mariadb/storage/innobase/include/ut0wqueue.h
2019-10-25 17:33:39 +03:00

114 lines
3.6 KiB
C

/*****************************************************************************
Copyright (c) 2006, 2014, Oracle and/or its affiliates. All Rights Reserved.
Copyright (c) 2017, 2019, MariaDB Corporation.
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.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA
*****************************************************************************/
/*******************************************************************//**
@file include/ut0wqueue.h
A work queue
Created 4/26/2006 Osku Salerma
************************************************************************/
/*******************************************************************//**
A Work queue. Threads can add work items to the queue and other threads can
wait for work items to be available and take them off the queue for
processing.
************************************************************************/
#ifndef IB_WORK_QUEUE_H
#define IB_WORK_QUEUE_H
#include "ut0list.h"
#include "mem0mem.h"
// Forward declaration
struct ib_list_t;
/** Work queue */
struct ib_wqueue_t
{
/** Mutex protecting everything */
ib_mutex_t mutex;
/** Work item list */
ib_list_t* items;
/** event we use to signal additions to list;
os_event_set() and os_event_reset() are protected by the mutex */
os_event_t event;
};
/****************************************************************//**
Create a new work queue.
@return work queue */
ib_wqueue_t*
ib_wqueue_create();
/*===============*/
/****************************************************************//**
Free a work queue. */
void
ib_wqueue_free(
/*===========*/
ib_wqueue_t* wq); /*!< in: work queue */
/** Add a work item to the queue.
@param[in,out] wq work queue
@param[in] item work item
@param[in,out] heap memory heap to use for allocating list node
@param[in] wq_locked work queue mutex locked */
void
ib_wqueue_add(ib_wqueue_t* wq, void* item, mem_heap_t* heap,
bool wq_locked = false);
/** Check if queue is empty.
@param wq wait queue
@return whether the queue is empty */
bool ib_wqueue_is_empty(ib_wqueue_t* wq);
/****************************************************************//**
Wait for a work item to appear in the queue.
@return work item */
void*
ib_wqueue_wait(
/*===========*/
ib_wqueue_t* wq); /*!< in: work queue */
/********************************************************************
Wait for a work item to appear in the queue for specified time. */
void*
ib_wqueue_timedwait(
/*================*/
/* out: work item or NULL on timeout*/
ib_wqueue_t* wq, /* in: work queue */
ulint wait_in_usecs); /* in: wait time in micro seconds */
/********************************************************************
Return first item on work queue or NULL if queue is empty
@return work item or NULL */
void*
ib_wqueue_nowait(
/*=============*/
ib_wqueue_t* wq); /*<! in: work queue */
/********************************************************************
Get number of items on queue.
@return number of items on queue */
ulint
ib_wqueue_len(
/*==========*/
ib_wqueue_t* wq); /*<! in: work queue */
#endif /* IB_WORK_QUEUE_H */