The read-write lock (for threads, not for database transactions) More...

#include "univ.i"
#include "os0event.h"
#include "ut0counter.h"
#include <atomic>
#include "ut0mutex.h"
#include "sync0rw.ic"

Classes
struct	rw_lock_stats_t
	Counters for RW locks. More...

struct	rw_lock_t
	The structure used in the spin lock implementation of a read-write lock. More...

struct	rw_lock_debug_t
	The structure for storing debug info of an rw-lock. More...

Macros
#define	X_LOCK_DECR 0x20000000

#define	X_LOCK_HALF_DECR 0x10000000

#define	rw_lock_create(K, L, level) pfs_rw_lock_create_func((K), (L), (level), #L, __FILE__, __LINE__)

#define	rw_lock_s_lock(M) pfs_rw_lock_s_lock_func((M), 0, __FILE__, __LINE__)

#define	rw_lock_s_lock_inline(M, P, F, L) pfs_rw_lock_s_lock_func((M), (P), (F), (L))

#define	rw_lock_s_lock_gen(M, P) pfs_rw_lock_s_lock_func((M), (P), __FILE__, __LINE__)

#define	rw_lock_s_lock_nowait(M, F, L) pfs_rw_lock_s_lock_low((M), 0, (F), (L))

#define	rw_lock_s_unlock_gen(L, P) pfs_rw_lock_s_unlock_func(P, L)

#define	rw_lock_sx_lock(M) pfs_rw_lock_sx_lock_func((M), 0, __FILE__, __LINE__)

#define	rw_lock_sx_lock_inline(M, P, F, L) pfs_rw_lock_sx_lock_func((M), (P), (F), (L))

#define	rw_lock_sx_lock_gen(M, P) pfs_rw_lock_sx_lock_func((M), (P), __FILE__, __LINE__)

#define	rw_lock_sx_lock_nowait(M, P) pfs_rw_lock_sx_lock_low((M), (P), __FILE__, __LINE__)

#define	rw_lock_sx_unlock(L) pfs_rw_lock_sx_unlock_func(0, L)

#define	rw_lock_sx_unlock_gen(L, P) pfs_rw_lock_sx_unlock_func(P, L)

#define	rw_lock_x_lock(M) pfs_rw_lock_x_lock_func((M), 0, __FILE__, __LINE__)

#define	rw_lock_x_lock_inline(M, P, F, L) pfs_rw_lock_x_lock_func((M), (P), (F), (L))

#define	rw_lock_x_lock_gen(M, P) pfs_rw_lock_x_lock_func((M), (P), __FILE__, __LINE__)

#define	rw_lock_x_lock_nowait(M) pfs_rw_lock_x_lock_func_nowait((M), __FILE__, __LINE__)

#define	rw_lock_x_lock_func_nowait_inline(M, F, L) pfs_rw_lock_x_lock_func_nowait((M), (F), (L))

#define	rw_lock_x_unlock_gen(L, P) pfs_rw_lock_x_unlock_func(P, L)

#define	rw_lock_free(M) pfs_rw_lock_free_func(M)

#define	rw_lock_s_unlock(L) rw_lock_s_unlock_gen(L, 0)

#define	rw_lock_x_unlock(L) rw_lock_x_unlock_gen(L, 0)

Enumerations
enum	rw_lock_type_t { RW_S_LATCH = 1, RW_X_LATCH = 2, RW_SX_LATCH = 4, RW_NO_LATCH = 8 }

Functions
typedef	UT_LIST_BASE_NODE_T (rw_lock_t) rw_lock_list_t

void	rw_lock_create_func (rw_lock_t lock, latch_level_t level, const char cmutex_name, const char *cfile_name, ulint cline)
	Creates, or rather, initializes an rw-lock object in a specified memory location (which must be appropriately aligned). More...

void	rw_lock_free_func (rw_lock_t *lock)
	Calling this function is obligatory only if the memory buffer containing the rw-lock is freed. More...

bool	rw_lock_validate (const rw_lock_t *lock)
	Checks that the rw-lock has been initialized and that there are no simultaneous shared and exclusive locks. More...

UNIV_INLINE ibool	rw_lock_s_lock_low (rw_lock_t lock, ulint pass, const char file_name, ulint line)
	Low-level function which tries to lock an rw-lock in s-mode. More...

