[lttng-tools.git] / ltt-sessiond / session.h

/*
 * Copyright (C) 2011 - David Goulet <david.goulet@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; only version 2
 * of the License.
 *
 * 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 _LTT_SESSION_H
#define _LTT_SESSION_H

#include <pthread.h>
#include <urcu/list.h>

#include "trace-kernel.h"
#include "trace-ust.h"

/*
 * Tracing session list
 *
 * Statically declared in session.c and can be accessed by using
 * session_get_list() function that returns the pointer to the list.
 */
struct ltt_session_list {
	/*
	 * This lock protects any read/write access to the list and count (which is
	 * basically the list size). All public functions in session.c acquire this
	 * lock and release it before returning. If none of those functions are
	 * used, the lock MUST be acquired in order to iterate or/and do any
	 * actions on that list.
	 */
	pthread_mutex_t lock;

	/*
	 * Number of element in the list. The session list lock MUST be acquired if
	 * this counter is used when iterating over the session list.
	 */
	unsigned int count;

	/* Linked list head */
	struct cds_list_head head;
};

/*
 * This data structure contains information needed to identify a tracing
 * session for both LTTng and UST.
 */
struct ltt_session {
	char *name;
	char *path;
	struct ltt_kernel_session *kernel_session;
	struct ltt_ust_session_list ust_session_list;
	/*
	 * Protect any read/write on this session data structure. This lock must be
	 * acquired *before* using any public functions declared below. Use
	 * session_lock() and session_unlock() for that.
	 */
	pthread_mutex_t lock;
	struct cds_list_head list;
};

/* Prototypes */
int session_create(char *name, char *path);
int session_destroy(char *name);

void session_lock(struct ltt_session *session);
void session_lock_list(void);
void session_unlock(struct ltt_session *session);
void session_unlock_list(void);

struct ltt_session *session_find_by_name(char *name);
struct ltt_session_list *session_get_list(void);

#endif /* _LTT_SESSION_H */
Commit	Line	Data
	1	/*
	2	* Copyright (C) 2011 - David Goulet <david.goulet@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; only version 2
	7	* of the License.
	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 _LTT_SESSION_H
	20	#define _LTT_SESSION_H
	21
	22	#include <pthread.h>
	23	#include <urcu/list.h>
	24
	25	#include "trace-kernel.h"
	26	#include "trace-ust.h"
	27
	28	/*
	29	* Tracing session list
	30	*
	31	* Statically declared in session.c and can be accessed by using
	32	* session_get_list() function that returns the pointer to the list.
	33	*/
	34	struct ltt_session_list {
	35	/*
	36	* This lock protects any read/write access to the list and count (which is
	37	* basically the list size). All public functions in session.c acquire this
	38	* lock and release it before returning. If none of those functions are
	39	* used, the lock MUST be acquired in order to iterate or/and do any
	40	* actions on that list.
	41	*/
	42	pthread_mutex_t lock;
	43
	44	/*
	45	* Number of element in the list. The session list lock MUST be acquired if
	46	* this counter is used when iterating over the session list.
	47	*/
	48	unsigned int count;
	49
	50	/* Linked list head */
	51	struct cds_list_head head;
	52	};
	53
	54	/*
	55	* This data structure contains information needed to identify a tracing
	56	* session for both LTTng and UST.
	57	*/
	58	struct ltt_session {
	59	char *name;
	60	char *path;
	61	struct ltt_kernel_session *kernel_session;
	62	struct ltt_ust_session_list ust_session_list;
	63	/*
	64	* Protect any read/write on this session data structure. This lock must be
	65	* acquired before using any public functions declared below. Use
	66	* session_lock() and session_unlock() for that.
	67	*/
	68	pthread_mutex_t lock;
	69	struct cds_list_head list;
	70	};
	71
	72	/* Prototypes */
	73	int session_create(char name, char path);
	74	int session_destroy(char *name);
	75
	76	void session_lock(struct ltt_session *session);
	77	void session_lock_list(void);
	78	void session_unlock(struct ltt_session *session);
	79	void session_unlock_list(void);
	80
	81	struct ltt_session session_find_by_name(char name);
	82	struct ltt_session_list *session_get_list(void);
	83
	84	#endif /* _LTT_SESSION_H */