git.sesse.net Git - vlc/blob - src/misc/objects.c

   1 /*****************************************************************************
   2  * objects.c: vlc_object_t handling
   3  *****************************************************************************
   4  * Copyright (C) 2002 VideoLAN
   5  * $Id: objects.c,v 1.16 2002/08/12 09:34:15 sam Exp $
   6  *
   7  * Authors: Samuel Hocevar <sam@zoy.org>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program 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
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
  22  *****************************************************************************/
  23
  24 /*****************************************************************************
  25  * Preamble
  26  *****************************************************************************/
  27 #include <vlc/vlc.h>
  28
  29 #ifdef HAVE_STDLIB_H
  30 #   include <stdlib.h>                                          /* realloc() */
  31 #endif
  32
  33 #include "stream_control.h"
  34 #include "input_ext-intf.h"
  35 #include "input_ext-dec.h"
  36
  37 #include "video.h"
  38 #include "video_output.h"
  39
  40 #include "audio_output.h"
  41 #include "aout_internal.h"
  42
  43 #include "vlc_playlist.h"
  44 #include "interface.h"
  45
  46 /*****************************************************************************
  47  * Local prototypes
  48  *****************************************************************************/
  49 static vlc_object_t * vlc_object_find_inner( vlc_object_t *, int, int );
  50 static void vlc_object_detach_inner( vlc_object_t * );
  51 static void vlc_dumpstructure_inner( vlc_object_t *, int, char * );
  52 static int  find_index_inner( vlc_object_t *, vlc_object_t **, int );
  53 static void set_attachment_flag( vlc_object_t *, vlc_bool_t );
  54
  55 /*****************************************************************************
  56  * vlc_object_create: initialize a vlc object
  57  *****************************************************************************
  58  * This function allocates memory for a vlc object and initializes it. If
  59  * i_type is not a known value such as VLC_OBJECT_ROOT, VLC_OBJECT_VOUT and
  60  * so on, vlc_object_create will use its value for the object size.
  61  *****************************************************************************/
  62 void * __vlc_object_create( vlc_object_t *p_this, int i_type )
  63 {
  64     vlc_object_t * p_new;
  65     char *         psz_type;
  66     size_t         i_size;
  67
  68     switch( i_type )
  69     {
  70         case VLC_OBJECT_ROOT:
  71             i_size = sizeof(vlc_t);
  72             psz_type = "root";
  73             break;
  74         case VLC_OBJECT_MODULE:
  75             i_size = sizeof(module_t);
  76             psz_type = "module";
  77             break;
  78         case VLC_OBJECT_INTF:
  79             i_size = sizeof(intf_thread_t);
  80             psz_type = "interface";
  81             break;
  82         case VLC_OBJECT_PLAYLIST:
  83             i_size = sizeof(playlist_t);
  84             psz_type = "playlist";
  85             break;
  86         case VLC_OBJECT_INPUT:
  87             i_size = sizeof(input_thread_t);
  88             psz_type = "input";
  89             break;
  90         case VLC_OBJECT_DECODER:
  91             i_size = sizeof(decoder_fifo_t);
  92             psz_type = "decoder";
  93             break;
  94         case VLC_OBJECT_VOUT:
  95             i_size = sizeof(vout_thread_t);
  96             psz_type = "video output";
  97             break;
  98         case VLC_OBJECT_AOUT:
  99             i_size = sizeof(aout_instance_t);
 100             psz_type = "audio output";
 101             break;
 102         default:
 103             i_size = i_type > sizeof(vlc_object_t)
 104                    ? i_type : sizeof(vlc_object_t);
 105             i_type = VLC_OBJECT_GENERIC;
 106             psz_type = "generic";
 107             break;
 108     }
 109
 110     p_new = malloc( i_size );
 111
 112     if( !p_new )
 113     {
 114         return NULL;
 115     }
 116
 117     memset( p_new, 0, i_size );
 118
 119     p_new->i_object_type = i_type;
 120     p_new->psz_object_type = psz_type;
 121
 122     p_new->psz_object_name = NULL;
 123
 124     p_new->i_refcount = 0;
 125     p_new->b_die = VLC_FALSE;
 126     p_new->b_error = VLC_FALSE;
 127     p_new->b_dead = VLC_FALSE;
 128     p_new->b_attached = VLC_FALSE;
 129
 130     /* If i_type is root, then p_new is our own p_vlc */
 131     if( i_type == VLC_OBJECT_ROOT )
 132     {
 133         /* We are the first object ... no need to lock. */
 134         p_new->p_vlc = (vlc_t*)p_new;
 135
 136         p_new->p_vlc->i_counter = 0;
 137         p_new->i_object_id = 0;
