mirror of
https://sourceware.org/git/glibc.git
synced 2025-12-05 00:02:41 +03:00
3dd2cbfa35
commit 7fec8a5de6
Author: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Date: Thu Nov 13 14:26:08 2025 -0300
Revert __HAVE_64B_ATOMICS configure check
uses 64-bit atomic operations on sem_t if 64-bit atomics are supported.
But sem_t may be aligned to 32-bit on 32-bit architectures.
1. Add a macro, SEM_T_ALIGN, for sem_t alignment.
2. Add a macro, HAVE_UNALIGNED_64B_ATOMICS. Define it if unaligned 64-bit
atomic operations are supported.
3. Add a macro, USE_64B_ATOMICS_ON_SEM_T. Define to 1 if 64-bit atomic
operations are supported and SEM_T_ALIGN is at least 8-byte aligned or
HAVE_UNALIGNED_64B_ATOMICS is defined.
4. Assert that size and alignment of sem_t are not lower than those of
the internal struct new_sem.
5. Check USE_64B_ATOMICS_ON_SEM_T, instead of USE_64B_ATOMICS, when using
64-bit atomic operations on sem_t.
This fixes BZ #33632.
Reviewed-by: Wilco Dijkstra <Wilco.Dijkstra@arm.com>
41 lines
1.4 KiB
C
41 lines
1.4 KiB
C
/* Get the value of a semaphore. Generic version.
|
|
Copyright (C) 2005-2025 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>
|
|
#include <shlib-compat.h>
|
|
|
|
int
|
|
__sem_getvalue (sem_t *restrict sem, int *restrict value)
|
|
{
|
|
struct new_sem *isem = (struct new_sem *) sem;
|
|
|
|
#if USE_64B_ATOMICS_ON_SEM_T
|
|
*value = atomic_load_relaxed (&isem->data) & SEM_VALUE_MASK;
|
|
#else
|
|
*value = atomic_load_relaxed (&isem->value) >> SEM_VALUE_SHIFT;
|
|
#endif
|
|
|
|
return 0;
|
|
}
|
|
|
|
versioned_symbol (libc, __sem_getvalue, sem_getvalue, GLIBC_2_43);
|
|
# if OTHER_SHLIB_COMPAT (libpthread, GLIBC_2_12, GLIBC_2_43)
|
|
compat_symbol (libpthread, __sem_getvalue, sem_getvalue, GLIBC_2_12);
|
|
#endif
|