diff options
Diffstat (limited to 'contrib/librdns/ref.h')
-rw-r--r-- | contrib/librdns/ref.h | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/contrib/librdns/ref.h b/contrib/librdns/ref.h new file mode 100644 index 000000000..a8016b16d --- /dev/null +++ b/contrib/librdns/ref.h @@ -0,0 +1,71 @@ +/* Copyright (c) 2014, Vsevolod Stakhov + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED ''AS IS'' AND ANY + * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED + * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + * DISCLAIMED. IN NO EVENT SHALL AUTHOR BE LIABLE FOR ANY + * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND + * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ +#ifndef REF_H_ +#define REF_H_ + +/** + * @file ref.h + * A set of macros to handle refcounts + */ + +typedef void (*ref_dtor_cb_t)(void *data); + +typedef struct ref_entry_s { + unsigned int refcount; + ref_dtor_cb_t dtor; +} ref_entry_t; + +#define REF_INIT(obj, dtor_cb) do { \ + (obj)->ref.refcount = 0; \ + (obj)->ref.dtor = (ref_dtor_cb_t)(dtor_cb); \ +} while (0) + +#define REF_INIT_RETAIN(obj, dtor_cb) do { \ + (obj)->ref.refcount = 1; \ + (obj)->ref.dtor = (ref_dtor_cb_t)(dtor_cb); \ +} while (0) + +#ifdef HAVE_ATOMIC_BUILTINS +#define REF_RETAIN(obj) do { \ + __sync_add_and_fetch (&(obj)->ref.refcount, 1); \ +} while (0) + +#define REF_RELEASE(obj) do { \ + unsigned int rc = __sync_sub_and_fetch (&(obj)->ref.refcount, 1); \ + if (rc == 0 && (obj)->ref.dtor) { \ + (obj)->ref.dtor (obj); \ + } \ +} while (0) +#else +#define REF_RETAIN(obj) do { \ + (obj)->ref.refcount ++; \ +} while (0) + +#define REF_RELEASE(obj) do { \ + if (--(obj)->ref.refcount == 0 && (obj)->ref.dtor) { \ + (obj)->ref.dtor (obj); \ + } \ +} while (0) +#endif + +#endif /* REF_H_ */ |