UNIV_INLINE void	rw_lock_s_lock_func (rw_lock_t lock, ulint pass, const char file_name, ulint line)
	NOTE! Use the corresponding macro, not directly this function, except if you supply the file name and line number. More...

UNIV_INLINE ibool	rw_lock_x_lock_func_nowait (rw_lock_t lock, const char file_name, ulint line)
	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. More...

UNIV_INLINE void	rw_lock_s_unlock_func (ulint pass, rw_lock_t *lock)
	Releases a shared mode lock. More...

void	rw_lock_x_lock_func (rw_lock_t lock, ulint pass, const char file_name, ulint line)
	NOTE! Use the corresponding macro, not directly this function! Lock an rw-lock in exclusive mode for the current thread. More...

ibool	rw_lock_sx_lock_low (rw_lock_t lock, ulint pass, const char file_name, ulint line)
	Low-level function for acquiring an sx lock. More...

void	rw_lock_sx_lock_func (rw_lock_t lock, ulint pass, const char file_name, ulint line)
	NOTE! Use the corresponding macro, not directly this function! Lock an rw-lock in SX mode for the current thread. More...

UNIV_INLINE void	rw_lock_x_unlock_func (ulint pass, rw_lock_t *lock)
	Releases an exclusive mode lock. More...

UNIV_INLINE void	rw_lock_sx_unlock_func (ulint pass, rw_lock_t *lock)
	Releases an sx mode lock. More...

void	rw_lock_x_lock_move_ownership (rw_lock_t *lock)
	This function is used in the insert buffer to move the ownership of an x-latch on a buffer frame to the current thread. More...

UNIV_INLINE ulint	rw_lock_get_x_lock_count (const rw_lock_t *lock)
	Returns the value of writer_count for the lock. More...

UNIV_INLINE ulint	rw_lock_get_sx_lock_count (const rw_lock_t *lock)
	Returns the number of sx-lock for the lock. More...

UNIV_INLINE ulint	rw_lock_get_waiters (const rw_lock_t *lock)
	Check if there are threads waiting for the rw-lock. More...

UNIV_INLINE ulint	rw_lock_get_writer (const rw_lock_t *lock)
	Returns the write-status of the lock - this function made more sense with the old rw_lock implementation. More...

UNIV_INLINE ulint	rw_lock_get_reader_count (const rw_lock_t *lock)
	Returns the number of readers (s-locks). More...

UNIV_INLINE bool	rw_lock_lock_word_decr (rw_lock_t *lock, ulint amount, lint threshold)
	Decrements lock_word the specified amount if it is greater than 0. More...

UNIV_INLINE lint	rw_lock_lock_word_incr (rw_lock_t *lock, ulint amount)
	Increments lock_word the specified amount and returns new value. More...

UNIV_INLINE void	rw_lock_set_writer_id_and_recursion_flag (rw_lock_t *lock, bool recursive)
	This function sets the lock->writer_thread and lock->recursive fields. More...

ibool	rw_lock_own (rw_lock_t *lock, ulint lock_type)
	Checks if the thread has locked the rw-lock in the specified mode, with the pass value == 0. More...

bool	rw_lock_own_flagged (const rw_lock_t *lock, rw_lock_flags_t flags)
	Checks if the thread has locked the rw-lock in the specified mode, with the pass value == 0. More...

bool	rw_lock_is_locked (rw_lock_t *lock, ulint lock_type)
	Checks if somebody has locked the rw-lock in the specified mode. More...

void	rw_lock_list_print_info (FILE *file)
	Prints debug info of currently locked rw-locks. More...

void	rw_lock_debug_print (FILE f, const rw_lock_debug_t info)
	Prints info of a debug struct. More...

UNIV_INLINE void	pfs_rw_lock_create_func (mysql_pfs_key_t key, rw_lock_t lock, latch_level_t level, const char cmutex_name, const char *cfile_name, ulint cline)
	Performance schema instrumented wrap function for rw_lock_create_func() NOTE! Please use the corresponding macro rw_lock_create(), not directly this function! More...

UNIV_INLINE void	pfs_rw_lock_x_lock_func (rw_lock_t lock, ulint pass, const char file_name, ulint line)
	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! More...

UNIV_INLINE ibool	pfs_rw_lock_x_lock_func_nowait (rw_lock_t lock, const char file_name, ulint line)
	Performance schema instrumented wrap function for rw_lock_x_lock_func_nowait() NOTE! Please use the corresponding macro, not directly this function! More...

