/***************************************************************************** * vlc_gcrypt.h: VLC thread support for gcrypt ***************************************************************************** * Copyright (C) 2004-2008 Rémi Denis-Courmont * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA. *****************************************************************************//** * \file * This file implements gcrypt support functions in vlc */#ifdef LIBVLC_USE_PTHREAD/** * If possible, use gcrypt-provided thread implementation. This is so that * other non-VLC components (inside the process) can also use gcrypt safely. */GCRY_THREAD_OPTION_PTHREAD_IMPL;# define gcry_threads_vlc gcry_threads_pthread#else/** * gcrypt thread option VLC implementation */static int gcry_vlc_mutex_init( void **p_sys ){    int i_val;    vlc_mutex_t *p_lock = (vlc_mutex_t *)malloc( sizeof( vlc_mutex_t ) );    if( p_lock == NULL)        return ENOMEM;    i_val = vlc_mutex_init( p_lock );    if( i_val )        free( p_lock );    else        *p_sys = p_lock;    return i_val;}static int gcry_vlc_mutex_destroy( void **p_sys ){    vlc_mutex_t *p_lock = (vlc_mutex_t *)*p_sys;    vlc_mutex_destroy( p_lock );    free( p_lock );    return VLC_SUCCESS;}static int gcry_vlc_mutex_lock( void **p_sys ){    vlc_mutex_lock( (vlc_mutex_t *)*p_sys );    return VLC_SUCCESS;}static int gcry_vlc_mutex_unlock( void **lock ){    vlc_mutex_unlock( (vlc_mutex_t *)*lock );    return VLC_SUCCESS;}static const struct gcry_thread_cbs gcry_threads_vlc ={    GCRY_THREAD_OPTION_USER,    NULL,    gcry_vlc_mutex_init,    gcry_vlc_mutex_destroy,    gcry_vlc_mutex_lock,    gcry_vlc_mutex_unlock};#endif/** * Initializes gcrypt with proper locking. */static inline void vlc_gcrypt_init (void){    /* This would need a process-wide static mutex with all libraries linking     * to a given instance of libgcrypt. We cannot do this as we have different     * plugins linking with gcrypt, and some underlying libraries may use it     * behind our back. Only way is to always link gcrypt statically (ouch!) or     * have upstream gcrypt provide one shared object per threading system. */    static vlc_mutex_t lock = VLC_STATIC_MUTEX;    static bool done = false;    vlc_mutex_lock (&lock);    if (!done)    {        gcry_control (GCRYCTL_SET_THREAD_CBS, &gcry_threads_vlc);        done = true;    }    vlc_mutex_unlock (&lock);}