include/lttng/ref-internal.hpp

   1 /*
   2  * LTTng - Non thread-safe reference counting
   3  *
   4  * Copyright 2013, 2014 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   5  *
   6  * SPDX-License-Identifier: LGPL-2.1-only
   7  *
   8  */
   9
  10 #ifndef LTTNG_REF_INTERNAL_H
  11 #define LTTNG_REF_INTERNAL_H
  12
  13 #include <common/macros.hpp>
  14
  15 #include <urcu/urcu.h>
  16
  17 using lttng_release_func = void (*)(void *);
  18
  19 struct lttng_ref {
  20         unsigned long count;
  21         lttng_release_func release;
  22 };
  23
  24 static inline void lttng_ref_init(struct lttng_ref *ref, lttng_release_func release)
  25 {
  26         LTTNG_ASSERT(ref);
  27         ref->count = 1;
  28         ref->release = release;
  29 }
  30
  31 static inline void lttng_ref_get(struct lttng_ref *ref)
  32 {
  33         LTTNG_ASSERT(ref);
  34         ref->count++;
  35         /* Overflow check. */
  36         LTTNG_ASSERT(ref->count);
  37 }
  38
  39 static inline void lttng_ref_put(struct lttng_ref *ref)
  40 {
  41         LTTNG_ASSERT(ref);
  42         /* Underflow check. */
  43         LTTNG_ASSERT(ref->count);
  44         if (caa_unlikely((--ref->count) == 0)) {
  45                 ref->release(ref);
  46         }
  47 }
  48
  49 #endif /* LTTNG_REF_INTERNAL_H */