srv0conc.h File Reference

InnoDB concurrency manager header file. More...

Go to the source code of this file.

Functions
dberr_t	srv_conc_enter_innodb (row_prebuilt_t *prebuilt)
	Puts an OS thread to wait if there are too many concurrent threads (>= srv_thread_concurrency) inside InnoDB. More...
void	srv_conc_force_enter_innodb (trx_t *trx)
	This lets a thread enter InnoDB regardless of the number of threads inside InnoDB. More...
void	srv_conc_force_exit_innodb (trx_t *trx)
	This must be called when a thread exits InnoDB in a lock wait or at the end of an SQL statement. More...
int32_t	srv_conc_get_waiting_threads (void)
	Get the count of threads waiting inside InnoDB. More...
int32_t	srv_conc_get_active_threads (void)
	Get the count of threads active inside InnoDB. More...

Variables
uint32_t	srv_max_n_threads
	We are prepared for a situation that we have this many threads waiting for a semaphore inside InnoDB. More...
ulong	srv_thread_concurrency
	The following controls how many threads we let inside InnoDB concurrently: threads waiting for locks are not counted into the number because otherwise we could get a deadlock. More...

Detailed Description

InnoDB concurrency manager header file.

Created 2011/04/18 Sunny Bains

Function Documentation

srv_conc_enter_innodb()

dberr_t srv_conc_enter_innodb

(

row_prebuilt_t *

prebuilt

)

Puts an OS thread to wait if there are too many concurrent threads (>= srv_thread_concurrency) inside InnoDB.

The threads wait in a FIFO queue.

Parameters

[in,out]

prebuilt

row prebuilt handler

Returns

Innodb error code.

srv_conc_force_enter_innodb()

void srv_conc_force_enter_innodb

(

trx_t *

trx

)

This lets a thread enter InnoDB regardless of the number of threads inside InnoDB.

This must be called when a thread ends a lock wait. in: transaction object associated with the thread

This must be called when a thread ends a lock wait.

Parameters

trx	in: transaction object associated with the thread

srv_conc_force_exit_innodb()

void srv_conc_force_exit_innodb

(

trx_t *

trx

)

This must be called when a thread exits InnoDB in a lock wait or at the end of an SQL statement.

in: transaction object associated with the thread

Parameters

trx	in: transaction object associated with the thread

srv_conc_get_active_threads()

int32_t srv_conc_get_active_threads

(

void

)

Get the count of threads active inside InnoDB.

srv_conc_get_waiting_threads()

int32_t srv_conc_get_waiting_threads

(

void

)

Get the count of threads waiting inside InnoDB.

Variable Documentation

srv_max_n_threads

uint32_t srv_max_n_threads

extern

We are prepared for a situation that we have this many threads waiting for a semaphore inside InnoDB.

Maximum number of threads inside InnoDB.

innodb_init_params() sets the value.

srv_thread_concurrency

ulong srv_thread_concurrency

extern

The following controls how many threads we let inside InnoDB concurrently: threads waiting for locks are not counted into the number because otherwise we could get a deadlock.

Value of 0 will disable the concurrency check.