1 #ifndef BABELTRACE_OBJECT_INTERNAL_H
2 #define BABELTRACE_OBJECT_INTERNAL_H
5 * Babeltrace - Base object
7 * Copyright 2015 Jérémie Galarneau <jeremie.galarneau@efficios.com>
9 * Author: Jérémie Galarneau <jeremie.galarneau@efficios.com>
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:
18 * The above copyright notice and this permission notice shall be included in
19 * all copies or substantial portions of the Software.
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
30 #include <babeltrace/ref-internal.h>
31 #include <babeltrace/ref.h>
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
36 * mechanisms and may be used to provide more base functionality to all
40 struct bt_ref ref_count
;
41 /* Class-specific, optional release function. */
42 bt_object_release_func release
;
43 /* Class-specific, optional "parent is owner" notification listener. */
44 bt_object_release_func parent_is_owner_listener
;
45 /* @see doc/ref-counting.md */
46 struct bt_object
*parent
;
50 long bt_object_get_ref_count(const void *ptr
)
52 const struct bt_object
*obj
= ptr
;
54 return obj
->ref_count
.count
;
58 void bt_object_release(void *ptr
)
60 struct bt_object
*obj
= ptr
;
63 BT_LOGV("Releasing object: addr=%p, ref-count=%lu", ptr
,
64 obj
->ref_count
.count
);
67 if (obj
&& obj
->release
&& bt_object_get_ref_count(obj
) == 0) {
73 void generic_release(struct bt_object
*obj
)
76 struct bt_object
*parent
= obj
->parent
;
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
);
85 if (obj
->parent_is_owner_listener
) {
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.
92 obj
->parent_is_owner_listener(obj
);
95 /* The release function will be invoked by the parent. */
98 bt_object_release(obj
);
103 struct bt_object
*bt_object_borrow_parent(void *ptr
)
105 struct bt_object
*obj
= ptr
;
107 return obj
? obj
->parent
: NULL
;
111 struct bt_object
*bt_object_get_parent(void *ptr
)
113 return bt_get(bt_object_borrow_parent(ptr
));
117 void bt_object_set_parent(void *child_ptr
, void *parent
)
119 struct bt_object
*child
= child_ptr
;
126 BT_LOGV("Setting object's parent: addr=%p, parent-addr=%p",
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
136 BT_PUT(child
->parent
);
137 child
->parent
= bt_get(parent
);
141 void bt_object_init(void *ptr
, bt_object_release_func release
)
143 struct bt_object
*obj
= ptr
;
145 obj
->release
= release
;
147 bt_ref_init(&obj
->ref_count
, generic_release
);
151 void bt_object_set_parent_is_owner_listener(void *obj
,
152 bt_object_release_func cb
)
155 ((struct bt_object
*) obj
)->parent_is_owner_listener
= cb
;
158 #endif /* BABELTRACE_OBJECT_INTERNAL_H */