[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(const void *obj);

static inline
void bt_object_put_no_null_check(const void *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(const struct bt_object *c_obj)
{
	struct bt_object *obj = (void *) c_obj;

	BT_ASSERT(obj);
	BT_ASSERT(obj->is_shared);
	return obj->ref_count;
}

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

	BT_ASSERT(obj);
	BT_ASSERT(obj->is_shared);
	return obj->parent;
}

static inline
struct bt_object *bt_object_get_parent(const struct bt_object *c_obj)
{
	struct bt_object *obj = (void *) c_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(const struct bt_object *c_obj)
{
	struct bt_object *obj = (void *) c_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(const struct bt_object *c_obj)
{
	struct bt_object *obj = (void *) c_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(const void *c_obj)
{
	struct bt_object *obj = (void *) c_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(const void *c_obj)
{
	struct bt_object *obj = (void *) c_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
398454ed	39	void bt_object_get_no_null_check(const void *obj);
3fea54f6 PP	40
3fea54f6 PP	41	static inline
398454ed	42	void bt_object_put_no_null_check(const void *obj);
3fea54f6 PP	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
398454ed	92	unsigned long long bt_object_get_ref_count(const struct bt_object *c_obj)
7c56f3cc	93	{
398454ed PP	94	struct bt_object obj = (void ) c_obj;
398454ed PP	95
3fea54f6 PP	96	BT_ASSERT(obj);
	97	BT_ASSERT(obj->is_shared);
	98	return obj->ref_count;
	99	}
5d2d9981	100
3fea54f6	101	static inline
398454ed	102	struct bt_object bt_object_borrow_parent(const struct bt_object c_obj)
3fea54f6	103	{
398454ed PP	104	struct bt_object obj = (void ) c_obj;
398454ed PP	105
3fea54f6 PP	106	BT_ASSERT(obj);
	107	BT_ASSERT(obj->is_shared);
	108	return obj->parent;
7c56f3cc MD	109	}
	110
	111	static inline
398454ed	112	struct bt_object bt_object_get_parent(const struct bt_object c_obj)
5d2d9981	113	{
398454ed	114	struct bt_object obj = (void ) c_obj;
3fea54f6 PP	115	struct bt_object *parent = bt_object_borrow_parent(obj);
	116
	117	if (parent) {
	118	bt_object_get_no_null_check(parent);
	119	}
	120
	121	return parent;
	122	}
	123
	124	static inline
	125	void bt_object_set_parent(struct bt_object child, struct bt_object parent)
	126	{
	127	BT_ASSERT(child);
	128	BT_ASSERT(child->is_shared);
5d2d9981	129
0f5e83e5	130	#ifdef BT_LOGV
3fea54f6 PP	131	BT_LOGV("Setting object's parent: addr=%p, parent-addr=%p",
3fea54f6 PP	132	child, parent);
0f5e83e5 PP	133	#endif
0f5e83e5 PP	134
3fea54f6 PP	135	/*
	136	* It is assumed that a "child" having a parent is publicly
	137	* reachable. Therefore, a reference to its parent must be
	138	* taken. The reference to the parent will be released once the
	139	* object's reference count falls to zero.
	140	*/
	141	if (parent) {
	142	BT_ASSERT(!child->parent);
	143	child->parent = parent;
	144	bt_object_get_no_null_check(parent);
	145	} else {
	146	if (child->parent) {
	147	bt_object_put_no_null_check(child->parent);
	148	}
	149
	150	child->parent = NULL;
5d2d9981 JG	151	}
	152	}
	153
7c56f3cc	154	static inline
3fea54f6 PP	155	void bt_object_try_spec_release(struct bt_object *obj)
	156	{
	157	BT_ASSERT(obj);
	158	BT_ASSERT(obj->is_shared);
	159	BT_ASSERT(obj->spec_release_func);
	160
	161	if (bt_object_get_ref_count(obj) == 0) {
	162	obj->spec_release_func(obj);
	163	}
	164	}
	165
	166	static inline
	167	void bt_object_with_parent_release_func(struct bt_object *obj)
5d2d9981 JG	168	{
5d2d9981 JG	169	if (obj->parent) {
3fea54f6 PP	170	/*
	171	* Keep our own copy of the parent address because `obj`
	172	* could be destroyed in
	173	* obj->parent_is_owner_listener_func().
	174	*/
0f5e83e5 PP	175	struct bt_object *parent = obj->parent;
	176
	177	#ifdef BT_LOGV
3fea54f6 PP	178	BT_LOGV("Releasing parented object: addr=%p, ref-count=%llu, "
	179	"parent-addr=%p, parent-ref-count=%llu",
	180	obj, obj->ref_count,
	181	parent, parent->ref_count);
0f5e83e5	182	#endif
f167d3c0	183
3fea54f6	184	if (obj->parent_is_owner_listener_func) {
f167d3c0 PP	185	/*
	186	* Object has a chance to destroy itself here
	187	* under certain conditions and notify its
	188	* parent. At this point the parent is
	189	* guaranteed to exist because it's not put yet.
	190	*/
3fea54f6	191	obj->parent_is_owner_listener_func(obj);
