diff options
| -rw-r--r-- | storage/innobase/include/os0sync.h | 75 | ||||
| -rw-r--r-- | storage/innobase/include/os0sync.ic | 32 | ||||
| -rw-r--r-- | storage/innobase/include/sync0sync.h | 2 | ||||
| -rw-r--r-- | storage/innobase/include/sync0sync.ic | 18 | ||||
| -rw-r--r-- | storage/innobase/os/os0sync.cc | 19 | ||||
| -rw-r--r-- | storage/innobase/sync/sync0sync.cc | 2 | ||||
| -rw-r--r-- | storage/xtradb/include/os0sync.h | 75 | ||||
| -rw-r--r-- | storage/xtradb/include/os0sync.ic | 31 | ||||
| -rw-r--r-- | storage/xtradb/include/sync0sync.h | 2 | ||||
| -rw-r--r-- | storage/xtradb/include/sync0sync.ic | 18 | ||||
| -rw-r--r-- | storage/xtradb/os/os0sync.cc | 19 | ||||
| -rw-r--r-- | storage/xtradb/sync/sync0sync.cc | 2 |
12 files changed, 219 insertions, 76 deletions
diff --git a/storage/innobase/include/os0sync.h b/storage/innobase/include/os0sync.h index 8bf57677ecf..b16a99b51c0 100644 --- a/storage/innobase/include/os0sync.h +++ b/storage/innobase/include/os0sync.h @@ -322,12 +322,29 @@ pfs_os_fast_mutex_unlock( #endif /* UNIV_PFS_MUTEX */ /**********************************************************//** +Acquires ownership of a fast mutex. Implies a full memory barrier even on +platforms such as PowerPC where this is not normally required. +@return 0 if success, != 0 if was reserved by another thread */ +UNIV_INLINE +ulint +os_fast_mutex_trylock_full_barrier( +/*==================*/ + os_fast_mutex_t* fast_mutex); /*!< in: mutex to acquire */ +/**********************************************************//** Releases ownership of a fast mutex. */ UNIV_INTERN void os_fast_mutex_unlock_func( /*======================*/ fast_mutex_t* fast_mutex); /*!< in: mutex to release */ +/**********************************************************//** +Releases ownership of a fast mutex. Implies a full memory barrier even on +platforms such as PowerPC where this is not normally required. */ +UNIV_INTERN +void +os_fast_mutex_unlock_full_barrier( +/*=================*/ + os_fast_mutex_t* fast_mutex); /*!< in: mutex to release */ /*********************************************************//** Initializes an operating system fast mutex semaphore. */ UNIV_INTERN @@ -432,14 +449,31 @@ amount to decrement. */ /**********************************************************//** Returns the old value of *ptr, atomically sets *ptr to new_val */ -# define os_atomic_test_and_set_byte(ptr, new_val) \ - __sync_lock_test_and_set(ptr, (byte) new_val) - # define os_atomic_test_and_set_ulint(ptr, new_val) \ __sync_lock_test_and_set(ptr, new_val) -# define os_atomic_lock_release_byte(ptr) \ - __sync_lock_release(ptr) +#ifdef __powerpc__ +/* + os_atomic_test_and_set_byte_release() should imply a release barrier before + setting, and a full barrier after. But __sync_lock_test_and_set() is only + documented as an aquire barrier. So on PowerPC we need to add the full + barrier explicitly. */ +# define os_atomic_test_and_set_byte_release(ptr, new_val) \ + do { __sync_lock_release(ptr); \ + __sync_synchronize(); } while (0) +#else +/* + On x86, __sync_lock_test_and_set() happens to be full barrier, due to + LOCK prefix. +*/ +# define os_atomic_test_and_set_byte_release(ptr, new_val) \ + __sync_lock_test_and_set(ptr, (byte) new_val) +#endif +/* + os_atomic_test_and_set_byte_acquire() is a full memory barrier on x86. But + in general, just an aquire barrier should be sufficient. */ +# define os_atomic_test_and_set_byte_acquire(ptr, new_val) \ + __sync_lock_test_and_set(ptr, (byte) new_val) #elif defined(HAVE_IB_SOLARIS_ATOMICS) @@ -517,14 +551,14 @@ amount to decrement. */ /**********************************************************//** Returns the old value