glibc/sysdeps/htl/sem-getvalue.c

37 lines
1.2 KiB
C

/* Get the value of a semaphore. Generic version.
Copyright (C) 2005-2024 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 <pt-internal.h>
int
__sem_getvalue (sem_t *restrict sem, int *restrict value)
{
struct new_sem *isem = (struct new_sem *) sem;
#if __HAVE_64B_ATOMICS
*value = atomic_load_relaxed (&isem->data) & SEM_VALUE_MASK;
#else
*value = atomic_load_relaxed (&isem->value) >> SEM_VALUE_SHIFT;
#endif
return 0;
}
strong_alias (__sem_getvalue, sem_getvalue);