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- /*----------------------------------------------------------------------------
- * RL-ARM - RTX
- *----------------------------------------------------------------------------
- * Name: RT_MEMORY.C
- * Purpose: Interface functions for Dynamic Memory Management System
- * Rev.: V4.60
- *----------------------------------------------------------------------------
- *
- * Copyright (c) 1999-2009 KEIL, 2009-2012 ARM Germany GmbH
- * All rights reserved.
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are met:
- * - Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * - 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.
- * - Neither the name of ARM nor the names of its contributors may be used
- * to endorse or promote products derived from this software without
- * specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT HOLDERS AND 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.
- *---------------------------------------------------------------------------*/
-
- #include "rt_TypeDef.h"
- #include "rt_Memory.h"
-
-
- /* Functions */
-
- // Initialize Dynamic Memory pool
- // Parameters:
- // pool: Pointer to memory pool
- // size: Size of memory pool in bytes
- // Return: 0 - OK, 1 - Error
-
- int rt_init_mem (void *pool, U32 size) {
- MEMP *ptr;
-
- if ((pool == NULL) || (size < sizeof(MEMP))) return (1);
-
- ptr = (MEMP *)pool;
- ptr->next = (MEMP *)((U32)pool + size - sizeof(MEMP *));
- ptr->next->next = NULL;
- ptr->len = 0;
-
- return (0);
- }
-
- // Allocate Memory from Memory pool
- // Parameters:
- // pool: Pointer to memory pool
- // size: Size of memory in bytes to allocate
- // Return: Pointer to allocated memory
-
- void *rt_alloc_mem (void *pool, U32 size) {
- MEMP *p, *p_search, *p_new;
- U32 hole_size;
-
- if ((pool == NULL) || (size == 0)) return NULL;
-
- /* Add header offset to 'size' */
- size += sizeof(MEMP);
- /* Make sure that block is 4-byte aligned */
- size = (size + 3) & ~3;
-
- p_search = (MEMP *)pool;
- while (1) {
- hole_size = (U32)p_search->next - (U32)p_search;
- hole_size -= p_search->len;
- /* Check if hole size is big enough */
- if (hole_size >= size) break;
- p_search = p_search->next;
- if (p_search->next == NULL) {
- /* Failed, we are at the end of the list */
- return NULL;
- }
- }
-
- if (p_search->len == 0) {
- /* No block is allocated, set the Length of the first element */
- p_search->len = size;
- p = (MEMP *)(((U32)p_search) + sizeof(MEMP));
- } else {
- /* Insert new list element into the memory list */
- p_new = (MEMP *)((U32)p_search + p_search->len);
- p_new->next = p_search->next;
- p_new->len = size;
- p_search->next = p_new;
- p = (MEMP *)(((U32)p_new) + sizeof(MEMP));
- }
-
- return (p);
- }
-
- // Free Memory and return it to Memory pool
- // Parameters:
- // pool: Pointer to memory pool
- // mem: Pointer to memory to free
- // Return: 0 - OK, 1 - Error
-
- int rt_free_mem (void *pool, void *mem) {
- MEMP *p_search, *p_prev, *p_return;
-
- if ((pool == NULL) || (mem == NULL)) return (1);
-
- p_return = (MEMP *)((U32)mem - sizeof(MEMP));
-
- /* Set list header */
- p_prev = NULL;
- p_search = (MEMP *)pool;
- while (p_search != p_return) {
- p_prev = p_search;
- p_search = p_search->next;
- if (p_search == NULL) {
- /* Valid Memory block not found */
- return (1);
- }
- }
-
- if (p_prev == NULL) {
- /* First block to be released, only set length to 0 */
- p_search->len = 0;
- } else {
- /* Discard block from chain list */
- p_prev->next = p_search->next;
- }
-
- return (0);
- }
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