f167d3c0 PP	192	}
f167d3c0 PP	193
5d2d9981	194	/* The release function will be invoked by the parent. */
3fea54f6	195	bt_object_put_no_null_check(parent);
5d2d9981	196	} else {
3fea54f6	197	bt_object_try_spec_release(obj);
5d2d9981 JG	198	}
	199	}
	200
	201	static inline
3fea54f6 PP	202	void bt_object_init(struct bt_object *obj, bool is_shared,
3fea54f6 PP	203	bt_object_release_func release_func)
5d2d9981	204	{
3fea54f6 PP	205	BT_ASSERT(obj);
	206	BT_ASSERT(!is_shared \|\| release_func);
	207	obj->is_shared = is_shared;
	208	obj->release_func = release_func;
	209	obj->parent_is_owner_listener_func = NULL;
	210	obj->spec_release_func = NULL;
	211	obj->parent = NULL;
	212	obj->ref_count = 1;
dc3fffef PP	213	}
	214
	215	static inline
3fea54f6 PP	216	void bt_object_init_shared(struct bt_object *obj,
3fea54f6 PP	217	bt_object_release_func release_func)
dc3fffef	218	{
3fea54f6	219	bt_object_init(obj, true, release_func);
5d2d9981 JG	220	}
	221
	222	static inline
3fea54f6	223	void bt_object_init_unique(struct bt_object *obj)
273b65be	224	{
3fea54f6 PP	225	bt_object_init(obj, false, NULL);
3fea54f6 PP	226	}
5d2d9981	227
3fea54f6 PP	228	static inline
	229	void bt_object_init_shared_with_parent(struct bt_object *obj,
	230	bt_object_release_func spec_release_func)
	231	{
	232	BT_ASSERT(obj);
	233	BT_ASSERT(spec_release_func);
	234	bt_object_init_shared(obj, bt_object_with_parent_release_func);
	235	obj->spec_release_func = spec_release_func;
	236	}
0f5e83e5	237
3fea54f6 PP	238	static inline
	239	void bt_object_set_parent_is_owner_listener_func(struct bt_object *obj,
	240	bt_object_parent_is_owner_listener_func func)
	241	{
	242	BT_ASSERT(obj);
	243	BT_ASSERT(obj->is_shared);
	244	BT_ASSERT(obj->spec_release_func);
	245	((struct bt_object *) obj)->parent_is_owner_listener_func = func;
5d2d9981 JG	246	}
5d2d9981 JG	247
312c056a	248	static inline
398454ed	249	void bt_object_inc_ref_count(const struct bt_object *c_obj)
312c056a	250	{
398454ed PP	251	struct bt_object obj = (void ) c_obj;
398454ed PP	252
3fea54f6 PP	253	BT_ASSERT(obj);
	254	BT_ASSERT(obj->is_shared);
	255	obj->ref_count++;
	256	BT_ASSERT(obj->ref_count != 0);
312c056a PP	257	}
312c056a PP	258
6c677fb5	259	static inline
398454ed	260	void bt_object_get_no_null_check_no_parent_check(const struct bt_object *c_obj)
6c677fb5	261	{
398454ed PP	262	struct bt_object obj = (void ) c_obj;
398454ed PP	263
6c677fb5 PP	264	BT_ASSERT(obj);
	265	BT_ASSERT(obj->is_shared);
	266
	267	#ifdef BT_LOGV
	268	BT_LOGV("Incrementing object's reference count: %llu -> %llu: "
	269	"addr=%p, cur-count=%llu, new-count=%llu",
	270	obj->ref_count, obj->ref_count + 1,
	271	obj, obj->ref_count, obj->ref_count + 1);
	272	#endif
	273
	274	bt_object_inc_ref_count(obj);
	275	}
	276
5d2d9981	277	static inline
398454ed	278	void bt_object_get_no_null_check(const void *c_obj)
5d2d9981	279	{
398454ed PP	280	struct bt_object obj = (void ) c_obj;
398454ed PP	281
3fea54f6 PP	282	BT_ASSERT(obj);
3fea54f6 PP	283	BT_ASSERT(obj->is_shared);
5d2d9981	284
3fea54f6 PP	285	if (unlikely(obj->parent && bt_object_get_ref_count(obj) == 0)) {
	286	#ifdef BT_LOGV
	287	BT_LOGV("Incrementing object's parent's reference count: "
	288	"addr=%p, parent-addr=%p", obj, obj->parent);
	289	#endif
	290
	291	bt_object_get_no_null_check(obj->parent);
	292	}
	293
	294	#ifdef BT_LOGV
	295	BT_LOGV("Incrementing object's reference count: %llu -> %llu: "
	296	"addr=%p, cur-count=%llu, new-count=%llu",
	297	obj->ref_count, obj->ref_count + 1,
	298	obj, obj->ref_count, obj->ref_count + 1);
	299	#endif
	300
	301	bt_object_inc_ref_count(obj);
273b65be JG	302	}
273b65be JG	303
f167d3c0	304	static inline
398454ed	305	void bt_object_put_no_null_check(const void *c_obj)
f167d3c0	306	{
398454ed PP	307	struct bt_object obj = (void ) c_obj;
398454ed PP	308
f6ccaed9	309	BT_ASSERT(obj);
3fea54f6 PP	310	BT_ASSERT(obj->is_shared);
	311	BT_ASSERT(obj->ref_count > 0);
	312
	313	#ifdef BT_LOGV
	314	BT_LOGV("Decrementing object's reference count: %llu -> %llu: "
	315	"addr=%p, cur-count=%llu, new-count=%llu",
	316	obj->ref_count, obj->ref_count - 1,
	317	obj, obj->ref_count, obj->ref_count - 1);
	318	#endif
	319
	320	obj->ref_count--;
	321
	322	if (obj->ref_count == 0) {
	323	BT_ASSERT(obj->release_func);
	324	obj->release_func(obj);
	325	}
f167d3c0 PP	326	}
f167d3c0 PP	327
83509119	328	#endif /* BABELTRACE_OBJECT_INTERNAL_H */