UNIV_INLINE void	pfs_rw_lock_s_lock_func (rw_lock_t lock, ulint pass, const char file_name, ulint line)
	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! More...

UNIV_INLINE ibool	pfs_rw_lock_s_lock_low (rw_lock_t lock, ulint pass, const char file_name, ulint line)
	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! More...

UNIV_INLINE void	pfs_rw_lock_s_unlock_func (ulint pass, rw_lock_t *lock)
	Performance schema instrumented wrap function for rw_lock_s_unlock_func() NOTE! Please use the corresponding macro rw_lock_s_unlock(), not directly this function! More...

UNIV_INLINE void	pfs_rw_lock_x_unlock_func (ulint pass, rw_lock_t *lock)
	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! More...

UNIV_INLINE void	pfs_rw_lock_sx_lock_func (rw_lock_t lock, ulint pass, const char file_name, ulint line)
	Performance schema instrumented wrap function for rw_lock_sx_lock_func() NOTE! Please use the corresponding macro rw_lock_sx_lock(), not directly this function! More...

UNIV_INLINE ibool	pfs_rw_lock_sx_lock_low (rw_lock_t lock, ulint pass, const char file_name, ulint line)
	Performance schema instrumented wrap function for rw_lock_sx_lock_nowait() NOTE! Please use the corresponding macro, not directly this function! More...

UNIV_INLINE void	pfs_rw_lock_sx_unlock_func (ulint pass, rw_lock_t *lock)
	Performance schema instrumented wrap function for rw_lock_sx_unlock_func() NOTE! Please use the corresponding macro rw_lock_sx_unlock(), not directly this function! More...

UNIV_INLINE void	pfs_rw_lock_free_func (rw_lock_t *lock)
	Performance schema instrumented wrap function for rw_lock_free_func() NOTE! Please use the corresponding macro rw_lock_free(), not directly this function! More...

Variables
rw_lock_list_t	rw_lock_list

ib_mutex_t	rw_lock_list_mutex

rw_lock_stats_t	rw_lock_stats
	Counters for RW locks. More...

Detailed Description

The read-write lock (for threads, not for database transactions)

Created 9/11/1995 Heikki Tuuri

Macro Definition Documentation

◆ rw_lock_create

#define rw_lock_create	(	K,
		L,
		level
	)	pfs_rw_lock_create_func((K), (L), (level), #L, __FILE__, __LINE__)

◆ rw_lock_free

#define rw_lock_free ( M ) pfs_rw_lock_free_func(M)

◆ rw_lock_s_lock

#define rw_lock_s_lock ( M ) pfs_rw_lock_s_lock_func((M), 0, __FILE__, __LINE__)

◆ rw_lock_s_lock_gen

#define rw_lock_s_lock_gen	(	M,
		P
	)	pfs_rw_lock_s_lock_func((M), (P), __FILE__, __LINE__)

◆ rw_lock_s_lock_inline

#define rw_lock_s_lock_inline	(	M,
		P,
		F,
		L
	)	pfs_rw_lock_s_lock_func((M), (P), (F), (L))

◆ rw_lock_s_lock_nowait

#define rw_lock_s_lock_nowait	(	M,
		F,
		L
	)	pfs_rw_lock_s_lock_low((M), 0, (F), (L))

◆ rw_lock_s_unlock

#define rw_lock_s_unlock ( L ) rw_lock_s_unlock_gen(L, 0)

◆ rw_lock_s_unlock_gen

#define rw_lock_s_unlock_gen	(	L,
		P
	)	pfs_rw_lock_s_unlock_func(P, L)

◆ rw_lock_sx_lock

#define rw_lock_sx_lock ( M ) pfs_rw_lock_sx_lock_func((M), 0, __FILE__, __LINE__)

◆ rw_lock_sx_lock_gen

#define rw_lock_sx_lock_gen	(	M,
		P
	)	pfs_rw_lock_sx_lock_func((M), (P), __FILE__, __LINE__)

◆ rw_lock_sx_lock_inline

#define rw_lock_sx_lock_inline	(	M,
		P,
		F,
		L
	)	pfs_rw_lock_sx_lock_func((M), (P), (F), (L))

◆ rw_lock_sx_lock_nowait

#define rw_lock_sx_lock_nowait	(	M,
		P
	)	pfs_rw_lock_sx_lock_low((M), (P), __FILE__, __LINE__)

