5.5 merge

1 files changed, 7 insertions, 11 deletions

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);