src/misc/threads.c

   1 /*****************************************************************************
   2  * threads.c : threads implementation for the VideoLAN client
   3  *****************************************************************************
   4  * Copyright (C) 1999-2008 the VideoLAN team
   5  * $Id$
   6  *
   7  * Authors: Jean-Marc Dressler <polux@via.ecp.fr>
   8  *          Samuel Hocevar <sam@zoy.org>
   9  *          Gildas Bazin <gbazin@netcourrier.com>
  10  *          Clément Sténac
  11  *          Rémi Denis-Courmont
  12  *
  13  * This program is free software; you can redistribute it and/or modify
  14  * it under the terms of the GNU General Public License as published by
  15  * the Free Software Foundation; either version 2 of the License, or
  16  * (at your option) any later version.
  17  *
  18  * This program is distributed in the hope that it will be useful,
  19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21  * GNU General Public License for more details.
  22  *
  23  * You should have received a copy of the GNU General Public License
  24  * along with this program; if not, write to the Free Software
  25  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  26  *****************************************************************************/
  27
  28 #ifdef HAVE_CONFIG_H
  29 # include "config.h"
  30 #endif
  31
  32 #include <vlc_common.h>
  33
  34 #include "libvlc.h"
  35 #include <assert.h>
  36 #include <errno.h>
  37 #ifdef HAVE_UNISTD_H
  38 # include <unistd.h>
  39 #endif
  40
  41 #if defined( LIBVLC_USE_PTHREAD )
  42 # include <sched.h>
  43 #endif
  44
  45 struct vlc_thread_boot
  46 {
  47     void * (*entry) (vlc_object_t *);
  48     vlc_object_t *object;
  49 };
  50
  51 static void *thread_entry (void *data)
  52 {
  53     vlc_object_t *obj = ((struct vlc_thread_boot *)data)->object;
  54     void *(*func) (vlc_object_t *) = ((struct vlc_thread_boot *)data)->entry;
  55
  56     free (data);
  57     msg_Dbg (obj, "thread started");
  58     func (obj);
  59     msg_Dbg (obj, "thread ended");
  60
  61     return NULL;
  62 }
  63
  64 #undef vlc_thread_create
  65 /*****************************************************************************
  66  * vlc_thread_create: create a thread
  67  *****************************************************************************
  68  * Note that i_priority is only taken into account on platforms supporting
  69  * userland real-time priority threads.
  70  *****************************************************************************/
  71 int vlc_thread_create( vlc_object_t *p_this, const char * psz_file, int i_line,
  72                        const char *psz_name, void *(*func) ( vlc_object_t * ),
  73                        int i_priority )
  74 {
  75     int i_ret;
  76     vlc_object_internals_t *p_priv = vlc_internals( p_this );
  77
  78     struct vlc_thread_boot *boot = malloc (sizeof (*boot));
  79     if (boot == NULL)
  80         return errno;
  81     boot->entry = func;
  82     boot->object = p_this;
  83
  84     /* Make sure we don't re-create a thread if the object has already one */
  85     assert( !p_priv->b_thread );
  86
  87     p_priv->b_thread = true;
  88     i_ret = vlc_clone( &p_priv->thread_id, thread_entry, boot, i_priority );
  89     if( i_ret == 0 )
  90         msg_Dbg( p_this, "thread (%s) created at priority %d (%s:%d)",
  91                  psz_name, i_priority, psz_file, i_line );
  92     else
  93     {
  94         p_priv->b_thread = false;
  95         errno = i_ret;
  96         msg_Err( p_this, "%s thread could not be created at %s:%d (%m)",
  97                          psz_name, psz_file, i_line );
  98     }
  99
 100     return i_ret;
 101 }
 102
 103 #undef vlc_thread_set_priority
 104 /*****************************************************************************
 105  * vlc_thread_set_priority: set the priority of the current thread when we
 106  * couldn't set it in vlc_thread_create (for instance for the main thread)
 107  *****************************************************************************/
 108 int vlc_thread_set_priority( vlc_object_t *p_this, const char * psz_file,
 109                              int i_line, int i_priority )
 110 {
 111     vlc_object_internals_t *p_priv = vlc_internals( p_this );
 112
 113     if( !p_priv->b_thread )
 114     {
 115         msg_Err( p_this, "couldn't set priority of non-existent thread" );
 116         return ESRCH;
 117     }
 118
 119 #if defined( LIBVLC_USE_PTHREAD )
 120 # ifndef __APPLE__
 121     if( var_InheritBool( p_this, "rt-priority" ) )
