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

#ifndef BABELTRACE_OBJECT_INTERNAL_H
#define BABELTRACE_OBJECT_INTERNAL_H

/*
 * 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/assert-internal.h>
#include <stdbool.h>

struct bt_object;

typedef void (*bt_object_release_func)(struct bt_object *);
typedef void (*bt_object_parent_is_owner_listener_func)(
		struct bt_object *);

static inline
void bt_object_get_no_null_check(struct bt_object *obj);

static inline
void bt_object_put_no_null_check(struct bt_object *obj);

/*
 * Babeltrace object base.
 *
 * All objects publicly exposed by Babeltrace APIs must contain this
 * object as their first member.
 */
struct bt_object {
	/*
	 * True if this object is shared, that is, it has a reference
	 * count.
	 */
	bool is_shared;

	/*
	 * Current reference count.
	 */
	unsigned long long ref_count;

	/*
	 * Release function called when the object's reference count
	 * falls to zero. For an object with a parent, this function is
	 * bt_object_with_parent_release_func(), which calls
	 * `spec_release_func` below if there's no current parent.
	 */
	bt_object_release_func release_func;

	/*
	 * Specific release function called by
	 * bt_object_with_parent_release_func() or directly by a
	 * parent object.
	 */
	bt_object_release_func spec_release_func;

	/*
	 * Optional callback for an object with a parent, called by
	 * bt_object_with_parent_release_func() to indicate to the
	 * object that its parent is its owner.
	 */
	bt_object_parent_is_owner_listener_func
		parent_is_owner_listener_func;

	/*
	 * Optional parent object.
	 */
	struct bt_object *parent;
};

static inline
unsigned long long bt_object_get_ref_count(struct bt_object *obj)
{
	BT_ASSERT(obj);
	BT_ASSERT(obj->is_shared);
	return obj->ref_count;
}

static inline
struct bt_object *bt_object_borrow_parent(struct bt_object *obj)
{
	BT_ASSERT(obj);
	BT_ASSERT(obj->is_shared);
	return obj->parent;
}

static inline
struct bt_object *bt_object_get_parent(struct bt_object *obj)
{
	struct bt_object *parent = bt_object_borrow_parent(obj);

	if (parent) {
		bt_object_get_no_null_check(parent);
	}

	return parent;
}

static inline
void bt_object_set_parent(struct bt_object *child, struct bt_object *parent)
{
	BT_ASSERT(child);
	BT_ASSERT(child->is_shared);

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

	/*
	 * It is assumed that a "child" having a parent 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.
	 */
	if (parent) {
		BT_ASSERT(!child->parent);
		child->parent = parent;
		bt_object_get_no_null_check(parent);
	} else {
		if (child->parent) {
			bt_object_put_no_null_check(child->parent);
		}

		child->parent = NULL;
	}
}

static inline
void bt_object_try_spec_release(struct bt_object *obj)
{
	BT_ASSERT(obj);
	BT_ASSERT(obj->is_shared);
	BT_ASSERT(obj->spec_release_func);

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

static inline
void bt_object_with_parent_release_func(struct bt_object *obj)
{
	if (obj->parent) {
		/*
		 * Keep our own copy of the parent address because `obj`
		 * could be destroyed in
		 * obj->parent_is_owner_listener_func().
		 */
		struct bt_object *parent = obj->parent;

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

		if (obj->parent_is_owner_listener_func) {
			/*
			 * 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_func(obj);
		}

