diff options
Diffstat (limited to 'storage/xtradb/include/sync0rw.h')
| -rw-r--r-- | storage/xtradb/include/sync0rw.h | 336 |
1 files changed, 177 insertions, 159 deletions
diff --git a/storage/xtradb/include/sync0rw.h b/storage/xtradb/include/sync0rw.h index e3fe0dc9ccc..aedfd5f3f86 100644 --- a/storage/xtradb/include/sync0rw.h +++ b/storage/xtradb/include/sync0rw.h @@ -23,7 +23,8 @@ Place, Suite 330, Boston, MA 02111-1307 USA *****************************************************************************/ -/****************************************************** +/**************************************************//** +@file include/sync0rw.h The read-write lock (for threads, not for database transactions) Created 9/11/1995 Heikki Tuuri @@ -33,6 +34,7 @@ Created 9/11/1995 Heikki Tuuri #define sync0rw_h #include "univ.i" +#ifndef UNIV_HOTBACKUP #include "ut0lst.h" #include "sync0sync.h" #include "os0sync.h" @@ -40,6 +42,7 @@ Created 9/11/1995 Heikki Tuuri /* The following undef is to prevent a name conflict with a macro in MySQL: */ #undef rw_lock_t +#endif /* !UNIV_HOTBACKUP */ /* Latch types; these are used also in btr0btr.h: keep the numerical values smaller than 30 and the order of the numerical values like below! */ @@ -47,6 +50,7 @@ smaller than 30 and the order of the numerical values like below! */ #define RW_X_LATCH 2 #define RW_NO_LATCH 3 +#ifndef UNIV_HOTBACKUP /* We decrement lock_word by this amount for each x_lock. It is also the start value for the lock_word, meaning that it limits the maximum number of concurrent read locks before the rw_lock breaks. The current value of @@ -69,23 +73,39 @@ To modify the debug info list of an rw-lock, this mutex has to be acquired in addition to the mutex protecting the lock. */ extern mutex_t rw_lock_debug_mutex; -extern os_event_t rw_lock_debug_event; /* If deadlock detection does +extern os_event_t rw_lock_debug_event; /*!< If deadlock detection does not get immediately the mutex it may wait for this event */ -extern ibool rw_lock_debug_waiters; /* This is set to TRUE, if +extern ibool rw_lock_debug_waiters; /*!< This is set to TRUE, if there may be waiters for the event */ #endif /* UNIV_SYNC_DEBUG */ +/** number of spin waits on rw-latches, +resulted during exclusive (write) locks */ extern ib_int64_t rw_s_spin_wait_count; +/** number of spin loop rounds on rw-latches, +resulted during exclusive (write) locks */ extern ib_int64_t rw_s_spin_round_count; +/** number of unlocks (that unlock shared locks), +set only when UNIV_SYNC_PERF_STAT is defined */ extern ib_int64_t rw_s_exit_count; +/** number of OS waits on rw-latches, +resulted during shared (read) locks */ extern ib_int64_t rw_s_os_wait_count; +/** number of spin waits on rw-latches, +resulted during shared (read) locks */ extern ib_int64_t rw_x_spin_wait_count; +/** number of spin loop rounds on rw-latches, +resulted during shared (read) locks */ extern ib_int64_t rw_x_spin_round_count; +/** number of OS waits on rw-latches, +resulted during exclusive (write) locks */ extern ib_int64_t rw_x_os_wait_count; +/** number of unlocks (that unlock exclusive locks), +set only when UNIV_SYNC_PERF_STAT is defined */ extern ib_int64_t rw_x_exit_count; -/********************************************************************** +/******************************************************************//** Creates, or rather, initializes an rw-lock object in a specified memory location (which must be appropriately aligned). The rw-lock is initialized to the non-locked state. Explicit freeing of the rw-lock with rw_lock_free @@ -103,7 +123,7 @@ is necessary only if the memory block containing it is freed. */ rw_lock_create_func((L), __FILE__, __LINE__) #endif /* UNIV_DEBUG */ -/********************************************************************** +/******************************************************************//** Creates, or rather, initializes an rw-lock object in a specified memory location (which must be appropriately aligned). The rw-lock is initialized to the non-locked state. Explicit freeing of the rw-lock with rw_lock_free @@ -112,16 +132,16 @@ UNIV_INTERN void rw_lock_create_func( /*================*/ - rw_lock_t* lock, /* in: pointer to memory */ + rw_lock_t* lock, /*!< in: pointer to memory */ #ifdef UNIV_DEBUG # ifdef UNIV_SYNC_DEBUG - ulint level, /* in: level */ + ulint level, /*!