/***************************************************************************** Copyright (c) 1995, 2009, Innobase Oy. All Rights Reserved. Copyright (c) 2008, Google Inc. Portions of this file contain modifications contributed and copyrighted by Google, Inc. Those modifications are gratefully acknowledged and are described briefly in the InnoDB documentation. The contributions by Google are incorporated with their permission, and subject to the conditions contained in the file COPYING.Google. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; version 2 of the License. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA *****************************************************************************/ /**************************************************//** @file include/sync0rw.ic The read-write lock (for threads) Created 9/11/1995 Heikki Tuuri *******************************************************/ /******************************************************************//** Lock an rw-lock in shared mode for the current thread. If the rw-lock is locked in exclusive mode, or there is an exclusive lock request waiting, the function spins a preset time (controlled by SYNC_SPIN_ROUNDS), waiting for the lock before suspending the thread. */ UNIV_INTERN void rw_lock_s_lock_spin( /*================*/ rw_lock_t* lock, /*!< in: pointer to rw-lock */ ulint pass, /*!< in: pass value; != 0, if the lock will be passed to another thread to unlock */ const char* file_name,/*!< in: file name where lock requested */ ulint line); /*!< in: line where requested */ #ifdef UNIV_SYNC_DEBUG /******************************************************************//** Inserts the debug information for an rw-lock. */ UNIV_INTERN void rw_lock_add_debug_info( /*===================*/ rw_lock_t* lock, /*!< in: rw-lock */ ulint pass, /*!< in: pass value */ ulint lock_type, /*!< in: lock type */ const char* file_name, /*!< in: file where requested */ ulint line); /*!< in: line where requested */ /******************************************************************//** Removes a debug information struct for an rw-lock. */ UNIV_INTERN void rw_lock_remove_debug_info( /*======================*/ rw_lock_t* lock, /*!< in: rw-lock */ ulint pass, /*!< in: pass value */ ulint lock_type); /*!< in: lock type */ #endif /* UNIV_SYNC_DEBUG */ /********************************************************************//** Check if there are threads waiting for the rw-lock. @return 1 if waiters, 0 otherwise */ UNIV_INLINE ulint rw_lock_get_waiters( /*================*/ const rw_lock_t* lock) /*!< in: rw-lock */ { return(lock->waiters); } /********************************************************************//** Sets lock->waiters to 1. It is not an error if lock->waiters is already 1. On platforms where ATOMIC builtins are used this function enforces a memory barrier. */ UNIV_INLINE void rw_lock_set_waiter_flag( /*====================*/ rw_lock_t* lock) /*!< in/out: rw-lock */ { #ifdef INNODB_RW_LOCKS_USE_ATOMICS (void) os_compare_and_swap_ulint(&lock->waiters, 0, 1); #else /* INNODB_RW_LOCKS_USE_ATOMICS */ lock->waiters = 1; #endif /* INNODB_RW_LOCKS_USE_ATOMICS */ } /********************************************************************//** Resets lock->waiters to 0. It is not an error if lock->waiters is already 0. On platforms where ATOMIC builtins are used this function enforces a memory barrier. */ UNIV_INLINE void rw_lock_reset_waiter_flag( /*======================*/ rw_lock_t* lock) /*!