[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 _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
6c1c0768	18	#define _LGPL_SOURCE
4063050c MD	19	#include <urcu/uatomic.h>
	20	#include <sys/time.h>
	21	#include <sys/resource.h>
	22	#include <errno.h>
	23	#include <stdio.h>
	24	#include "fd-limit.h"
6f04ed72	25	#include <common/error.h>
4063050c MD	26
	27	/* total count of fd. */
	28	static long fd_count;
	29
	30	/*
	31	* threshold in % of number of fd allowed.
	32	*/
	33	static long fd_threshold[LTTNG_FD_NR_TYPES] = {
	34	[LTTNG_FD_APPS] = 75,
	35	};
	36
	37	static rlim_t max_nr_fd;
	38
	39	int lttng_fd_get(enum lttng_fd_type type, unsigned int nr)
	40	{
	41	long newval;
	42
	43	if (type >= LTTNG_FD_NR_TYPES) {
	44	return -EINVAL;
	45	}
	46
	47	newval = uatomic_add_return(&fd_count, (long) nr);
	48	if ((long) (newval * 100)
	49	- (long) (max_nr_fd * fd_threshold[type]) > 0) {
	50	uatomic_sub(&fd_count, (long) nr);
	51	return -EPERM;
	52	}
	53	return 0;
	54	}
	55
	56	void lttng_fd_put(enum lttng_fd_type type, unsigned int nr)
	57	{
	58	uatomic_sub(&fd_count, (long) nr);
	59	}
	60
	61	void lttng_fd_init(void)
	62	{
	63	struct rlimit rlim;
	64	int ret;
	65
	66	ret = getrlimit(RLIMIT_NOFILE, &rlim);
	67	if (ret < 0) {
6f04ed72	68	PERROR("getrlimit");
4063050c MD	69	}
	70	max_nr_fd = rlim.rlim_cur;
	71	}