lib/ref.c

   1 /*
   2  * ref.c: reference counting
   3  *
   4  * Babeltrace Library
   5  *
   6  * Copyright (c) 2015 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   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
  27 #define BT_LOG_TAG "REF"
  28 #include <babeltrace/lib-logging-internal.h>
  29
  30 #include <babeltrace/assert-pre-internal.h>
  31 #include <babeltrace/ref-internal.h>
  32 #include <babeltrace/object-internal.h>
  33
  34 void *bt_get(void *ptr)
  35 {
  36         struct bt_object *obj = ptr;
  37
  38         if (unlikely(!obj)) {
  39                 goto end;
  40         }
  41
  42         BT_ASSERT_PRE(obj->is_shared, "Object is not shared: addr=%p", obj);
  43
  44         if (unlikely(!obj->ref_count.release)) {
  45                 goto end;
  46         }
  47
  48         if (unlikely(obj->parent && bt_object_get_ref_count(obj) == 0)) {
  49                 BT_LOGV("Incrementing object's parent's reference count: "
  50                         "addr=%p, parent-addr=%p", ptr, obj->parent);
  51                 bt_get(obj->parent);
  52         }
  53         BT_LOGV("Incrementing object's reference count: %lu -> %lu: "
  54                 "addr=%p, cur-count=%lu, new-count=%lu",
  55                 obj->ref_count.count, obj->ref_count.count + 1,
  56                 ptr,
  57                 obj->ref_count.count, obj->ref_count.count + 1);
  58         bt_ref_get(&obj->ref_count);
  59
  60 end:
  61         return obj;
  62 }
  63
  64 void bt_put(void *ptr)
  65 {
  66         struct bt_object *obj = ptr;
  67
  68         if (unlikely(!obj)) {
  69                 return;
  70         }
  71
  72         BT_ASSERT_PRE(obj->is_shared, "Object is not shared: addr=%p", obj);
  73
  74         if (unlikely(!obj->ref_count.release)) {
  75                 return;
  76         }
  77
  78         if (BT_LOG_ON_WARN && unlikely(bt_object_get_ref_count(obj) == 0)) {
  79                 BT_LOGW("Decrementing a reference count set to 0: addr=%p",
  80                         ptr);
  81         }
  82
  83         BT_LOGV("Decrementing object's reference count: %lu -> %lu: "
  84                 "addr=%p, cur-count=%lu, new-count=%lu",
  85                 obj->ref_count.count, obj->ref_count.count - 1,
  86                 ptr,
  87                 obj->ref_count.count, obj->ref_count.count - 1);
  88         bt_ref_put(&obj->ref_count);
  89 }