mariadb/innobase/include/sync0arr.h
tsmith@quadxeon.mysql.com f1e0cf9d28 This ChangeSet must be null-merged to 5.1. Applied innodb-5.0-ss982, -ss998, -ss1003
Fixes:
- Bug #15815: Very poor performance with multiple queries running concurrently
- Bug #22868: 'Thread thrashing' with > 50 concurrent conns under an upd-intensive workloadw
- Bug #23769: Debug assertion failure with innodb_locks_unsafe_for_binlog
- Bug #24089: Race condition in fil_flush_file_spaces()
2006-11-09 05:02:37 +01:00

122 lines
3.9 KiB
C

/******************************************************
The wait array used in synchronization primitives
(c) 1995 Innobase Oy
Created 9/5/1995 Heikki Tuuri
*******************************************************/
#ifndef sync0arr_h
#define sync0arr_h
#include "univ.i"
#include "ut0lst.h"
#include "ut0mem.h"
#include "os0thread.h"
typedef struct sync_cell_struct sync_cell_t;
typedef struct sync_array_struct sync_array_t;
#define SYNC_ARRAY_OS_MUTEX 1
#define SYNC_ARRAY_MUTEX 2
/***********************************************************************
Creates a synchronization wait array. It is protected by a mutex
which is automatically reserved when the functions operating on it
are called. */
sync_array_t*
sync_array_create(
/*==============*/
/* out, own: created wait array */
ulint n_cells, /* in: number of cells in the array
to create */
ulint protection); /* in: either SYNC_ARRAY_OS_MUTEX or
SYNC_ARRAY_MUTEX: determines the type
of mutex protecting the data structure */
/**********************************************************************
Frees the resources in a wait array. */
void
sync_array_free(
/*============*/
sync_array_t* arr); /* in, own: sync wait array */
/**********************************************************************
Reserves a wait array cell for waiting for an object.
The event of the cell is reset to nonsignalled state. */
void
sync_array_reserve_cell(
/*====================*/
sync_array_t* arr, /* in: wait array */
void* object, /* in: pointer to the object to wait for */
ulint type, /* in: lock request type */
const char* file, /* in: file where requested */
ulint line, /* in: line where requested */
ulint* index); /* out: index of the reserved cell */
/**********************************************************************
This function should be called when a thread starts to wait on
a wait array cell. In the debug version this function checks
if the wait for a semaphore will result in a deadlock, in which
case prints info and asserts. */
void
sync_array_wait_event(
/*==================*/
sync_array_t* arr, /* in: wait array */
ulint index); /* in: index of the reserved cell */
/**********************************************************************
Frees the cell. NOTE! sync_array_wait_event frees the cell
automatically! */
void
sync_array_free_cell(
/*=================*/
sync_array_t* arr, /* in: wait array */
ulint index); /* in: index of the cell in array */
/**************************************************************************
Note that one of the wait objects was signalled. */
void
sync_array_object_signalled(
/*========================*/
sync_array_t* arr); /* in: wait array */
/**************************************************************************
If the wakeup algorithm does not work perfectly at semaphore relases,
this function will do the waking (see the comment in mutex_exit). This
function should be called about every 1 second in the server. */
void
sync_arr_wake_threads_if_sema_free(void);
/*====================================*/
/**************************************************************************
Prints warnings of long semaphore waits to stderr. */
ibool
sync_array_print_long_waits(void);
/*=============================*/
/* out: TRUE if fatal semaphore wait threshold
was exceeded */
/************************************************************************
Validates the integrity of the wait array. Checks
that the number of reserved cells equals the count variable. */
void
sync_array_validate(
/*================*/
sync_array_t* arr); /* in: sync wait array */
/**************************************************************************
Prints info of the wait array. */
void
sync_array_print_info(
/*==================*/
FILE* file, /* in: file where to print */
sync_array_t* arr); /* in: wait array */
#ifndef UNIV_NONINL
#include "sync0arr.ic"
#endif
#endif