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83509119 JG |
1 | #ifndef BABELTRACE_OBJECT_INTERNAL_H |
2 | #define BABELTRACE_OBJECT_INTERNAL_H | |
273b65be JG |
3 | |
4 | /* | |
e2f7325d | 5 | * Copyright 2017-2018 Philippe Proulx <pproulx@efficios.com> |
83509119 | 6 | * Copyright 2015 Jérémie Galarneau <jeremie.galarneau@efficios.com> |
273b65be JG |
7 | * |
8 | * Permission is hereby granted, free of charge, to any person obtaining a copy | |
9 | * of this software and associated documentation files (the "Software"), to deal | |
10 | * in the Software without restriction, including without limitation the rights | |
11 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell | |
12 | * copies of the Software, and to permit persons to whom the Software is | |
13 | * furnished to do so, subject to the following conditions: | |
14 | * | |
15 | * The above copyright notice and this permission notice shall be included in | |
16 | * all copies or substantial portions of the Software. | |
17 | * | |
18 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
19 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
20 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE | |
21 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | |
22 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, | |
23 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE | |
24 | * SOFTWARE. | |
25 | */ | |
26 | ||
91d81473 | 27 | #include "common/macros.h" |
578e048b | 28 | #include "common/assert.h" |
312c056a | 29 | #include <stdbool.h> |
273b65be | 30 | |
9358ceb3 PP |
31 | /* |
32 | * Some parts of the Babeltrace project use this internal library header | |
33 | * for internal reference counting. Until we make this header generic | |
34 | * for the whole project, make it possible to disable logging in this | |
35 | * file by defining `BT_OBJECT_DONT_LOG` because it's possible that the | |
ef267d12 | 36 | * BT_LOGT() statements here won't find the log level |
9358ceb3 PP |
37 | * (`BT_LOG_OUTPUT_LEVEL`). |
38 | */ | |
ef267d12 | 39 | #if defined(BT_LOGT) && !defined(BT_OBJECT_DONT_LOG) |
9358ceb3 PP |
40 | # define _BT_OBJECT_LOGGING_ENABLED |
41 | #endif | |
42 | ||
3fea54f6 PP |
43 | struct bt_object; |
44 | ||
45 | typedef void (*bt_object_release_func)(struct bt_object *); | |
46 | typedef void (*bt_object_parent_is_owner_listener_func)( | |
47 | struct bt_object *); | |
48 | ||
49 | static inline | |
6871026b | 50 | void bt_object_get_ref_no_null_check(const void *obj); |
3fea54f6 PP |
51 | |
52 | static inline | |
6871026b | 53 | void bt_object_put_ref_no_null_check(const void *obj); |
3fea54f6 PP |
54 | |
55 | /* | |
56 | * Babeltrace object base. | |
57 | * | |
58 | * All objects publicly exposed by Babeltrace APIs must contain this | |
59 | * object as their first member. | |
de3dd40e | 60 | */ |
83509119 | 61 | struct bt_object { |
312c056a | 62 | /* |
3fea54f6 PP |
63 | * True if this object is shared, that is, it has a reference |
64 | * count. | |
312c056a PP |
65 | */ |
66 | bool is_shared; | |
3fea54f6 PP |
67 | |
68 | /* | |
69 | * Current reference count. | |
70 | */ | |
71 | unsigned long long ref_count; | |
72 | ||
73 | /* | |
74 | * Release function called when the object's reference count | |
75 | * falls to zero. For an object with a parent, this function is | |
76 | * bt_object_with_parent_release_func(), which calls | |
77 | * `spec_release_func` below if there's no current parent. | |
78 | */ | |
79 | bt_object_release_func release_func; | |
80 | ||
81 | /* | |
82 | * Specific release function called by | |
83 | * bt_object_with_parent_release_func() or directly by a | |