< in: level */ # endif /* UNIV_SYNC_DEBUG */ - const char* cmutex_name, /* in: mutex name */ + 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 */ -/********************************************************************** + const char* cfile_name, /*!< in: file name where created */ + ulint cline); /*!< in: file line where created */ +/******************************************************************//** Calling this function is obligatory only if the memory buffer containing the rw-lock is freed. Removes an rw-lock object from the global list. The rw-lock is checked to be in the non-locked state. */ @@ -129,50 +149,51 @@ UNIV_INTERN void rw_lock_free( /*=========*/ - rw_lock_t* lock); /* in: rw-lock */ + rw_lock_t* lock); /*!< in: rw-lock */ #ifdef UNIV_DEBUG -/********************************************************************** +/******************************************************************//** Checks that the rw-lock has been initialized and that there are no -simultaneous shared and exclusive locks. */ +simultaneous shared and exclusive locks. +@return TRUE */ UNIV_INTERN ibool rw_lock_validate( /*=============*/ - rw_lock_t* lock); + rw_lock_t* lock); /*!< in: rw-lock */ #endif /* UNIV_DEBUG */ -/****************************************************************** +/**************************************************************//** NOTE! The following macros should be used in rw s-locking, not the corresponding function. */ #define rw_lock_s_lock(M) rw_lock_s_lock_func(\ (M), 0, __FILE__, __LINE__) -/****************************************************************** +/**************************************************************//** NOTE! The following macros should be used in rw s-locking, not the corresponding function. */ #define rw_lock_s_lock_gen(M, P) rw_lock_s_lock_func(\ (M), (P), __FILE__, __LINE__) -/****************************************************************** +/**************************************************************//** NOTE! The following macros should be used in rw s-locking, not the corresponding function. */ #define rw_lock_s_lock_nowait(M, F, L) rw_lock_s_lock_low(\ (M), 0, (F), (L)) -/********************************************************************** +/******************************************************************//** Low-level function which tries to lock an rw-lock in s-mode. Performs no -spinning. */ +spinning. +@return TRUE if success */ UNIV_INLINE ibool rw_lock_s_lock_low( /*===============*/ - /* out: TRUE if success */ - rw_lock_t* lock, /* in: pointer to rw-lock */ + rw_lock_t* lock, /*!< in: pointer to rw-lock */ ulint pass __attribute__((unused)), - /* in: pass value; != 0, if the lock will be + /*!< 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 */ -/********************************************************************** + const char* file_name, /*!< in: file name where lock requested */ + ulint line); /*!< in: line where requested */ +/******************************************************************//** NOTE! Use the corresponding macro, not directly this function, except if you supply the file name and line number. Lock an rw-lock in shared mode for the current thread. If the rw-lock is locked in exclusive mode, or @@ -183,70 +204,63 @@ 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 + 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 */ -/********************************************************************** + const char* file_name,/*!< in: file name where lock requested */ + ulint line); /*!< in: line where requested */ +/******************************************************************//** 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. */ +obtained immediately. +@return TRUE if success */ UNIV_INLINE ibool rw_lock_x_lock_func_nowait( /*=======================*/ - /* out: TRUE if success */ - 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 */ -/********************************************************************** + 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 */ +/******************************************************************//** Releases a shared mode lock. */ UNIV_INLINE void rw_lock_s_unlock_func( /*==================*/ - rw_lock_t* lock /* in: rw-lock */ #ifdef UNIV_SYNC_DEBUG - ,ulint pass /* in: pass value; != 0, if the lock may have + ulint pass, /*!< in: pass value; != 0, if the lock may have been passed to another thread to unlock */ #endif - ); -/*********************************************************************** -Releases a shared mode lock. */ + rw_lock_t* lock); /*!