include/babeltrace/ctf-ir/ref.h

   1 #ifndef BABELTRACE_CTF_IR_REF_H
   2 #define BABELTRACE_CTF_IR_REF_H
   3
   4 /*
   5  * BabelTrace - CTF IR: common reference counting
   6  *
   7  * Copyright (c) 2015 EfficiOS Inc. and Linux Foundation
   8  * Copyright (c) 2015 Philippe Proulx <pproulx@efficios.com>
   9  *
  10  * Permission is hereby granted, free of charge, to any person obtaining a copy
  11  * of this software and associated documentation files (the "Software"), to deal
  12  * in the Software without restriction, including without limitation the rights
  13  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  14  * copies of the Software, and to permit persons to whom the Software is
  15  * furnished to do so, subject to the following conditions:
  16  *
  17  * The above copyright notice and this permission notice shall be included in
  18  * all copies or substantial portions of the Software.
  19  *
  20  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  21  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  23  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  24  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  25  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  26  * SOFTWARE.
  27  */
  28
  29 #include <assert.h>
  30 #include <babeltrace/ref-internal.h>
  31 #include <babeltrace/ctf-ir/common-internal.h>
  32
  33 /*
  34  * BT_CTF_PUT: calls bt_ctf_put() with a variable, then sets this
  35  *      variable to NULL.
  36  *
  37  * A common action with CTF IR objects is to create or get one, do
  38  * something with it, and then put it. To avoid putting it a second time
  39  * later (if an error occurs, for example), the variable is often reset
  40  * to NULL after putting the object it points to. Since this is so
  41  * common, you can use the BT_CTF_PUT() macro, which does just that.
  42  *
  43  * It is safe to call this function with a NULL object.
  44  *
  45  * @param obj CTF IR object.
  46  */
  47 #define BT_CTF_PUT(_obj)                \
  48         do {                            \
  49                 bt_ctf_put(_obj);       \
  50                 (_obj) = NULL;          \
  51         } while (0)
  52
  53 /*
  54  * bt_ctf_get: increments the reference count of a CTF IR object.
  55  *
  56  * The same number of bt_ctf_get() and bt_ctf_put() (plus one extra
  57  * bt_ctf_put() to release the initial reference done at creation) have
  58  * to be done to destroy a CTF IR object.
  59  *
  60  * It is safe to call this function with a NULL object.
  61  *
  62  * @param obj CTF IR object.
  63  */
  64 static inline
  65 void bt_ctf_get(void *obj)
  66 {
  67         if (obj) {
  68                 struct bt_ctf_base *base = obj;
  69
  70                 bt_ref_get(&base->ref_count);
  71         }
  72 }
  73
  74 /*
  75  * bt_ctf_put: decrements the reference count of a CTF IR object.
  76  *
  77  * The same number of bt_ctf_get() and bt_ctf_put() (plus one extra
  78  * bt_ctf_put() to release the initial reference done at creation) have
  79  * to be done to destroy a CTF IR object.
  80  *
  81  * When the object's reference count is decremented to 0 by a call to
  82  * bt_ctf_put(), the object is freed.
  83  *
  84  * It is safe to call this function with a NULL object.
  85  *
  86  * @param obj CTF IR object.
  87  */
  88 static inline
  89 void bt_ctf_put(void *obj)
  90 {
  91         if (obj) {
  92                 struct bt_ctf_base *base = obj;
  93
  94                 bt_ref_put(&base->ref_count);
  95         }
  96 }
  97
  98 #endif /* BABELTRACE_CTF_IR_REF_H */