| /* |
| * Copyright 2009 Nicolai Hähnle <nhaehnle@gmail.com> |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining a |
| * copy of this software and associated documentation files (the "Software"), |
| * to deal in the Software without restriction, including without limitation |
| * on the rights to use, copy, modify, merge, publish, distribute, sub |
| * license, and/or sell copies of the Software, and to permit persons to whom |
| * the Software is furnished to do so, subject to the following conditions: |
| * |
| * The above copyright notice and this permission notice (including the next |
| * paragraph) shall be included in all copies or substantial portions of the |
| * Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL |
| * THE AUTHOR(S) AND/OR THEIR SUPPLIERS BE LIABLE FOR ANY CLAIM, |
| * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR |
| * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE |
| * USE OR OTHER DEALINGS IN THE SOFTWARE. */ |
| |
| #include "memory_pool.h" |
| |
| #include <assert.h> |
| #include <stdlib.h> |
| #include <string.h> |
| |
| |
| #define POOL_LARGE_ALLOC 4096 |
| #define POOL_ALIGN 8 |
| |
| |
| struct memory_block { |
| struct memory_block * next; |
| }; |
| |
| void memory_pool_init(struct memory_pool * pool) |
| { |
| memset(pool, 0, sizeof(struct memory_pool)); |
| } |
| |
| |
| void memory_pool_destroy(struct memory_pool * pool) |
| { |
| while(pool->blocks) { |
| struct memory_block * block = pool->blocks; |
| pool->blocks = block->next; |
| free(block); |
| } |
| } |
| |
| static void refill_pool(struct memory_pool * pool) |
| { |
| unsigned int blocksize = pool->total_allocated; |
| struct memory_block * newblock; |
| |
| if (!blocksize) |
| blocksize = 2*POOL_LARGE_ALLOC; |
| |
| newblock = (struct memory_block*)malloc(blocksize); |
| newblock->next = pool->blocks; |
| pool->blocks = newblock; |
| |
| pool->head = (unsigned char*)(newblock + 1); |
| pool->end = ((unsigned char*)newblock) + blocksize; |
| pool->total_allocated += blocksize; |
| } |
| |
| |
| void * memory_pool_malloc(struct memory_pool * pool, unsigned int bytes) |
| { |
| if (bytes < POOL_LARGE_ALLOC) { |
| void * ptr; |
| |
| if (pool->head + bytes > pool->end) |
| refill_pool(pool); |
| |
| assert(pool->head + bytes <= pool->end); |
| |
| ptr = pool->head; |
| |
| pool->head += bytes; |
| pool->head = (unsigned char*)(((unsigned long)pool->head + POOL_ALIGN - 1) & ~(POOL_ALIGN - 1)); |
| |
| return ptr; |
| } else { |
| struct memory_block * block = (struct memory_block*)malloc(bytes + sizeof(struct memory_block)); |
| |
| block->next = pool->blocks; |
| pool->blocks = block; |
| |
| return (block + 1); |
| } |
| } |
| |
| |