glibc/nptl/sysdeps/unix/sysv/linux/sem_post.c
Ulrich Drepper 3d2dd6ca71 * semaphoreP.h: Declare __old_sem_init and __old_sem_wait.
* sem_init.c (__new_sem_init): Rewrite to initialize all three
	fields in the structure.
	(__old_sem_init): New function.
	* sem_open.c: Initialize all fields of the structure.
	* sem_getvalue.c: Adjust for renamed element.
	* sysdeps/unix/sysv/linux/Makefile [subdir=nptl]
	(gen-as-const-headers): Add structsem.sym.
	* sysdeps/unix/sysv/linux/structsem.sym: New file.
	* sysdeps/unix/sysv/linux/internaltypes.h: Rename struct sem to
	struct new_sem.  Add struct old_sem.
	* sysdeps/unix/sysv/linux/sem_post.c: Wake only when there are waiters.
	* sysdeps/unix/sysv/linux/i386/i486/sem_post.S: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/sem_post.S: Likewise.
	* sysdeps/unix/sysv/linux/sem_wait.c: Indicate that there are waiters.
	* sysdeps/unix/sysv/linux/i386/i486/sem_wait.S: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/sem_wait.S: Likewise.
	* sysdeps/unix/sysv/linux/sem_timedwait.c: Likewise.
	* sysdeps/unix/sysv/linux/i386/i486/sem_timedwait.S: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/sem_timedwait.S: Likewise.
	* Makefile (tests): Add tst-sem10, tst-sem11, tst-sem12.
	* tst-sem10.c: New file.
	* tst-sem11.c: New file.
	* tst-sem12.c: New file.
	* tst-typesizes.c: Test struct new_sem and struct old_sem instead
	of struct sem.

2007-05-25  Ulrich Drepper  <drepper@redhat.com>
2007-05-26 01:31:40 +00:00

68 lines
1.9 KiB
C

/* sem_post -- post to a POSIX semaphore. Generic futex-using version.
Copyright (C) 2003, 2004, 2007 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Jakub Jelinek <jakub@redhat.com>, 2003.
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, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <errno.h>
#include <sysdep.h>
#include <lowlevellock.h>
#include <internaltypes.h>
#include <semaphore.h>
#include <shlib-compat.h>
int
__new_sem_post (sem_t *sem)
{
struct new_sem *isem = (struct new_sem *) sem;
int nr = atomic_increment_val (&isem->value);
atomic_full_barrier ();
if (isem->nwaiters > 0)
{
int err = lll_futex_wake (&isem->value, 1);
if (__builtin_expect (err, 0) < 0)
{
__set_errno (-err);
return -1;
}
}
return 0;
}
versioned_symbol (libpthread, __new_sem_post, sem_post, GLIBC_2_1);
#if SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_1)
int
attribute_compat_text_section
__old_sem_post (sem_t *sem)
{
int *futex = (int *) sem;
int nr = atomic_increment_val (futex);
int err = lll_futex_wake (futex, 1);
if (__builtin_expect (err, 0) < 0)
{
__set_errno (-err);
return -1;
}
return 0;
}
compat_symbol (libpthread, __old_sem_post, sem_post, GLIBC_2_0);
#endif