1 /* $OpenBSD: pool.c,v 1.3 2017/08/29 21:10:20 deraadt 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/types.h> 23 #include <sys/queue.h> 24 25 #include <assert.h> 26 #include <stdio.h> 27 #include <stdlib.h> 28 #include <string.h> 29 30 #include "xmalloc.h" 31 #include "pool.h" 32 33 #define MAXIMUM(a, b) (((a) > (b)) ? (a) : (b)) 34 35 struct pool_item { 36 SLIST_ENTRY(pool_item) pi_list; 37 }; 38 39 SIMPLEQ_HEAD(, pool) pool_head = SIMPLEQ_HEAD_INITIALIZER(pool_head); 40 41 void 42 pool_init(struct pool *pp, const char *name, size_t nmemb, size_t size) 43 { 44 size = MAXIMUM(size, sizeof(struct pool_item)); 45 46 SLIST_INIT(&pp->pr_free); 47 pp->pr_name = name; 48 pp->pr_nmemb = nmemb; 49 pp->pr_size = size; 50 pp->pr_nitems = 0; 51 pp->pr_nfree = 0; 52 53 SIMPLEQ_INSERT_TAIL(&pool_head, pp, pr_list); 54 } 55 56 void * 57 pool_get(struct pool *pp) 58 { 59 struct pool_item *pi; 60 61 if (SLIST_EMPTY(&pp->pr_free)) { 62 char *p; 63 size_t i; 64 65 p = xreallocarray(NULL, pp->pr_nmemb, pp->pr_size); 66 for (i = 0; i < pp->pr_nmemb; i++) { 67 pi = (struct pool_item *)p; 68 SLIST_INSERT_HEAD(&pp->pr_free, pi, pi_list); 69 p += pp->pr_size; 70 } 71 pp->pr_nitems += pp->pr_nmemb; 72 pp->pr_nfree += pp->pr_nmemb; 73 } 74 75 pi = SLIST_FIRST(&pp->pr_free); 76 SLIST_REMOVE_HEAD(&pp->pr_free, pi_list); 77 pp->pr_nfree--; 78 79 return pi; 80 } 81 82 void 83 pool_put(struct pool *pp, void *p) 84 { 85 struct pool_item *pi = (struct pool_item *)p; 86 87 if (pi == NULL) 88 return; 89 90 assert(pp->pr_nfree < pp->pr_nitems); 91 92 SLIST_INSERT_HEAD(&pp->pr_free, pi, pi_list); 93 pp->pr_nfree++; 94 } 95 96 void 97 pool_dump(void) 98 { 99 struct pool *pp; 100 101 SIMPLEQ_FOREACH(pp, &pool_head, pr_list) 102 printf("%s: %zd items, %zd free\n", pp->pr_name, pp->pr_nitems, 103 pp->pr_nfree); 104 } 105 #endif /* NOPOOL */ 106