diff options
Diffstat (limited to 'storage/innobase/include/sync0rw.ic')
| -rw-r--r-- | storage/innobase/include/sync0rw.ic | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/storage/innobase/include/sync0rw.ic b/storage/innobase/include/sync0rw.ic index bb05ae7daf1..69251da6e35 100644 --- a/storage/innobase/include/sync0rw.ic +++ b/storage/innobase/include/sync0rw.ic @@ -386,6 +386,7 @@ rw_lock_x_lock_func_nowait( ulint line) /*!< in: line where requested */ { ibool success; + ibool local_recursive= lock->recursive; #ifdef INNODB_RW_LOCKS_USE_ATOMICS success = os_compare_and_swap_lint(&lock->lock_word, X_LOCK_DECR, 0); @@ -400,10 +401,14 @@ rw_lock_x_lock_func_nowait( mutex_exit(&(lock->mutex)); #endif + /* Note: recursive must be loaded before writer_thread see + comment for rw_lock_set_writer_id_and_recursion_flag(). + To achieve this we load it before os_compare_and_swap_lint(), + which implies full memory barrier in current implementation. */ if (success) { rw_lock_set_writer_id_and_recursion_flag(lock, TRUE); - } else if (lock->recursive + } else if (local_recursive && os_thread_eq(lock->writer_thread, os_thread_get_curr_id())) { /* Relock: this lock_word modification is safe since no other |