◆ rw_lock_sx_unlock

#define rw_lock_sx_unlock ( L ) pfs_rw_lock_sx_unlock_func(0, L)

◆ rw_lock_sx_unlock_gen

#define rw_lock_sx_unlock_gen	(	L,
		P
	)	pfs_rw_lock_sx_unlock_func(P, L)

◆ rw_lock_x_lock

#define rw_lock_x_lock ( M ) pfs_rw_lock_x_lock_func((M), 0, __FILE__, __LINE__)

◆ rw_lock_x_lock_func_nowait_inline

#define rw_lock_x_lock_func_nowait_inline	(	M,
		F,
		L
	)	pfs_rw_lock_x_lock_func_nowait((M), (F), (L))

◆ rw_lock_x_lock_gen

#define rw_lock_x_lock_gen	(	M,
		P
	)	pfs_rw_lock_x_lock_func((M), (P), __FILE__, __LINE__)

◆ rw_lock_x_lock_inline

#define rw_lock_x_lock_inline	(	M,
		P,
		F,
		L
	)	pfs_rw_lock_x_lock_func((M), (P), (F), (L))

◆ rw_lock_x_lock_nowait

#define rw_lock_x_lock_nowait ( M ) pfs_rw_lock_x_lock_func_nowait((M), __FILE__, __LINE__)

◆ rw_lock_x_unlock

#define rw_lock_x_unlock ( L ) rw_lock_x_unlock_gen(L, 0)

◆ rw_lock_x_unlock_gen

#define rw_lock_x_unlock_gen	(	L,
		P
	)	pfs_rw_lock_x_unlock_func(P, L)

◆ X_LOCK_DECR

#define X_LOCK_DECR 0x20000000

◆ X_LOCK_HALF_DECR

#define X_LOCK_HALF_DECR 0x10000000

Enumeration Type Documentation

◆ rw_lock_type_t

enum rw_lock_type_t

Enumerator
RW_S_LATCH
RW_X_LATCH
RW_SX_LATCH
RW_NO_LATCH

Function Documentation

◆ pfs_rw_lock_create_func()

UNIV_INLINE void pfs_rw_lock_create_func	(	mysql_pfs_key_t	key,
		rw_lock_t *	lock,
		latch_level_t	level,
		const char *	cmutex_name,
		const char *	cfile_name,
		ulint	cline
	)

Performance schema instrumented wrap function for rw_lock_create_func() NOTE! Please use the corresponding macro rw_lock_create(), not directly this function!

Parameters

[in]	key	key registered with performance schema
[in]	lock	rw lock
[in]	level	level
[in]	cmutex_name	mutex name
[in]	cline	file line where created
[in]	cfile_name	file name where created

◆ pfs_rw_lock_free_func()

UNIV_INLINE void pfs_rw_lock_free_func ( rw_lock_t * lock )

Performance schema instrumented wrap function for rw_lock_free_func() NOTE! Please use the corresponding macro rw_lock_free(), not directly this function!

in: rw-lock

◆ pfs_rw_lock_s_lock_func()

UNIV_INLINE void pfs_rw_lock_s_lock_func	(	rw_lock_t *	lock,
		ulint	pass,
		const char *	file_name,
		ulint	line
	)

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!

Parameters

[in]	lock	pointer to rw-lock
[in]	pass	pass value; != 0, if the lock will be passed to another thread to unlock
[in]	file_name	file name where lock requested
[in]	line	line where requested

◆ pfs_rw_lock_s_lock_low()

UNIV_INLINE ibool pfs_rw_lock_s_lock_low	(	rw_lock_t *	lock,
		ulint	pass,
		const char *	file_name,
		ulint	line
	)

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!

Parameters

[in]	lock	pointer to rw-lock
[in]	pass	pass value; != 0, if the lock will be passed to another thread to unlock
[in]	file_name	file name where lock requested
[in]	line	line where requested

Returns: true if success

◆ pfs_rw_lock_s_unlock_func()

UNIV_INLINE void pfs_rw_lock_s_unlock_func	(	ulint	pass,
		rw_lock_t *	lock
	)

Performance schema instrumented wrap function for rw_lock_s_unlock_func() NOTE! Please use the corresponding macro rw_lock_s_unlock(), not directly this function!

