diff options
Diffstat (limited to 'storage/innobase/sync/sync0sync.cc')
| -rw-r--r-- | storage/innobase/sync/sync0sync.cc | 32 |
1 files changed, 17 insertions, 15 deletions
diff --git a/storage/innobase/sync/sync0sync.cc b/storage/innobase/sync/sync0sync.cc index 3532f513646..9fc21005d47 100644 --- a/storage/innobase/sync/sync0sync.cc +++ b/storage/innobase/sync/sync0sync.cc @@ -45,6 +45,7 @@ Created 9/5/1995 Heikki Tuuri # include "srv0start.h" /* srv_is_being_started */ #endif /* UNIV_SYNC_DEBUG */ #include "ha_prototypes.h" +#include "my_cpu.h" /* REASONS FOR IMPLEMENTING THE SPIN LOCK MUTEX @@ -126,7 +127,7 @@ it and did not see the waiters byte set to 1, a case which would lead the other thread to an infinite wait. LEMMA 1: After a thread resets the event of a mutex (or rw_lock), some -======= +====== thread will eventually call os_event_set() on that particular event. Thus no infinite wait is possible in this case. @@ -139,7 +140,7 @@ os_event_set() with the mutex as an argument. Q.E.D. LEMMA 2: If an os_event_set() call is made after some thread has called -======= +====== the os_event_reset() and before it starts wait on that event, the call will not be lost to the second thread. This is true even if there is an intervening call to os_event_reset() by another thread. @@ -456,6 +457,8 @@ mutex_set_waiters( ptr = &(mutex->waiters); + os_wmb; + *ptr = n; /* Here we assume that the write of a single word in memory is atomic */ } @@ -500,15 +503,17 @@ mutex_loop: spin_loop: + HMT_low(); + os_rmb; while (mutex_get_lock_word(mutex) != 0 && i < SYNC_SPIN_ROUNDS) { if (srv_spin_wait_delay) { ut_delay(ut_rnd_interval(0, srv_spin_wait_delay)); } - i++; } + HMT_medium(); - if (i == SYNC_SPIN_ROUNDS) { + if (i >= SYNC_SPIN_ROUNDS) { os_thread_yield(); } @@ -1473,11 +1478,7 @@ sync_init(void) SYNC_NO_ORDER_CHECK); #ifdef UNIV_SYNC_DEBUG - mutex_create(rw_lock_debug_mutex_key, &rw_lock_debug_mutex, - SYNC_NO_ORDER_CHECK); - - rw_lock_debug_event = os_event_create(); - rw_lock_debug_waiters = FALSE; + os_fast_mutex_init(rw_lock_debug_mutex_key, &rw_lock_debug_mutex); #endif /* UNIV_SYNC_DEBUG */ } @@ -1545,6 +1546,7 @@ sync_close(void) sync_order_checks_on = FALSE; sync_thread_level_arrays_free(); + os_fast_mutex_free(&rw_lock_debug_mutex); #endif /* UNIV_SYNC_DEBUG */ sync_initialized = FALSE; @@ -1559,12 +1561,12 @@ sync_print_wait_info( FILE* file) /*!< in: file where to print */ { fprintf(file, - "Mutex spin waits "UINT64PF", rounds "UINT64PF", " - "OS waits "UINT64PF"\n" - "RW-shared spins "UINT64PF", rounds "UINT64PF", " - "OS waits "UINT64PF"\n" - "RW-excl spins "UINT64PF", rounds "UINT64PF", " - "OS waits "UINT64PF"\n", + "Mutex spin waits " UINT64PF ", rounds " UINT64PF ", " + "OS waits " UINT64PF "\n" + "RW-shared spins " UINT64PF ", rounds " UINT64PF ", " + "OS waits " UINT64PF "\n" + "RW-excl spins " UINT64PF ", rounds " UINT64PF ", " + "OS waits " UINT64PF "\n", (ib_uint64_t) mutex_spin_wait_count, (ib_uint64_t) mutex_spin_round_count, (ib_uint64_t) mutex_os_wait_count, |