git.sesse.net Git - vlc/blob - src/playlist/engine.c

   1 /*****************************************************************************
   2  * engine.c : Run the playlist and handle its control
   3  *****************************************************************************
   4  * Copyright (C) 1999-2007 the VideoLAN team
   5  * $Id$
   6  *
   7  * Authors: Samuel Hocevar <sam@zoy.org>
   8  *          Clément Stenac <zorglub@videolan.org>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  23  *****************************************************************************/
  24
  25 #ifdef HAVE_CONFIG_H
  26 # include "config.h"
  27 #endif
  28
  29 #include <assert.h>
  30 #include <vlc_common.h>
  31 #include <vlc_sout.h>
  32 #include <vlc_playlist.h>
  33 #include <vlc_interface.h>
  34 #include "playlist_internal.h"
  35 #include "stream_output/stream_output.h" /* sout_DeleteInstance */
  36
  37 /*****************************************************************************
  38  * Local prototypes
  39  *****************************************************************************/
  40 static void VariablesInit( playlist_t *p_playlist );
  41 static void playlist_Destructor( vlc_object_t * p_this );
  42
  43 static int RandomCallback( vlc_object_t *p_this, char const *psz_cmd,
  44                            vlc_value_t oldval, vlc_value_t newval, void *a )
  45 {
  46     (void)psz_cmd; (void)oldval; (void)newval; (void)a;
  47
  48     ((playlist_t*)p_this)->b_reset_currently_playing = true;
  49     playlist_Signal( ((playlist_t*)p_this) );
  50     return VLC_SUCCESS;
  51 }
  52
  53 /**
  54  * Create playlist
  55  *
  56  * Create a playlist structure.
  57  * \param p_parent the vlc object that is to be the parent of this playlist
  58  * \return a pointer to the created playlist, or NULL on error
  59  */
  60 playlist_t * playlist_Create( vlc_object_t *p_parent )
  61 {
  62     static const char playlist_name[] = "playlist";
  63     playlist_t *p_playlist;
  64     bool b_save;
  65
  66     /* Allocate structure */
  67     p_playlist = vlc_custom_create( p_parent, sizeof( *p_playlist ),
  68                                     VLC_OBJECT_PLAYLIST, playlist_name );
  69     if( !p_playlist )
  70     {
  71         msg_Err( p_parent, "out of memory" );
  72         return NULL;
  73     }
  74
  75     TAB_INIT( p_playlist->i_sds, p_playlist->pp_sds );
  76
  77     libvlc_priv(p_parent->p_libvlc)->p_playlist = p_playlist;
  78
  79     VariablesInit( p_playlist );
  80
  81     /* Initialise data structures */
  82     vlc_mutex_init( &p_playlist->gc_lock );
  83     p_playlist->i_last_playlist_id = 0;
  84     p_playlist->p_input = NULL;
  85
  86     p_playlist->gc_date = 0;
  87     p_playlist->b_cant_sleep = false;
  88
  89     ARRAY_INIT( p_playlist->items );
  90     ARRAY_INIT( p_playlist->all_items );
  91     ARRAY_INIT( p_playlist->current );
  92
  93     p_playlist->i_current_index = 0;
  94     p_playlist->b_reset_currently_playing = true;
  95     p_playlist->last_rebuild_date = 0;
  96
  97     p_playlist->b_tree = var_CreateGetBool( p_playlist, "playlist-tree" );
  98
  99     p_playlist->b_doing_ml = false;
 100
 101     p_playlist->b_auto_preparse =
 102                         var_CreateGetBool( p_playlist, "auto-preparse" ) ;
 103
 104     p_playlist->p_root_category = playlist_NodeCreate( p_playlist, NULL, NULL,
 105                                     0, NULL );
 106     p_playlist->p_root_onelevel = playlist_NodeCreate( p_playlist, NULL, NULL,
 107                                     0, p_playlist->p_root_category->p_input );
 108
 109     if( !p_playlist->p_root_category || !p_playlist->p_root_onelevel )