< in/out: rw-lock */ { #ifdef INNODB_RW_LOCKS_USE_ATOMICS (void) os_compare_and_swap_ulint(&lock->waiters, 1, 0); #else /* INNODB_RW_LOCKS_USE_ATOMICS */ lock->waiters = 0; #endif /* INNODB_RW_LOCKS_USE_ATOMICS */ } /******************************************************************//** Returns the write-status of the lock - this function made more sense with the old rw_lock implementation. @return RW_LOCK_NOT_LOCKED, RW_LOCK_EX, RW_LOCK_WAIT_EX */ UNIV_INLINE ulint rw_lock_get_writer( /*===============*/ const rw_lock_t* lock) /*!< in: rw-lock */ { lint lock_word = lock->lock_word; if (lock_word > 0) { /* return NOT_LOCKED in s-lock state, like the writer member of the old lock implementation. */ return(RW_LOCK_NOT_LOCKED); } else if (((-lock_word) % X_LOCK_DECR) == 0) { return(RW_LOCK_EX); } else { ut_ad(lock_word > -X_LOCK_DECR); return(RW_LOCK_WAIT_EX); } } /******************************************************************//** Returns the number of readers. @return number of readers */ UNIV_INLINE ulint rw_lock_get_reader_count( /*=====================*/ const rw_lock_t* lock) /*!< in: rw-lock */ { lint lock_word = lock->lock_word; if (lock_word > 0) { /* s-locked, no x-waiters */ return(X_LOCK_DECR - lock_word); } else if (lock_word < 0 && lock_word > -X_LOCK_DECR) { /* s-locked, with x-waiters */ return((ulint)(-lock_word)); } return(0); } #ifndef INNODB_RW_LOCKS_USE_ATOMICS UNIV_INLINE mutex_t* rw_lock_get_mutex( /*==============*/ rw_lock_t* lock) { return(&(lock->mutex)); } #endif /******************************************************************//** Returns the value of writer_count for the lock. Does not reserve the lock mutex, so the caller must be sure it is not changed during the call. @return value of writer_count */ UNIV_INLINE ulint rw_lock_get_x_lock_count( /*=====================*/ const rw_lock_t* lock) /*!< in: rw-lock */ { lint lock_copy = lock->lock_word; /* If there is a reader, lock_word is not divisible by X_LOCK_DECR */ if (lock_copy > 0 || (-lock_copy) % X_LOCK_DECR != 0) { return(0); } return(((-lock_copy) / X_LOCK_DECR) + 1); } /******************************************************************//** Two different implementations for decrementing the lock_word of a rw_lock: one for systems supporting atomic operations, one for others. This does does not support recusive x-locks: they should be handled by the caller and need not be atomic since they are performed by the current lock holder. Returns true if the decrement was made, false if not. @return TRUE if decr occurs */ UNIV_INLINE ibool rw_lock_lock_word_decr( /*===================*/ rw_lock_t* lock, /*!< in/out: rw-lock */ ulint amount) /*!< in: amount to decrement */ { #ifdef INNODB_RW_LOCKS_USE_ATOMICS lint local_lock_word = lock->lock_word; while (local_lock_word > 0) { if (os_compare_and_swap_lint(&lock->lock_word, local_lock_word, local_lock_word - amount)) { return(TRUE); } local_lock_word = lock->lock_word; } return(FALSE); #else /* INNODB_RW_LOCKS_USE_ATOMICS */ ibool success = FALSE; mutex_enter(&(lock->mutex)); if (lock->lock_word > 0) { lock->lock_word -= amount; success = TRUE; } mutex_exit(&(lock->mutex)); return(success); #endif /* INNODB_RW_LOCKS_USE_ATOMICS */ } /******************************************************************//** Increments lock_word the specified amount and returns new value. @return lock->lock_word after increment */ UNIV_INLINE lint rw_lock_lock_word_incr( /*===================*/ rw_lock_t* lock, /*!< in/out: rw-lock */ ulint amount) /*!