[lttng-tools.git] / include / lttng / notification / channel-internal.h

/*
 * Copyright (C) 2017 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
 *
 * This library is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License, version 2.1 only,
 * as published by the Free Software Foundation.
 *
 * This library 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 Lesser General Public License
 * for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#ifndef LTTNG_NOTIFICATION_CHANNEL_INTERNAL_H
#define LTTNG_NOTIFICATION_CHANNEL_INTERNAL_H

#include <lttng/notification/channel.h>
#include <common/macros.h>
#include <common/dynamic-buffer.h>
#include <stdint.h>
#include <stdbool.h>
#include <pthread.h>
#include <urcu/list.h>

/*
 * Protocol version change log:
 * - v1.0
 *   - Initial implementation of the notification channel protocol,
 *   - Supported conditions are LOW/HIGH buffer usage conditions,
 * - v1.1
 *   - New condition type "LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE" added,
 *   - New condition type "LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING" added,
 *   - New condition type "LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED" added,
 */
#define LTTNG_NOTIFICATION_CHANNEL_VERSION_MAJOR 1
#define LTTNG_NOTIFICATION_CHANNEL_VERSION_MINOR 1

enum lttng_notification_channel_message_type {
	LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNKNOWN = -1,
	LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE = 0,
	LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE = 1,
	LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNSUBSCRIBE = 2,
	LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_COMMAND_REPLY = 3,
	LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION = 4,
	LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION_DROPPED = 5,
};

struct lttng_notification_channel_message {
	/* enum lttng_notification_channel_message_type */
	int8_t type;
	/* Size of the payload following this field. */
	uint32_t size;
	char payload[];
} LTTNG_PACKED;

struct lttng_notification_channel_command_handshake {
	uint8_t major;
	uint8_t minor;
} LTTNG_PACKED;

struct lttng_notification_channel_command_reply {
	/* enum lttng_notification_channel_status */
	int8_t status;
} LTTNG_PACKED;

struct pending_notification {
	/* NULL means "notification dropped". */
	struct lttng_notification *notification;
	struct cds_list_head node;
};

/*
 * The notification channel protocol is bidirectional and accomodates
 * synchronous and asynchronous communication modes:
 *
 *   - Synchronous: commands emitted by the client to which a reply is expected
 *     (e.g. subscribing/unsubscribing to conditions),
 *   - Asynchronous: notifications which are sent by the lttng_endpoint to the
 *     client as one of the subscribed condition has occurred.
 *
 * The nature of this hybrid communication mode means that asynchronous messages
 * (e.g. notifications) may be interleaved between synchronous messages (e.g. a
 * command and its reply).
 *
 * Notifications that are received between a command and its reply and enqueued
 * in the pending_notifications list.
 */
struct lttng_notification_channel {
	pthread_mutex_t lock;
	int socket;
	struct {
		/* Count of pending notifications. */
		unsigned int count;
		/* List of struct pending_notification. */
		struct cds_list_head list;
	} pending_notifications;
	struct lttng_dynamic_buffer reception_buffer;
	/* Sessiond notification protocol version. */
	struct {
		bool set;
		int8_t major, minor;
	} version;
};

#endif /* LTTNG_NOTIFICATION_CHANNEL_INTERNAL_H */
Commit	Line	Data
a58c490f JG	1	/*
	2	* Copyright (C) 2017 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
	3	*
	4	* This library is free software; you can redistribute it and/or modify it
	5	* under the terms of the GNU Lesser General Public License, version 2.1 only,
	6	* as published by the Free Software Foundation.
	7	*
	8	* This library is distributed in the hope that it will be useful, but WITHOUT
	9	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	10	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
	11	* for more details.
	12	*
	13	* You should have received a copy of the GNU Lesser General Public License
	14	* along with this library; if not, write to the Free Software Foundation,
	15	* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	16	*/
	17
	18	#ifndef LTTNG_NOTIFICATION_CHANNEL_INTERNAL_H
	19	#define LTTNG_NOTIFICATION_CHANNEL_INTERNAL_H
	20
	21	#include <lttng/notification/channel.h>
	22	#include <common/macros.h>
	23	#include <common/dynamic-buffer.h>
	24	#include <stdint.h>
	25	#include <stdbool.h>
	26	#include <pthread.h>
	27	#include <urcu/list.h>
	28
5e1d3533 JG	29	/*
	30	* Protocol version change log:
	31	* - v1.0
	32	* - Initial implementation of the notification channel protocol,
	33	* - Supported conditions are LOW/HIGH buffer usage conditions,
	34	* - v1.1
	35	* - New condition type "LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE" added,
	36	* - New condition type "LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING" added,
	37	* - New condition type "LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED" added,
	38	*/
a58c490f	39	#define LTTNG_NOTIFICATION_CHANNEL_VERSION_MAJOR 1
5e1d3533	40	#define LTTNG_NOTIFICATION_CHANNEL_VERSION_MINOR 1
a58c490f JG	41
	42	enum lttng_notification_channel_message_type {
	43	LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNKNOWN = -1,
	44	LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE = 0,
	45	LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE = 1,
	46	LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNSUBSCRIBE = 2,
	47	LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_COMMAND_REPLY = 3,
	48	LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION = 4,
	49	LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION_DROPPED = 5,
	50	};
	51
	52	struct lttng_notification_channel_message {
	53	/* enum lttng_notification_channel_message_type */
	54	int8_t type;
	55	/* Size of the payload following this field. */
	56	uint32_t size;
	57	char payload[];
	58	} LTTNG_PACKED;
	59
	60	struct lttng_notification_channel_command_handshake {
	61	uint8_t major;
	62	uint8_t minor;
	63	} LTTNG_PACKED;
	64
	65	struct lttng_notification_channel_command_reply {
	66	/* enum lttng_notification_channel_status */
	67	int8_t status;
	68	} LTTNG_PACKED;
	69
	70	struct pending_notification {
	71	/* NULL means "notification dropped". */
	72	struct lttng_notification *notification;
	73	struct cds_list_head node;
	74	};
	75
	76	/*
	77	* The notification channel protocol is bidirectional and accomodates
	78	* synchronous and asynchronous communication modes:
	79	*
	80	* - Synchronous: commands emitted by the client to which a reply is expected
	81	* (e.g. subscribing/unsubscribing to conditions),
	82	* - Asynchronous: notifications which are sent by the lttng_endpoint to the
4149ace8	83	* client as one of the subscribed condition has occurred.
a58c490f JG	84	*
	85	* The nature of this hybrid communication mode means that asynchronous messages
	86	* (e.g. notifications) may be interleaved between synchronous messages (e.g. a
	87	* command and its reply).
	88	*
	89	* Notifications that are received between a command and its reply and enqueued
	90	* in the pending_notifications list.
	91	*/
	92	struct lttng_notification_channel {
	93	pthread_mutex_t lock;
	94	int socket;
	95	struct {
	96	/* Count of pending notifications. */
	97	unsigned int count;
	98	/* List of struct pending_notification. */
	99	struct cds_list_head list;
	100	} pending_notifications;
	101	struct lttng_dynamic_buffer reception_buffer;
	102	/* Sessiond notification protocol version. */
	103	struct {
	104	bool set;
	105	int8_t major, minor;
	106	} version;
	107	};
	108
	109	#endif /* LTTNG_NOTIFICATION_CHANNEL_INTERNAL_H */