Fix: add missing rcu read side lock/unlock

[lttng-tools.git] / src / bin / lttng-sessiond / utils.c

/*
 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
 *                      Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License, version 2 only,
 * as published by the Free Software Foundation.
 *
 * 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.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#define _GNU_SOURCE
#include <stdlib.h>
#include <unistd.h>

#include <common/error.h>

#include "utils.h"

/*
 * Write to writable pipe used to notify a thread.
 */
int notify_thread_pipe(int wpipe)
{
	int ret;

	/* Ignore if the pipe is invalid. */
	if (wpipe < 0) {
		return 0;
	}

	do {
		ret = write(wpipe, "!", 1);
	} while (ret < 0 && errno == EINTR);
	if (ret < 0) {
		PERROR("write poll pipe");
	}

	return ret;
}

/*
 * Return pointer to home directory path using the env variable HOME.
 *
 * No home, NULL is returned.
 */
const char *get_home_dir(void)
{
	return ((const char *) getenv("HOME"));
}