< in: amount of increment */ { #ifdef INNODB_RW_LOCKS_USE_ATOMICS return(os_atomic_increment_lint(&lock->lock_word, amount)); #else /* INNODB_RW_LOCKS_USE_ATOMICS */ lint local_lock_word; mutex_enter(&(lock->mutex)); lock->lock_word += amount; local_lock_word = lock->lock_word; mutex_exit(&(lock->mutex)); return(local_lock_word); #endif /* INNODB_RW_LOCKS_USE_ATOMICS */ } /******************************************************************//** This function sets the lock->writer_thread and lock->recursive fields. For platforms where we are using atomic builtins instead of lock->mutex it sets the lock->writer_thread field using atomics to ensure memory ordering. Note that it is assumed that the caller of this function effectively owns the lock i.e.: nobody else is allowed to modify lock->writer_thread at this point in time. The protocol is that lock->writer_thread MUST be updated BEFORE the lock->recursive flag is set. */ UNIV_INLINE void rw_lock_set_writer_id_and_recursion_flag( /*=====================================*/ rw_lock_t* lock, /*!< in/out: lock to work on */ ibool recursive) /*!< in: TRUE if recursion allowed */ { os_thread_id_t curr_thread = os_thread_get_curr_id(); #ifdef INNODB_RW_LOCKS_USE_ATOMICS os_thread_id_t local_thread; ibool success; /* Prevent Valgrind warnings about writer_thread being uninitialized. It does not matter if writer_thread is uninitialized, because we are comparing writer_thread against itself, and the operation should always succeed. */ UNIV_MEM_VALID(&lock->writer_thread, sizeof lock->writer_thread); local_thread = lock->writer_thread; success = os_compare_and_swap_thread_id( &lock->writer_thread, local_thread, curr_thread); ut_a(success); lock->recursive = recursive; #else /* INNODB_RW_LOCKS_USE_ATOMICS */ mutex_enter(&lock->mutex); lock->writer_thread = curr_thread; lock->recursive = recursive; mutex_exit(&lock->mutex); #endif /* INNODB_RW_LOCKS_USE_ATOMICS */ } /******************************************************************//** Low-level function which tries to lock an rw-lock in s-mode. Performs no spinning. @return TRUE if success */ UNIV_INLINE ibool rw_lock_s_lock_low( /*===============*/ rw_lock_t* lock, /*!< in: pointer to rw-lock */ ulint pass __attribute__((unused)), /*!< in: pass value; != 0, if the lock will be passed to another thread to unlock */ const char* file_name, /*!< in: file name where lock requested */ ulint line) /*!< in: line where requested */ { /* TODO: study performance of UNIV_LIKELY branch prediction hints. */ if (!rw_lock_lock_word_decr(lock, 1)) { /* Locking did not succeed */ return(FALSE); } #ifdef UNIV_SYNC_DEBUG rw_lock_add_debug_info(lock, pass, RW_LOCK_SHARED, file_name, line); #endif /* These debugging values are not set safely: they may be incorrect or even refer to a line that is invalid for the file name. */ lock->last_s_file_name = file_name; lock->last_s_line = line; return(TRUE); /* locking succeeded */ } /******************************************************************//** Low-level function which locks an rw-lock in s-mode when we know that it is possible and none else is currently accessing the rw-lock structure. Then we can do the locking without reserving the mutex. */ UNIV_INLINE void rw_lock_s_lock_direct( /*==================*/ rw_lock_t* lock, /*!< in/out: rw-lock */ const char* file_name, /*!< in: file name where requested */ ulint line) /*!< in: line where lock requested */ { ut_ad(lock->lock_word == X_LOCK_DECR); /* Indicate there is a new reader by decrementing lock_word */ lock->lock_word--; lock->last_s_file_name = file_name; lock->last_s_line = line; #ifdef UNIV_SYNC_DEBUG rw_lock_add_debug_info(lock, 0, RW_LOCK_SHARED, file_name, line); #endif } /******************************************************************//** Low-level function which locks an rw-lock in x-mode when we know that it is not locked and none else is currently accessing the rw-lock structure. Then we can do the locking without reserving the mutex. */ UNIV_INLINE void rw_lock_x_lock_direct( /*==================*/ rw_lock_t* lock, /*!