1/*
2 * Copyright (C) 2004-2007  Internet Systems Consortium, Inc. ("ISC")
3 * Copyright (C) 1999-2001  Internet Software Consortium.
4 *
5 * Permission to use, copy, modify, and/or distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
10 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
11 * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
12 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
13 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
14 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
15 * PERFORMANCE OF THIS SOFTWARE.
16 */
17
18/* $Id: taskpool.h,v 1.15 2007/06/19 23:47:18 tbox Exp $ */
19
20#ifndef ISC_TASKPOOL_H
21#define ISC_TASKPOOL_H 1
22
23/*****
24 ***** Module Info
25 *****/
26
27/*! \file isc/taskpool.h
28 * \brief A task pool is a mechanism for sharing a small number of tasks
29 * among a large number of objects such that each object is
30 * assigned a unique task, but each task may be shared by several
31 * objects.
32 *
33 * Task pools are used to let objects that can exist in large
34 * numbers (e.g., zones) use tasks for synchronization without
35 * the memory overhead and unfair scheduling competition that
36 * could result from creating a separate task for each object.
37 */
38
39
40/***
41 *** Imports.
42 ***/
43
44#include <isc/lang.h>
45#include <isc/task.h>
46
47ISC_LANG_BEGINDECLS
48
49/*****
50 ***** Types.
51 *****/
52
53typedef struct isc_taskpool isc_taskpool_t;
54
55/*****
56 ***** Functions.
57 *****/
58
59isc_result_t
60isc_taskpool_create(isc_taskmgr_t *tmgr, isc_mem_t *mctx,
61		    unsigned int ntasks, unsigned int quantum,
62		    isc_taskpool_t **poolp);
63/*%<
64 * Create a task pool of "ntasks" tasks, each with quantum
65 * "quantum".
66 *
67 * Requires:
68 *
69 *\li	'tmgr' is a valid task manager.
70 *
71 *\li	'mctx' is a valid memory context.
72 *
73 *\li	poolp != NULL && *poolp == NULL
74 *
75 * Ensures:
76 *
77 *\li	On success, '*taskp' points to the new task pool.
78 *
79 * Returns:
80 *
81 *\li	#ISC_R_SUCCESS
82 *\li	#ISC_R_NOMEMORY
83 *\li	#ISC_R_UNEXPECTED
84 */
85
86void
87isc_taskpool_gettask(isc_taskpool_t *pool, unsigned int hash,
88			  isc_task_t **targetp);
89/*%<
90 * Attach to the task corresponding to the hash value "hash".
91 */
92
93void
94isc_taskpool_destroy(isc_taskpool_t **poolp);
95/*%<
96 * Destroy a task pool.  The tasks in the pool are detached but not
97 * shut down.
98 *
99 * Requires:
100 * \li	'*poolp' is a valid task pool.
101 */
102
103ISC_LANG_ENDDECLS
104
105#endif /* ISC_TASKPOOL_H */
106