< in/out: rw-lock */ #ifdef UNIV_SYNC_DEBUG -#define rw_lock_s_unlock(L) rw_lock_s_unlock_func(L, 0) +# define rw_lock_s_unlock_gen(L, P) rw_lock_s_unlock_func(P, L) #else -#define rw_lock_s_unlock(L) rw_lock_s_unlock_func(L) +# define rw_lock_s_unlock_gen(L, P) rw_lock_s_unlock_func(L) #endif -/*********************************************************************** +/*******************************************************************//** Releases a shared mode lock. */ +#define rw_lock_s_unlock(L) rw_lock_s_unlock_gen(L, 0) -#ifdef UNIV_SYNC_DEBUG -#define rw_lock_s_unlock_gen(L, P) rw_lock_s_unlock_func(L, P) -#else -#define rw_lock_s_unlock_gen(L, P) rw_lock_s_unlock_func(L) -#endif -/****************************************************************** +/**************************************************************//** NOTE! The following macro should be used in rw x-locking, not the corresponding function. */ #define rw_lock_x_lock(M) rw_lock_x_lock_func(\ (M), 0, __FILE__, __LINE__) -/****************************************************************** +/**************************************************************//** NOTE! The following macro should be used in rw x-locking, not the corresponding function. */ #define rw_lock_x_lock_gen(M, P) rw_lock_x_lock_func(\ (M), (P), __FILE__, __LINE__) -/****************************************************************** +/**************************************************************//** NOTE! The following macros should be used in rw x-locking, not the corresponding function. */ #define rw_lock_x_lock_nowait(M) rw_lock_x_lock_func_nowait(\ (M), __FILE__, __LINE__) -/********************************************************************** +/******************************************************************//** NOTE! Use the corresponding macro, not directly this function! Lock an rw-lock in exclusive mode for the current thread. If the rw-lock is locked in shared or exclusive mode, or there is an exclusive lock request waiting, @@ -259,40 +273,33 @@ UNIV_INTERN void rw_lock_x_lock_func( /*================*/ - rw_lock_t* lock, /* in: pointer to rw-lock */ - ulint pass, /* in: pass value; != 0, if the lock will + 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 */ -/********************************************************************** + const char* file_name,/*!< in: file name where lock requested */ + ulint line); /*!< in: line where requested */ +/******************************************************************//** Releases an exclusive mode lock. */ UNIV_INLINE void rw_lock_x_unlock_func( /*==================*/ - rw_lock_t* lock /* in: rw-lock */ #ifdef UNIV_SYNC_DEBUG - ,ulint pass /* in: pass value; != 0, if the lock may have + ulint pass, /*!< in: pass value; != 0, if the lock may have been passed to another thread to unlock */ #endif - ); -/*********************************************************************** -Releases an exclusive mode lock. */ + rw_lock_t* lock); /*!< in/out: rw-lock */ #ifdef UNIV_SYNC_DEBUG -#define rw_lock_x_unlock(L) rw_lock_x_unlock_func(L, 0) +# define rw_lock_x_unlock_gen(L, P) rw_lock_x_unlock_func(P, L) #else -#define rw_lock_x_unlock(L) rw_lock_x_unlock_func(L) +# define rw_lock_x_unlock_gen(L, P) rw_lock_x_unlock_func(L) #endif -/*********************************************************************** +/*******************************************************************//** Releases an exclusive mode lock. */ +#define rw_lock_x_unlock(L) rw_lock_x_unlock_gen(L, 0) -#ifdef UNIV_SYNC_DEBUG -#define rw_lock_x_unlock_gen(L, P) rw_lock_x_unlock_func(L, P) -#else -#define rw_lock_x_unlock_gen(L, P) rw_lock_x_unlock_func(L) -#endif -/********************************************************************** +/******************************************************************//** 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. */ @@ -300,11 +307,10 @@ UNIV_INLINE void rw_lock_s_lock_direct( /*==================*/ - rw_lock_t* lock, /* in: pointer to rw-lock */ - const char* file_name, /* in: file name where requested */ - ulint line /* in: line where lock requested */ -); -/********************************************************************** + rw_lock_t* lock, /*!< in/out: rw-lock */ + const char* file_name, /*!< in: file name where requested */ + ulint line); /*!