84 | * parent object. | |
85 | */ | |
86 | bt_object_release_func spec_release_func; | |
87 | ||
88 | /* | |
89 | * Optional callback for an object with a parent, called by | |
90 | * bt_object_with_parent_release_func() to indicate to the | |
91 | * object that its parent is its owner. | |
92 | */ | |
93 | bt_object_parent_is_owner_listener_func | |
94 | parent_is_owner_listener_func; | |
95 | ||
96 | /* | |
97 | * Optional parent object. | |
98 | */ | |
99 | struct bt_object *parent; | |
273b65be JG |
100 | }; |
101 | ||
102 | static inline | |
398454ed | 103 | unsigned long long bt_object_get_ref_count(const struct bt_object *c_obj) |
7c56f3cc | 104 | { |
398454ed PP |
105 | struct bt_object *obj = (void *) c_obj; |
106 | ||
3fea54f6 PP |
107 | BT_ASSERT(obj); |
108 | BT_ASSERT(obj->is_shared); | |
109 | return obj->ref_count; | |
110 | } | |
5d2d9981 | 111 | |
3fea54f6 | 112 | static inline |
398454ed | 113 | struct bt_object *bt_object_borrow_parent(const struct bt_object *c_obj) |
3fea54f6 | 114 | { |
398454ed PP |
115 | struct bt_object *obj = (void *) c_obj; |
116 | ||
3fea54f6 PP |
117 | BT_ASSERT(obj); |
118 | BT_ASSERT(obj->is_shared); | |
119 | return obj->parent; | |
7c56f3cc MD |
120 | } |
121 | ||
122 | static inline | |
398454ed | 123 | struct bt_object *bt_object_get_parent(const struct bt_object *c_obj) |
5d2d9981 | 124 | { |
398454ed | 125 | struct bt_object *obj = (void *) c_obj; |
3fea54f6 PP |
126 | struct bt_object *parent = bt_object_borrow_parent(obj); |
127 | ||
128 | if (parent) { | |
6871026b | 129 | bt_object_get_ref_no_null_check(parent); |
3fea54f6 PP |
130 | } |
131 | ||
132 | return parent; | |
133 | } | |
134 | ||
135 | static inline | |
136 | void bt_object_set_parent(struct bt_object *child, struct bt_object *parent) | |
137 | { | |
138 | BT_ASSERT(child); | |
139 | BT_ASSERT(child->is_shared); | |
5d2d9981 | 140 | |
9358ceb3 | 141 | #ifdef _BT_OBJECT_LOGGING_ENABLED |
ef267d12 | 142 | BT_LOGT("Setting object's parent: addr=%p, parent-addr=%p", |
3fea54f6 | 143 | child, parent); |
0f5e83e5 PP |
144 | #endif |
145 | ||
3fea54f6 PP |
146 | /* |
147 | * It is assumed that a "child" having a parent is publicly | |
148 | * reachable. Therefore, a reference to its parent must be | |
149 | * taken. The reference to the parent will be released once the | |
150 | * object's reference count falls to zero. | |
151 | */ | |
152 | if (parent) { | |
153 | BT_ASSERT(!child->parent); | |
154 | child->parent = parent; | |
6871026b | 155 | bt_object_get_ref_no_null_check(parent); |
3fea54f6 PP |
156 | } else { |
157 | if (child->parent) { | |
6871026b | 158 | bt_object_put_ref_no_null_check(child->parent); |
3fea54f6 PP |
159 | } |
160 | ||
161 | child->parent = NULL; | |
5d2d9981 JG |
162 | } |
163 | } | |
164 | ||
7c56f3cc | 165 | static inline |
3fea54f6 PP |
166 | void bt_object_try_spec_release(struct bt_object *obj) |
167 | { | |
168 | BT_ASSERT(obj); | |
169 | BT_ASSERT(obj->is_shared); | |
170 | BT_ASSERT(obj->spec_release_func); | |
171 | ||
172 | if (bt_object_get_ref_count(obj) == 0) { | |
173 | obj->spec_release_func(obj); | |
174 | } | |
175 | } | |
176 | ||
177 | static inline | |
178 | void bt_object_with_parent_release_func(struct bt_object *obj) | |
5d2d9981 JG |
179 | { |
180 | if (obj->parent) { | |
3fea54f6 PP |
181 | /* |
182 | * Keep our own copy of the parent address because `obj` | |
183 | * could be destroyed in | |
184 | * obj->parent_is_owner_listener_func(). | |
185 | */ | |
0f5e83e5 PP |
186 | struct bt_object *parent = obj->parent; |
187 | ||
9358ceb3 | 188 | #ifdef _BT_OBJECT_LOGGING_ENABLED |