 122 # endif
 123     {
 124         int i_error, i_policy;
 125         struct sched_param param;
 126
 127         memset( &param, 0, sizeof(struct sched_param) );
 128         if( config_GetType( p_this, "rt-offset" ) )
 129             i_priority += var_InheritInteger( p_this, "rt-offset" );
 130         if( i_priority <= 0 )
 131         {
 132             param.sched_priority = (-1) * i_priority;
 133             i_policy = SCHED_OTHER;
 134         }
 135         else
 136         {
 137             param.sched_priority = i_priority;
 138             i_policy = SCHED_RR;
 139         }
 140         if( (i_error = pthread_setschedparam( p_priv->thread_id,
 141                                               i_policy, &param )) )
 142         {
 143             errno = i_error;
 144             msg_Warn( p_this, "couldn't set thread priority (%s:%d): %m",
 145                       psz_file, i_line );
 146             i_priority = 0;
 147         }
 148     }
 149
 150 #elif defined( WIN32 ) || defined( UNDER_CE )
 151     VLC_UNUSED( psz_file); VLC_UNUSED( i_line );
 152
 153 #ifndef UNDER_CE
 154     if( !SetThreadPriority(p_priv->thread_id, i_priority) )
 155 #else
 156     if( !SetThreadPriority(p_priv->thread_id->handle, i_priority) )
 157 #endif
 158     {
 159         msg_Warn( p_this, "couldn't set a faster priority" );
 160         return 1;
 161     }
 162
 163 #endif
 164
 165     return 0;
 166 }
 167
 168 #undef vlc_thread_join
 169 /*****************************************************************************
 170  * vlc_thread_join: wait until a thread exits, inner version
 171  *****************************************************************************/
 172 void vlc_thread_join( vlc_object_t *p_this )
 173 {
 174     vlc_object_internals_t *p_priv = vlc_internals( p_this );
 175
 176 #if defined( WIN32 ) && !defined( UNDER_CE )
 177     HANDLE hThread;
 178     FILETIME create_ft, exit_ft, kernel_ft, user_ft;
 179     int64_t real_time, kernel_time, user_time;
 180
 181     if( ! DuplicateHandle(GetCurrentProcess(),
 182             p_priv->thread_id,
 183             GetCurrentProcess(),
 184             &hThread,
 185             0,
 186             FALSE,
 187             DUPLICATE_SAME_ACCESS) )
 188     {
 189         p_priv->b_thread = false;
 190         return; /* We have a problem! */
 191     }
 192 #endif
 193
 194     vlc_join( p_priv->thread_id, NULL );
 195
 196 #if defined( WIN32 ) && !defined( UNDER_CE )
 197     /* FIXME: this could work on WinCE too... except that it seems always to
 198      * return 0 for exit_ft and kernel_ft */
 199     if( GetThreadTimes( hThread, &create_ft, &exit_ft, &kernel_ft, &user_ft ) )
 200     {
 201         real_time =
 202           ((((int64_t)exit_ft.dwHighDateTime)<<32)| exit_ft.dwLowDateTime) -
 203           ((((int64_t)create_ft.dwHighDateTime)<<32)| create_ft.dwLowDateTime);
 204         real_time /= 10;
 205
 206         kernel_time =
 207           ((((int64_t)kernel_ft.dwHighDateTime)<<32)|
 208            kernel_ft.dwLowDateTime) / 10;
 209
 210         user_time =
 211           ((((int64_t)user_ft.dwHighDateTime)<<32)|
 212            user_ft.dwLowDateTime) / 10;
 213
 214         msg_Dbg( p_this, "thread times: "
 215                  "real %"PRId64"m%fs, kernel %"PRId64"m%fs, user %"PRId64"m%fs",
 216                  real_time/60/1000000,
 217                  (double)((real_time%(60*1000000))/1000000.0),
 218                  kernel_time/60/1000000,
 219                  (double)((kernel_time%(60*1000000))/1000000.0),
 220                  user_time/60/1000000,
 221                  (double)((user_time%(60*1000000))/1000000.0) );
 222     }
 223     CloseHandle( hThread );
 224 #endif
 225
 226     p_priv->b_thread = false;
 227 }
 228
 229 void vlc_thread_cancel (vlc_object_t *obj)
 230 {
 231     vlc_object_internals_t *priv = vlc_internals (obj);
 232
 233     if (priv->b_thread)
 234         vlc_cancel (priv->thread_id);
 235 }
 236
 237 /*** Global locks ***/
 238
 239 void vlc_global_mutex (unsigned n, bool acquire)
 240 {
 241     static vlc_mutex_t locks[] = {
 242         VLC_STATIC_MUTEX,
 243         VLC_STATIC_MUTEX,
 244         VLC_STATIC_MUTEX,
 245     };
 246     assert (n < (sizeof (locks) / sizeof (locks[0])));
 247     vlc_mutex_t *lock = locks + n;
 248
 249     if (acquire)
 250         vlc_mutex_lock (lock);
 251     else
 252         vlc_mutex_unlock (lock);
 253
 254     /* Compile-time assertion ;-) */
 255     char enough_locks[(sizeof (locks) / sizeof (locks[0])) - VLC_MAX_MUTEX];
 256     (void) enough_locks;
 257 }