| 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/ref-internal.h> |
| 31 | #include <babeltrace/ref.h> |
| 32 | |
| 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 |
| 36 | * mechanisms and may be used to provide more base functionality to all |
| 37 | * objects. |
| 38 | */ |
| 39 | struct bt_object { |
| 40 | struct bt_ref ref_count; |
| 41 | /* Class-specific release function. */ |
| 42 | bt_object_release_func release; |
| 43 | /* @see doc/ref-counting.md */ |
| 44 | struct bt_object *parent; |
| 45 | }; |
| 46 | |
| 47 | static inline |
| 48 | long bt_object_get_ref_count(const void *ptr) |
| 49 | { |
| 50 | const struct bt_object *obj = ptr; |
| 51 | |
| 52 | return obj->ref_count.count; |
| 53 | } |
| 54 | |
| 55 | static inline |
| 56 | void bt_object_release(void *ptr) |
| 57 | { |
| 58 | struct bt_object *obj = ptr; |
| 59 | |
| 60 | if (obj && obj->release && !bt_object_get_ref_count(obj)) { |
| 61 | obj->release(obj); |
| 62 | } |
| 63 | } |
| 64 | |
| 65 | static inline |
| 66 | void generic_release(struct bt_object *obj) |
| 67 | { |
| 68 | if (obj->parent) { |
| 69 | /* The release function will be invoked by the parent. */ |
| 70 | bt_put(obj->parent); |
| 71 | } else { |
| 72 | bt_object_release(obj); |
| 73 | } |
| 74 | } |
| 75 | |
| 76 | static inline |
| 77 | struct bt_object *bt_object_get_parent(void *ptr) |
| 78 | { |
| 79 | struct bt_object *obj = ptr; |
| 80 | |
| 81 | return ptr ? bt_get(obj->parent) : NULL; |
| 82 | } |
| 83 | |
| 84 | static inline |
| 85 | void bt_object_set_parent(void *child_ptr, void *parent) |
| 86 | { |
| 87 | struct bt_object *child = child_ptr; |
| 88 | |
| 89 | if (!child) { |
| 90 | return; |
| 91 | } |
| 92 | |
| 93 | /* |
| 94 | * It is assumed that a "child" being "parented" is publicly reachable. |
| 95 | * Therefore, a reference to its parent must be taken. The reference |
| 96 | * to the parent will be released once the object's reference count |
| 97 | * falls to zero. |
| 98 | */ |
| 99 | child->parent = bt_get(parent); |
| 100 | } |
| 101 | |
| 102 | static inline |
| 103 | void bt_object_init(void *ptr, bt_object_release_func release) |
| 104 | { |
| 105 | struct bt_object *obj = ptr; |
| 106 | |
| 107 | obj->release = release; |
| 108 | obj->parent = NULL; |
| 109 | bt_ref_init(&obj->ref_count, generic_release); |
| 110 | } |
| 111 | |
| 112 | #endif /* BABELTRACE_OBJECT_INTERNAL_H */ |