Diff: rtx_ca/rt_Memory.c

Revision:

48:e9a2c7cb57a4

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/rtx_ca/rt_Memory.c	Thu Nov 06 11:00:33 2014 +0000
@@ -0,0 +1,140 @@
+/*----------------------------------------------------------------------------
+ *      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);
+}