Parameters

[in]	pass	pass value; != 0, if the lock may have been passed to another thread to unlock
[in,out]	lock	rw-lock

◆ pfs_rw_lock_sx_lock_func()

UNIV_INLINE void pfs_rw_lock_sx_lock_func	(	rw_lock_t *	lock,
		ulint	pass,
		const char *	file_name,
		ulint	line
	)

Performance schema instrumented wrap function for rw_lock_sx_lock_func() NOTE! Please use the corresponding macro rw_lock_sx_lock(), not directly this function!

Parameters

[in]	lock	pointer to rw-lock
[in]	pass	pass value; != 0, if the lock will be passed to another thread to unlock
[in]	file_name	file name where lock requested
[in]	line	line where requested

◆ pfs_rw_lock_sx_lock_low()

UNIV_INLINE ibool pfs_rw_lock_sx_lock_low	(	rw_lock_t *	lock,
		ulint	pass,
		const char *	file_name,
		ulint	line
	)

Performance schema instrumented wrap function for rw_lock_sx_lock_nowait() NOTE! Please use the corresponding macro, not directly this function!

Parameters

[in]	lock	pointer to rw-lock
[in]	pass	pass value; != 0, if the lock will be passed to another thread to unlock
[in]	file_name	file name where lock requested
[in]	line	line where requested

◆ pfs_rw_lock_sx_unlock_func()

UNIV_INLINE void pfs_rw_lock_sx_unlock_func	(	ulint	pass,
		rw_lock_t *	lock
	)

Performance schema instrumented wrap function for rw_lock_sx_unlock_func() NOTE! Please use the corresponding macro rw_lock_sx_unlock(), not directly this function!

Parameters

[in,out]	lock	pointer to rw-lock
[in]	pass	pass value; != 0, if the lock will be passed to another thread to unlock

◆ pfs_rw_lock_x_lock_func()

UNIV_INLINE void pfs_rw_lock_x_lock_func	(	rw_lock_t *	lock,
		ulint	pass,
		const char *	file_name,
		ulint	line
	)

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!

Parameters

[in]	lock	pointer to rw-lock
[in]	pass	pass value; != 0, if the lock will be passed to another thread to unlock
[in]	file_name	file name where lock requested
[in]	line	line where requested

◆ pfs_rw_lock_x_lock_func_nowait()

UNIV_INLINE ibool pfs_rw_lock_x_lock_func_nowait	(	rw_lock_t *	lock,
		const char *	file_name,
		ulint	line
	)

Performance schema instrumented wrap function for rw_lock_x_lock_func_nowait() NOTE! Please use the corresponding macro, not directly this function!

Parameters

[in]	lock	pointer to rw-lock
[in]	file_name	file name where lock requested
[in]	line	line where requested

Returns: true if success

◆ pfs_rw_lock_x_unlock_func()

UNIV_INLINE void pfs_rw_lock_x_unlock_func	(	ulint	pass,
		rw_lock_t *	lock
	)

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!

Parameters

[in]	pass	pass value; != 0, if the lock may have been passed to another thread to unlock
[in,out]	lock	rw-lock

◆ rw_lock_create_func()

void rw_lock_create_func	(	rw_lock_t *	lock,
		latch_level_t	level,
		const char *	cmutex_name,
		const char *	cfile_name,
		ulint	cline
	)

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 is necessary only if the memory block containing it is freed. in: file line where created

The rw-lock is initialized to the non-locked state. Explicit freeing of the rw-lock with rw_lock_free is necessary only if the memory block containing it is freed.

Parameters

lock	in: pointer to memory
level	in: level
cmutex_name	in: rw-lock name
cfile_name	in: file name where created
cline	in: file line where created

◆ rw_lock_debug_print()

void rw_lock_debug_print	(	FILE *	f,
		const rw_lock_debug_t *	info
	)

Prints info of a debug struct.

in: debug struct

Parameters

f	in: output stream
info	in: debug struct

◆ rw_lock_free_func()

void rw_lock_free_func ( rw_lock_t * lock )

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. in/out: rw-lock

Removes an rw-lock object from the global list. The rw-lock is checked to be in the non-locked state.

Parameters

lock	in/out: rw-lock

◆ rw_lock_get_reader_count()

UNIV_INLINE ulint rw_lock_get_reader_count ( const rw_lock_t * lock )

Returns the number of readers (s-locks).

Returns: number of readers in: rw-lock

◆ rw_lock_get_sx_lock_count()

UNIV_INLINE ulint rw_lock_get_sx_lock_count ( const rw_lock_t * lock )

Returns the number of sx-lock for the lock.

