141 lines
		
	
	
		
			4.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			141 lines
		
	
	
		
			4.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*----------------------------------------------------------------------------
 | 
						|
 *      RL-ARM - RTX
 | 
						|
 *----------------------------------------------------------------------------
 | 
						|
 *      Name:    RT_MEMORY.C
 | 
						|
 *      Purpose: Interface functions for Dynamic Memory Management System
 | 
						|
 *      Rev.:    V4.70
 | 
						|
 *----------------------------------------------------------------------------
 | 
						|
 *
 | 
						|
 * Copyright (c) 1999-2009 KEIL, 2009-2013 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);
 | 
						|
}
 |