< in/out: rw-lock */ const char* file_name, /*!< in: file name where requested */ ulint line) /*!< in: line where lock requested */ { ut_ad(rw_lock_validate(lock)); ut_ad(lock->lock_word == X_LOCK_DECR); lock->lock_word -= X_LOCK_DECR; lock->writer_thread = os_thread_get_curr_id(); lock->recursive = TRUE; lock->last_x_file_name = file_name; lock->last_x_line = line; #ifdef UNIV_SYNC_DEBUG rw_lock_add_debug_info(lock, 0, RW_LOCK_EX, file_name, line); #endif } /******************************************************************//** NOTE! Use the corresponding macro, not directly this function! Lock an rw-lock in shared mode for the current thread. If the rw-lock is locked in exclusive mode, or there is an exclusive lock request waiting, the function spins a preset time (controlled by SYNC_SPIN_ROUNDS), waiting for the lock, before suspending the thread. */ UNIV_INLINE void rw_lock_s_lock_func( /*================*/ rw_lock_t* lock, /*!< in: pointer to rw-lock */ ulint pass, /*!< in: pass value; != 0, if the lock will be passed to another thread to unlock */ const char* file_name,/*!< in: file name where lock requested */ ulint line) /*!< in: line where requested */ { /* NOTE: As we do not know the thread ids for threads which have s-locked a latch, and s-lockers will be served only after waiting x-lock requests have been fulfilled, then if this thread already owns an s-lock here, it may end up in a deadlock with another thread which requests an x-lock here. Therefore, we will forbid recursive s-locking of a latch: the following assert will warn the programmer of the possibility of this kind of a deadlock. If we want to implement safe recursive s-locking, we should keep in a list the thread ids of the threads which have s-locked a latch. This would use some CPU time. */ #ifdef UNIV_SYNC_DEBUG ut_ad(!rw_lock_own(lock, RW_LOCK_SHARED)); /* see NOTE above */ ut_ad(!rw_lock_own(lock, RW_LOCK_EX)); #endif /* UNIV_SYNC_DEBUG */ /* TODO: study performance of UNIV_LIKELY branch prediction hints. */ if (rw_lock_s_lock_low(lock, pass, file_name, line)) { return; /* Success */ } else { /* Did not succeed, try spin wait */ rw_lock_s_lock_spin(lock, pass, file_name, line); return; } } /******************************************************************//** NOTE! Use the corresponding macro, not directly this function! Lock an rw-lock in exclusive mode for the current thread if the lock can be obtained immediately. @return TRUE if success */ UNIV_INLINE ibool rw_lock_x_lock_func_nowait( /*=======================*/ rw_lock_t* lock, /*!< in: pointer to rw-lock */ const char* file_name,/*!< in: file name where lock requested */ ulint line) /*!< in: line where requested */ { os_thread_id_t curr_thread = os_thread_get_curr_id(); ibool success; #ifdef INNODB_RW_LOCKS_USE_ATOMICS success = os_compare_and_swap_lint(&lock->lock_word, X_LOCK_DECR, 0); #else success = FALSE; mutex_enter(&(lock->mutex)); if (lock->lock_word == X_LOCK_DECR) { lock->lock_word = 0; success = TRUE; } mutex_exit(&(lock->mutex)); #endif if (success) { rw_lock_set_writer_id_and_recursion_flag(lock, TRUE); } else if (lock->recursive && os_thread_eq(lock->writer_thread, curr_thread)) { /* Relock: this lock_word modification is safe since no other threads can modify (lock, unlock, or reserve) lock_word while there is an exclusive writer and this is the writer thread. */ lock->lock_word -= X_LOCK_DECR; ut_ad(((-lock->lock_word) % X_LOCK_DECR) == 0); } else { /* Failure */ return(FALSE); } #ifdef UNIV_SYNC_DEBUG rw_lock_add_debug_info(lock, 0, RW_LOCK_EX, file_name, line); #endif lock->last_x_file_name = file_name; lock->last_x_line = line; ut_ad(rw_lock_validate(lock)); return(TRUE); } /******************************************************************//** Releases a shared mode lock. */ UNIV_INLINE void rw_lock_s_unlock_func( /*==================*/ #ifdef UNIV_SYNC_DEBUG ulint pass, /*!