1 /*****************************************************************************
2 
3 Copyright (c) 2006, 2009, Oracle and/or its affiliates. All Rights Reserved.
4 
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License, version 2.0,
7 as published by the Free Software Foundation.
8 
9 This program is also distributed with certain software (including
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12 documentation.  The authors of MySQL hereby grant you an additional
13 permission to link the program and your derivative works with the
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16 This program is distributed in the hope that it will be useful,
17 but WITHOUT ANY WARRANTY; without even the implied warranty of
18 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19 GNU General Public License, version 2.0, for more details.
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21 You should have received a copy of the GNU General Public License along with
22 this program; if not, write to the Free Software Foundation, Inc.,
23 51 Franklin Street, Suite 500, Boston, MA 02110-1335 USA
24 
25 *****************************************************************************/
26 
27 /*******************************************************************//**
28 @file include/ut0wqueue.h
29 A work queue
30 
31 Created 4/26/2006 Osku Salerma
32 ************************************************************************/
33 
34 /*******************************************************************//**
35 A Work queue. Threads can add work items to the queue and other threads can
36 wait for work items to be available and take them off the queue for
37 processing.
38 ************************************************************************/
39 
40 #ifndef IB_WORK_QUEUE_H
41 #define IB_WORK_QUEUE_H
42 
43 #include "ut0list.h"
44 #include "mem0mem.h"
45 #include "os0sync.h"
46 #include "sync0types.h"
47 
48 struct ib_wqueue_t;
49 
50 /****************************************************************//**
51 Create a new work queue.
52 @return	work queue */
53 UNIV_INTERN
54 ib_wqueue_t*
55 ib_wqueue_create(void);
56 /*===================*/
57 
58 /****************************************************************//**
59 Free a work queue. */
60 UNIV_INTERN
61 void
62 ib_wqueue_free(
63 /*===========*/
64 	ib_wqueue_t*	wq);	/*!< in: work queue */
65 
66 /****************************************************************//**
67 Add a work item to the queue. */
68 UNIV_INTERN
69 void
70 ib_wqueue_add(
71 /*==========*/
72 	ib_wqueue_t*	wq,	/*!< in: work queue */
73 	void*		item,	/*!< in: work item */
74 	mem_heap_t*	heap);	/*!< in: memory heap to use for allocating the
75 				list node */
76 
77 /********************************************************************
78 Check if queue is empty. */
79 
80 ibool
81 ib_wqueue_is_empty(
82 /*===============*/
83 					/* out: TRUE if queue empty
84 					else FALSE */
85 	const ib_wqueue_t*      wq);    /* in: work queue */
86 
87 /****************************************************************//**
88 Wait for a work item to appear in the queue.
89 @return	work item */
90 UNIV_INTERN
91 void*
92 ib_wqueue_wait(
93 /*===========*/
94 	ib_wqueue_t*	wq);	/*!< in: work queue */
95 
96 /********************************************************************
97 Wait for a work item to appear in the queue for specified time. */
98 
99 void*
100 ib_wqueue_timedwait(
101 /*================*/
102 					/* out: work item or NULL on timeout*/
103 	ib_wqueue_t*	wq,		/* in: work queue */
104 	ib_time_t	wait_in_usecs); /* in: wait time in micro seconds */
105 
106 /* Work queue. */
107 struct ib_wqueue_t {
108 	ib_mutex_t		mutex;	/*!< mutex protecting everything */
109 	ib_list_t*	items;	/*!< work item list */
110 	os_event_t	event;	/*!< event we use to signal additions to list */
111 };
112 
113 #endif
114