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- /* 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
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