include/lttng/ref-internal.hpp

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