[lttng-tools.git] / liblttkconsumerd / liblttkconsumerd.h

/*
 * Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca>
 *
 * 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.
 */

#ifndef _LIBLTTKCONSUMERD_H
#define _LIBLTTKCONSUMERD_H

#include "lttng-kconsumerd.h"
#include "liblttsessiondcomm.h"

/*
 * When the receiving thread dies, we need to have a way to make
 * the polling thread exit eventually.
 * If all FDs hang up (normal case when the ltt-sessiond stops),
 * we can exit cleanly, but if there is a problem and for whatever
 * reason some FDs remain open, the consumer should still exit eventually.
 *
 * If the timeout is reached, it means that during this period
 * no events occurred on the FDs so we need to force an exit.
 * This case should not happen but it is a safety to ensure we won't block
 * the consumer indefinitely.
 *
 * The value of 2 seconds is an arbitrary choice.
 */
#define KCONSUMERD_POLL_GRACE_PERIOD 2000

struct kconsumerd_fd_list {
	struct cds_list_head head;
};

/*
 * Internal representation of the FDs,
 * sessiond_fd is used to identify uniquely a fd
 */
struct kconsumerd_fd {
	struct cds_list_head list;
	int sessiond_fd; /* used to identify uniquely a fd with sessiond */
	int consumerd_fd; /* fd to consume */
	int out_fd; /* output file to write the data */
	off_t out_fd_offset; /* write position in the output file descriptor */
	char path_name[PATH_MAX]; /* tracefile name */
	enum kconsumerd_fd_state state;
	unsigned long max_sb_size; /* the subbuffer size for this channel */
};

int kconsumerd_create_poll_pipe();
int kconsumerd_send_error(enum lttcomm_return_code cmd);
void *kconsumerd_thread_poll_fds(void *data);
void *kconsumerd_thread_receive_fds(void *data);
void kconsumerd_cleanup();
void kconsumerd_set_error_socket(int sock);
void kconsumerd_set_command_socket_path(char *sock);

#endif /* _LIBLTTKCONSUMERD_H */
Commit	Line	Data
	1	/*
	2	* Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca>
	3	*
	4	* This program is free software; you can redistribute it and/or
	5	* modify it under the terms of the GNU General Public License
	6	* as published by the Free Software Foundation; either version 2
	7	* of the License, or (at your option) any later version.
	8	*
	9	* This program is distributed in the hope that it will be useful,
	10	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	* GNU General Public License for more details.
	13	*
	14	* You should have received a copy of the GNU General Public License
	15	* along with this program; if not, write to the Free Software
	16	* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
	17	*/
	18
	19	#ifndef _LIBLTTKCONSUMERD_H
	20	#define _LIBLTTKCONSUMERD_H
	21
	22	#include "lttng-kconsumerd.h"
	23	#include "liblttsessiondcomm.h"
	24
	25	/*
	26	* When the receiving thread dies, we need to have a way to make
	27	* the polling thread exit eventually.
	28	* If all FDs hang up (normal case when the ltt-sessiond stops),
	29	* we can exit cleanly, but if there is a problem and for whatever
	30	* reason some FDs remain open, the consumer should still exit eventually.
	31	*
	32	* If the timeout is reached, it means that during this period
	33	* no events occurred on the FDs so we need to force an exit.
	34	* This case should not happen but it is a safety to ensure we won't block
	35	* the consumer indefinitely.
	36	*
	37	* The value of 2 seconds is an arbitrary choice.
	38	*/
	39	#define KCONSUMERD_POLL_GRACE_PERIOD 2000
	40
	41	struct kconsumerd_fd_list {
	42	struct cds_list_head head;
	43	};
	44
	45	/*
	46	* Internal representation of the FDs,
	47	* sessiond_fd is used to identify uniquely a fd
	48	*/
	49	struct kconsumerd_fd {
	50	struct cds_list_head list;
	51	int sessiond_fd; /* used to identify uniquely a fd with sessiond */
	52	int consumerd_fd; /* fd to consume */
	53	int out_fd; /* output file to write the data */
	54	off_t out_fd_offset; /* write position in the output file descriptor */
	55	char path_name[PATH_MAX]; /* tracefile name */
	56	enum kconsumerd_fd_state state;
	57	unsigned long max_sb_size; /* the subbuffer size for this channel */
	58	};
	59
	60	int kconsumerd_create_poll_pipe();
	61	int kconsumerd_send_error(enum lttcomm_return_code cmd);
	62	void kconsumerd_thread_poll_fds(void data);
	63	void kconsumerd_thread_receive_fds(void data);
	64	void kconsumerd_cleanup();
	65	void kconsumerd_set_error_socket(int sock);
	66	void kconsumerd_set_command_socket_path(char *sock);
	67
	68	#endif /* _LIBLTTKCONSUMERD_H */