[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/babeltrace-internal.h>
#include <babeltrace/ref-internal.h>
#include <babeltrace/ref.h>
#include <babeltrace/assert-internal.h>
#include <stdbool.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;

	/*
	 * True if this object is shared, that is, it uses reference
	 * counting. Only used in developer mode.
	 */
	bool is_shared;
};

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);
}

#ifdef BT_DEV_MODE
static inline
void _bt_object_set_is_shared(struct bt_object *obj, bool is_shared)
{
	obj->is_shared = is_shared;
}

# define bt_object_set_is_shared	_bt_object_set_is_shared
#else
# define bt_object_set_is_shared(_obj, _is_shared)
#endif

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_object_set_is_shared(obj, true);
	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)
{
	BT_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/babeltrace-internal.h>
	31	#include <babeltrace/ref-internal.h>
	32	#include <babeltrace/ref.h>
	33	#include <babeltrace/assert-internal.h>
	34	#include <stdbool.h>
	35
	36	/**
	37	* All objects publicly exposed by Babeltrace APIs must contain this structure
	38	* as their first member. This allows the unification of all ref counting
	39	* mechanisms and may be used to provide more base functionality to all
	40	* objects.
	41	*/
	42	struct bt_object {
	43	struct bt_ref ref_count;
	44	/* Class-specific, optional release function. */
	45	bt_object_release_func release;
	46	/* Class-specific, optional "parent is owner" notification listener. */
	47	bt_object_release_func parent_is_owner_listener;
	48	/* @see doc/ref-counting.md */
	49	struct bt_object *parent;
	50
	51	/*
	52	* True if this object is shared, that is, it uses reference
	53	* counting. Only used in developer mode.
	54	*/
	55	bool is_shared;
	56	};
	57
	58	static inline
	59	long bt_object_get_ref_count(const void *ptr)
	60	{
	61	const struct bt_object *obj = ptr;
	62
	63	return obj->ref_count.count;
	64	}
	65
	66	static inline
	67	void bt_object_release(void *ptr)
	68	{
	69	struct bt_object *obj = ptr;
	70
	71	#ifdef BT_LOGV
	72	BT_LOGV("Releasing object: addr=%p, ref-count=%lu", ptr,
	73	obj->ref_count.count);
	74	#endif
	75
	76	if (obj && obj->release && bt_object_get_ref_count(obj) == 0) {
	77	obj->release(obj);
	78	}
	79	}
	80
	81	static inline
	82	void generic_release(struct bt_object *obj)
	83	{
	84	if (obj->parent) {
	85	struct bt_object *parent = obj->parent;
	86
	87	#ifdef BT_LOGV
	88	BT_LOGV("Releasing parented object: addr=%p, ref-count=%lu, "
	89	"parent-addr=%p, parent-ref-count=%lu",
	90	obj, obj->ref_count.count,
	91	parent, parent->ref_count.count);
	92	#endif
	93
	94	if (obj->parent_is_owner_listener) {
	95	/*
	96	* Object has a chance to destroy itself here
	97	* under certain conditions and notify its
	98	* parent. At this point the parent is
	99	* guaranteed to exist because it's not put yet.
	100	*/
	101	obj->parent_is_owner_listener(obj);
	102	}
	103
	104	/* The release function will be invoked by the parent. */
	105	bt_put(parent);
	106	} else {
	107	bt_object_release(obj);
	108	}
	109	}
	110
	111	static inline
	112	struct bt_object bt_object_borrow_parent(void ptr)
	113	{
	114	struct bt_object *obj = ptr;
	115
	116	return obj ? obj->parent : NULL;
	117	}
	118
	119	static inline
	120	struct bt_object bt_object_get_parent(void ptr)
	121	{
	122	return bt_get(bt_object_borrow_parent(ptr));
	123	}
	124
	125	static inline
	126	void bt_object_set_parent(void child_ptr, void parent)
	127	{
	128	struct bt_object *child = child_ptr;
	129
	130	if (!child) {
	131	return;
	132	}
	133
	134	#ifdef BT_LOGV
	135	BT_LOGV("Setting object's parent: addr=%p, parent-addr=%p",
	136	child_ptr, parent);
	137	#endif
	138
	139	/*
	140	* It is assumed that a "child" being "parented" is publicly reachable.
	141	* Therefore, a reference to its parent must be taken. The reference
	142	* to the parent will be released once the object's reference count
	143	* falls to zero.
	144	*/
	145	BT_PUT(child->parent);
	146	child->parent = bt_get(parent);
	147	}
	148
	149	#ifdef BT_DEV_MODE
	150	static inline
	151	void _bt_object_set_is_shared(struct bt_object *obj, bool is_shared)
	152	{
	153	obj->is_shared = is_shared;
	154	}
	155
	156	# define bt_object_set_is_shared _bt_object_set_is_shared
	157	#else
	158	# define bt_object_set_is_shared(_obj, _is_shared)
	159	#endif
	160
	161	static inline
	162	void bt_object_init(void *ptr, bt_object_release_func release)
	163	{
	164	struct bt_object *obj = ptr;
	165
	166	obj->release = release;
	167	obj->parent = NULL;
	168	bt_object_set_is_shared(obj, true);
	169	bt_ref_init(&obj->ref_count, generic_release);
	170	}
	171
	172	static inline
	173	void bt_object_set_parent_is_owner_listener(void *obj,
	174	bt_object_release_func cb)
	175	{
	176	BT_ASSERT(obj);
	177	((struct bt_object *) obj)->parent_is_owner_listener = cb;
	178	}
	179
	180	#endif /* BABELTRACE_OBJECT_INTERNAL_H */