Does not reserve the lock mutex, so the caller must be sure it is not changed during the call.

Returns: value of writer_count in: rw-lock

◆ rw_lock_get_waiters()

UNIV_INLINE ulint rw_lock_get_waiters ( const rw_lock_t * lock )

Check if there are threads waiting for the rw-lock.

Returns: 1 if waiters, 0 otherwise in: rw-lock

◆ rw_lock_get_writer()

UNIV_INLINE ulint rw_lock_get_writer ( const rw_lock_t * lock )

Returns the write-status of the lock - this function made more sense with the old rw_lock implementation.

Returns: RW_LOCK_NOT_LOCKED, RW_LOCK_X, RW_LOCK_X_WAIT, RW_LOCK_SX in: rw-lock

◆ rw_lock_get_x_lock_count()

UNIV_INLINE ulint rw_lock_get_x_lock_count ( const rw_lock_t * 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.

Returns: value of writer_count in: rw-lock

◆ rw_lock_is_locked()

bool rw_lock_is_locked	(	rw_lock_t *	lock,
		ulint	lock_type
	)

Checks if somebody has locked the rw-lock in the specified mode.

Returns: true if locked in: lock type: RW_LOCK_S, RW_LOCK_X or RW_LOCK_SX; true if locked

Parameters

lock	in: rw-lock
lock_type	in: lock type: RW_LOCK_S, RW_LOCK_X or RW_LOCK_SX

◆ rw_lock_list_print_info()

void rw_lock_list_print_info ( FILE * file )

Prints debug info of currently locked rw-locks.

in: file where to print

Parameters

file	in: file where to print

◆ rw_lock_lock_word_decr()

UNIV_INLINE bool rw_lock_lock_word_decr	(	rw_lock_t *	lock,
		ulint	amount,
		lint	threshold
	)

Decrements lock_word the specified amount if it is greater than 0.

This is used by both s_lock and x_lock operations.

Parameters

[in,out]	lock	rw-lock
[in]	amount	amount to decrement
[in]	threshold	threshold of judgement

Returns: true if decr occurs

◆ rw_lock_lock_word_incr()

UNIV_INLINE lint rw_lock_lock_word_incr	(	rw_lock_t *	lock,
		ulint	amount
	)

Increments lock_word the specified amount and returns new value.

Parameters

[in,out]	lock	rw-lock
[in]	amount	amount to decrement

Returns: lock->lock_word after increment

◆ rw_lock_own()

ibool rw_lock_own	(	rw_lock_t *	lock,
		ulint	lock_type
	)

Checks if the thread has locked the rw-lock in the specified mode, with the pass value == 0.

Returns: true if locked

Parameters

lock	in: rw-lock
lock_type	in: lock type: RW_LOCK_S, RW_LOCK_X

◆ rw_lock_own_flagged()

bool rw_lock_own_flagged	(	const rw_lock_t *	lock,
		rw_lock_flags_t	flags
	)

Checks if the thread has locked the rw-lock in the specified mode, with the pass value == 0.

Parameters

[in]	lock	rw-lock
[in]	flags	specify lock types with OR of the rw_lock_flag_t values

Returns: true if locked

Parameters

lock	in: rw-lock
flags	in: specify lock types with OR of the rw_lock_flag_t values

◆ rw_lock_s_lock_func()

UNIV_INLINE void rw_lock_s_lock_func	(	rw_lock_t *	lock,
		ulint	pass,
		const char *	file_name,
		ulint	line
	)

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 there is an exclusive lock request waiting, the function spins a preset time (controlled by srv_n_spin_wait_rounds), waiting for the lock, before suspending the thread.

Parameters

[in]	lock	pointer to rw-lock
[in]	pass	pass value; != 0, if the lock will be passed to another thread to unlock
[in]	file_name	file name where lock requested
[in]	line	line where requested

◆ rw_lock_s_lock_low()

UNIV_INLINE ibool rw_lock_s_lock_low	(	rw_lock_t *	lock,
		ulint	pass,
		const char *	file_name,
		ulint	line
	)

Low-level function which tries to lock an rw-lock in s-mode.

Performs no spinning.