 110         return NULL;
 111
 112     /* Create playlist and media library */
 113     playlist_NodesPairCreate( p_playlist, _( "Playlist" ),
 114                             &p_playlist->p_local_category,
 115                             &p_playlist->p_local_onelevel, false );
 116
 117     p_playlist->p_local_category->i_flags |= PLAYLIST_RO_FLAG;
 118     p_playlist->p_local_onelevel->i_flags |= PLAYLIST_RO_FLAG;
 119
 120     if( !p_playlist->p_local_category || !p_playlist->p_local_onelevel ||
 121         !p_playlist->p_local_category->p_input ||
 122         !p_playlist->p_local_onelevel->p_input )
 123         return NULL;
 124
 125     if( config_GetInt( p_playlist, "media-library") )
 126     {
 127         playlist_NodesPairCreate( p_playlist, _( "Media Library" ),
 128                             &p_playlist->p_ml_category,
 129                             &p_playlist->p_ml_onelevel, false );
 130
 131         if(!p_playlist->p_ml_category || !p_playlist->p_ml_onelevel)
 132             return NULL;
 133
 134         p_playlist->p_ml_category->i_flags |= PLAYLIST_RO_FLAG;
 135         p_playlist->p_ml_onelevel->i_flags |= PLAYLIST_RO_FLAG;
 136     }
 137     else
 138     {
 139         p_playlist->p_ml_category = p_playlist->p_ml_onelevel = NULL;
 140     }
 141
 142     /* Initial status */
 143     p_playlist->status.p_item = NULL;
 144     p_playlist->status.p_node = p_playlist->p_local_onelevel;
 145     p_playlist->request.b_request = false;
 146     p_playlist->status.i_status = PLAYLIST_STOPPED;
 147
 148     p_playlist->i_sort = SORT_ID;
 149     p_playlist->i_order = ORDER_NORMAL;
 150
 151
 152     b_save = p_playlist->b_auto_preparse;
 153     p_playlist->b_auto_preparse = false;
 154     playlist_MLLoad( p_playlist );
 155     p_playlist->b_auto_preparse = true;
 156
 157     vlc_object_set_destructor( p_playlist, playlist_Destructor );
 158
 159     return p_playlist;
 160 }
 161
 162 /**
 163  * Destroy playlist
 164  *
 165  * Destroy a playlist structure.
 166  * \param p_playlist the playlist object
 167  * \return nothing
 168  */
 169
 170 static void playlist_Destructor( vlc_object_t * p_this )
 171 {
 172     playlist_t * p_playlist = (playlist_t *)p_this;
 173
 174     if( p_playlist->p_preparse )
 175         vlc_object_release( p_playlist->p_preparse );
 176
 177     if( p_playlist->p_fetcher )
 178         vlc_object_release( p_playlist->p_fetcher );
 179 #ifndef NDEBUG
 180     libvlc_priv (p_this->p_libvlc)->p_playlist = NULL; /* pl_Yield() will fail */
 181 #endif
 182 }
 183
 184 /* Destroy remaining objects */
 185 static void ObjectGarbageCollector( playlist_t *p_playlist, bool b_force )
 186 {
 187     vlc_object_t *p_obj;
 188
 189     if( !b_force )
 190     {
 191         if( mdate() - p_playlist->gc_date < 1000000 )
 192         {
 193             p_playlist->b_cant_sleep = true;
 194             return;
 195         }
 196         else if( p_playlist->gc_date == 0 )
 197             return;
 198     }
 199
 200     vlc_mutex_lock( &p_playlist->gc_lock );
 201     p_playlist->b_cant_sleep = false;
 202     vlc_mutex_unlock( &p_playlist->gc_lock );
 203 }
 204
 205 /**
 206  * Main loop
 207  *
 208  * Main loop for the playlist
 209  * \param p_playlist the playlist object
 210  * \return nothing
 211  */
 212 void playlist_MainLoop( playlist_t *p_playlist )
 213 {
 214     playlist_item_t *p_item = NULL;
 215     bool b_playexit = var_GetBool( p_playlist, "play-and-exit" );
 216     PL_LOCK;
 217
 218     if( p_playlist->b_reset_currently_playing &&
 219         mdate() - p_playlist->last_rebuild_date > 30000 ) // 30 ms
 220     {
 221         ResetCurrentlyPlaying( p_playlist, var_GetBool( p_playlist, "random" ),