ef267d12 | 189 | BT_LOGT("Releasing parented object: addr=%p, ref-count=%llu, " |
3fea54f6 PP |
190 | "parent-addr=%p, parent-ref-count=%llu", |
191 | obj, obj->ref_count, | |
192 | parent, parent->ref_count); | |
0f5e83e5 | 193 | #endif |
f167d3c0 | 194 | |
3fea54f6 | 195 | if (obj->parent_is_owner_listener_func) { |
f167d3c0 PP |
196 | /* |
197 | * Object has a chance to destroy itself here | |
198 | * under certain conditions and notify its | |
199 | * parent. At this point the parent is | |
200 | * guaranteed to exist because it's not put yet. | |
201 | */ | |
3fea54f6 | 202 | obj->parent_is_owner_listener_func(obj); |
f167d3c0 PP |
203 | } |
204 | ||
5d2d9981 | 205 | /* The release function will be invoked by the parent. */ |
6871026b | 206 | bt_object_put_ref_no_null_check(parent); |
5d2d9981 | 207 | } else { |
3fea54f6 | 208 | bt_object_try_spec_release(obj); |
5d2d9981 JG |
209 | } |
210 | } | |
211 | ||
212 | static inline | |
3fea54f6 PP |
213 | void bt_object_init(struct bt_object *obj, bool is_shared, |
214 | bt_object_release_func release_func) | |
5d2d9981 | 215 | { |
3fea54f6 PP |
216 | BT_ASSERT(obj); |
217 | BT_ASSERT(!is_shared || release_func); | |
218 | obj->is_shared = is_shared; | |
219 | obj->release_func = release_func; | |
220 | obj->parent_is_owner_listener_func = NULL; | |
221 | obj->spec_release_func = NULL; | |
222 | obj->parent = NULL; | |
223 | obj->ref_count = 1; | |
dc3fffef PP |
224 | } |
225 | ||
226 | static inline | |
3fea54f6 PP |
227 | void bt_object_init_shared(struct bt_object *obj, |
228 | bt_object_release_func release_func) | |
dc3fffef | 229 | { |
3fea54f6 | 230 | bt_object_init(obj, true, release_func); |
5d2d9981 JG |
231 | } |
232 | ||
233 | static inline | |
3fea54f6 | 234 | void bt_object_init_unique(struct bt_object *obj) |
273b65be | 235 | { |
3fea54f6 PP |
236 | bt_object_init(obj, false, NULL); |
237 | } | |
5d2d9981 | 238 | |
3fea54f6 PP |
239 | static inline |
240 | void bt_object_init_shared_with_parent(struct bt_object *obj, | |
241 | bt_object_release_func spec_release_func) | |
242 | { | |
243 | BT_ASSERT(obj); | |
244 | BT_ASSERT(spec_release_func); | |
245 | bt_object_init_shared(obj, bt_object_with_parent_release_func); | |
246 | obj->spec_release_func = spec_release_func; | |
247 | } | |
0f5e83e5 | 248 | |
3fea54f6 PP |
249 | static inline |
250 | void bt_object_set_parent_is_owner_listener_func(struct bt_object *obj, | |
251 | bt_object_parent_is_owner_listener_func func) | |
252 | { | |
253 | BT_ASSERT(obj); | |
254 | BT_ASSERT(obj->is_shared); | |
255 | BT_ASSERT(obj->spec_release_func); | |
256 | ((struct bt_object *) obj)->parent_is_owner_listener_func = func; | |
5d2d9981 JG |
257 | } |
258 | ||
312c056a | 259 | static inline |
398454ed | 260 | void bt_object_inc_ref_count(const struct bt_object *c_obj) |
312c056a | 261 | { |
398454ed PP |
262 | struct bt_object *obj = (void *) c_obj; |
263 | ||
3fea54f6 PP |
264 | BT_ASSERT(obj); |
265 | BT_ASSERT(obj->is_shared); | |
266 | obj->ref_count++; | |
267 | BT_ASSERT(obj->ref_count != 0); | |
312c056a PP |
268 | } |
269 | ||
6c677fb5 | 270 | static inline |
6871026b | 271 | void bt_object_get_ref_no_null_check_no_parent_check(const struct bt_object *c_obj) |
6c677fb5 | 272 | { |
398454ed PP |
273 | struct bt_object *obj = (void *) c_obj; |
274 | ||
6c677fb5 PP |
275 | BT_ASSERT(obj); |
276 | BT_ASSERT(obj->is_shared); | |
277 | ||
9358ceb3 | 278 | #ifdef _BT_OBJECT_LOGGING_ENABLED |
ef267d12 | 279 | BT_LOGT("Incrementing object's reference count: %llu -> %llu: " |
6c677fb5 PP |
280 | "addr=%p, cur-count=%llu, new-count=%llu", |
281 | obj->ref_count, obj->ref_count + 1, | |
