From 9da8fdcb33373b4b2e1de2a8b7af3ed4b5811245 Mon Sep 17 00:00:00 2001 From: rpj Date: Fri, 8 Oct 2004 12:03:18 +0000 Subject: Mutex speedups --- pthread_mutex_timedlock.c | 175 +++++++++++++++++++--------------------------- 1 file changed, 73 insertions(+), 102 deletions(-) (limited to 'pthread_mutex_timedlock.c') diff --git a/pthread_mutex_timedlock.c b/pthread_mutex_timedlock.c index 58f5613..cf929bc 100644 --- a/pthread_mutex_timedlock.c +++ b/pthread_mutex_timedlock.c @@ -206,7 +206,7 @@ int pthread_mutex_timedlock (pthread_mutex_t * mutex, const struct timespec *abstime) { - int result = 0; + LONG c; pthread_mutex_t mx; #ifdef NEED_SEM @@ -226,6 +226,8 @@ pthread_mutex_timedlock (pthread_mutex_t * mutex, */ if (*mutex >= PTHREAD_ERRORCHECK_MUTEX_INITIALIZER) { + int result; + if ((result = ptw32_mutex_check_need_init (mutex)) != 0) { return (result); @@ -236,63 +238,51 @@ pthread_mutex_timedlock (pthread_mutex_t * mutex, if (mx->kind == PTHREAD_MUTEX_NORMAL) { - if (0 != InterlockedIncrement (&mx->lock_idx)) + if ((c = (LONG) PTW32_INTERLOCKED_COMPARE_EXCHANGE( + (PTW32_INTERLOCKED_LPLONG) &mx->lock_idx, + (PTW32_INTERLOCKED_LONG) 0, + (PTW32_INTERLOCKED_LONG) -1)) != -1) { - switch (ptw32_timed_semwait (&mx->wait_sema, abstime)) - { - case 0: /* We got the mutex. */ - { - break; - } - case 1: /* Timed out. */ - case 2: /* abstime passed before we started to wait. */ - { - /* - * If we timeout, it is up to us to adjust lock_idx to say - * we're no longer waiting. - * - * The owner thread may still have posted wait_sema thinking - * we were waiting. We must check but then NOT do any - * programmed work if we have acquired the mutex because - * we don't know how long ago abstime was. We MUST just release it - * immediately. - */ - EnterCriticalSection (&mx->wait_cs); - - result = ETIMEDOUT; - - if (-1 == sem_trywait (&mx->wait_sema)) + do + { + if (c == 1 || + (LONG) PTW32_INTERLOCKED_COMPARE_EXCHANGE( + (PTW32_INTERLOCKED_LPLONG) &mx->lock_idx, + (PTW32_INTERLOCKED_LONG) 1, + (PTW32_INTERLOCKED_LONG) 0) != -1) + { + switch (ptw32_timed_semwait (&mx->wait_sema, abstime)) { - (void) InterlockedDecrement (&mx->lock_idx); - } - else - { - if (InterlockedDecrement (&mx->lock_idx) >= 0) - { - /* Someone else is waiting on that mutex */ - if (sem_post (&mx->wait_sema) != 0) - { - result = errno; - } - } - } - - LeaveCriticalSection (&mx->wait_cs); - break; - } - default: - { - result = errno; - break; + case 0: /* We got woken up so try get the lock again. */ + { + break; + } + case 1: /* Timed out. */ + case 2: /* abstime passed before we started to wait. */ + { + return ETIMEDOUT; + } + default: + { + return errno; + } + } } - } + } + while ((c = (LONG) PTW32_INTERLOCKED_COMPARE_EXCHANGE( + (PTW32_INTERLOCKED_LPLONG) &mx->lock_idx, + (PTW32_INTERLOCKED_LONG) 1, + (PTW32_INTERLOCKED_LONG) -1)) != -1); } } else { pthread_t self = pthread_self(); - if (0 == InterlockedIncrement (&mx->lock_idx)) + if ((c = (LONG) PTW32_INTERLOCKED_COMPARE_EXCHANGE( + (PTW32_INTERLOCKED_LPLONG) &mx->lock_idx, + (PTW32_INTERLOCKED_LONG) 0, + (PTW32_INTERLOCKED_LONG) -1)) == -1) { mx->recursive_count = 1; mx->ownerThread = self; @@ -301,72 +291,53 @@ pthread_mutex_timedlock (pthread_mutex_t * mutex, { if (pthread_equal (mx->ownerThread, self)) { - (void) InterlockedDecrement (&mx->lock_idx); - if (mx->kind == PTHREAD_MUTEX_RECURSIVE) { mx->recursive_count++; } else { - result = EDEADLK; + return EDEADLK; } } else { - switch (ptw32_timed_semwait (&mx->wait_sema, abstime)) - { - case 0: /* We got the mutex. */ - { - mx->recursive_count = 1; - mx->ownerThread = self; - break; + do + { + if (c == 1 || + (LONG) PTW32_INTERLOCKED_COMPARE_EXCHANGE( + (PTW32_INTERLOCKED_LPLONG) &mx->lock_idx, + (PTW32_INTERLOCKED_LONG) 1, + (PTW32_INTERLOCKED_LONG) 0) != -1) + { + switch (ptw32_timed_semwait (&mx->wait_sema, abstime)) + { + case 0: /* We got woken up so try get the lock again. */ + { + break; + } + case 1: /* Timed out. */ + case 2: /* abstime passed before we started to wait. */ + { + return ETIMEDOUT; + } + default: + { + return errno; + } + } } - case 1: /* Timedout. */ - case 2: /* abstime passed before we started to wait. */ - { - /* - * If we timeout, it is up to us to adjust lock_idx to say - * we're no longer waiting. - * - * The owner thread may still have posted wait_sema thinking - * we were waiting. We must check but then NOT do any - * programmed work if we have acquired the mutex because - * we don't know how long ago abstime was. We MUST just release it - * immediately. - */ - EnterCriticalSection (&mx->wait_cs); - - result = ETIMEDOUT; - - if (-1 == sem_trywait (&mx->wait_sema)) - { - (void) InterlockedDecrement (&mx->lock_idx); - } - else - { - if (InterlockedDecrement (&mx->lock_idx) >= 0) - { - /* Someone else is waiting on that mutex */ - if (sem_post (&mx->wait_sema) != 0) - { - result = errno; - } - } - } - - LeaveCriticalSection (&mx->wait_cs); - break; - } - default: - { - result = errno; - break; - } - } + } + while ((c = (LONG) PTW32_INTERLOCKED_COMPARE_EXCHANGE( + (PTW32_INTERLOCKED_LPLONG) &mx->lock_idx, + (PTW32_INTERLOCKED_LONG) 1, + (PTW32_INTERLOCKED_LONG) -1)) != -1); + + mx->recursive_count = 1; + mx->ownerThread = self; } } } - return (result); + return 0; } -- cgit v1.2.3