 222                              p_playlist->status.p_item );
 223         p_playlist->last_rebuild_date = mdate();
 224     }
 225
 226 check_input:
 227     /* If there is an input, check that it doesn't need to die. */
 228     if( p_playlist->p_input )
 229     {
 230         if( p_playlist->request.b_request && !p_playlist->p_input->b_die )
 231         {
 232             PL_DEBUG( "incoming request - stopping current input" );
 233             input_StopThread( p_playlist->p_input );
 234         }
 235
 236         /* This input is dead. Remove it ! */
 237         if( p_playlist->p_input->b_dead )
 238         {
 239             int i_activity;
 240             input_thread_t *p_input;
 241             sout_instance_t **pp_sout =
 242                 &libvlc_priv(p_playlist->p_libvlc)->p_sout;
 243
 244             PL_DEBUG( "dead input" );
 245
 246             p_input = p_playlist->p_input;
 247             p_playlist->p_input = NULL;
 248             assert( *pp_sout == NULL );
 249             if( var_CreateGetBool( p_input, "sout-keep" ) )
 250                 *pp_sout = input_DetachSout( p_input );
 251
 252             /* Release the playlist lock, because we may get stuck
 253              * in vlc_object_release() for some time. */
 254             PL_UNLOCK;
 255
 256             /* Destroy input */
 257             vlc_object_release( p_input );
 258
 259             PL_LOCK;
 260
 261             p_playlist->gc_date = mdate();
 262             p_playlist->b_cant_sleep = true;
 263
 264             if( p_playlist->status.p_item->i_flags
 265                 & PLAYLIST_REMOVE_FLAG )
 266             {
 267                  PL_DEBUG( "%s was marked for deletion, deleting",
 268                                  PLI_NAME( p_playlist->status.p_item  ) );
 269                  playlist_ItemDelete( p_playlist->status.p_item );
 270                  if( p_playlist->request.p_item == p_playlist->status.p_item )
 271                      p_playlist->request.p_item = NULL;
 272                  p_playlist->status.p_item = NULL;
 273             }
 274
 275             i_activity= var_GetInteger( p_playlist, "activity" );
 276             var_SetInteger( p_playlist, "activity", i_activity -
 277                             DEFAULT_INPUT_ACTIVITY );
 278             goto check_input;
 279         }
 280         /* This input is dying, let it do */
 281         else if( p_playlist->p_input->b_die )
 282         {
 283             PL_DEBUG( "dying input" );
 284             PL_UNLOCK;
 285             msleep( INTF_IDLE_SLEEP );
 286             PL_LOCK;
 287             goto check_input;
 288         }
 289         /* This input has finished, ask it to die ! */
 290         else if( p_playlist->p_input->b_error
 291                   || p_playlist->p_input->b_eof )
 292         {
 293             PL_DEBUG( "finished input" );
 294             input_StopThread( p_playlist->p_input );
 295             /* No need to wait here, we'll wait in the p_input->b_die case */
 296             goto check_input;
 297         }
 298         else if( p_playlist->p_input->i_state != INIT_S )
 299         {
 300             PL_UNLOCK;
 301             ObjectGarbageCollector( p_playlist, false );
 302             PL_LOCK;
 303         }
 304     }
 305     else
 306     {
 307         /* No input. Several cases
 308          *  - No request, running status -> start new item
 309          *  - No request, stopped status -> collect garbage
 310          *  - Request, running requested -> start new item
 311          *  - Request, stopped requested -> collect garbage
 312         */
 313         int i_status = p_playlist->request.b_request ?
