include/babeltrace/ref-internal.h

   1 #ifndef BABELTRACE_REF_INTERNAL_H
   2 #define BABELTRACE_REF_INTERNAL_H
   3
   4 /*
   5  * Babeltrace - Reference Counting
   6  *
   7  * Copyright 2013, 2014 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/babeltrace-internal.h>
  31 #include <assert.h>
  32
  33 struct bt_object;
  34 typedef void (*bt_object_release_func)(struct bt_object *);
  35
  36 struct bt_ref {
  37         unsigned long count;
  38         bt_object_release_func release;
  39 };
  40
  41 static inline
  42 void bt_ref_init(struct bt_ref *ref, bt_object_release_func release)
  43 {
  44         assert(ref);
  45         ref->count = 1;
  46         ref->release = release;
  47 }
  48
  49 static inline
  50 void bt_ref_get(struct bt_ref *ref)
  51 {
  52         assert(ref);
  53
  54         if (unlikely(!ref->release)) {
  55                 return;
  56         }
  57
  58         ref->count++;
  59         /* Overflow check. */
  60         assert(ref->count);
  61 }
  62
  63 static inline
  64 void bt_ref_put(struct bt_ref *ref)
  65 {
  66         assert(ref);
  67         /* Only assert if the object has opted-in for reference counting. */
  68         if (unlikely((--ref->count) == 0 && ref->release)) {
  69                 ref->release((struct bt_object *) ref);
  70         }
  71 }
  72
  73 #endif /* BABELTRACE_REF_INTERNAL_H */