include/lttng/ref-internal.h

   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 #include <assert.h>
  14
  15 typedef void (*lttng_release_func)(void *);
  16
  17 struct lttng_ref {
  18         unsigned long count;
  19         lttng_release_func release;
  20 };
  21
  22 static inline
  23 void lttng_ref_init(struct lttng_ref *ref, lttng_release_func release)
  24 {
  25         assert(ref);
  26         ref->count = 1;
  27         ref->release = release;
  28 }
  29
  30 static inline
  31 void lttng_ref_get(struct lttng_ref *ref)
  32 {
  33         assert(ref);
  34         ref->count++;
  35         /* Overflow check. */
  36         assert(ref->count);
  37 }
  38
  39 static inline
  40 void lttng_ref_put(struct lttng_ref *ref)
  41 {
  42         assert(ref);
  43         /* Underflow check. */
  44         assert(ref->count);
  45         if (caa_unlikely((--ref->count) == 0)) {
  46                 ref->release(ref);
  47         }
  48 }
  49
  50 #endif /* LTTNG_REF_INTERNAL_H */