAGIC_UNNAMED) return einval();
|
|
waiters = atomic_load_explicit(&sem->sem_waiters, memory_order_relaxed);
|
|
unassert(waiters >= 0);
|
|
if (waiters) return ebusy();
|
|
atomic_store_explicit(&sem->sem_value, INT_MIN, memory_order_relaxed);
|
|
return 0;
|
|
}
|