diff options
Diffstat (limited to 'nptl/pthread_mutex_lock.c')
| -rw-r--r-- | nptl/pthread_mutex_lock.c | 34 |
1 files changed, 32 insertions, 2 deletions
diff --git a/nptl/pthread_mutex_lock.c b/nptl/pthread_mutex_lock.c index ac770c5c00..ee39f20820 100644 --- a/nptl/pthread_mutex_lock.c +++ b/nptl/pthread_mutex_lock.c @@ -1,4 +1,4 @@ -/* Copyright (C) 2002, 2003 Free Software Foundation, Inc. +/* 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. @@ -25,6 +25,7 @@ #ifndef LLL_MUTEX_LOCK # define LLL_MUTEX_LOCK(mutex) lll_mutex_lock (mutex) +# define LLL_MUTEX_TRYLOCK(mutex) lll_mutex_trylock (mutex) #endif @@ -32,6 +33,8 @@ 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)) @@ -68,10 +71,37 @@ __pthread_mutex_lock (mutex) default: /* Correct code cannot set any other type. */ case PTHREAD_MUTEX_TIMED_NP: - case PTHREAD_MUTEX_ADAPTIVE_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. */ |