< in: line where lock requested */ +/******************************************************************//** 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. */ @@ -312,11 +318,10 @@ UNIV_INLINE void rw_lock_x_lock_direct( /*==================*/ - rw_lock_t* lock, /* in: pointer to rw-lock */ - const char* file_name, /* in: file name where requested */ - ulint line /* in: line where lock requested */ -); -/********************************************************************** + rw_lock_t* lock, /*!< in/out: rw-lock */ + const char* file_name, /*!< in: file name where requested */ + ulint line); /*!< in: line where lock requested */ +/******************************************************************//** This function is used in the insert buffer to move the ownership of an x-latch on a buffer frame to the current thread. The x-latch was set by the buffer read operation and it protected the buffer frame while the @@ -328,70 +333,78 @@ UNIV_INTERN void rw_lock_x_lock_move_ownership( /*==========================*/ - rw_lock_t* lock); /* in: lock which was x-locked in the + rw_lock_t* lock); /*!< in: lock which was x-locked in the buffer read */ -/********************************************************************** +/******************************************************************//** 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: rw-lock */ -/********************************************************************** + rw_lock_t* lock); /*!< in/out: rw-lock */ +/******************************************************************//** Releases an exclusive mode lock when we know there are no waiters, and none else will access the lock durint the time this function is executed. */ UNIV_INLINE void rw_lock_x_unlock_direct( /*====================*/ - rw_lock_t* lock); /* in: rw-lock */ -/********************************************************************** + rw_lock_t* lock); /*!< in/out: rw-lock */ +/******************************************************************//** 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. */ +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( /*=====================*/ - /* out: value of writer_count */ - rw_lock_t* lock); /* in: rw-lock */ -/************************************************************************ -Accessor functions for rw lock. */ + const rw_lock_t* lock); /*!< in: rw-lock */ +/********************************************************************//** +Check if there are threads waiting for the rw-lock. +@return 1 if waiters, 0 otherwise */ UNIV_INLINE ulint rw_lock_get_waiters( /*================*/ - rw_lock_t* lock); + const rw_lock_t* lock); /*!< in: rw-lock */ +/******************************************************************//** +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( /*===============*/ - rw_lock_t* lock); + const rw_lock_t* lock); /*!< in: rw-lock */ +/******************************************************************//** +Returns the number of readers. +@return number of readers */ UNIV_INLINE ulint rw_lock_get_reader_count( /*=====================*/ - rw_lock_t* lock); -/********************************************************************** + const rw_lock_t* lock); /*!< in: rw-lock */ +/******************************************************************//** Decrements lock_word the specified amount if it is greater than 0. -This is used by both s_lock and x_lock operations. */ +This is used by both s_lock and x_lock operations. +@return TRUE if decr occurs */ UNIV_INLINE ibool rw_lock_lock_word_decr( /*===================*/ - /* out: TRUE if decr occurs */ - rw_lock_t* lock, /* in: rw-lock */ - ulint amount); /* in: amount to decrement */ -/********************************************************************** -Increments lock_word the specified amount and returns new value. */ + rw_lock_t* lock, /*!< in/out: rw-lock */ + ulint amount); /*!< in: amount to decrement */ +/******************************************************************//** +Increments lock_word the specified amount and returns new value. +@return lock->lock_word after increment */ UNIV_INLINE lint rw_lock_lock_word_incr( /*===================*/ - /* out: TRUE if decr occurs */ - rw_lock_t* lock, - ulint amount); /* in: rw-lock */ -/********************************************************************** + rw_lock_t* lock, /*!< in/out: rw-lock */ + ulint amount); /*!