1 /* $OpenBSD: pool.c,v 1.4 2023/04/19 12:58:15 jsg Exp $ */
2
3 /*
4 * Copyright (c) 2017 Martin Pieuchot
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19 #ifndef NOPOOL
20
21 #include <sys/types.h>
22 #include <sys/queue.h>
23
24 #include <assert.h>
25 #include <stdio.h>
26 #include <stdlib.h>
27 #include <string.h>
28
29 #include "xmalloc.h"
30 #include "pool.h"
31
32 #define MAXIMUM(a, b) (((a) > (b)) ? (a) : (b))
33
34 struct pool_item {
35 SLIST_ENTRY(pool_item) pi_list;
36 };
37
38 SIMPLEQ_HEAD(, pool) pool_head = SIMPLEQ_HEAD_INITIALIZER(pool_head);
39
40 void
pool_init(struct pool * pp,const char * name,size_t nmemb,size_t size)41 pool_init(struct pool *pp, const char *name, size_t nmemb, size_t size)
42 {
43 size = MAXIMUM(size, sizeof(struct pool_item));
44
45 SLIST_INIT(&pp->pr_free);
46 pp->pr_name = name;
47 pp->pr_nmemb = nmemb;
48 pp->pr_size = size;
49 pp->pr_nitems = 0;
50 pp->pr_nfree = 0;
51
52 SIMPLEQ_INSERT_TAIL(&pool_head, pp, pr_list);
53 }
54
55 void *
pool_get(struct pool * pp)56 pool_get(struct pool *pp)
57 {
58 struct pool_item *pi;
59
60 if (SLIST_EMPTY(&pp->pr_free)) {
61 char *p;
62 size_t i;
63
64 p = xreallocarray(NULL, pp->pr_nmemb, pp->pr_size);
65 for (i = 0; i < pp->pr_nmemb; i++) {
66 pi = (struct pool_item *)p;
67 SLIST_INSERT_HEAD(&pp->pr_free, pi, pi_list);
68 p += pp->pr_size;
69 }
70 pp->pr_nitems += pp->pr_nmemb;
71 pp->pr_nfree += pp->pr_nmemb;
72 }
73
74 pi = SLIST_FIRST(&pp->pr_free);
75 SLIST_REMOVE_HEAD(&pp->pr_free, pi_list);
76 pp->pr_nfree--;
77
78 return pi;
79 }
80
81 void
pool_put(struct pool * pp,void * p)82 pool_put(struct pool *pp, void *p)
83 {
84 struct pool_item *pi = (struct pool_item *)p;
85
86 if (pi == NULL)
87 return;
88
89 assert(pp->pr_nfree < pp->pr_nitems);
90
91 SLIST_INSERT_HEAD(&pp->pr_free, pi, pi_list);
92 pp->pr_nfree++;
93 }
94
95 void
pool_dump(void)96 pool_dump(void)
97 {
98 struct pool *pp;
99
100 SIMPLEQ_FOREACH(pp, &pool_head, pr_list)
101 printf("%s: %zd items, %zd free\n", pp->pr_name, pp->pr_nitems,
102 pp->pr_nfree);
103 }
104 #endif /* NOPOOL */
105