[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;

#ifdef BT_LOGV
	BT_LOGV("Releasing object: addr=%p, ref-count=%lu", ptr,
		obj->ref_count.count);
#endif

	if (obj && obj->release && bt_object_get_ref_count(obj) == 0) {
		obj->release(obj);
	}
}

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

#ifdef BT_LOGV
		BT_LOGV("Releasing parented object: addr=%p, ref-count=%lu, "
			"parent-addr=%p, parent-ref-count=%lu",
			obj, obj->ref_count.count,
			parent, parent->ref_count.count);
#endif

		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;
	}

#ifdef BT_LOGV
	BT_LOGV("Setting object's parent: addr=%p, parent-addr=%p",
		child_ptr, parent);
#endif

	/*
	 * 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
83509119 JG	1	#ifndef BABELTRACE_OBJECT_INTERNAL_H
83509119 JG	2	#define BABELTRACE_OBJECT_INTERNAL_H
273b65be JG	3
273b65be JG	4	/*
83509119	5	* Babeltrace - Base object
273b65be	6	*
83509119 JG	7	* Copyright 2015 Jérémie Galarneau <jeremie.galarneau@efficios.com>
	8	*
	9	* Author: Jérémie Galarneau <jeremie.galarneau@efficios.com>
273b65be JG	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
de3dd40e	30	#include <babeltrace/ref-internal.h>
5d2d9981	31	#include <babeltrace/ref.h>
273b65be	32
83509119 JG	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
78586d8a	36	* mechanisms and may be used to provide more base functionality to all
83509119	37	* objects.
de3dd40e	38	*/
83509119	39	struct bt_object {
de3dd40e	40	struct bt_ref ref_count;
f167d3c0	41	/* Class-specific, optional release function. */
5d2d9981	42	bt_object_release_func release;
f167d3c0 PP	43	/* Class-specific, optional "parent is owner" notification listener. */
f167d3c0 PP	44	bt_object_release_func parent_is_owner_listener;
5d2d9981 JG	45	/* @see doc/ref-counting.md */
5d2d9981 JG	46	struct bt_object *parent;
273b65be JG	47	};
	48
	49	static inline
7c56f3cc MD	50	long bt_object_get_ref_count(const void *ptr)
	51	{
	52	const struct bt_object *obj = ptr;
5d2d9981	53
7c56f3cc MD	54	return obj->ref_count.count;
	55	}
	56
	57	static inline
5d2d9981 JG	58	void bt_object_release(void *ptr)
	59	{
	60	struct bt_object *obj = ptr;
	61
0f5e83e5 PP	62	#ifdef BT_LOGV
	63	BT_LOGV("Releasing object: addr=%p, ref-count=%lu", ptr,
	64	obj->ref_count.count);
	65	#endif
	66
36712f1d	67	if (obj && obj->release && bt_object_get_ref_count(obj) == 0) {
5d2d9981 JG	68	obj->release(obj);
	69	}
	70	}
	71
7c56f3cc	72	static inline
5d2d9981 JG	73	void generic_release(struct bt_object *obj)
	74	{
	75	if (obj->parent) {
0f5e83e5 PP	76	struct bt_object *parent = obj->parent;
	77
	78	#ifdef BT_LOGV
	79	BT_LOGV("Releasing parented object: addr=%p, ref-count=%lu, "
	80	"parent-addr=%p, parent-ref-count=%lu",
	81	obj, obj->ref_count.count,
	82	parent, parent->ref_count.count);
	83	#endif
f167d3c0 PP	84
	85	if (obj->parent_is_owner_listener) {
	86	/*
	87	* Object has a chance to destroy itself here
	88	* under certain conditions and notify its
	89	* parent. At this point the parent is
	90	* guaranteed to exist because it's not put yet.
	91	*/
	92	obj->parent_is_owner_listener(obj);
	93	}
	94
5d2d9981	95	/* The release function will be invoked by the parent. */
f167d3c0	96	bt_put(parent);
5d2d9981 JG	97	} else {
	98	bt_object_release(obj);
	99	}
	100	}
	101
	102	static inline
dc3fffef	103	struct bt_object bt_object_borrow_parent(void ptr)
5d2d9981 JG	104	{
	105	struct bt_object *obj = ptr;
	106
dc3fffef PP	107	return obj ? obj->parent : NULL;
	108	}
	109
	110	static inline
	111	struct bt_object bt_object_get_parent(void ptr)
	112	{
	113	return bt_get(bt_object_borrow_parent(ptr));
5d2d9981 JG	114	}
	115
	116	static inline
	117	void bt_object_set_parent(void child_ptr, void parent)
273b65be	118	{
5d2d9981 JG	119	struct bt_object *child = child_ptr;
	120
	121	if (!child) {
	122	return;
	123	}
	124
0f5e83e5 PP	125	#ifdef BT_LOGV
	126	BT_LOGV("Setting object's parent: addr=%p, parent-addr=%p",
	127	child_ptr, parent);
	128	#endif
	129
5d2d9981 JG	130	/*
	131	* It is assumed that a "child" being "parented" is publicly reachable.
	132	* Therefore, a reference to its parent must be taken. The reference
	133	* to the parent will be released once the object's reference count
	134	* falls to zero.
	135	*/
5ed18445	136	BT_PUT(child->parent);
5d2d9981 JG	137	child->parent = bt_get(parent);
	138	}
	139
	140	static inline
	141	void bt_object_init(void *ptr, bt_object_release_func release)
	142	{
	143	struct bt_object *obj = ptr;
	144
	145	obj->release = release;
935e7ed6	146	obj->parent = NULL;
5d2d9981	147	bt_ref_init(&obj->ref_count, generic_release);
273b65be JG	148	}
273b65be JG	149
f167d3c0 PP	150	static inline
	151	void bt_object_set_parent_is_owner_listener(void *obj,
	152	bt_object_release_func cb)
	153	{
	154	assert(obj);
	155	((struct bt_object *) obj)->parent_is_owner_listener = cb;
	156	}
	157
83509119	158	#endif /* BABELTRACE_OBJECT_INTERNAL_H */