< in: pass value; != 0, if the lock may have been passed to another thread to unlock */ #endif rw_lock_t* lock) /*!< in/out: rw-lock */ { ut_ad((lock->lock_word % X_LOCK_DECR) != 0); #ifdef UNIV_SYNC_DEBUG rw_lock_remove_debug_info(lock, pass, RW_LOCK_SHARED); #endif /* Increment lock_word to indicate 1 less reader */ if (rw_lock_lock_word_incr(lock, 1) == 0) { /* wait_ex waiter exists. It may not be asleep, but we signal anyway. We do not wake other waiters, because they can't exist without wait_ex waiter and wait_ex waiter goes first.*/ os_event_set(lock->wait_ex_event); sync_array_object_signalled(sync_primary_wait_array); } ut_ad(rw_lock_validate(lock)); #ifdef UNIV_SYNC_PERF_STAT rw_s_exit_count++; #endif } /******************************************************************//** Releases a shared mode lock when we know there are no waiters and none else will access the lock during the time this function is executed. */ UNIV_INLINE void rw_lock_s_unlock_direct( /*====================*/ rw_lock_t* lock) /*!< in/out: rw-lock */ { ut_ad(lock->lock_word < X_LOCK_DECR); #ifdef UNIV_SYNC_DEBUG rw_lock_remove_debug_info(lock, 0, RW_LOCK_SHARED); #endif /* Decrease reader count by incrementing lock_word */ lock->lock_word++; ut_ad(!lock->waiters); ut_ad(rw_lock_validate(lock)); #ifdef UNIV_SYNC_PERF_STAT rw_s_exit_count++; #endif } /******************************************************************//** Releases an exclusive mode lock. */ UNIV_INLINE void rw_lock_x_unlock_func( /*==================*/ #ifdef UNIV_SYNC_DEBUG ulint pass, /*!< in: pass value; != 0, if the lock may have been passed to another thread to unlock */ #endif rw_lock_t* lock) /*!< in/out: rw-lock */ { ut_ad((lock->lock_word % X_LOCK_DECR) == 0); /* lock->recursive flag also indicates if lock->writer_thread is valid or stale. If we are the last of the recursive callers then we must unset lock->recursive flag to indicate that the lock->writer_thread is now stale. Note that since we still hold the x-lock we can safely read the lock_word. */ if (lock->lock_word == 0) { /* Last caller in a possible recursive chain. */ lock->recursive = FALSE; UNIV_MEM_INVALID(&lock->writer_thread, sizeof lock->writer_thread); } #ifdef UNIV_SYNC_DEBUG rw_lock_remove_debug_info(lock, pass, RW_LOCK_EX); #endif if (rw_lock_lock_word_incr(lock, X_LOCK_DECR) == X_LOCK_DECR) { /* Lock is now free. May have to signal read/write waiters. We do not need to signal wait_ex waiters, since they cannot exist when there is a writer. */ if (lock->waiters) { rw_lock_reset_waiter_flag(lock); os_event_set(lock->event); sync_array_object_signalled(sync_primary_wait_array); } } ut_ad(rw_lock_validate(lock)); #ifdef UNIV_SYNC_PERF_STAT rw_x_exit_count++; #endif } /******************************************************************//** Releases an exclusive mode lock when we know there are no waiters, and none else will access the lock during the time this function is executed. */ UNIV_INLINE void rw_lock_x_unlock_direct( /*====================*/ rw_lock_t* lock) /*!