Parameters

[in]	lock	pointer to rw-lock
[in]	pass	pass value; != 0, if the lock will be passed to another thread to unlock
[in]	file_name	file name where lock requested
[in]	line	line where requested

Returns: true if success

◆ rw_lock_s_unlock_func()

UNIV_INLINE void rw_lock_s_unlock_func	(	ulint	pass,
		rw_lock_t *	lock
	)

Releases a shared mode lock.

Parameters

[in]	pass	pass value; != 0, if the lock will be passed to another thread to unlock
[in,out]	lock	rw-lock

◆ rw_lock_set_writer_id_and_recursion_flag()

UNIV_INLINE void rw_lock_set_writer_id_and_recursion_flag	(	rw_lock_t *	lock,
		bool	recursive
	)

This function sets the lock->writer_thread and lock->recursive fields.

Sets lock->recursive field using atomic release after setting lock->writer thread to ensure proper memory ordering of the two. 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.

Parameters

[in,out]	lock	lock to work on
[in]	recursive	true if recursion allowed

◆ rw_lock_sx_lock_func()

void rw_lock_sx_lock_func	(	rw_lock_t *	lock,
		ulint	pass,
		const char *	file_name,
		ulint	line
	)

NOTE! Use the corresponding macro, not directly this function! Lock an rw-lock in SX 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. If the same thread has an x-lock on the rw-lock, locking succeed, with the following exception: if pass != 0, only a single sx-lock may be taken on the lock. NOTE: If the same thread has an s-lock, locking does not succeed! in: line where requested

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. If the same thread has an x-lock on the rw-lock, locking succeed, with the following exception: if pass != 0, only a single sx-lock may be taken on the lock. NOTE: If the same thread has an s-lock, locking does not succeed!

Parameters

lock	in: pointer to rw-lock
pass	in: pass value; != 0, if the lock will be passed to another thread to unlock
file_name	in: file name where lock requested
line	in: line where requested

◆ rw_lock_sx_lock_low()

ibool rw_lock_sx_lock_low	(	rw_lock_t *	lock,
		ulint	pass,
		const char *	file_name,
		ulint	line
	)

Low-level function for acquiring an sx lock.

Returns: false if did not succeed, true if success. in: line where requested; false if did not succeed, true if success.

Parameters

lock	in: pointer to rw-lock
pass	in: pass value; != 0, if the lock will be passed to another thread to unlock
file_name	in: file name where lock requested
line	in: line where requested

◆ rw_lock_sx_unlock_func()

UNIV_INLINE void rw_lock_sx_unlock_func	(	ulint	pass,
		rw_lock_t *	lock
	)

Releases an sx mode lock.

Parameters

[in]	pass	pass value; != 0, if the lock will be passed to another thread to unlock
[in,out]	lock	rw-lock

◆ rw_lock_validate()

bool rw_lock_validate ( const rw_lock_t * lock )

Checks that the rw-lock has been initialized and that there are no simultaneous shared and exclusive locks.

Returns: true in: rw-lock; true

Parameters

lock	in: rw-lock

◆ rw_lock_x_lock_func()

void rw_lock_x_lock_func	(	rw_lock_t *	lock,
		ulint	pass,
		const char *	file_name,
		ulint	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, the function spins a preset time (controlled by srv_n_spin_wait_rounds), waiting for the lock, before suspending the thread. If the same thread has an x-lock on the rw-lock, locking succeed, with the following exception: if pass != 0, only a single x-lock may be taken on the lock. NOTE: If the same thread has an s-lock, locking does not succeed! in: line where requested

If the rw-lock is locked in shared or exclusive mode, or there is an exclusive lock request waiting, the function spins a preset time (controlled by srv_n_spin_wait_rounds), waiting for the lock before suspending the thread. If the same thread has an x-lock on the rw-lock, locking succeed, with the following exception: if pass != 0, only a single x-lock may be taken on the lock. NOTE: If the same thread has an s-lock, locking does not succeed!

Parameters

lock	in: pointer to rw-lock
pass	in: pass value; != 0, if the lock will be passed to another thread to unlock
file_name	in: file name where lock requested
line	in: line where requested

◆ rw_lock_x_lock_func_nowait()

UNIV_INLINE ibool rw_lock_x_lock_func_nowait	(	rw_lock_t *	lock,
		const char *	file_name,
		ulint	line
	)

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.

