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/*
*
* Copyright (c) International Business Machines Corp., 2001
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
* the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Module: memman.c
*
*/
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <fullengine.h>
#include "memman.h"
#include "engine.h"
#define MEM_OBJ_HEAD_SIGNATURE 0x54455448 /* "MEMH" */
typedef struct mem_object_header_s {
u_int32_t signature;
void (*free_function)(void *);
} mem_object_header_t;
/*
* Allocate a structure for returning to an application.
* A header, which contains a signature and a pointer to a function for
* freeing the contents of the user structure, is prepended to the buffer
* that is allocated.
*/
void * alloc_app_struct(uint size, void (*free_function)(void *)) {
void * pMem;
mem_object_header_t * mem_obj = calloc(1, sizeof(mem_object_header_t) + size);
LOG_PROC_ENTRY();
if (mem_obj != NULL) {
mem_obj->signature = MEM_OBJ_HEAD_SIGNATURE;
mem_obj->free_function = free_function;
pMem = mem_obj + 1;
} else {
pMem = NULL;
}
LOG_PROC_EXIT_PTR(pMem);
return pMem;
}
/*
* Free an application buffer.
* Look for a header before the beginning of the buffer. If one is there and
* is has a function for freeing the contents of the buffer, then call the
* function. If we don't find a header before the buffer, ignore this call.
* In that case we don't know where the memory came from so we don't know how
* to free it. It will be cleaned up when the process exits.
*/
void evms_free(void * buffer) {
mem_object_header_t * mem_obj = buffer - sizeof(mem_object_header_t);
LOG_PROC_ENTRY();
LOG_DEBUG("Request to free application buffer at %p.\n", buffer);
if (buffer != NULL) {
if (mem_obj->signature == MEM_OBJ_HEAD_SIGNATURE) {
if (mem_obj->free_function != NULL) {
mem_obj->free_function(buffer);
} else {
LOG_DEBUG("Application buffer has no supplementary free_function().\n");
}
free(mem_obj);
} else {
LOG_WARNING("Application buffer does not have our memory object header. Request ignored.\n");
}
}
LOG_PROC_EXIT_VOID();
}
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