 138
 139         p_new->p_vlc->i_objects = 1;
 140         p_new->p_vlc->pp_objects = malloc( sizeof(vlc_object_t *) );
 141         p_new->p_vlc->pp_objects[0] = p_new;
 142         p_new->b_attached = VLC_TRUE;
 143     }
 144     else
 145     {
 146         p_new->p_vlc = p_this->p_vlc;
 147
 148         vlc_mutex_lock( &p_this->p_vlc->structure_lock );
 149
 150         p_new->p_vlc->i_counter++;
 151         p_new->i_object_id = p_new->p_vlc->i_counter;
 152
 153         /* Wooohaa! If *this* fails, we're in serious trouble! Anyway it's
 154          * useless to try and recover anything if pp_objects gets smashed. */
 155         p_new->p_vlc->i_objects++;
 156         p_new->p_vlc->pp_objects =
 157                   realloc( p_new->p_vlc->pp_objects,
 158                            p_new->p_vlc->i_objects * sizeof(vlc_object_t *) );
 159         p_new->p_vlc->pp_objects[ p_new->p_vlc->i_objects - 1 ] = p_new;
 160
 161         vlc_mutex_unlock( &p_this->p_vlc->structure_lock );
 162     }
 163
 164     p_new->p_parent = NULL;
 165     p_new->pp_children = NULL;
 166     p_new->i_children = 0;
 167
 168     p_new->p_private = NULL;
 169
 170     vlc_mutex_init( p_new, &p_new->object_lock );
 171     vlc_cond_init( p_new, &p_new->object_wait );
 172
 173     return p_new;
 174 }
 175
 176 /*****************************************************************************
 177  * vlc_object_destroy: destroy a vlc object
 178  *****************************************************************************
 179  * This function destroys an object that has been previously allocated with
 180  * vlc_object_create. The object's refcount must be zero and it must not be
 181  * attached to other objects in any way.
 182  *****************************************************************************/
 183 void __vlc_object_destroy( vlc_object_t *p_this )
 184 {
 185     int i_delay = 0;
 186
 187     if( p_this->i_children )
 188     {
 189         msg_Err( p_this, "cannot delete object with children" );
 190         vlc_dumpstructure( p_this );
 191         return;
 192     }
 193
 194     if( p_this->p_parent )
 195     {
 196         msg_Err( p_this, "cannot delete object with a parent" );
 197         vlc_dumpstructure( p_this );
 198         return;
 199     }
 200
 201     while( p_this->i_refcount )
 202     {
 203         i_delay++;
 204
 205         /* Don't warn immediately ... 100ms seems OK */
 206         if( i_delay == 2 )
 207         {
 208             msg_Warn( p_this, "refcount is %i, delaying before deletion",
 209                               p_this->i_refcount );
 210         }
 211         else if( i_delay == 12 )
 212         {
 213             msg_Err( p_this, "refcount is %i, I have a bad feeling about this",
 214                              p_this->i_refcount );
 215         }
 216         else if( i_delay == 42 )
 217         {
 218             msg_Err( p_this, "we waited too long, cancelling destruction" );
 219             return;
 220         }
 221
 222         msleep( 100000 );
 223     }
 224
 225     vlc_mutex_lock( &p_this->p_vlc->structure_lock );
 226
 227     /* Wooohaa! If *this* fails, we're in serious trouble! Anyway it's
 228      * useless to try and recover anything if pp_objects gets smashed. */
 229     if( p_this->p_vlc->i_objects > 1 )
 230     {
 231         int i_index = find_index_inner( p_this, p_this->p_vlc->pp_objects,
 232                                                 p_this->p_vlc->i_objects );
 233         memmove( p_this->p_vlc->pp_objects + i_index,
 234                  p_this->p_vlc->pp_objects + i_index + 1,
 235                  p_this->p_vlc->i_objects - i_index - 1 );
 236
 237         p_this->p_vlc->pp_objects =
 238             realloc( p_this->p_vlc->pp_objects,
 239                      (p_this->p_vlc->i_objects - 1) * sizeof(vlc_object_t *) );
 240     }
 241     else
 242     {
 243         free( p_this->p_vlc->pp_objects );
 244         p_this->p_vlc->pp_objects = NULL;
 245     }
 246
 247     p_this->p_vlc->i_objects--;
 248
 249     vlc_mutex_unlock( &p_this->p_vlc->structure_lock );
 250
 251     vlc_mutex_destroy( &p_this->object_lock );
 252     vlc_cond_destroy( &p_this->object_wait );
 253
 254     free( p_this );
 255 }
 256
 257 /*****************************************************************************
 258  * find_index_inner: find the index of an object in an array of objects
 259  *****************************************************************************
 260  * This function assumes that p_this can be found in pp_objects. It will not
 261  * crash if p_this cannot be found, but will return a random value. It is your
 262  * duty to check the return value if you are not certain that the object could
 263  * be found for sure.