of *ptr, atomically sets *ptr to new_val */ -# define os_atomic_test_and_set_byte(ptr, new_val) \ - atomic_swap_uchar(ptr, new_val) - # define os_atomic_test_and_set_ulint(ptr, new_val) \ atomic_swap_ulong(ptr, new_val) -# define os_atomic_lock_release_byte(ptr) \ - (void) atomic_swap_uchar(ptr, 0) +# define os_atomic_test_and_set_byte_acquire(ptr, new_val) \ + atomic_swap_uchar(ptr, new_val) + +# define os_atomic_test_and_set_byte_release(ptr, new_val) \ + atomic_swap_uchar(ptr, new_val) #elif defined(HAVE_WINDOWS_ATOMICS) @@ -644,7 +678,9 @@ Returns the old value of *ptr, atomically sets *ptr to new_val. InterlockedExchange() operates on LONG, and the LONG will be clobbered */ -# define os_atomic_test_and_set_byte(ptr, new_val) \ +# define os_atomic_test_and_set_byte_acquire(ptr, new_val) \ + ((byte) InterlockedExchange(ptr, new_val)) +# define os_atomic_test_and_set_byte_release(ptr, new_val) \ ((byte) InterlockedExchange(ptr, new_val)) # define os_atomic_test_and_set_ulong(ptr, new_val) \ @@ -713,11 +749,7 @@ architecture. Disable memory barrier for Intel architecture for now. */ # define HAVE_MEMORY_BARRIER # define os_rmb __atomic_thread_fence(__ATOMIC_ACQUIRE) # define os_wmb __atomic_thread_fence(__ATOMIC_RELEASE) -#ifdef __powerpc__ -# define os_isync __asm __volatile ("isync":::"memory") -#else -#define os_isync do { } while(0) -#endif +# define os_mb __atomic_thread_fence(__ATOMIC_SEQ_CST) # define IB_MEMORY_BARRIER_STARTUP_MSG \ "GCC builtin __atomic_thread_fence() is used for memory barrier" @@ -726,7 +758,7 @@ architecture. Disable memory barrier for Intel architecture for now. */ # define HAVE_MEMORY_BARRIER # define os_rmb __sync_synchronize() # define os_wmb __sync_synchronize() -# define os_isync __sync_synchronize() +# define os_mb __sync_synchronize() # define IB_MEMORY_BARRIER_STARTUP_MSG \ "GCC builtin __sync_synchronize() is used for memory barrier" @@ -735,7 +767,7 @@ architecture. Disable memory barrier for Intel architecture for now. */ # include <mbarrier.h> # define os_rmb __machine_r_barrier() # define os_wmb __machine_w_barrier() -# define os_isync os_rmb; os_wmb +# define os_mb __machine_rw_barrier() # define IB_MEMORY_BARRIER_STARTUP_MSG \ "Solaris memory ordering functions are used for memory barrier" @@ -744,17 +776,14 @@ architecture. Disable memory barrier for Intel architecture for now. */ # include <intrin.h> # define os_rmb _mm_lfence() # define os_wmb _mm_sfence() -# define os_isync os_rmb; os_wmb +# define os_mb _mm_mfence() # define IB_MEMORY_BARRIER_STARTUP_MSG \ "_mm_lfence() and _mm_sfence() are used for memory barrier" -# define os_atomic_lock_release_byte(ptr) \ - (void) InterlockedExchange(ptr, 0) - #else # define os_rmb do { } while(0) # define os_wmb do { } while(0) -# define os_isync do { } while(0) +# define os_mb do { } while(0) # define IB_MEMORY_BARRIER_STARTUP_MSG \ "Memory barrier is not used" #endif diff --git a/storage/innobase/include/os0sync.ic b/storage/innobase/include/os0sync.ic index 9a7e520ece6..4ebf84dba98 100644 --- a/storage/innobase/include/os0sync.ic +++ b/storage/innobase/include/os0sync.ic @@ -232,3 +232,35 @@ win_cmp_and_xchg_dword( #endif /* HAVE_WINDOWS_ATOMICS */ + +/**********************************************************//** +Acquires ownership of a fast mutex. Implies a full memory barrier even on +platforms such as PowerPC where this is not normally required. +@return 0 if success, != 0 if was reserved by another thread */ +UNIV_INLINE +ulint +os_fast_mutex_trylock_full_barrier( +/*==================*/ + os_fast_mutex_t* fast_mutex) /*!