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

/*
 * Copyright (C) 2012 - 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
#define _LGPL_SOURCE
#include <urcu/uatomic.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <errno.h>
#include <stdio.h>
#include "fd-limit.h"
#include <common/error.h>

/* total count of fd. */
static long fd_count;

/*
 * threshold in % of number of fd allowed.
 */
static long fd_threshold[LTTNG_FD_NR_TYPES] = {
	[LTTNG_FD_APPS] = 75,
};

static rlim_t max_nr_fd;

int lttng_fd_get(enum lttng_fd_type type, unsigned int nr)
{
	long newval;

	if (type >= LTTNG_FD_NR_TYPES) {
		return -EINVAL;
	}

	newval = uatomic_add_return(&fd_count, (long) nr);
	if ((long) (newval * 100)
			- (long) (max_nr_fd * fd_threshold[type]) > 0) {
		uatomic_sub(&fd_count, (long) nr);
		return -EPERM;
	}
	return 0;
}

void lttng_fd_put(enum lttng_fd_type type, unsigned int nr)
{
	uatomic_sub(&fd_count, (long) nr);
}

void lttng_fd_init(void)
{
	struct rlimit rlim;
	int ret;

	ret = getrlimit(RLIMIT_NOFILE, &rlim);
	if (ret < 0) {
		PERROR("getrlimit");
	}
	max_nr_fd = rlim.rlim_cur;
}
Commit	Line	Data
4063050c MD	1	/*
	2	* Copyright (C) 2012 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License, version 2 only,
	6	* as published by the Free Software Foundation.
	7	*
	8	* This program is distributed in the hope that it will be useful,
	9	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	10	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	11	* GNU General Public License for more details.
	12	*
	13	* You should have received a copy of the GNU General Public License along
	14	* with this program; if not, write to the Free Software Foundation, Inc.,
	15	* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
	16	*/
	17
	18	#define _GNU_SOURCE
6c1c0768	19	#define _LGPL_SOURCE
4063050c MD	20	#include <urcu/uatomic.h>
	21	#include <sys/time.h>
	22	#include <sys/resource.h>
	23	#include <errno.h>
	24	#include <stdio.h>
	25	#include "fd-limit.h"
6f04ed72	26	#include <common/error.h>
4063050c MD	27
	28	/* total count of fd. */
	29	static long fd_count;
	30
	31	/*
	32	* threshold in % of number of fd allowed.
	33	*/
	34	static long fd_threshold[LTTNG_FD_NR_TYPES] = {
	35	[LTTNG_FD_APPS] = 75,
	36	};
	37
	38	static rlim_t max_nr_fd;
	39
	40	int lttng_fd_get(enum lttng_fd_type type, unsigned int nr)
	41	{
	42	long newval;
	43
	44	if (type >= LTTNG_FD_NR_TYPES) {
	45	return -EINVAL;
	46	}
	47
	48	newval = uatomic_add_return(&fd_count, (long) nr);
	49	if ((long) (newval * 100)
	50	- (long) (max_nr_fd * fd_threshold[type]) > 0) {
	51	uatomic_sub(&fd_count, (long) nr);
	52	return -EPERM;
	53	}
	54	return 0;
	55	}
	56
	57	void lttng_fd_put(enum lttng_fd_type type, unsigned int nr)
	58	{
	59	uatomic_sub(&fd_count, (long) nr);
	60	}
	61
	62	void lttng_fd_init(void)
	63	{
	64	struct rlimit rlim;
	65	int ret;
	66
	67	ret = getrlimit(RLIMIT_NOFILE, &rlim);
	68	if (ret < 0) {
6f04ed72	69	PERROR("getrlimit");
4063050c MD	70	}
	71	max_nr_fd = rlim.rlim_cur;
	72	}