1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
|
/*
* Copyright (C) Internet Systems Consortium, Inc. ("ISC")
*
* SPDX-License-Identifier: MPL-2.0
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, you can obtain one at https://mozilla.org/MPL/2.0/.
*
* See the COPYRIGHT file distributed with this work for additional
* information regarding copyright ownership.
*/
#pragma once
/*****
***** Module Info
*****/
/*! \file isc/taskpool.h
* \brief A task pool is a mechanism for sharing a small number of tasks
* among a large number of objects such that each object is
* assigned a unique task, but each task may be shared by several
* objects.
*
* Task pools are used to let objects that can exist in large
* numbers (e.g., zones) use tasks for synchronization without
* the memory overhead and unfair scheduling competition that
* could result from creating a separate task for each object.
*/
/***
*** Imports.
***/
#include <stdbool.h>
#include <isc/lang.h>
#include <isc/task.h>
ISC_LANG_BEGINDECLS
/*****
***** Types.
*****/
typedef struct isc_taskpool isc_taskpool_t;
/*****
***** Functions.
*****/
isc_result_t
isc_taskpool_create(isc_taskmgr_t *tmgr, isc_mem_t *mctx, unsigned int ntasks,
unsigned int quantum, bool priv, isc_taskpool_t **poolp);
/*%<
* Create a task pool of "ntasks" tasks, each with quantum
* "quantum".
*
* Requires:
*
*\li 'tmgr' is a valid task manager.
*
*\li 'mctx' is a valid memory context.
*
*\li poolp != NULL && *poolp == NULL
*
* Ensures:
*
*\li On success, '*taskp' points to the new task pool.
*
* Returns:
*
*\li #ISC_R_SUCCESS
*\li #ISC_R_NOMEMORY
*\li #ISC_R_UNEXPECTED
*/
void
isc_taskpool_gettask(isc_taskpool_t *pool, isc_task_t **targetp);
/*%<
* Attach to a task from the pool. Currently the next task is chosen
* from the pool at random. (This may be changed in the future to
* something that guaratees balance.)
*/
int
isc_taskpool_size(isc_taskpool_t *pool);
/*%<
* Returns the number of tasks in the task pool 'pool'.
*/
isc_result_t
isc_taskpool_expand(isc_taskpool_t **sourcep, unsigned int size, bool priv,
isc_taskpool_t **targetp);
/*%<
* If 'size' is larger than the number of tasks in the pool pointed to by
* 'sourcep', then a new taskpool of size 'size' is allocated, the existing
* tasks from are moved into it, additional tasks are created to bring the
* total number up to 'size', and the resulting pool is attached to
* 'targetp'.
*
* If 'size' is less than or equal to the tasks in pool 'source', then
* 'sourcep' is attached to 'targetp' without any other action being taken.
*
* In either case, 'sourcep' is detached.
*
* Requires:
*
* \li 'sourcep' is not NULL and '*source' is not NULL
* \li 'targetp' is not NULL and '*source' is NULL
*
* Ensures:
*
* \li On success, '*targetp' points to a valid task pool.
* \li On success, '*sourcep' points to NULL.
*
* Returns:
*
* \li #ISC_R_SUCCESS
* \li #ISC_R_NOMEMORY
*/
void
isc_taskpool_destroy(isc_taskpool_t **poolp);
/*%<
* Destroy a task pool. The tasks in the pool are detached but not
* shut down.
*
* Requires:
* \li '*poolp' is a valid task pool.
*/
ISC_LANG_ENDDECLS
|