< in: mutex to acquire */ +{ +#ifdef __WIN__ + if (TryEnterCriticalSection(&fast_mutex->mutex)) { + + return(0); + } else { + + return(1); + } +#else + /* NOTE that the MySQL my_pthread.h redefines pthread_mutex_trylock + so that it returns 0 on success. In the operating system + libraries, HP-UX-10.20 follows the old Posix 1003.4a Draft 4 and + returns 1 on success (but MySQL remaps that to 0), while Linux, + FreeBSD, Solaris, AIX, Tru64 Unix, HP-UX-11.0 return 0 on success. */ + +#ifdef __powerpc__ + os_mb; +#endif + return((ulint) pthread_mutex_trylock(&fast_mutex->mutex)); +#endif +} diff --git a/storage/innobase/include/sync0sync.h b/storage/innobase/include/sync0sync.h index 82fb353a41b..7b00e16476b 100644 --- a/storage/innobase/include/sync0sync.h +++ b/storage/innobase/include/sync0sync.h @@ -49,8 +49,6 @@ extern "C" my_bool timed_mutexes; #ifdef HAVE_WINDOWS_ATOMICS typedef LONG lock_word_t; /*!< On Windows, InterlockedExchange operates on LONG variable */ -#elif defined(HAVE_ATOMIC_BUILTINS) && !defined(HAVE_ATOMIC_BUILTINS_BYTE) -typedef ulint lock_word_t; #else typedef byte lock_word_t; #endif diff --git a/storage/innobase/include/sync0sync.ic b/storage/innobase/include/sync0sync.ic index 687f7ee5142..97ec63c0dd2 100644 --- a/storage/innobase/include/sync0sync.ic +++ b/storage/innobase/include/sync0sync.ic @@ -80,15 +80,11 @@ ib_mutex_test_and_set( ib_mutex_t* mutex) /*!< in: mutex */ { #if defined(HAVE_ATOMIC_BUILTINS) -# if defined(HAVE_ATOMIC_BUILTINS_BYTE) - return(os_atomic_test_and_set_byte(&mutex->lock_word, 1)); -# else - return(os_atomic_test_and_set_ulint(&mutex->lock_word, 1)); -# endif + return(os_atomic_test_and_set_byte_acquire(&mutex->lock_word, 1)); #else ibool ret; - ret = os_fast_mutex_trylock(&(mutex->os_fast_mutex)); + ret = os_fast_mutex_trylock_full_barrier(&(mutex->os_fast_mutex)); if (ret == 0) { /* We check that os_fast_mutex_trylock does not leak @@ -96,7 +92,6 @@ ib_mutex_test_and_set( ut_a(mutex->lock_word == 0); mutex->lock_word = 1; - os_wmb; } return((byte) ret); @@ -113,11 +108,14 @@ mutex_reset_lock_word( ib_mutex_t* mutex) /*!< in: mutex */ { #if defined(HAVE_ATOMIC_BUILTINS) - os_atomic_lock_release_byte(&mutex->lock_word); + /* In theory __sync_lock_release should be used to release the lock. + Unfortunately, it does not work properly alone. The workaround is + that more conservative __sync_lock_test_and_set is used instead. */ + os_atomic_test_and_set_byte_release(&mutex->lock_word, 0); #else mutex->lock_word = 0; - os_fast_mutex_unlock(&(mutex->os_fast_mutex)); + os_fast_mutex_unlock_full_barrier(&(mutex->os_fast_mutex)); #endif } @@ -149,7 +147,6 @@ mutex_get_waiters( ptr = &(mutex->waiters); - os_rmb; return(*ptr); /* Here we assume that the read of a single word from memory is atomic */ } @@ -184,7 +181,6 @@ mutex_exit_func( to wake up possible hanging threads if they are missed in mutex_signal_object. */ - os_isync; if (mutex_get_waiters(mutex) != 0) { mutex_signal_object(mutex); diff --git a/storage/innobase/os/os0sync.cc b/storage/innobase/os/os0sync.cc index 779152a3a56..451ba5285e3 100644 --- a/storage/innobase/os/os0sync.cc +++ b/storage/innobase/os/os0sync.cc @@ -890,6 +890,25 @@ os_fast_mutex_unlock_func( } /**********************************************************//** +Releases ownership of a fast mutex. Implies a full memory barrier even on +platforms such as PowerPC where this is not normally required. */ +UNIV_INTERN +void +os_fast_mutex_unlock_full_barrier( +/*=================*/ + os_fast_mutex_t* fast_mutex) /*!