mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-26 06:50:07 +00:00
70d0dda0c1
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com> Message-Id: <20230520115531.3911877-2-bugaevc@gmail.com>
66 lines
1.9 KiB
C
66 lines
1.9 KiB
C
/* Post a semaphore. Generic version.
|
|
Copyright (C) 2005-2023 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Lesser General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2.1 of the License, or (at your option) any later version.
|
|
|
|
The GNU C Library is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
License along with the GNU C Library; if not, see
|
|
<https://www.gnu.org/licenses/>. */
|
|
|
|
#include <semaphore.h>
|
|
#include <assert.h>
|
|
|
|
#include <hurdlock.h>
|
|
#include <hurd.h>
|
|
|
|
#include <pt-internal.h>
|
|
|
|
int
|
|
__sem_post (sem_t *sem)
|
|
{
|
|
struct new_sem *isem = (struct new_sem *) sem;
|
|
int flags = isem->pshared ? GSYNC_SHARED : 0;
|
|
|
|
#if __HAVE_64B_ATOMICS
|
|
uint64_t d = atomic_load_relaxed (&isem->data);
|
|
|
|
do
|
|
{
|
|
if ((d & SEM_VALUE_MASK) == SEM_VALUE_MAX)
|
|
return __hurd_fail (EOVERFLOW);
|
|
}
|
|
while (!atomic_compare_exchange_weak_release (&isem->data, &d, d + 1));
|
|
|
|
if ((d >> SEM_NWAITERS_SHIFT) != 0)
|
|
/* Wake one waiter. */
|
|
__lll_wake (((unsigned int *) &isem->data) + SEM_VALUE_OFFSET, flags);
|
|
#else
|
|
unsigned int v = atomic_load_relaxed (&isem->value);
|
|
|
|
do
|
|
{
|
|
if ((v >> SEM_VALUE_SHIFT) == SEM_VALUE_MAX)
|
|
return __hurd_fail (EOVERFLOW);
|
|
}
|
|
while (!atomic_compare_exchange_weak_release
|
|
(&isem->value, &v, v + (1 << SEM_VALUE_SHIFT)));
|
|
|
|
if ((v & SEM_NWAITERS_MASK) != 0)
|
|
/* Wake one waiter. */
|
|
__lll_wake (&isem->value, flags);
|
|
#endif
|
|
|
|
return 0;
|
|
}
|
|
libpthread_hidden_def (__sem_post)
|
|
strong_alias (__sem_post, sem_post);
|