< in: amount to increment */ +/******************************************************************//** 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 @@ -404,48 +417,49 @@ 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 + rw_lock_t* lock, /*!< in/out: lock to work on */ + ibool recursive); /*!< in: TRUE if recursion allowed */ #ifdef UNIV_SYNC_DEBUG -/********************************************************************** +/******************************************************************//** Checks if the thread has locked the rw-lock in the specified mode, with the pass value == 0. */ UNIV_INTERN ibool rw_lock_own( /*========*/ - rw_lock_t* lock, /* in: rw-lock */ - ulint lock_type); /* in: lock type: RW_LOCK_SHARED, + rw_lock_t* lock, /*!< in: rw-lock */ + ulint lock_type); /*!< in: lock type: RW_LOCK_SHARED, RW_LOCK_EX */ #endif /* UNIV_SYNC_DEBUG */ -/********************************************************************** +/******************************************************************//** Checks if somebody has locked the rw-lock in the specified mode. */ UNIV_INTERN ibool rw_lock_is_locked( /*==============*/ - rw_lock_t* lock, /* in: rw-lock */ - ulint lock_type); /* in: lock type: RW_LOCK_SHARED, + rw_lock_t* lock, /*!< in: rw-lock */ + ulint lock_type); /*!< in: lock type: RW_LOCK_SHARED, RW_LOCK_EX */ #ifdef UNIV_SYNC_DEBUG -/******************************************************************* +/***************************************************************//** Prints debug info of an rw-lock. */ UNIV_INTERN void rw_lock_print( /*==========*/ - rw_lock_t* lock); /* in: rw-lock */ -/******************************************************************* + rw_lock_t* lock); /*!< in: rw-lock */ +/***************************************************************//** Prints debug info of currently locked rw-locks. */ UNIV_INTERN void rw_lock_list_print_info( /*====================*/ - FILE* file); /* in: file where to print */ -/******************************************************************* + FILE* file); /*!< in: file where to print */ +/***************************************************************//** Returns the number of currently locked rw-locks. -Works only in the debug version. */ +Works only in the debug version. +@return number of locked rw-locks */ UNIV_INTERN ulint rw_lock_n_locked(void); @@ -453,7 +467,7 @@ rw_lock_n_locked(void); /*#####################################################################*/ -/********************************************************************** +/******************************************************************//** Acquires the debug mutex. We cannot use the mutex defined in sync0sync, because the debug mutex is also acquired in sync0arr while holding the OS mutex protecting the sync array, and the ordinary mutex_enter might @@ -463,34 +477,36 @@ UNIV_INTERN void rw_lock_debug_mutex_enter(void); /*==========================*/ -/********************************************************************** +/******************************************************************//** Releases the debug mutex. */ UNIV_INTERN void rw_lock_debug_mutex_exit(void); /*==========================*/ -/************************************************************************* +/*********************************************************************//** Prints info of a debug struct. */ UNIV_INTERN void rw_lock_debug_print( /*================*/ - rw_lock_debug_t* info); /* in: debug struct */ + rw_lock_debug_t* info); /*!< in: debug struct */ #endif /* UNIV_SYNC_DEBUG */ /* NOTE! The structure appears here only for the compiler to know its size. -Do not use its fields directly! The structure used in the spin lock -implementation of a read-write lock. Several threads may have a shared lock -simultaneously in this lock, but only one writer may have an exclusive lock, -in which case no shared locks are allowed. To prevent starving of a writer -blocked by readers, a writer may queue for x-lock by decrementing lock_word: -no new readers will be let in while the thread waits for readers to exit. */ - +Do not use its fields directly! */ + +/** The structure used in the spin lock implementation of a read-write +lock. Several threads may have a shared lock simultaneously in this +lock, but only one writer may have an exclusive lock, in which case no +shared locks are allowed. To prevent starving of a writer blocked by +readers, a writer may queue for x-lock by decrementing lock_word: no +new readers will be let in while the thread waits for readers to +exit. */ struct rw_lock_struct { volatile lint lock_word; - /* Holds the state of the lock. */ - volatile ulint waiters;/* 1: there are waiters */ - volatile ibool recursive;/* Default value FALSE which means the lock + /*!