< in: mutex to release */ +{ +#ifdef __WIN__ + LeaveCriticalSection(&fast_mutex->mutex); +#else + pthread_mutex_unlock(&fast_mutex->mutex); +#ifdef __powerpc__ + os_mb; +#endif +#endif +} + +/**********************************************************//** Frees a mutex object. */ UNIV_INTERN void diff --git a/storage/innobase/sync/sync0sync.cc b/storage/innobase/sync/sync0sync.cc index 6494191bfe9..2729bc39228 100644 --- a/storage/innobase/sync/sync0sync.cc +++ b/storage/innobase/sync/sync0sync.cc @@ -457,8 +457,6 @@ mutex_set_waiters( ptr = &(mutex->waiters); - os_wmb; - *ptr = n; /* Here we assume that the write of a single word in memory is atomic */ } diff --git a/storage/xtradb/include/os0sync.h b/storage/xtradb/include/os0sync.h index 066fd34d668..f968de7c6dd 100644 --- a/storage/xtradb/include/os0sync.h +++ b/storage/xtradb/include/os0sync.h @@ -322,12 +322,29 @@ pfs_os_fast_mutex_unlock( #endif /* UNIV_PFS_MUTEX */ /**********************************************************//** +Acquires ownership of a fast mutex. Implies a full memory barrier even on +platforms such as PowerPC where this is not normally required. +@return 0 if success, != 0 if was reserved by another thread */ +UNIV_INLINE +ulint +os_fast_mutex_trylock_full_barrier( +/*==================*/ + os_fast_mutex_t* fast_mutex); /*!< in: mutex to acquire */ +/**********************************************************//** Releases ownership of a fast mutex. */ UNIV_INTERN void os_fast_mutex_unlock_func( /*======================*/ fast_mutex_t* fast_mutex); /*!< in: mutex to release */ +/**********************************************************//** +Releases ownership of a fast mutex. Implies a full memory barrier even on +platforms such as PowerPC where this is not normally required. */ +UNIV_INTERN +void +os_fast_mutex_unlock_full_barrier( +/*=================*/ + os_fast_mutex_t* fast_mutex); /*!< in: mutex to release */ /*********************************************************//** Initializes an operating system fast mutex semaphore. */ UNIV_INTERN @@ -432,14 +449,31 @@ amount to decrement. */ /**********************************************************//** Returns the old value of *ptr, atomically sets *ptr to new_val */ -# define os_atomic_test_and_set_byte(ptr, new_val) \ - __sync_lock_test_and_set(ptr, (byte) new_val) - # define os_atomic_test_and_set_ulint(ptr, new_val) \ __sync_lock_test_and_set(ptr, new_val) -# define os_atomic_lock_release_byte(ptr) \ - __sync_lock_release(ptr) +#ifdef __powerpc__ +/* + os_atomic_test_and_set_byte_release() should imply a release barrier before + setting, and a full barrier after. But __sync_lock_test_and_set() is only + documented as an aquire barrier. So on PowerPC we need to add the full + barrier explicitly. */ +# define os_atomic_test_and_set_byte_release(ptr, new_val) \ + do { __sync_lock_release(ptr); \ + __sync_synchronize(); } while (0) +#else +/* + On x86, __sync_lock_test_and_set() happens to be full barrier, due to + LOCK prefix. +*/ +# define os_atomic_test_and_set_byte_release(ptr, new_val) \ + __sync_lock_test_and_set(ptr, (byte) new_val) +#endif +/* + os_atomic_test_and_set_byte_acquire() is a full memory barrier on x86. But + in general, just an aquire barrier should be sufficient. */ +# define os_atomic_test_and_set_byte_acquire(ptr, new_val) \ + __sync_lock_test_and_set(ptr, (byte) new_val) #elif defined(HAVE_IB_SOLARIS_ATOMICS) @@ -517,14 +551,14 @@ amount to decrement. */ /**********************************************************//** Returns the old value of *ptr, atomically sets *ptr to new_val */ -# define os_atomic_test_and_set_byte(ptr, new_val) \ - atomic_swap_uchar(ptr, new_val) - # define os_atomic_test_and_set_ulint(ptr, new_val) \ atomic_swap_ulong(ptr, new_val) -# define os_atomic_lock_release_byte(ptr) \ - (void) atomic_swap_uchar(ptr, 0) +# define os_atomic_test_and_set_byte_acquire(ptr, new_val) \ + atomic_swap_uchar(ptr, new_val) + +# define os_atomic_test_and_set_byte_release(ptr, new_val) \ + atomic_swap_uchar(ptr, new_val) #elif defined(HAVE_WINDOWS_ATOMICS) @@ -644,7 +678,9 @@ Returns the old value of *ptr, atomically sets *ptr to new_val. InterlockedExchange() operates on LONG, and the LONG will be clobbered */ -# define os_atomic_test_and_set_byte(ptr, new_val) \ +# define os_atomic_test_and_set_byte_acquire(ptr, new_val) \ + ((byte) InterlockedExchange(ptr, new_val)) +# define os_atomic_test_and_set_byte_release(ptr, new_val) \ ((byte) InterlockedExchange(ptr, new_val)) # define os_atomic_test_and_set_ulong(ptr, new_val) \ @@ -713,11 +749,7 @@ architecture. Disable memory barrier for Intel architecture for now. */ # define HAVE_MEMORY_BARRIER # define os_rmb __atomic_thread_fence(__ATOMIC_ACQUIRE) # define os_wmb __atomic_thread_fence(__ATOMIC_RELEASE) -#ifdef __powerpc__ -# define os_isync __asm __volatile ("isync":::"memory") -#else -#define os_isync do { } while(0) -#endif +# define os_mb __atomic_thread_fence(__ATOMIC_SEQ_CST) # define IB_MEMORY_BARRIER_STARTUP_MSG \ "GCC builtin __atomic_thread_fence() is used for memory barrier" @@ -726,7 +758,7 @@ architecture. Disable memory barrier for Intel architecture for now. */ # define HAVE_MEMORY_BARRIER # define os_rmb __sync_synchronize() # define os_wmb __sync_synchronize() -# define os_isync __sync_synchronize() +# define os_mb __sync_synchronize() # define IB_MEMORY_BARRIER_STARTUP_MSG \ "GCC builtin __sync_synchronize() is used for memory barrier" @@ -735,7 +767,7 @@ architecture. Disable memory barrier for Intel architecture for now. */ # include <mbarrier.h> # define os_rmb __machine_r_barrier() # define os_wmb __machine_w_barrier() -# define os_isync os_rmb; os_wmb +# define os_mb __machine_rw_barrier() # define IB_MEMORY_BARRIER_STARTUP_MSG \ "Solaris memory ordering functions are used for memory barrier" @@ -744,17 +776,14 @@ architecture. Disable memory barrier for Intel architecture for now. */ # include <intrin.h> # define os_rmb _mm_lfence() # define os_wmb _mm_sfence() -# define os_isync os_rmb; os_wmb +# define os_mb _mm_mfence() # define IB_MEMORY_BARRIER_STARTUP_MSG \ "_mm_lfence() and _mm_sfence() are used for memory barrier" -# define os_atomic_lock_release_byte(ptr) \ - (void) InterlockedExchange(ptr, 0) - #else # define os_rmb do { } while(0) # define os_wmb do { } while(0) -# define os_isync do { } while(0) +# define os_mb do { } while(0) # define IB_MEMORY_BARRIER_STARTUP_MSG \ "Memory barrier is not used" #endif diff --git a/storage/xtradb/include/os0sync.ic b/storage/xtradb/include/os0sync.ic index 9a7e520ece6..5f4b0d24089 100644 --- a/storage/xtradb/include/os0sync.ic +++ b/storage/xtradb/include/os0sync.ic @@ -232,3 +232,34 @@ win_cmp_and_xchg_dword( #endif /* HAVE_WINDOWS_ATOMICS */ +/**********************************************************//** +Acquires ownership of a fast mutex. Implies a full memory barrier even on +platforms such as PowerPC where this is not normally required. +@return 0 if success, != 0 if was reserved by another thread */ +UNIV_INLINE +ulint +os_fast_mutex_trylock_full_barrier( +/*==================*/ + os_fast_mutex_t* fast_mutex) /*!< in: mutex to acquire */ +{ +#ifdef __WIN__ + if (TryEnterCriticalSection(&fast_mutex->mutex)) { + + return(0); + } else { + + return(1); + } +#else + /* NOTE that the MySQL my_pthread.h redefines pthread_mutex_trylock + so that it returns 0 on success. In the operating system + libraries, HP-UX-10.20 follows the old Posix 1003.4a Draft 4 and + returns 1 on success (but MySQL remaps that to 0), while Linux, + FreeBSD, Solaris, AIX, Tru64 Unix, HP-UX-11.0 return 0 on success. */ + +#ifdef __powerpc__ + os_mb; +#endif + return((ulint) pthread_mutex_trylock(&fast_mutex->mutex)); +#endif +} diff --git a/storage/xtradb/include/sync0sync.h b/storage/xtradb/include/sync0sync.h index 8c5dde4c142..788f765f919 100644 --- a/storage/xtradb/include/sync0sync.h +++ b/storage/xtradb/include/sync0sync.h @@ -50,8 +50,6 @@ extern "C" my_bool timed_mutexes; #ifdef _WIN32 typedef LONG lock_word_t; /*!