Update readme

[lttng-ust.git] / libustinstr-malloc / mallocwrap.c

/*
 * Copyright (C) 2009  Pierre-Marc Fournier
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
 */

#define _GNU_SOURCE
#include <dlfcn.h>
#include <sys/types.h>
#include <stdio.h>
#include <ust/marker.h>

void *malloc(size_t size)
{
	static void *(*plibc_malloc)(size_t size) = NULL;
	void *retval;

	if (plibc_malloc == NULL) {
		plibc_malloc = dlsym(RTLD_NEXT, "malloc");
		if (plibc_malloc == NULL) {
			fprintf(stderr, "mallocwrap: unable to find malloc\n");
			return NULL;
		}
	}

	retval = plibc_malloc(size);

	ust_marker(malloc, "size %d ptr %p", (int)size, retval);

	return retval;
}

void free(void *ptr)
{
	static void *(*plibc_free)(void *ptr) = NULL;

	if (plibc_free == NULL) {
		plibc_free = dlsym(RTLD_NEXT, "free");
		if (plibc_free == NULL) {
			fprintf(stderr, "mallocwrap: unable to find free\n");
			return;
		}
	}

	ust_marker(free, "ptr %p", ptr);

	plibc_free(ptr);
}

UST_MARKER_LIB