< in/out: rw-lock */ { /* Reset the exclusive lock if this thread no longer has an x-mode lock */ ut_ad((lock->lock_word % X_LOCK_DECR) == 0); #ifdef UNIV_SYNC_DEBUG rw_lock_remove_debug_info(lock, 0, RW_LOCK_EX); #endif if (lock->lock_word == 0) { lock->recursive = FALSE; UNIV_MEM_INVALID(&lock->writer_thread, sizeof lock->writer_thread); } lock->lock_word += X_LOCK_DECR; ut_ad(!lock->waiters); ut_ad(rw_lock_validate(lock)); #ifdef UNIV_SYNC_PERF_STAT rw_x_exit_count++; #endif } #ifdef UNIV_PFS_RWLOCK /******************************************************************//** Performance schema instrumented wrap function for rw_lock_create_func(). NOTE! Please use the corresponding macro rw_lock_create(), not directly this function! */ UNIV_INLINE void pfs_rw_lock_create_func( /*====================*/ mysql_pfs_key_t key, /*!< in: key registered with performance schema */ rw_lock_t* lock, /*!< in: pointer to memory */ # ifdef UNIV_DEBUG # ifdef UNIV_SYNC_DEBUG ulint level, /*!< in: level */ # endif /* UNIV_SYNC_DEBUG */ const char* cmutex_name, /*!< in: mutex name */ # endif /* UNIV_DEBUG */ const char* cfile_name, /*!< in: file name where created */ ulint cline) /*!< in: file line where created */ { /* Initialize the rwlock for performance schema */ lock->pfs_psi = (PSI_server && PFS_IS_INSTRUMENTED(key)) ? PSI_server->init_rwlock(key, lock) : NULL; /* The actual function to initialize an rwlock */ rw_lock_create_func(lock, # ifdef UNIV_DEBUG # ifdef UNIV_SYNC_DEBUG level, # endif /* UNIV_SYNC_DEBUG */ cmutex_name, # endif /* UNIV_DEBUG */ cfile_name, cline); } /******************************************************************//** Performance schema instrumented wrap function for rw_lock_x_lock_func() NOTE! Please use the corresponding macro rw_lock_x_lock(), not directly this function! */ UNIV_INLINE void pfs_rw_lock_x_lock_func( /*====================*/ rw_lock_t* lock, /*!< in: pointer to rw-lock */ ulint pass, /*!< in: pass value; != 0, if the lock will be passed to another thread to unlock */ const char* file_name,/*!< in: file name where lock requested */ ulint line) /*!< in: line where requested */ { struct PSI_rwlock_locker* locker = NULL; PSI_rwlock_locker_state state; /* Record the entry of rw x lock request in performance schema */ if (UNIV_LIKELY(PSI_server && lock->pfs_psi)) { locker = PSI_server->get_thread_rwlock_locker( &state, lock->pfs_psi, PSI_RWLOCK_WRITELOCK); if (locker) { PSI_server->start_rwlock_wrwait(locker, file_name, line); } } rw_lock_x_lock_func(lock, pass, file_name, line); if (locker) { PSI_server->end_rwlock_wrwait(locker, 0); } } /******************************************************************//** Performance schema instrumented wrap function for rw_lock_x_lock_func_nowait() NOTE! Please use the corresponding macro rw_lock_x_lock_func(), not directly this function! @return TRUE if success */ UNIV_INLINE ibool pfs_rw_lock_x_lock_func_nowait( /*===========================*/ rw_lock_t* lock, /*!< in: pointer to rw-lock */ const char* file_name,/*!< in: file name where lock requested */ ulint line) /*!< in: line where requested */ { struct PSI_rwlock_locker* locker = NULL; PSI_rwlock_locker_state state; ibool ret; /* Record the entry of rw x lock request in performance schema */ if (UNIV_LIKELY(PSI_server && lock->pfs_psi)) { locker = PSI_server->get_thread_rwlock_locker( &state, lock->pfs_psi, PSI_RWLOCK_WRITELOCK); if (locker) { PSI_server->start_rwlock_wrwait(locker, file_name, line); } } ret = rw_lock_x_lock_func_nowait(lock, file_name, line); if (locker) { PSI_server->end_rwlock_wrwait(locker, 0); } return(ret); } /******************************************************************//** Performance schema instrumented wrap function for rw_lock_free_func() NOTE! Please use the corresponding macro rw_lock_free(), not directly this function! */ UNIV_INLINE void pfs_rw_lock_free_func( /*==================*/ rw_lock_t* lock) /*!