Parameters

[in]	lock	pointer to rw-lock
[in]	file_name	file name where lock requested
[in]	line	line where requested

Returns: true if success

◆ rw_lock_x_lock_move_ownership()

void rw_lock_x_lock_move_ownership ( rw_lock_t * lock )

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 read was done. The ownership is moved because we want that the current thread is able to acquire a second x-latch which is stored in an mtr. This, in turn, is needed to pass the debug checks of index page operations. in: lock which was x-locked in the buffer read

The x-latch was set by the buffer read operation and it protected the buffer frame while the read was done. The ownership is moved because we want that the current thread is able to acquire a second x-latch which is stored in an mtr. This, in turn, is needed to pass the debug checks of index page operations.

Parameters

lock	in: lock which was x-locked in the buffer read

◆ rw_lock_x_unlock_func()

UNIV_INLINE void rw_lock_x_unlock_func	(	ulint	pass,
		rw_lock_t *	lock
	)

Releases an exclusive mode lock.

Parameters

[in]	pass	pass value; != 0, if the lock will be passed to another thread to unlock
[in,out]	lock	rw-lock

◆ UT_LIST_BASE_NODE_T()

typedef UT_LIST_BASE_NODE_T ( rw_lock_t )

Variable Documentation

◆ rw_lock_list

rw_lock_list_t rw_lock_list

◆ rw_lock_list_mutex

ib_mutex_t rw_lock_list_mutex

◆ rw_lock_stats

rw_lock_stats_t rw_lock_stats

Counters for RW locks.

Classes

Macros

Enumerations

Functions

Variables

Detailed Description

Macro Definition Documentation

◆ rw_lock_create

◆ rw_lock_free

◆ rw_lock_s_lock

◆ rw_lock_s_lock_gen

◆ rw_lock_s_lock_inline

◆ rw_lock_s_lock_nowait

◆ rw_lock_s_unlock

◆ rw_lock_s_unlock_gen

◆ rw_lock_sx_lock

◆ rw_lock_sx_lock_gen

◆ rw_lock_sx_lock_inline

◆ rw_lock_sx_lock_nowait

◆ rw_lock_sx_unlock

◆ rw_lock_sx_unlock_gen

◆ rw_lock_x_lock

◆ rw_lock_x_lock_func_nowait_inline

◆ rw_lock_x_lock_gen

◆ rw_lock_x_lock_inline

◆ rw_lock_x_lock_nowait

◆ rw_lock_x_unlock

◆ rw_lock_x_unlock_gen

◆ X_LOCK_DECR

◆ X_LOCK_HALF_DECR

Enumeration Type Documentation

◆ rw_lock_type_t

Function Documentation

◆ pfs_rw_lock_create_func()

◆ pfs_rw_lock_free_func()

◆ pfs_rw_lock_s_lock_func()

◆ pfs_rw_lock_s_lock_low()

◆ pfs_rw_lock_s_unlock_func()

◆ pfs_rw_lock_sx_lock_func()

◆ pfs_rw_lock_sx_lock_low()

◆ pfs_rw_lock_sx_unlock_func()

◆ pfs_rw_lock_x_lock_func()

◆ pfs_rw_lock_x_lock_func_nowait()

◆ pfs_rw_lock_x_unlock_func()

◆ rw_lock_create_func()

◆ rw_lock_debug_print()

◆ rw_lock_free_func()

◆ rw_lock_get_reader_count()

◆ rw_lock_get_sx_lock_count()

◆ rw_lock_get_waiters()

◆ rw_lock_get_writer()

◆ rw_lock_get_x_lock_count()

◆ rw_lock_is_locked()

◆ rw_lock_list_print_info()

◆ rw_lock_lock_word_decr()

◆ rw_lock_lock_word_incr()

◆ rw_lock_own()

◆ rw_lock_own_flagged()

◆ rw_lock_s_lock_func()

◆ rw_lock_s_lock_low()

◆ rw_lock_s_unlock_func()

◆ rw_lock_set_writer_id_and_recursion_flag()

◆ rw_lock_sx_lock_func()

◆ rw_lock_sx_lock_low()

◆ rw_lock_sx_unlock_func()

◆ rw_lock_validate()

◆ rw_lock_x_lock_func()

◆ rw_lock_x_lock_func_nowait()

◆ rw_lock_x_lock_move_ownership()

◆ rw_lock_x_unlock_func()

◆ UT_LIST_BASE_NODE_T()

Variable Documentation

◆ rw_lock_list

◆ rw_lock_list_mutex

◆ rw_lock_stats