mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-25 22:40:05 +00:00
120 lines
3.1 KiB
C
120 lines
3.1 KiB
C
/* Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
|
|
|
|
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 <assert.h>
|
|
#include <errno.h>
|
|
#include "pthreadP.h"
|
|
#include <lowlevellock.h>
|
|
|
|
|
|
#ifndef LLL_MUTEX_LOCK
|
|
# define LLL_MUTEX_LOCK(mutex) lll_mutex_lock (mutex)
|
|
# define LLL_MUTEX_TRYLOCK(mutex) lll_mutex_trylock (mutex)
|
|
#endif
|
|
|
|
|
|
int
|
|
__pthread_mutex_lock (mutex)
|
|
pthread_mutex_t *mutex;
|
|
{
|
|
assert (sizeof (mutex->__size) >= sizeof (mutex->__data));
|
|
|
|
pid_t id = THREAD_GETMEM (THREAD_SELF, tid);
|
|
|
|
switch (__builtin_expect (mutex->__data.__kind, PTHREAD_MUTEX_TIMED_NP))
|
|
{
|
|
/* Recursive mutex. */
|
|
case PTHREAD_MUTEX_RECURSIVE_NP:
|
|
/* Check whether we already hold the mutex. */
|
|
if (mutex->__data.__owner == id)
|
|
{
|
|
/* Just bump the counter. */
|
|
if (__builtin_expect (mutex->__data.__count + 1 == 0, 0))
|
|
/* Overflow of the counter. */
|
|
return EAGAIN;
|
|
|
|
++mutex->__data.__count;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* We have to get the mutex. */
|
|
LLL_MUTEX_LOCK (mutex->__data.__lock);
|
|
|
|
mutex->__data.__count = 1;
|
|
break;
|
|
|
|
/* Error checking mutex. */
|
|
case PTHREAD_MUTEX_ERRORCHECK_NP:
|
|
/* Check whether we already hold the mutex. */
|
|
if (mutex->__data.__owner == id)
|
|
return EDEADLK;
|
|
|
|
/* FALLTHROUGH */
|
|
|
|
default:
|
|
/* Correct code cannot set any other type. */
|
|
case PTHREAD_MUTEX_TIMED_NP:
|
|
simple:
|
|
/* Normal mutex. */
|
|
LLL_MUTEX_LOCK (mutex->__data.__lock);
|
|
break;
|
|
|
|
case PTHREAD_MUTEX_ADAPTIVE_NP:
|
|
if (! __is_smp)
|
|
goto simple;
|
|
|
|
if (LLL_MUTEX_TRYLOCK (mutex->__data.__lock) != 0)
|
|
{
|
|
int cnt = 0;
|
|
int max_cnt = MIN (MAX_ADAPTIVE_COUNT,
|
|
mutex->__data.__spins * 2 + 10);
|
|
do
|
|
{
|
|
if (cnt++ >= max_cnt)
|
|
{
|
|
LLL_MUTEX_LOCK (mutex->__data.__lock);
|
|
break;
|
|
}
|
|
|
|
#ifdef BUSY_WAIT_NOP
|
|
BUSY_WAIT_NOP;
|
|
#endif
|
|
}
|
|
while (LLL_MUTEX_TRYLOCK (mutex->__data.__lock) != 0);
|
|
|
|
mutex->__data.__spins += (cnt - mutex->__data.__spins) / 8;
|
|
}
|
|
break;
|
|
}
|
|
|
|
/* Record the ownership. */
|
|
assert (mutex->__data.__owner == 0);
|
|
mutex->__data.__owner = id;
|
|
#ifndef NO_INCR
|
|
++mutex->__data.__nusers;
|
|
#endif
|
|
|
|
return 0;
|
|
}
|
|
#ifndef __pthread_mutex_lock
|
|
strong_alias (__pthread_mutex_lock, pthread_mutex_lock)
|
|
strong_alias (__pthread_mutex_lock, __pthread_mutex_lock_internal)
|
|
#endif
|