1/*	$NetBSD: taskpool.c,v 1.1 2024/02/18 20:57:50 christos Exp $	*/
2
3/*
4 * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
5 *
6 * SPDX-License-Identifier: MPL-2.0
7 *
8 * This Source Code Form is subject to the terms of the Mozilla Public
9 * License, v. 2.0. If a copy of the MPL was not distributed with this
10 * file, you can obtain one at https://mozilla.org/MPL/2.0/.
11 *
12 * See the COPYRIGHT file distributed with this work for additional
13 * information regarding copyright ownership.
14 */
15
16/*! \file */
17
18#include <stdbool.h>
19
20#include <isc/mem.h>
21#include <isc/random.h>
22#include <isc/taskpool.h>
23#include <isc/util.h>
24
25/***
26 *** Types.
27 ***/
28
29struct isc_taskpool {
30	isc_mem_t *mctx;
31	isc_taskmgr_t *tmgr;
32	unsigned int ntasks;
33	unsigned int quantum;
34	isc_task_t **tasks;
35};
36
37/***
38 *** Functions.
39 ***/
40
41static void
42alloc_pool(isc_taskmgr_t *tmgr, isc_mem_t *mctx, unsigned int ntasks,
43	   unsigned int quantum, isc_taskpool_t **poolp) {
44	isc_taskpool_t *pool;
45	unsigned int i;
46
47	pool = isc_mem_get(mctx, sizeof(*pool));
48
49	pool->mctx = NULL;
50	isc_mem_attach(mctx, &pool->mctx);
51	pool->ntasks = ntasks;
52	pool->quantum = quantum;
53	pool->tmgr = tmgr;
54	pool->tasks = isc_mem_get(mctx, ntasks * sizeof(isc_task_t *));
55	for (i = 0; i < ntasks; i++) {
56		pool->tasks[i] = NULL;
57	}
58
59	*poolp = pool;
60}
61
62isc_result_t
63isc_taskpool_create(isc_taskmgr_t *tmgr, isc_mem_t *mctx, unsigned int ntasks,
64		    unsigned int quantum, bool priv, isc_taskpool_t **poolp) {
65	unsigned int i;
66	isc_taskpool_t *pool = NULL;
67
68	INSIST(ntasks > 0);
69
70	/* Allocate the pool structure */
71	alloc_pool(tmgr, mctx, ntasks, quantum, &pool);
72
73	/* Create the tasks */
74	for (i = 0; i < ntasks; i++) {
75		isc_result_t result = isc_task_create_bound(tmgr, quantum,
76							    &pool->tasks[i], i);
77		if (result != ISC_R_SUCCESS) {
78			isc_taskpool_destroy(&pool);
79			return (result);
80		}
81		isc_task_setprivilege(pool->tasks[i], priv);
82		isc_task_setname(pool->tasks[i], "taskpool", NULL);
83	}
84
85	*poolp = pool;
86	return (ISC_R_SUCCESS);
87}
88
89void
90isc_taskpool_gettask(isc_taskpool_t *pool, isc_task_t **targetp) {
91	isc_task_attach(pool->tasks[isc_random_uniform(pool->ntasks)], targetp);
92}
93
94int
95isc_taskpool_size(isc_taskpool_t *pool) {
96	REQUIRE(pool != NULL);
97	return (pool->ntasks);
98}
99
100isc_result_t
101isc_taskpool_expand(isc_taskpool_t **sourcep, unsigned int size, bool priv,
102		    isc_taskpool_t **targetp) {
103	isc_taskpool_t *pool;
104
105	REQUIRE(sourcep != NULL && *sourcep != NULL);
106	REQUIRE(targetp != NULL && *targetp == NULL);
107
108	pool = *sourcep;
109	*sourcep = NULL;
110	if (size > pool->ntasks) {
111		isc_taskpool_t *newpool = NULL;
112		unsigned int i;
113
114		/* Allocate a new pool structure */
115		alloc_pool(pool->tmgr, pool->mctx, size, pool->quantum,
116			   &newpool);
117
118		/* Copy over the tasks from the old pool */
119		for (i = 0; i < pool->ntasks; i++) {
120			newpool->tasks[i] = pool->tasks[i];
121			pool->tasks[i] = NULL;
122		}
123
124		/* Create new tasks */
125		for (i = pool->ntasks; i < size; i++) {
126			isc_result_t result =
127				isc_task_create_bound(pool->tmgr, pool->quantum,
128						      &newpool->tasks[i], i);
129			if (result != ISC_R_SUCCESS) {
130				*sourcep = pool;
131				isc_taskpool_destroy(&newpool);
132				return (result);
133			}
134			isc_task_setprivilege(newpool->tasks[i], priv);
135			isc_task_setname(newpool->tasks[i], "taskpool", NULL);
136		}
137
138		isc_taskpool_destroy(&pool);
139		pool = newpool;
140	}
141
142	*targetp = pool;
143	return (ISC_R_SUCCESS);
144}
145
146void
147isc_taskpool_destroy(isc_taskpool_t **poolp) {
148	unsigned int i;
149	isc_taskpool_t *pool = *poolp;
150	*poolp = NULL;
151	for (i = 0; i < pool->ntasks; i++) {
152		if (pool->tasks[i] != NULL) {
153			isc_task_detach(&pool->tasks[i]);
154		}
155	}
156	isc_mem_put(pool->mctx, pool->tasks,
157		    pool->ntasks * sizeof(isc_task_t *));
158	isc_mem_putanddetach(&pool->mctx, pool, sizeof(*pool));
159}
160