[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 release function. */
	bt_object_release_func release;
	/* @see doc/ref-counting.md */
	struct bt_object *parent;
};

static inline
long bt_object_get_ref_count(const void *);
static inline
void bt_object_set_parent(void *, void *);

static
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
void generic_release(struct bt_object *obj)
{
	if (obj->parent) {
		/* The release function will be invoked by the parent. */
		bt_put(obj->parent);
	} else {
		bt_object_release(obj);
	}
}

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

	return ptr ? bt_get(obj->parent) : NULL;
}

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.
	 */
	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
long bt_object_get_ref_count(const void *ptr)
{
	const struct bt_object *obj = ptr;

	return obj->ref_count.count;
}

#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;
5d2d9981 JG	41	/* Class-specific release function. */
	42	bt_object_release_func release;
	43	/* @see doc/ref-counting.md */
	44	struct bt_object *parent;
273b65be JG	45	};
	46
	47	static inline
5d2d9981 JG	48	long bt_object_get_ref_count(const void *);
	49	static inline
	50	void bt_object_set_parent(void , void );
	51
	52	static
	53	void bt_object_release(void *ptr)
	54	{
	55	struct bt_object *obj = ptr;
	56
	57	if (obj && obj->release && !bt_object_get_ref_count(obj)) {
	58	obj->release(obj);
	59	}
	60	}
	61
	62	static
	63	void generic_release(struct bt_object *obj)
	64	{
	65	if (obj->parent) {
	66	/* The release function will be invoked by the parent. */
	67	bt_put(obj->parent);
	68	} else {
	69	bt_object_release(obj);
	70	}
	71	}
	72
	73	static inline
	74	struct bt_object bt_object_get_parent(void ptr)
	75	{
	76	struct bt_object *obj = ptr;
	77
	78	return ptr ? bt_get(obj->parent) : NULL;
	79	}
	80
	81	static inline
	82	void bt_object_set_parent(void child_ptr, void parent)
273b65be	83	{
5d2d9981 JG	84	struct bt_object *child = child_ptr;
	85
	86	if (!child) {
	87	return;
	88	}
	89
	90	/*
	91	* It is assumed that a "child" being "parented" is publicly reachable.
	92	* Therefore, a reference to its parent must be taken. The reference
	93	* to the parent will be released once the object's reference count
	94	* falls to zero.
	95	*/
	96	child->parent = bt_get(parent);
	97	}
	98
	99	static inline
	100	void bt_object_init(void *ptr, bt_object_release_func release)
	101	{
	102	struct bt_object *obj = ptr;
	103
	104	obj->release = release;
935e7ed6	105	obj->parent = NULL;
5d2d9981	106	bt_ref_init(&obj->ref_count, generic_release);
273b65be JG	107	}
273b65be JG	108
935e7ed6 JG	109	static inline
	110	long bt_object_get_ref_count(const void *ptr)
	111	{
	112	const struct bt_object *obj = ptr;
	113
	114	return obj->ref_count.count;
	115	}
	116
83509119	117	#endif /* BABELTRACE_OBJECT_INTERNAL_H */