 314             p_playlist->request.i_status : p_playlist->status.i_status;
 315         if( i_status != PLAYLIST_STOPPED )
 316         {
 317             msg_Dbg( p_playlist, "starting new item" );
 318             p_item = playlist_NextItem( p_playlist );
 319
 320             if( p_item == NULL )
 321             {
 322                 msg_Dbg( p_playlist, "nothing to play" );
 323                 p_playlist->status.i_status = PLAYLIST_STOPPED;
 324                 PL_UNLOCK;
 325
 326                 if( b_playexit == true )
 327                 {
 328                     msg_Info( p_playlist, "end of playlist, exiting" );
 329                     vlc_object_kill( p_playlist->p_libvlc );
 330                 }
 331                 ObjectGarbageCollector( p_playlist, true );
 332                 return;
 333              }
 334              playlist_PlayItem( p_playlist, p_item );
 335          }
 336          else
 337          {
 338             const bool b_gc_forced = p_playlist->status.i_status != PLAYLIST_STOPPED;
 339
 340             p_playlist->status.i_status = PLAYLIST_STOPPED;
 341             if( p_playlist->status.p_item &&
 342                 p_playlist->status.p_item->i_flags & PLAYLIST_REMOVE_FLAG )
 343             {
 344                 PL_DEBUG( "deleting item marked for deletion" );
 345                 playlist_ItemDelete( p_playlist->status.p_item );
 346                 p_playlist->status.p_item = NULL;
 347             }
 348
 349             /* Collect garbage */
 350             PL_UNLOCK;
 351             ObjectGarbageCollector( p_playlist, b_gc_forced );
 352             PL_LOCK;
 353         }
 354     }
 355     PL_UNLOCK;
 356 }
 357
 358 /**
 359  * Last loop
 360  *
 361  * The playlist is dying so do the last loop
 362  * \param p_playlist the playlist object
 363  * \return nothing
 364 */
 365 void playlist_LastLoop( playlist_t *p_playlist )
 366 {
 367     vlc_object_t *p_obj;
 368
 369     /* If there is an input, kill it */
 370     while( 1 )
 371     {
 372         PL_LOCK;
 373         if( p_playlist->p_input == NULL )
 374         {
 375             PL_UNLOCK;
 376             break;
 377         }
 378
 379         if( p_playlist->p_input->b_dead )
 380         {
 381             input_thread_t *p_input;
 382
 383             /* Unlink current input */
 384             p_input = p_playlist->p_input;
 385             p_playlist->p_input = NULL;
 386             PL_UNLOCK;
 387
 388             /* sout-keep: no need to anything here.
 389              * The last input will destroy its sout, if any, by itself */
 390
 391             /* Destroy input */
 392             vlc_object_release( p_input );
 393             continue;
 394         }
 395         else if( p_playlist->p_input->b_die )
 396         {
 397             /* This input is dying, leave it alone */
 398             ;
 399         }
 400         else if( p_playlist->p_input->b_error || p_playlist->p_input->b_eof )
 401         {
 402             input_StopThread( p_playlist->p_input );
 403             PL_UNLOCK;
 404             continue;
 405         }
 406         else
 407         {
 408             p_playlist->p_input->b_eof = 1;
 409         }
 410         PL_UNLOCK;
 411
 412         msleep( INTF_IDLE_SLEEP );
 413     }
 414
 415 #ifdef ENABLE_SOUT
 416     /* close the remaining sout-keep (if there was no input atm) */
 417     sout_instance_t *p_sout = libvlc_priv (p_playlist->p_libvlc)->p_sout;
 418     if (p_sout)
 419         sout_DeleteInstance( p_sout );
 420 #endif
 421
 422     /* Core should have terminated all SDs before the playlist */
 423     assert( p_playlist->i_sds == 0 );
 424     playlist_MLDump( p_playlist );
 425
 426     PL_LOCK;
 427     FOREACH_ARRAY( playlist_item_t *p_del, p_playlist->all_items )
 428         free( p_del->pp_children );
 429         vlc_gc_decref( p_del->p_input );
 430         free( p_del );
 431     FOREACH_END();
 432     ARRAY_RESET( p_playlist->all_items );
 433
 434     ARRAY_RESET( p_playlist->items );
 435     ARRAY_RESET( p_playlist->current );
 436
 437     PL_UNLOCK;
