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+/*
+ * Copyright (c) 2004, Swedish Institute of Computer Science.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. 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.
+ * 3. Neither the name of the Institute 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 INSTITUTE 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 THE INSTITUTE OR 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.
+ *
+ * This file is part of the uIP TCP/IP stack
+ *
+ * Author: Adam Dunkels <adam@sics.se>
+ *
+ * $Id: memb.c,v 1.1 2006/06/12 08:21:43 adam Exp $
+ */
+
+/**
+ * \addtogroup memb
+ * @{
+ */
+
+ /**
+ * \file
+ * Memory block allocation routines.
+ * \author Adam Dunkels <adam@sics.se>
+ */
+#include <string.h>
+
+#include "memb.h"
+
+/*---------------------------------------------------------------------------*/
+void
+memb_init(struct memb_blocks *m)
+{
+ memset(m->count, 0, m->num);
+ memset(m->mem, 0, m->size * m->num);
+}
+/*---------------------------------------------------------------------------*/
+void *
+memb_alloc(struct memb_blocks *m)
+{
+ int i;
+
+ for(i = 0; i < m->num; ++i) {
+ if(m->count[i] == 0) {
+ /* If this block was unused, we increase the reference count to
+ indicate that it now is used and return a pointer to the
+ memory block. */
+ ++(m->count[i]);
+ return (void *)((char *)m->mem + (i * m->size));
+ }
+ }
+
+ /* No free block was found, so we return NULL to indicate failure to
+ allocate block. */
+ return NULL;
+}
+/*---------------------------------------------------------------------------*/
+char
+memb_free(struct memb_blocks *m, void *ptr)
+{
+ int i;
+ char *ptr2;
+
+ /* Walk through the list of blocks and try to find the block to
+ which the pointer "ptr" points to. */
+ ptr2 = (char *)m->mem;
+ for(i = 0; i < m->num; ++i) {
+
+ if(ptr2 == (char *)ptr) {
+ /* We've found to block to which "ptr" points so we decrease the
+ reference count and return the new value of it. */
+ if(m->count[i] > 0) {
+ /* Make sure that we don't deallocate free memory. */
+ --(m->count[i]);
+ }
+ return m->count[i];
+ }
+ ptr2 += m->size;
+ }
+ return -1;
+}
+/*---------------------------------------------------------------------------*/
+
+/** @} */