< in: pointer to rw-lock */ { if (UNIV_LIKELY(PSI_server && lock->pfs_psi)) { PSI_server->destroy_rwlock(lock->pfs_psi); lock->pfs_psi = NULL; } rw_lock_free_func(lock); } /******************************************************************//** Performance schema instrumented wrap function for rw_lock_s_lock_func() NOTE! Please use the corresponding macro rw_lock_s_lock(), not directly this function! */ UNIV_INLINE void pfs_rw_lock_s_lock_func( /*====================*/ rw_lock_t* lock, /*!< in: pointer to rw-lock */ ulint pass, /*!< in: pass value; != 0, if the lock will be passed to another thread to unlock */ const char* file_name,/*!< in: file name where lock requested */ ulint line) /*!< in: line where requested */ { struct PSI_rwlock_locker* locker = NULL; PSI_rwlock_locker_state state; /* Instrumented to inform we are aquiring a shared rwlock */ if (UNIV_LIKELY(PSI_server && lock->pfs_psi)) { locker = PSI_server->get_thread_rwlock_locker( &state, lock->pfs_psi, PSI_RWLOCK_READLOCK); if (locker) { PSI_server->start_rwlock_rdwait(locker, file_name, line); } } rw_lock_s_lock_func(lock, pass, file_name, line); if (locker) { PSI_server->end_rwlock_rdwait(locker, 0); } } /******************************************************************//** Performance schema instrumented wrap function for rw_lock_s_lock_func() NOTE! Please use the corresponding macro rw_lock_s_lock(), not directly this function! @return TRUE if success */ UNIV_INLINE ibool pfs_rw_lock_s_lock_low( /*===================*/ rw_lock_t* lock, /*!< in: pointer to rw-lock */ ulint pass, /*!< in: pass value; != 0, if the lock will be passed to another thread to unlock */ const char* file_name, /*!< in: file name where lock requested */ ulint line) /*!< in: line where requested */ { struct PSI_rwlock_locker* locker = NULL; PSI_rwlock_locker_state state; ibool ret; /* Instrumented to inform we are aquiring a shared rwlock */ if (UNIV_LIKELY(PSI_server && lock->pfs_psi)) { locker = PSI_server->get_thread_rwlock_locker( &state, lock->pfs_psi, PSI_RWLOCK_READLOCK); if (locker) { PSI_server->start_rwlock_rdwait(locker, file_name, line); } } ret = rw_lock_s_lock_low(lock, pass, file_name, line); if (locker) { PSI_server->end_rwlock_rdwait(locker, 0); } return(ret); } /******************************************************************//** Performance schema instrumented wrap function for rw_lock_x_unlock_func() NOTE! Please use the corresponding macro rw_lock_x_unlock(), not directly this function! */ UNIV_INLINE void pfs_rw_lock_x_unlock_func( /*======================*/ #ifdef UNIV_SYNC_DEBUG ulint pass, /*!< in: pass value; != 0, if the lock may have been passed to another thread to unlock */ #endif rw_lock_t* lock) /*!< in/out: rw-lock */ { /* Inform performance schema we are unlocking the lock */ if (UNIV_LIKELY(PSI_server && lock->pfs_psi)) { PSI_server->unlock_rwlock(lock->pfs_psi); } rw_lock_x_unlock_func( #ifdef UNIV_SYNC_DEBUG pass, #endif lock); } /******************************************************************//** Performance schema instrumented wrap function for rw_lock_s_unlock_func() NOTE! Please use the corresponding macro pfs_rw_lock_s_unlock(), not directly this function! */ UNIV_INLINE void pfs_rw_lock_s_unlock_func( /*======================*/ #ifdef UNIV_SYNC_DEBUG ulint pass, /*!< in: pass value; != 0, if the lock may have been passed to another thread to unlock */ #endif rw_lock_t* lock) /*!< in/out: rw-lock */ { /* Inform performance schema we are unlocking the lock */ if (UNIV_LIKELY(PSI_server && lock->pfs_psi)) { PSI_server->unlock_rwlock(lock->pfs_psi); } rw_lock_s_unlock_func( #ifdef UNIV_SYNC_DEBUG pass, #endif lock); } #endif /* UNIV_PFS_RWLOCK */