282 | obj, obj->ref_count, obj->ref_count + 1); | |
283 | #endif | |
284 | ||
285 | bt_object_inc_ref_count(obj); | |
286 | } | |
287 | ||
5d2d9981 | 288 | static inline |
6871026b | 289 | void bt_object_get_ref_no_null_check(const void *c_obj) |
5d2d9981 | 290 | { |
398454ed PP |
291 | struct bt_object *obj = (void *) c_obj; |
292 | ||
3fea54f6 PP |
293 | BT_ASSERT(obj); |
294 | BT_ASSERT(obj->is_shared); | |
5d2d9981 | 295 | |
91d81473 | 296 | if (G_UNLIKELY(obj->parent && bt_object_get_ref_count(obj) == 0)) { |
9358ceb3 | 297 | #ifdef _BT_OBJECT_LOGGING_ENABLED |
ef267d12 | 298 | BT_LOGT("Incrementing object's parent's reference count: " |
3fea54f6 PP |
299 | "addr=%p, parent-addr=%p", obj, obj->parent); |
300 | #endif | |
301 | ||
6871026b | 302 | bt_object_get_ref_no_null_check(obj->parent); |
3fea54f6 PP |
303 | } |
304 | ||
9358ceb3 | 305 | #ifdef _BT_OBJECT_LOGGING_ENABLED |
ef267d12 | 306 | BT_LOGT("Incrementing object's reference count: %llu -> %llu: " |
3fea54f6 PP |
307 | "addr=%p, cur-count=%llu, new-count=%llu", |
308 | obj->ref_count, obj->ref_count + 1, | |
309 | obj, obj->ref_count, obj->ref_count + 1); | |
310 | #endif | |
311 | ||
312 | bt_object_inc_ref_count(obj); | |
273b65be JG |
313 | } |
314 | ||
f167d3c0 | 315 | static inline |
6871026b | 316 | void bt_object_put_ref_no_null_check(const void *c_obj) |
f167d3c0 | 317 | { |
398454ed PP |
318 | struct bt_object *obj = (void *) c_obj; |
319 | ||
f6ccaed9 | 320 | BT_ASSERT(obj); |
3fea54f6 PP |
321 | BT_ASSERT(obj->is_shared); |
322 | BT_ASSERT(obj->ref_count > 0); | |
323 | ||
9358ceb3 | 324 | #ifdef _BT_OBJECT_LOGGING_ENABLED |
ef267d12 | 325 | BT_LOGT("Decrementing object's reference count: %llu -> %llu: " |
3fea54f6 PP |
326 | "addr=%p, cur-count=%llu, new-count=%llu", |
327 | obj->ref_count, obj->ref_count - 1, | |
328 | obj, obj->ref_count, obj->ref_count - 1); | |
329 | #endif | |
330 | ||
331 | obj->ref_count--; | |
332 | ||
333 | if (obj->ref_count == 0) { | |
334 | BT_ASSERT(obj->release_func); | |
335 | obj->release_func(obj); | |
336 | } | |
f167d3c0 PP |
337 | } |
338 | ||
c5b9b441 PP |
339 | static inline |
340 | void bt_object_get_ref(const void *ptr) | |
341 | { | |
342 | struct bt_object *obj = (void *) ptr; | |
343 | ||
91d81473 | 344 | if (G_UNLIKELY(!obj)) { |
c5b9b441 PP |
345 | return; |
346 | } | |
347 | ||
bdb288b3 PP |
348 | #ifdef BT_ASSERT_PRE_DEV |
349 | BT_ASSERT_PRE_DEV(obj->is_shared, "Object is not shared: %!+O", obj); | |
c5b9b441 PP |
350 | #endif |
351 | ||
6871026b | 352 | bt_object_get_ref_no_null_check(obj); |
c5b9b441 PP |
353 | } |
354 | ||
355 | static inline | |
356 | void bt_object_put_ref(const void *ptr) | |
357 | { | |
358 | struct bt_object *obj = (void *) ptr; | |
359 | ||
91d81473 | 360 | if (G_UNLIKELY(!obj)) { |
c5b9b441 PP |
361 | return; |
362 | } | |
363 | ||
bdb288b3 PP |
364 | #ifdef BT_ASSERT_PRE_DEV |
365 | BT_ASSERT_PRE_DEV(obj->is_shared, "Object is not shared: %!+O", obj); | |
366 | BT_ASSERT_PRE_DEV(bt_object_get_ref_count(obj) > 0, | |
c5b9b441 PP |
367 | "Decrementing a reference count set to 0: %!+O", ptr); |
368 | #endif | |
369 | ||
6871026b | 370 | bt_object_put_ref_no_null_check(obj); |
c5b9b441 PP |
371 | } |
372 | ||
373 | #define BT_OBJECT_PUT_REF_AND_RESET(_var) \ | |
374 | do { \ | |
375 | bt_object_put_ref(_var); \ | |
376 | (_var) = NULL; \ | |
377 | } while (0) | |
378 | ||
379 | #define BT_OBJECT_MOVE_REF(_var_dst, _var_src) \ | |
380 | do { \ | |
381 | bt_object_put_ref(_var_dst); \ | |
382 | (_var_dst) = (_var_src); \ | |
383 | (_var_src) = NULL; \ | |
384 | } while (0) | |
385 | ||
83509119 | 386 | #endif /* BABELTRACE_OBJECT_INTERNAL_H */ |