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

static inline
void bt_object_init(struct bt_object *obj, bool is_shared,
		bt_object_release_func release_func)
{
	BT_ASSERT(obj);
	BT_ASSERT(!is_shared || release_func);
	obj->is_shared = is_shared;
	obj->release_func = release_func;
	obj->parent_is_owner_listener_func = NULL;
	obj->spec_release_func = NULL;
	obj->parent = NULL;
	obj->ref_count = 1;
}

static inline
void bt_object_init_shared(struct bt_object *obj,
		bt_object_release_func release_func)
{
	bt_object_init(obj, true, release_func);
}

static inline
void bt_object_init_unique(struct bt_object *obj)
{
	bt_object_init(obj, false, NULL);
}

static inline
void bt_object_init_shared_with_parent(struct bt_object *obj,
		bt_object_release_func spec_release_func)
{
	BT_ASSERT(obj);
	BT_ASSERT(spec_release_func);
	bt_object_init_shared(obj, bt_object_with_parent_release_func);
	obj->spec_release_func = spec_release_func;
}

static inline
void bt_object_set_parent_is_owner_listener_func(struct bt_object *obj,
		bt_object_parent_is_owner_listener_func func)
{
	BT_ASSERT(obj);
	BT_ASSERT(obj->is_shared);
	BT_ASSERT(obj->spec_release_func);
	((struct bt_object *) obj)->parent_is_owner_listener_func = func;
}

static inline
void bt_object_inc_ref_count(struct bt_object *obj)
{
	BT_ASSERT(obj);
	BT_ASSERT(obj->is_shared);
	obj->ref_count++;
	BT_ASSERT(obj->ref_count != 0);
}

static inline
void bt_object_get_no_null_check_no_parent_check(struct bt_object *obj)
{
	BT_ASSERT(obj);
	BT_ASSERT(obj->is_shared);

#ifdef BT_LOGV
	BT_LOGV("Incrementing object's reference count: %llu -> %llu: "
		"addr=%p, cur-count=%llu, new-count=%llu",
		obj->ref_count, obj->ref_count + 1,
		obj, obj->ref_count, obj->ref_count + 1);
#endif

	bt_object_inc_ref_count(obj);
}

static inline
void bt_object_get_no_null_check(struct bt_object *obj)
{
	BT_ASSERT(obj);
	BT_ASSERT(obj->is_shared);

	if (unlikely(obj->parent && bt_object_get_ref_count(obj) == 0)) {
#ifdef BT_LOGV
		BT_LOGV("Incrementing object's parent's reference count: "
			"addr=%p, parent-addr=%p", obj, obj->parent);
#endif

		bt_object_get_no_null_check(obj->parent);
	}

#ifdef BT_LOGV
	BT_LOGV("Incrementing object's reference count: %llu -> %llu: "
		"addr=%p, cur-count=%llu, new-count=%llu",
		obj->ref_count, obj->ref_count + 1,
		obj, obj->ref_count, obj->ref_count + 1);
#endif

	bt_object_inc_ref_count(obj);
}

static inline
void bt_object_put_no_null_check(struct bt_object *obj)
{
	BT_ASSERT(obj);
	BT_ASSERT(obj->is_shared);
	BT_ASSERT(obj->ref_count > 0);

#ifdef BT_LOGV
	BT_LOGV("Decrementing object's reference count: %llu -> %llu: "
		"addr=%p, cur-count=%llu, new-count=%llu",
		obj->ref_count, obj->ref_count - 1,
		obj, obj->ref_count, obj->ref_count - 1);
#endif

	obj->ref_count--;

	if (obj->ref_count == 0) {
		BT_ASSERT(obj->release_func);
		obj->release_func(obj);
	}
}

