| /* |
| * 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> |
| * |
| */ |
| |
| /** |
| * \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); |
| } |
| /*---------------------------------------------------------------------------*/ |
| int |
| memb_numfree(struct memb *m) |
| { |
| int i; |
| int num_free = 0; |
| |
| for(i = 0; i < m->num; ++i) { |
| if(m->count[i] == 0) { |
| ++num_free; |
| } |
| } |
| |
| return num_free; |
| } |
| /** @} */ |