[lttng-tools.git] / include / lttng / notification / notification-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_INTERNAL_H
#define LTTNG_NOTIFICATION_INTERNAL_H

#include <lttng/notification/notification.h>
#include <common/macros.h>
#include <common/buffer-view.h>
#include <common/dynamic-buffer.h>
#include <stdint.h>
#include <stdbool.h>
#include <sys/types.h>

struct lttng_notification {
	struct lttng_condition *condition;
	struct lttng_evaluation *evaluation;
	/*
	 * The ownership of the notification's inner-elements depends
	 * on the way it was created. The notification owns both
	 * the condition and evaluation if it was obtained from a notification
	 * channel (i.e. created using lttng_notification_create_from_buffer)
	 * as the user may never access the condition and evaluation,
	 * thus never getting a chance to free them.
	 *
	 * However, when the _private_ lttng_notification_create() function
	 * is used, no ownership of condition and evaluation is assumed by
	 * the notification object. The main reason for this change in
	 * behavior is that internal users of this API only use the object
	 * to use its serialization facilities.
	 */
	bool owns_elements;
};

struct lttng_notification_comm {
	/* Size of the payload following this field. */
	uint32_t length;
	/* Condition and evaluation objects follow. */
	char payload[];
} LTTNG_PACKED;

LTTNG_HIDDEN
struct lttng_notification *lttng_notification_create(
		struct lttng_condition *condition,
		struct lttng_evaluation *evaluation);

LTTNG_HIDDEN
int lttng_notification_serialize(struct lttng_notification *notification,
		struct lttng_dynamic_buffer *buf);

LTTNG_HIDDEN
ssize_t lttng_notification_create_from_buffer(
		const struct lttng_buffer_view *view,
		struct lttng_notification **notification);

#endif /* LTTNG_NOTIFICATION_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_INTERNAL_H
	19	#define LTTNG_NOTIFICATION_INTERNAL_H
	20
	21	#include <lttng/notification/notification.h>
	22	#include <common/macros.h>
	23	#include <common/buffer-view.h>
3647288f	24	#include <common/dynamic-buffer.h>
a58c490f JG	25	#include <stdint.h>
a58c490f JG	26	#include <stdbool.h>
72756a3f	27	#include <sys/types.h>
a58c490f JG	28
	29	struct lttng_notification {
	30	struct lttng_condition *condition;
	31	struct lttng_evaluation *evaluation;
	32	/*
	33	* The ownership of the notification's inner-elements depends
	34	* on the way it was created. The notification owns both
	35	* the condition and evaluation if it was obtained from a notification
	36	* channel (i.e. created using lttng_notification_create_from_buffer)
	37	* as the user may never access the condition and evaluation,
	38	* thus never getting a chance to free them.
	39	*
	40	* However, when the _private_ lttng_notification_create() function
	41	* is used, no ownership of condition and evaluation is assumed by
	42	* the notification object. The main reason for this change in
	43	* behavior is that internal users of this API only use the object
	44	* to use its serialization facilities.
	45	*/
	46	bool owns_elements;
	47	};
	48
	49	struct lttng_notification_comm {
	50	/* Size of the payload following this field. */
	51	uint32_t length;
	52	/* Condition and evaluation objects follow. */
	53	char payload[];
	54	} LTTNG_PACKED;
	55
	56	LTTNG_HIDDEN
	57	struct lttng_notification *lttng_notification_create(
	58	struct lttng_condition *condition,
	59	struct lttng_evaluation *evaluation);
	60
	61	LTTNG_HIDDEN
3647288f JG	62	int lttng_notification_serialize(struct lttng_notification *notification,
3647288f JG	63	struct lttng_dynamic_buffer *buf);
a58c490f JG	64
	65	LTTNG_HIDDEN
	66	ssize_t lttng_notification_create_from_buffer(
	67	const struct lttng_buffer_view *view,
	68	struct lttng_notification **notification);
	69
	70	#endif /* LTTNG_NOTIFICATION_INTERNAL_H */