#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 JG	5	* Copyright 2015 Jérémie Galarneau <jeremie.galarneau@efficios.com>
	6	*
	7	* Author: Jérémie Galarneau <jeremie.galarneau@efficios.com>
273b65be JG	8	*
	9	* Permission is hereby granted, free of charge, to any person obtaining a copy
	10	* of this software and associated documentation files (the "Software"), to deal
	11	* in the Software without restriction, including without limitation the rights
	12	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	13	* copies of the Software, and to permit persons to whom the Software is
	14	* furnished to do so, subject to the following conditions:
	15	*
	16	* The above copyright notice and this permission notice shall be included in
	17	* all copies or substantial portions of the Software.
	18	*
	19	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	20	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	21	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
	22	* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	23	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	24	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
	25	* SOFTWARE.
	26	*/
	27
312c056a	28	#include <babeltrace/babeltrace-internal.h>
f6ccaed9	29	#include <babeltrace/assert-internal.h>
312c056a	30	#include <stdbool.h>
273b65be	31
3fea54f6 PP	32	struct bt_object;
	33
	34	typedef void (bt_object_release_func)(struct bt_object );
	35	typedef void (*bt_object_parent_is_owner_listener_func)(
	36	struct bt_object *);
	37
	38	static inline
	39	void bt_object_get_no_null_check(struct bt_object *obj);
	40
	41	static inline
	42	void bt_object_put_no_null_check(struct bt_object *obj);
	43
	44	/*
	45	* Babeltrace object base.
	46	*
	47	* All objects publicly exposed by Babeltrace APIs must contain this
	48	* object as their first member.
de3dd40e	49	*/
83509119	50	struct bt_object {
312c056a	51	/*
3fea54f6 PP	52	* True if this object is shared, that is, it has a reference
3fea54f6 PP	53	* count.
312c056a PP	54	*/
312c056a PP	55	bool is_shared;
3fea54f6 PP	56
	57	/*
	58	* Current reference count.
	59	*/
	60	unsigned long long ref_count;
	61
	62	/*
	63	* Release function called when the object's reference count
	64	* falls to zero. For an object with a parent, this function is
	65	* bt_object_with_parent_release_func(), which calls
	66	* `spec_release_func` below if there's no current parent.
	67	*/
	68	bt_object_release_func release_func;
	69
	70	/*
	71	* Specific release function called by
	72	* bt_object_with_parent_release_func() or directly by a
	73	* parent object.
	74	*/
	75	bt_object_release_func spec_release_func;
	76
	77	/*
	78	* Optional callback for an object with a parent, called by
	79	* bt_object_with_parent_release_func() to indicate to the
	80	* object that its parent is its owner.
	81	*/
	82	bt_object_parent_is_owner_listener_func
	83	parent_is_owner_listener_func;
	84
	85	/*
	86	* Optional parent object.
	87	*/
	88	struct bt_object *parent;
273b65be JG	89	};
	90
	91	static inline
3fea54f6	92	unsigned long long bt_object_get_ref_count(struct bt_object *obj)
7c56f3cc	93	{
3fea54f6 PP	94	BT_ASSERT(obj);
	95	BT_ASSERT(obj->is_shared);
	96	return obj->ref_count;
	97	}
5d2d9981	98
3fea54f6 PP	99	static inline
	100	struct bt_object bt_object_borrow_parent(struct bt_object obj)