< Holds the state of the lock. */ + volatile ulint waiters;/*!< 1: there are waiters */ + volatile ibool recursive;/*!< Default value FALSE which means the lock is non-recursive. The value is typically set to TRUE making normal rw_locks recursive. In case of asynchronous IO, when a non-zero @@ -503,59 +519,60 @@ struct rw_lock_struct { This flag must be reset in x_unlock functions before incrementing the lock_word */ volatile os_thread_id_t writer_thread; - /* Thread id of writer thread. Is only + /*!< Thread id of writer thread. Is only guaranteed to have sane and non-stale value iff recursive flag is set. */ - os_event_t event; /* Used by sync0arr.c for thread queueing */ + os_event_t event; /*!< Used by sync0arr.c for thread queueing */ os_event_t wait_ex_event; - /* Event for next-writer to wait on. A thread + /*!< Event for next-writer to wait on. A thread must decrement lock_word before waiting. */ #ifndef INNODB_RW_LOCKS_USE_ATOMICS - mutex_t mutex; /* The mutex protecting rw_lock_struct */ + mutex_t mutex; /*!< The mutex protecting rw_lock_struct */ #endif /* INNODB_RW_LOCKS_USE_ATOMICS */ UT_LIST_NODE_T(rw_lock_t) list; - /* All allocated rw locks are put into a + /*!< All allocated rw locks are put into a list */ #ifdef UNIV_SYNC_DEBUG UT_LIST_BASE_NODE_T(rw_lock_debug_t) debug_list; - /* In the debug version: pointer to the debug + /*!< In the debug version: pointer to the debug info list of the lock */ - ulint level; /* Level in the global latching order. */ + ulint level; /*!< Level in the global latching order. */ #endif /* UNIV_SYNC_DEBUG */ - ulint count_os_wait; /* Count of os_waits. May not be accurate */ - const char* cfile_name;/* File name where lock created */ + ulint count_os_wait; /*!< Count of os_waits. May not be accurate */ + const char* cfile_name;/*!< File name where lock created */ /* last s-lock file/line is not guaranteed to be correct */ - const char* last_s_file_name;/* File name where last s-locked */ - const char* last_x_file_name;/* File name where last x-locked */ + const char* last_s_file_name;/*!< File name where last s-locked */ + const char* last_x_file_name;/*!< File name where last x-locked */ ibool writer_is_wait_ex; - /* This is TRUE if the writer field is + /*!< This is TRUE if the writer field is RW_LOCK_WAIT_EX; this field is located far from the memory update hotspot fields which are at the start of this struct, thus we can peek this field without causing much memory bus traffic */ - unsigned cline:14; /* Line where created */ - unsigned last_s_line:14; /* Line number where last time s-locked */ - unsigned last_x_line:14; /* Line number where last time x-locked */ - ulint magic_n; + unsigned cline:14; /*!< Line where created */ + unsigned last_s_line:14; /*!< Line number where last time s-locked */ + unsigned last_x_line:14; /*!< Line number where last time x-locked */ + ulint magic_n; /*!< RW_LOCK_MAGIC_N */ }; +/** Value of rw_lock_struct::magic_n */ #define RW_LOCK_MAGIC_N 22643 #ifdef UNIV_SYNC_DEBUG -/* The structure for storing debug info of an rw-lock */ +/** The structure for storing debug info of an rw-lock */ struct rw_lock_debug_struct { - os_thread_id_t thread_id; /* The thread id of the thread which + os_thread_id_t thread_id; /*!< The thread id of the thread which locked the rw-lock */ - ulint pass; /* Pass value given in the lock operation */ - ulint lock_type; /* Type of the lock: RW_LOCK_EX, + ulint pass; /*!< Pass value given in the lock operation */ + ulint lock_type; /*!< Type of the lock: RW_LOCK_EX, RW_LOCK_SHARED, RW_LOCK_WAIT_EX */ - const char* file_name;/* File name where the lock was obtained */ - ulint line; /* Line where the rw-lock was locked */ + const char* file_name;/*!< File name where the lock was obtained */ + ulint line; /*!< Line where the rw-lock was locked */ UT_LIST_NODE_T(rw_lock_debug_t) list; - /* Debug structs are linked in a two-way + /*!< Debug structs are linked in a two-way list */ }; #endif /* UNIV_SYNC_DEBUG */ @@ -563,5 +580,6 @@ struct rw_lock_debug_struct { #ifndef UNIV_NONINL #include "sync0rw.ic" #endif +#endif /* !UNIV_HOTBACKUP */ #endif |