< On Windows, InterlockedExchange operates on LONG variable */ -#elif defined(HAVE_ATOMIC_BUILTINS) && !defined(HAVE_ATOMIC_BUILTINS_BYTE) -typedef ulint lock_word_t; #else typedef byte lock_word_t; #endif diff --git a/storage/xtradb/include/sync0sync.ic b/storage/xtradb/include/sync0sync.ic index 6bd80ee7dea..a641ef8bb9e 100644 --- a/storage/xtradb/include/sync0sync.ic +++ b/storage/xtradb/include/sync0sync.ic @@ -83,15 +83,11 @@ ib_mutex_test_and_set( ib_mutex_t* mutex) /*!< in: mutex */ { #if defined(HAVE_ATOMIC_BUILTINS) -# if defined(HAVE_ATOMIC_BUILTINS_BYTE) - return(os_atomic_test_and_set_byte(&mutex->lock_word, 1)); -# else - return(os_atomic_test_and_set_ulint(&mutex->lock_word, 1)); -# endif + return(os_atomic_test_and_set_byte_acquire(&mutex->lock_word, 1)); #else ibool ret; - ret = os_fast_mutex_trylock(&(mutex->os_fast_mutex)); + ret = os_fast_mutex_trylock_full_barrier(&(mutex->os_fast_mutex)); if (ret == 0) { /* We check that os_fast_mutex_trylock does not leak @@ -99,7 +95,6 @@ ib_mutex_test_and_set( ut_a(mutex->lock_word == 0); mutex->lock_word = 1; - os_wmb; } return((byte) ret); @@ -116,11 +111,14 @@ mutex_reset_lock_word( ib_mutex_t* mutex) /*!< in: mutex */ { #if defined(HAVE_ATOMIC_BUILTINS) - os_atomic_lock_release_byte(&mutex->lock_word); + /* In theory __sync_lock_release should be used to release the lock. + Unfortunately, it does not work properly alone. The workaround is + that more conservative __sync_lock_test_and_set is used instead. */ + os_atomic_test_and_set_byte_release(&mutex->lock_word, 0); #else mutex->lock_word = 0; - os_fast_mutex_unlock(&(mutex->os_fast_mutex)); + os_fast_mutex_unlock_full_barrier(&(mutex->os_fast_mutex)); #endif } @@ -152,7 +150,6 @@ mutex_get_waiters( ptr = &(mutex->waiters); - os_rmb; return(*ptr); /* Here we assume that the read of a single word from memory is atomic */ } @@ -187,7 +184,6 @@ mutex_exit_func( to wake up possible hanging threads if they are missed in mutex_signal_object. */ - os_isync; if (mutex_get_waiters(mutex) != 0) { mutex_signal_object(mutex); diff --git a/storage/xtradb/os/os0sync.cc b/storage/xtradb/os/os0sync.cc index 779152a3a56..451ba5285e3 100644 --- a/storage/xtradb/os/os0sync.cc +++ b/storage/xtradb/os/os0sync.cc @@ -890,6 +890,25 @@ os_fast_mutex_unlock_func( } /**********************************************************//** +Releases ownership of a fast mutex. Implies a full memory barrier even on +platforms such as PowerPC where this is not normally required. */ +UNIV_INTERN +void +os_fast_mutex_unlock_full_barrier( +/*=================*/ + os_fast_mutex_t* fast_mutex) /*!< in: mutex to release */ +{ +#ifdef __WIN__ + LeaveCriticalSection(&fast_mutex->mutex); +#else + pthread_mutex_unlock(&fast_mutex->mutex); +#ifdef __powerpc__ + os_mb; +#endif +#endif +} + +/**********************************************************//** Frees a mutex object. */ UNIV_INTERN void diff --git a/storage/xtradb/sync/sync0sync.cc b/storage/xtradb/sync/sync0sync.cc index 67d4835ed95..ca630531086 100644 --- a/storage/xtradb/sync/sync0sync.cc +++ b/storage/xtradb/sync/sync0sync.cc @@ -536,8 +536,6 @@ mutex_set_waiters( ptr = &(mutex->waiters); - os_wmb; - *ptr = n; /* Here we assume that the write of a single word in memory is atomic */ } |