Clone of mbed rtos 2 for easy accessibility.
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rtx/TARGET_CORTEX_M/rt_Memory.c
- Committer:
- Kojto
- Date:
- 2017-07-04
- Revision:
- 125:5713cbbdb706
- Parent:
- 112:53ace74b190c
File content as of revision 125:5713cbbdb706:
/*---------------------------------------------------------------------------- * CMSIS-RTOS - RTX *---------------------------------------------------------------------------- * Name: RT_MEMORY.C * Purpose: Interface functions for Dynamic Memory Management System * Rev.: V4.79 *---------------------------------------------------------------------------- * * Copyright (c) 1999-2009 KEIL, 2009-2015 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 U32 rt_init_mem (void *pool, U32 size) { MEMP *ptr; if ((pool == NULL) || (size < sizeof(MEMP))) { return (1U); } ptr = (MEMP *)pool; ptr->next = (MEMP *)((U32)pool + size - sizeof(MEMP *)); ptr->next->next = NULL; ptr->len = 0U; return (0U); } // 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 == 0U)) { return NULL; } /* Add header offset to 'size' */ size += sizeof(MEMP); /* Make sure that block is 4-byte aligned */ size = (size + 3U) & ~(U32)3U; 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 == 0U) { /* 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 U32 rt_free_mem (void *pool, void *mem) { MEMP *p_search, *p_prev, *p_return; if ((pool == NULL) || (mem == NULL)) { return (1U); } 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 (1U); } } if (p_prev == NULL) { /* First block to be released, only set length to 0 */ p_search->len = 0U; } else { /* Discard block from chain list */ p_prev->next = p_search->next; } return (0U); }