libringbuffer/shm_internal.h

   1 #ifndef _LIBRINGBUFFER_SHM_INTERNAL_H
   2 #define _LIBRINGBUFFER_SHM_INTERNAL_H
   3
   4 /*
   5  * libringbuffer/shm_internal.h
   6  *
   7  * Copyright (C) 2011-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   8  *
   9  * This library is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Lesser General Public
  11  * License as published by the Free Software Foundation; only
  12  * version 2.1 of the License.
  13  *
  14  * This library is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  17  * Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public
  20  * License along with this library; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  22  */
  23
  24 struct shm_ref {
  25         volatile ssize_t index;         /* within the object table */
  26         volatile ssize_t offset;        /* within the object */
  27 };
  28
  29 #define DECLARE_SHMP(type, name)        \
  30         union {                         \
  31                 struct shm_ref _ref;    \
  32                 type *_type;            \
  33         } name
  34
  35 #endif /* _LIBRINGBUFFER_SHM_INTERNAL_H */