From df2b172626f794f93dd2e8fc849163a703070dda Mon Sep 17 00:00:00 2001 From: "matthias.ringwald" Date: Sat, 23 Jul 2011 14:33:33 +0000 Subject: [PATCH] basic memory pool implementation --- include/btstack/memory_pool.h | 54 +++++++++++++++++++++++ src/Makefile.in | 1 + src/memory_pool.c | 80 +++++++++++++++++++++++++++++++++++ 3 files changed, 135 insertions(+) create mode 100644 include/btstack/memory_pool.h create mode 100644 src/memory_pool.c diff --git a/include/btstack/memory_pool.h b/include/btstack/memory_pool.h new file mode 100644 index 000000000..08f1bf602 --- /dev/null +++ b/include/btstack/memory_pool.h @@ -0,0 +1,54 @@ +/* + * Copyright (C) 2011 by Matthias Ringwald + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the copyright holders nor the names of + * contributors may be used to endorse or promote products derived + * from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY MATTHIAS RINGWALD AND CONTRIBUTORS + * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS + * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF + * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + */ + +/* + * memory_pool.h + * + * @Brief Fixed-size block allocation + * + * @Assumption block_size >= sizeof(void *) + * @Assumption size of storage >= count * block_size + * + * @Note minimal implementation, no error checking/handling + */ + +#pragma once + +typedef void * memory_pool_t; + +// initialize memory pool with with given storage, block size and count +void memory_pool_create(memory_pool_t *pool, void * storage, int count, int block_size); + +// get free block from pool, @returns NULL or pointer to block +void * memory_pool_get(memory_pool_t *pool); + +// return previously reserved block to memory pool +void memory_pool_free(memory_pool_t *pool, void * block); diff --git a/src/Makefile.in b/src/Makefile.in index b060f54cf..5fa4af2c0 100644 --- a/src/Makefile.in +++ b/src/Makefile.in @@ -23,6 +23,7 @@ BTdaemon_SOURCES = $(libBTstack_SOURCES) \ $(usb_sources) \ l2cap.c \ l2cap_signaling.c \ + memory_pool.c \ $(remote_device_db_sources) \ rfcomm.c \ sdp.c \ diff --git a/src/memory_pool.c b/src/memory_pool.c new file mode 100644 index 000000000..71c825c69 --- /dev/null +++ b/src/memory_pool.c @@ -0,0 +1,80 @@ +/* + * Copyright (C) 2011 by Matthias Ringwald + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the copyright holders nor the names of + * contributors may be used to endorse or promote products derived + * from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY MATTHIAS RINGWALD AND CONTRIBUTORS + * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS + * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF + * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + */ + +/* + * memory_pool.c + * + * Fixed-size block allocation + * + * Free blocks are kept in singly linked list + * + */ + +#include +#include + +typedef struct node { + struct node * next; +} node_t; + +void memory_pool_create(memory_pool_t *pool, void * storage, int count, int block_size){ + node_t *free_blocks = (node_t*) pool; + char *mem_ptr = (char *) storage; + int i; + + // create singly linked list of all available blocks + free_blocks->next = NULL; + for (i = 0 ; i < count ; i++, mem_ptr += block_size){ + node_t * node = (node_t*) mem_ptr; + node->next = free_blocks->next; + free_blocks->next = node; + } +} + +void * memory_pool_get(memory_pool_t *pool){ + node_t *free_blocks = (node_t*) pool; + + if (!free_blocks) return NULL; + + // remove first + node_t *node = free_blocks->next; + free_blocks->next = node->next; + + return (void*) node; +} + +void memory_pool_free(memory_pool_t *pool, void * block){ + node_t *free_blocks = (node_t*) pool; + node_t *node = (node_t*) block; + // add block as node to list + node->next = free_blocks->next; + free_blocks->next = node; +}