112 lines
3.5 KiB
C
112 lines
3.5 KiB
C
/*
|
|
* 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 Contiki operating system.
|
|
*
|
|
* Author: Adam Dunkels <adam@sics.se>
|
|
*
|
|
* $Id: memb.c,v 1.4 2009/04/06 21:18:03 adamdunkels Exp $
|
|
*/
|
|
|
|
/**
|
|
* \addtogroup memb
|
|
* @{
|
|
*/
|
|
|
|
/**
|
|
* \file
|
|
* Memory block allocation routines.
|
|
* \author Adam Dunkels <adam@sics.se>
|
|
*/
|
|
#include <string.h>
|
|
|
|
#include "contiki.h"
|
|
#include "lib/memb.h"
|
|
|
|
/*---------------------------------------------------------------------------*/
|
|
void
|
|
memb_init(struct memb *m)
|
|
{
|
|
memset(m->count, 0, m->num);
|
|
memset(m->mem, 0, m->size * m->num);
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
void *
|
|
memb_alloc(struct memb *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 *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;
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
int
|
|
memb_inmemb(struct memb *m, void *ptr)
|
|
{
|
|
return (char *)ptr >= (char *)m->mem &&
|
|
(char *)ptr < (char *)m->mem + (m->num * m->size);
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
|
|
/** @} */
|