include/vlc_gcrypt.h

   1 /*****************************************************************************
   2  * vlc_gcrypt.h: VLC thread support for gcrypt
   3  *****************************************************************************
   4  * Copyright (C) 2004-2010 Rémi Denis-Courmont
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU Lesser General Public License as published by
   8  * the Free Software Foundation; either version 2.1 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  14  * GNU Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public License
  17  * along with this program; if not, write to the Free Software Foundation,
  18  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  19  *****************************************************************************/
  20
  21 /**
  22  * \file
  23  * This file implements gcrypt support functions in vlc
  24  */
  25
  26 #include <errno.h>
  27
  28 static inline void vlc_gcrypt_init (void)
  29 {
  30     /* This would need a process-wide static mutex with all libraries linking
  31      * to a given instance of libgcrypt. We cannot do this as we have different
  32      * plugins linking with gcrypt, and some underlying libraries may use it
  33      * behind our back. Only way is to always link gcrypt statically (ouch!) or
  34      * have upstream gcrypt provide one shared object per threading system. */
  35     static bool done = false;
  36
  37     vlc_global_lock (VLC_GCRYPT_MUTEX);
  38     if (!done)
  39     {
  40         /* The suggested way for an application to make sure that global_init
  41          * has been called is by using gcry_check_version. (see global_init
  42          * comments in gcrypt sources) */
  43         gcry_check_version(NULL);
  44         done = true;
  45     }
  46     vlc_global_unlock (VLC_GCRYPT_MUTEX);
  47 }