 438 }
 439
 440 /**
 441  * Preparse loop
 442  *
 443  * Main loop for preparser queue
 444  * \param p_obj items to preparse
 445  * \return nothing
 446  */
 447 void playlist_PreparseLoop( playlist_preparse_t *p_obj )
 448 {
 449     playlist_t *p_playlist = (playlist_t *)p_obj->p_parent;
 450     input_item_t *p_current;
 451     int i_activity;
 452
 453     vlc_object_lock( p_obj );
 454
 455     while( vlc_object_alive( p_obj ) )
 456     {
 457         if( p_obj->i_waiting == 0 )
 458         {
 459             vlc_object_wait( p_obj );
 460             continue;
 461         }
 462
 463         p_current = p_obj->pp_waiting[0];
 464         REMOVE_ELEM( p_obj->pp_waiting, p_obj->i_waiting, 0 );
 465         vlc_object_unlock( p_obj );
 466
 467         PL_LOCK;
 468         if( p_current )
 469         {
 470             if( p_current->i_type == ITEM_TYPE_FILE )
 471             {
 472                 stats_TimerStart( p_playlist, "Preparse run",
 473                                   STATS_TIMER_PREPARSE );
 474                 /* Do not preparse if it is already done (like by playing it) */
 475                 if( !input_item_IsPreparsed( p_current ) )
 476                 {
 477                     PL_UNLOCK;
 478                     input_Preparse( p_playlist, p_current );
 479                     PL_LOCK;
 480                 }
 481                 stats_TimerStop( p_playlist, STATS_TIMER_PREPARSE );
 482                 PL_UNLOCK;
 483                 input_item_SetPreparsed( p_current, true );
 484                 var_SetInteger( p_playlist, "item-change", p_current->i_id );
 485                 PL_LOCK;
 486             }
 487             /* If we haven't retrieved enough meta, add to secondary queue
 488              * which will run the "meta fetchers".
 489              * This only checks for meta, not for art
 490              * \todo don't do this for things we won't get meta for, like vids
 491              */
 492             char *psz_arturl = input_item_GetArtURL( p_current );
 493             char *psz_name = input_item_GetName( p_current );
 494             if( p_playlist->p_fetcher->i_art_policy == ALBUM_ART_ALL &&
 495                         ( !psz_arturl || strncmp( psz_arturl, "file://", 7 ) ) )
 496             {
 497                 PL_DEBUG("meta ok for %s, need to fetch art", psz_name );
 498                 vlc_object_lock( p_playlist->p_fetcher );
 499                 INSERT_ELEM( p_playlist->p_fetcher->pp_waiting,
 500                              p_playlist->p_fetcher->i_waiting,
 501                              p_playlist->p_fetcher->i_waiting, p_current);
 502                 vlc_object_signal_unlocked( p_playlist->p_fetcher );
 503                 vlc_object_unlock( p_playlist->p_fetcher );
 504             }
 505             else
 506             {
 507                 PL_DEBUG( "no fetch required for %s (art currently %s)",
 508                           psz_name, psz_arturl );
 509                 vlc_gc_decref( p_current );
 510             }
 511             free( psz_name );
 512             free( psz_arturl );
 513             PL_UNLOCK;
 514         }
 515         else
 516             PL_UNLOCK;
 517
 518         vlc_object_lock( p_obj );
 519         i_activity = var_GetInteger( p_playlist, "activity" );
 520         if( i_activity < 0 ) i_activity = 0;
 521         vlc_object_unlock( p_obj );
 522         /* Sleep at least 1ms */
 523         msleep( (i_activity+1) * 1000 );
 524         vlc_object_lock( p_obj );
 525     }
 526     vlc_object_unlock( p_obj );
 527 }
 528
 529 /**
 530  * Fetcher loop
 531  *
 532  * Main loop for secondary preparser queue
 533  * \param p_obj items to preparse
 534  * \return nothing
 535  */
 536 void playlist_FetcherLoop( playlist_fetcher_t *p_obj )
 537 {
 538     playlist_t *p_playlist = (playlist_t *)p_obj->p_parent;
 539     input_item_t *p_item;
 540     int i_activity;
 541
 542     vlc_mutex_lock( &p_obj->object_lock );
 543
 544     while( vlc_object_alive( p_obj ) )
 545     {
 546         if( p_obj->i_waiting == 0 )
 547         {