	101	{
	102	BT_ASSERT(obj);
	103	BT_ASSERT(obj->is_shared);
	104	return obj->parent;
7c56f3cc MD	105	}
	106
	107	static inline
3fea54f6	108	struct bt_object bt_object_get_parent(struct bt_object obj)
5d2d9981	109	{
3fea54f6 PP	110	struct bt_object *parent = bt_object_borrow_parent(obj);
	111
	112	if (parent) {
	113	bt_object_get_no_null_check(parent);
	114	}
	115
	116	return parent;
	117	}
	118
	119	static inline
	120	void bt_object_set_parent(struct bt_object child, struct bt_object parent)
	121	{
	122	BT_ASSERT(child);
	123	BT_ASSERT(child->is_shared);
5d2d9981	124
0f5e83e5	125	#ifdef BT_LOGV
3fea54f6 PP	126	BT_LOGV("Setting object's parent: addr=%p, parent-addr=%p",
3fea54f6 PP	127	child, parent);
0f5e83e5 PP	128	#endif
0f5e83e5 PP	129
3fea54f6 PP	130	/*
	131	* It is assumed that a "child" having a parent is publicly
	132	* reachable. Therefore, a reference to its parent must be
	133	* taken. The reference to the parent will be released once the
	134	* object's reference count falls to zero.
	135	*/
	136	if (parent) {
	137	BT_ASSERT(!child->parent);
	138	child->parent = parent;
	139	bt_object_get_no_null_check(parent);
	140	} else {
	141	if (child->parent) {
	142	bt_object_put_no_null_check(child->parent);
	143	}
	144
	145	child->parent = NULL;
5d2d9981 JG	146	}
	147	}
	148
7c56f3cc	149	static inline
3fea54f6 PP	150	void bt_object_try_spec_release(struct bt_object *obj)
	151	{
	152	BT_ASSERT(obj);
	153	BT_ASSERT(obj->is_shared);
	154	BT_ASSERT(obj->spec_release_func);
	155
	156	if (bt_object_get_ref_count(obj) == 0) {
	157	obj->spec_release_func(obj);
	158	}
	159	}
	160
	161	static inline
	162	void bt_object_with_parent_release_func(struct bt_object *obj)
5d2d9981 JG	163	{
5d2d9981 JG	164	if (obj->parent) {
3fea54f6 PP	165	/*
	166	* Keep our own copy of the parent address because `obj`
	167	* could be destroyed in
	168	* obj->parent_is_owner_listener_func().
	169	*/
0f5e83e5 PP	170	struct bt_object *parent = obj->parent;
	171
	172	#ifdef BT_LOGV
3fea54f6 PP	173	BT_LOGV("Releasing parented object: addr=%p, ref-count=%llu, "
	174	"parent-addr=%p, parent-ref-count=%llu",
	175	obj, obj->ref_count,
	176	parent, parent->ref_count);
0f5e83e5	177	#endif
f167d3c0	178
3fea54f6	179	if (obj->parent_is_owner_listener_func) {
f167d3c0 PP	180	/*
	181	* Object has a chance to destroy itself here
	182	* under certain conditions and notify its
	183	* parent. At this point the parent is
	184	* guaranteed to exist because it's not put yet.
	185	*/
3fea54f6	186	obj->parent_is_owner_listener_func(obj);
f167d3c0 PP	187	}
f167d3c0 PP	188
5d2d9981	189	/* The release function will be invoked by the parent. */
3fea54f6	190	bt_object_put_no_null_check(parent);
5d2d9981	191	} else {
3fea54f6	192	bt_object_try_spec_release(obj);
5d2d9981 JG	193	}
	194	}
	195
	196	static inline
3fea54f6 PP	197	void bt_object_init(struct bt_object *obj, bool is_shared,
3fea54f6 PP	198	bt_object_release_func release_func)
5d2d9981	199	{
3fea54f6 PP	200	BT_ASSERT(obj);
	201	BT_ASSERT(!is_shared \|\| release_func);
	202	obj->is_shared = is_shared;
	203	obj->release_func = release_func;
	204	obj->parent_is_owner_listener_func = NULL;
	205	obj->spec_release_func = NULL;
	206	obj->parent = NULL;
	207	obj->ref_count = 1;
dc3fffef PP	208	}
	209
	210	static inline
