[babeltrace.git] / include / babeltrace / object-internal.h

#ifndef BABELTRACE_OBJECT_INTERNAL_H
#define BABELTRACE_OBJECT_INTERNAL_H

/*
 * Babeltrace - Base object
 *
 * Copyright 2015 Jérémie Galarneau <jeremie.galarneau@efficios.com>
 *
 * Author: Jérémie Galarneau <jeremie.galarneau@efficios.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include <babeltrace/ref-internal.h>
#include <babeltrace/ref.h>

/**
 * All objects publicly exposed by Babeltrace APIs must contain this structure
 * as their first member. This allows the unification of all ref counting
 * mechanisms and may be used to provide more base functionality to all
 * objects.
 */
struct bt_object {
	struct bt_ref ref_count;
	/* Class-specific, optional release function. */
	bt_object_release_func release;
	/* Class-specific, optional "parent is owner" notification listener. */
	bt_object_release_func parent_is_owner_listener;
	/* @see doc/ref-counting.md */
	struct bt_object *parent;
};

static inline
long bt_object_get_ref_count(const void *ptr)
{
	const struct bt_object *obj = ptr;

	return obj->ref_count.count;
}

static inline
void bt_object_release(void *ptr)
{
	struct bt_object *obj = ptr;

	if (obj && obj->release && !bt_object_get_ref_count(obj)) {
		obj->release(obj);
	}
}

static inline
void generic_release(struct bt_object *obj)
{
	if (obj->parent) {
		void *parent = obj->parent;

		if (obj->parent_is_owner_listener) {
			/*
			 * Object has a chance to destroy itself here
			 * under certain conditions and notify its
			 * parent. At this point the parent is
			 * guaranteed to exist because it's not put yet.
			 */
			obj->parent_is_owner_listener(obj);
		}

		/* The release function will be invoked by the parent. */
		bt_put(parent);
	} else {
		bt_object_release(obj);
	}
}

static inline
struct bt_object *bt_object_borrow_parent(void *ptr)
{
	struct bt_object *obj = ptr;

	return obj ? obj->parent : NULL;
}

static inline
struct bt_object *bt_object_get_parent(void *ptr)
{
	return bt_get(bt_object_borrow_parent(ptr));
}

static inline
void bt_object_set_parent(void *child_ptr, void *parent)
{
	struct bt_object *child = child_ptr;

	if (!child) {
		return;
	}

	/*
	 * It is assumed that a "child" being "parented" is publicly reachable.
	 * Therefore, a reference to its parent must be taken. The reference
	 * to the parent will be released once the object's reference count
	 * falls to zero.
	 */
	BT_PUT(child->parent);
	child->parent = bt_get(parent);
}

static inline
void bt_object_init(void *ptr, bt_object_release_func release)
{
	struct bt_object *obj = ptr;

	obj->release = release;
	obj->parent = NULL;
	bt_ref_init(&obj->ref_count, generic_release);
}

static inline
void bt_object_set_parent_is_owner_listener(void *obj,
		bt_object_release_func cb)
{
	assert(obj);
	((struct bt_object *) obj)->parent_is_owner_listener = cb;
}

#endif /* BABELTRACE_OBJECT_INTERNAL_H */
Commit	Line	Data
	1	#ifndef BABELTRACE_OBJECT_INTERNAL_H
	2	#define BABELTRACE_OBJECT_INTERNAL_H
	3
	4	/*
	5	* Babeltrace - Base object
	6	*
	7	* Copyright 2015 Jérémie Galarneau <jeremie.galarneau@efficios.com>
	8	*
	9	* Author: Jérémie Galarneau <jeremie.galarneau@efficios.com>
	10	*
	11	* Permission is hereby granted, free of charge, to any person obtaining a copy
	12	* of this software and associated documentation files (the "Software"), to deal
	13	* in the Software without restriction, including without limitation the rights
	14	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	15	* copies of the Software, and to permit persons to whom the Software is
	16	* furnished to do so, subject to the following conditions:
	17	*
	18	* The above copyright notice and this permission notice shall be included in
	19	* all copies or substantial portions of the Software.
	20	*
	21	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	22	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	23	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
	24	* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	25	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	26	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
	27	* SOFTWARE.
	28	*/
	29
	30	#include <babeltrace/ref-internal.h>
	31	#include <babeltrace/ref.h>
	32
	33	/**
	34	* All objects publicly exposed by Babeltrace APIs must contain this structure
	35	* as their first member. This allows the unification of all ref counting
	36	* mechanisms and may be used to provide more base functionality to all
	37	* objects.
	38	*/
	39	struct bt_object {
	40	struct bt_ref ref_count;
	41	/* Class-specific, optional release function. */
	42	bt_object_release_func release;
	43	/* Class-specific, optional "parent is owner" notification listener. */
	44	bt_object_release_func parent_is_owner_listener;
	45	/* @see doc/ref-counting.md */
	46	struct bt_object *parent;
	47	};
	48
	49	static inline
	50	long bt_object_get_ref_count(const void *ptr)
	51	{
	52	const struct bt_object *obj = ptr;
	53
	54	return obj->ref_count.count;
	55	}
	56
	57	static inline
	58	void bt_object_release(void *ptr)
	59	{
	60	struct bt_object *obj = ptr;
	61
	62	if (obj && obj->release && !bt_object_get_ref_count(obj)) {
	63	obj->release(obj);
	64	}
	65	}
	66
	67	static inline
	68	void generic_release(struct bt_object *obj)
	69	{
	70	if (obj->parent) {
	71	void *parent = obj->parent;
	72
	73	if (obj->parent_is_owner_listener) {
	74	/*
	75	* Object has a chance to destroy itself here
	76	* under certain conditions and notify its
	77	* parent. At this point the parent is
	78	* guaranteed to exist because it's not put yet.
	79	*/
	80	obj->parent_is_owner_listener(obj);
	81	}
	82
	83	/* The release function will be invoked by the parent. */
	84	bt_put(parent);
	85	} else {
	86	bt_object_release(obj);
	87	}
	88	}
	89
	90	static inline
	91	struct bt_object bt_object_borrow_parent(void ptr)
	92	{
	93	struct bt_object *obj = ptr;
	94
	95	return obj ? obj->parent : NULL;
	96	}
	97
	98	static inline
	99	struct bt_object bt_object_get_parent(void ptr)
	100	{
	101	return bt_get(bt_object_borrow_parent(ptr));
	102	}
	103
	104	static inline
	105	void bt_object_set_parent(void child_ptr, void parent)
	106	{
	107	struct bt_object *child = child_ptr;
	108
	109	if (!child) {
	110	return;
	111	}
	112
	113	/*
	114	* It is assumed that a "child" being "parented" is publicly reachable.
	115	* Therefore, a reference to its parent must be taken. The reference
	116	* to the parent will be released once the object's reference count
	117	* falls to zero.
	118	*/
	119	BT_PUT(child->parent);
	120	child->parent = bt_get(parent);
	121	}
	122
	123	static inline
	124	void bt_object_init(void *ptr, bt_object_release_func release)
	125	{
	126	struct bt_object *obj = ptr;
	127
	128	obj->release = release;
	129	obj->parent = NULL;
	130	bt_ref_init(&obj->ref_count, generic_release);
	131	}
	132
	133	static inline
	134	void bt_object_set_parent_is_owner_listener(void *obj,
	135	bt_object_release_func cb)
	136	{
	137	assert(obj);
	138	((struct bt_object *) obj)->parent_is_owner_listener = cb;
	139	}
	140
	141	#endif /* BABELTRACE_OBJECT_INTERNAL_H */