text: /*
   * 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;
  }
  /*---------------------------------------------------------------------------*/
  
  /** @} */
  