3fea54f6 PP	211	void bt_object_init_shared(struct bt_object *obj,
3fea54f6 PP	212	bt_object_release_func release_func)
dc3fffef	213	{
3fea54f6	214	bt_object_init(obj, true, release_func);
5d2d9981 JG	215	}
	216
	217	static inline
3fea54f6	218	void bt_object_init_unique(struct bt_object *obj)
273b65be	219	{
3fea54f6 PP	220	bt_object_init(obj, false, NULL);
3fea54f6 PP	221	}
5d2d9981	222
3fea54f6 PP	223	static inline
	224	void bt_object_init_shared_with_parent(struct bt_object *obj,
	225	bt_object_release_func spec_release_func)
	226	{
	227	BT_ASSERT(obj);
	228	BT_ASSERT(spec_release_func);
	229	bt_object_init_shared(obj, bt_object_with_parent_release_func);
	230	obj->spec_release_func = spec_release_func;
	231	}
0f5e83e5	232
3fea54f6 PP	233	static inline
	234	void bt_object_set_parent_is_owner_listener_func(struct bt_object *obj,
	235	bt_object_parent_is_owner_listener_func func)
	236	{
	237	BT_ASSERT(obj);
	238	BT_ASSERT(obj->is_shared);
	239	BT_ASSERT(obj->spec_release_func);
	240	((struct bt_object *) obj)->parent_is_owner_listener_func = func;
5d2d9981 JG	241	}
5d2d9981 JG	242
312c056a	243	static inline
3fea54f6	244	void bt_object_inc_ref_count(struct bt_object *obj)
312c056a	245	{
3fea54f6 PP	246	BT_ASSERT(obj);
	247	BT_ASSERT(obj->is_shared);
	248	obj->ref_count++;
	249	BT_ASSERT(obj->ref_count != 0);
312c056a PP	250	}
312c056a PP	251
6c677fb5 PP	252	static inline
	253	void bt_object_get_no_null_check_no_parent_check(struct bt_object *obj)
	254	{
	255	BT_ASSERT(obj);
	256	BT_ASSERT(obj->is_shared);
	257
	258	#ifdef BT_LOGV
	259	BT_LOGV("Incrementing object's reference count: %llu -> %llu: "
	260	"addr=%p, cur-count=%llu, new-count=%llu",
	261	obj->ref_count, obj->ref_count + 1,
	262	obj, obj->ref_count, obj->ref_count + 1);
	263	#endif
	264
	265	bt_object_inc_ref_count(obj);
	266	}
	267
5d2d9981	268	static inline
3fea54f6	269	void bt_object_get_no_null_check(struct bt_object *obj)
5d2d9981	270	{
3fea54f6 PP	271	BT_ASSERT(obj);
3fea54f6 PP	272	BT_ASSERT(obj->is_shared);
5d2d9981	273
3fea54f6 PP	274	if (unlikely(obj->parent && bt_object_get_ref_count(obj) == 0)) {
	275	#ifdef BT_LOGV
	276	BT_LOGV("Incrementing object's parent's reference count: "
	277	"addr=%p, parent-addr=%p", obj, obj->parent);
	278	#endif
	279
	280	bt_object_get_no_null_check(obj->parent);
	281	}
	282
	283	#ifdef BT_LOGV
	284	BT_LOGV("Incrementing object's reference count: %llu -> %llu: "
	285	"addr=%p, cur-count=%llu, new-count=%llu",
	286	obj->ref_count, obj->ref_count + 1,
	287	obj, obj->ref_count, obj->ref_count + 1);
	288	#endif
	289
	290	bt_object_inc_ref_count(obj);
273b65be JG	291	}
273b65be JG	292
f167d3c0	293	static inline
3fea54f6	294	void bt_object_put_no_null_check(struct bt_object *obj)
f167d3c0	295	{
f6ccaed9	296	BT_ASSERT(obj);
3fea54f6 PP	297	BT_ASSERT(obj->is_shared);
	298	BT_ASSERT(obj->ref_count > 0);
	299
	300	#ifdef BT_LOGV
	301	BT_LOGV("Decrementing object's reference count: %llu -> %llu: "
	302	"addr=%p, cur-count=%llu, new-count=%llu",
	303	obj->ref_count, obj->ref_count - 1,
	304	obj, obj->ref_count, obj->ref_count - 1);
	305	#endif
	306
	307	obj->ref_count--;
	308
	309	if (obj->ref_count == 0) {
	310	BT_ASSERT(obj->release_func);
	311	obj->release_func(obj);
	312	}
f167d3c0 PP	313	}
f167d3c0 PP	314
83509119	315	#endif /* BABELTRACE_OBJECT_INTERNAL_H */