 548             vlc_object_wait( p_obj );
 549             continue;
 550         }
 551
 552         p_item = p_obj->pp_waiting[0];
 553         REMOVE_ELEM( p_obj->pp_waiting, p_obj->i_waiting, 0 );
 554         vlc_mutex_unlock( &p_obj->object_lock );
 555         if( p_item )
 556         {
 557             int i_ret;
 558
 559             /* Check if it is not yet preparsed and if so wait for it (at most 0.5s)
 560              * (This can happen if we fetch art on play)
 561              * FIXME this doesn't work if we need to fetch meta before art ... */
 562             for( i_ret = 0; i_ret < 10 && !input_item_IsPreparsed( p_item ); i_ret++ )
 563             {
 564                 bool b_break;
 565                 PL_LOCK;
 566                 b_break = ( !p_playlist->p_input || input_GetItem(p_playlist->p_input) != p_item  ||
 567                             p_playlist->p_input->b_die || p_playlist->p_input->b_eof || p_playlist->p_input->b_error );
 568                 PL_UNLOCK;
 569                 if( b_break )
 570                     break;
 571                 msleep( 50000 );
 572             }
 573
 574             i_ret = input_ArtFind( p_playlist, p_item );
 575             if( i_ret == 1 )
 576             {
 577                 PL_DEBUG( "downloading art for %s", p_item->psz_name );
 578                 if( input_DownloadAndCacheArt( p_playlist, p_item ) )
 579                     input_item_SetArtNotFound( p_item, true );
 580                 else {
 581                     input_item_SetArtFetched( p_item, true );
 582                     var_SetInteger( p_playlist, "item-change",
 583                                     p_item->i_id );
 584                 }
 585             }
 586             else if( i_ret == 0 ) /* Was in cache */
 587             {
 588                 PL_DEBUG( "found art for %s in cache", p_item->psz_name );
 589                 input_item_SetArtFetched( p_item, true );
 590                 var_SetInteger( p_playlist, "item-change", p_item->i_id );
 591             }
 592             else
 593             {
 594                 PL_DEBUG( "art not found for %s", p_item->psz_name );
 595                 input_item_SetArtNotFound( p_item, true );
 596             }
 597             vlc_gc_decref( p_item );
 598         }
 599         vlc_object_lock( p_obj );
 600         i_activity = var_GetInteger( p_playlist, "activity" );
 601         if( i_activity < 0 ) i_activity = 0;
 602         vlc_object_unlock( p_obj );
 603         /* Sleep at least 1ms */
 604         msleep( (i_activity+1) * 1000 );
 605         vlc_mutex_lock( &p_obj->object_lock );
 606     }
 607     vlc_mutex_unlock( &p_obj->object_lock );
 608 }
 609
 610 static void VariablesInit( playlist_t *p_playlist )
 611 {
 612     vlc_value_t val;
 613     /* These variables control updates */
 614     var_Create( p_playlist, "intf-change", VLC_VAR_BOOL );
 615     val.b_bool = true;
 616     var_Set( p_playlist, "intf-change", val );
 617
 618     var_Create( p_playlist, "item-change", VLC_VAR_INTEGER );
 619     val.i_int = -1;
 620     var_Set( p_playlist, "item-change", val );
 621
 622     var_Create( p_playlist, "item-deleted", VLC_VAR_INTEGER );
 623     val.i_int = -1;
 624     var_Set( p_playlist, "item-deleted", val );
 625
 626     var_Create( p_playlist, "item-append", VLC_VAR_ADDRESS );
 627
 628     var_Create( p_playlist, "playlist-current", VLC_VAR_INTEGER );
 629     val.i_int = -1;
 630     var_Set( p_playlist, "playlist-current", val );
 631
 632     var_Create( p_playlist, "intf-popupmenu", VLC_VAR_BOOL );
 633
 634     var_Create( p_playlist, "activity", VLC_VAR_INTEGER );
 635     var_SetInteger( p_playlist, "activity", 0 );
 636
 637     /* Variables to control playback */
 638     var_CreateGetBool( p_playlist, "play-and-stop" );
 639     var_CreateGetBool( p_playlist, "play-and-exit" );
 640     var_CreateGetBool( p_playlist, "random" );
 641     var_CreateGetBool( p_playlist, "repeat" );
 642     var_CreateGetBool( p_playlist, "loop" );
 643
 644     var_AddCallback( p_playlist, "random", RandomCallback, NULL );
 645 }