1 /* 2 * Copyright (C) 2014 BlueKitchen GmbH 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the copyright holders nor the names of 14 * contributors may be used to endorse or promote products derived 15 * from this software without specific prior written permission. 16 * 4. Any redistribution, use, or modification is done solely for 17 * personal benefit and not for any commercial purpose or for 18 * monetary gain. 19 * 20 * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS 24 * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 26 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 27 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 28 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 29 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF 30 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * Please inquire about commercial licensing options at 34 * [email protected] 35 * 36 */ 37 38 /* 39 * btstack_memory_pool.c 40 * 41 * Fixed-size block allocation 42 * 43 * Free blocks are kept in singly linked list 44 * 45 */ 46 47 #include "btstack_memory_pool.h" 48 49 #include <stddef.h> 50 #include "btstack_debug.h" 51 52 typedef struct node { 53 struct node * next; 54 } node_t; 55 56 void btstack_memory_pool_create(btstack_memory_pool_t *pool, void * storage, int count, int block_size){ 57 node_t *free_blocks = (node_t*) pool; 58 char *mem_ptr = (char *) storage; 59 int i; 60 61 // create singly linked list of all available blocks 62 free_blocks->next = NULL; 63 for (i = 0 ; i < count ; i++){ 64 btstack_memory_pool_free(pool, mem_ptr); 65 mem_ptr += block_size; 66 } 67 } 68 69 void * btstack_memory_pool_get(btstack_memory_pool_t *pool){ 70 node_t *free_blocks = (node_t*) pool; 71 72 if (!free_blocks->next) return NULL; 73 74 // remove first 75 node_t *node = free_blocks->next; 76 free_blocks->next = node->next; 77 78 return (void*) node; 79 } 80 81 void btstack_memory_pool_free(btstack_memory_pool_t *pool, void * block){ 82 node_t *free_blocks = (node_t*) pool; 83 node_t *node = (node_t*) block; 84 85 // raise error and abort if node already in list 86 node_t * it; 87 for (it = free_blocks->next; it ; it = it->next){ 88 if (it == node) { 89 log_error("btstack_memory_pool_free: block %p freed twice for pool %p", block, pool); 90 return; 91 } 92 } 93 94 // add block as node to list 95 node->next = free_blocks->next; 96 free_blocks->next = node; 97 } 98