 264  *****************************************************************************/
 265 static int find_index_inner( vlc_object_t *p_this,
 266                              vlc_object_t **pp_objects, int i_count )
 267 {
 268     int i_middle = i_count / 2;
 269
 270     if( i_count == 0 )
 271     {
 272         return 0;
 273     }
 274
 275     if( pp_objects[i_middle] == p_this )
 276     {
 277         return i_middle;
 278     }
 279
 280     if( i_count == 1 )
 281     {
 282         return 0;
 283     }
 284
 285     /* We take advantage of the sorted array */
 286     if( pp_objects[i_middle]->i_object_id < p_this->i_object_id )
 287     {
 288         return i_middle + find_index_inner( p_this, pp_objects + i_middle,
 289                                                     i_count - i_middle );
 290     }
 291     else
 292     {
 293         return find_index_inner( p_this, pp_objects, i_middle );
 294     }
 295 }
 296
 297 /*****************************************************************************
 298  * vlc_object_find: find a typed object and increment its refcount
 299  *****************************************************************************
 300  * This function recursively looks for a given object type. i_mode can be one
 301  * of FIND_PARENT, FIND_CHILD or FIND_ANYWHERE.
 302  *****************************************************************************/
 303 void * __vlc_object_find( vlc_object_t *p_this, int i_type, int i_mode )
 304 {
 305     vlc_object_t *p_found;
 306
 307     vlc_mutex_lock( &p_this->p_vlc->structure_lock );
 308
 309     /* If we are of the requested type ourselves, don't look further */
 310     if( !(i_mode & FIND_STRICT) && p_this->i_object_type == i_type )
 311     {
 312         p_this->i_refcount++;
 313         vlc_mutex_unlock( &p_this->p_vlc->structure_lock );
 314         return p_this;
 315     }
 316
 317     /* Otherwise, recursively look for the object */
 318     if( (i_mode & 0x000f) == FIND_ANYWHERE )
 319     {
 320         p_found = vlc_object_find_inner( VLC_OBJECT(p_this->p_vlc),
 321                                          i_type,
 322                                          (i_mode & ~0x000f) | FIND_CHILD );
 323     }
 324     else
 325     {
 326         p_found = vlc_object_find_inner( p_this, i_type, i_mode );
 327     }
 328
 329     vlc_mutex_unlock( &p_this->p_vlc->structure_lock );
 330
 331     return p_found;
 332 }
 333
 334 static vlc_object_t * vlc_object_find_inner( vlc_object_t *p_this,
 335                                              int i_type, int i_mode )
 336 {
 337     int i;
 338     vlc_object_t *p_tmp;
 339
 340     switch( i_mode & 0x000f )
 341     {
 342     case FIND_PARENT:
 343         p_tmp = p_this->p_parent;
 344         if( p_tmp )
 345         {
 346             if( p_tmp->i_object_type == i_type )
 347             {
 348                 p_tmp->i_refcount++;
 349                 return p_tmp;
 350             }
 351             else
 352             {
 353                 return vlc_object_find_inner( p_tmp, i_type, i_mode );
 354             }
 355         }
 356         break;
 357
 358     case FIND_CHILD:
 359         for( i = p_this->i_children; i--; )
 360         {
 361             p_tmp = p_this->pp_children[i];
 362             if( p_tmp->i_object_type == i_type )
 363             {
 364                 p_tmp->i_refcount++;
 365                 return p_tmp;
 366             }
 367             else if( p_tmp->i_children )
 368             {
 369                 p_tmp = vlc_object_find_inner( p_tmp, i_type, i_mode );
 370                 if( p_tmp )
 371                 {
 372                     return p_tmp;
 373                 }
 374             }
 375         }
 376         break;
 377
 378     case FIND_ANYWHERE:
 379         /* Handled in vlc_object_find */
 380         break;
 381     }
 382
 383     return NULL;
 384 }
 385
 386 /*****************************************************************************
 387  * vlc_object_yield: increment an object refcount
 388  *****************************************************************************/
 389 void __vlc_object_yield( vlc_object_t *p_this )
 390 {
 391     vlc_mutex_lock( &p_this->p_vlc->structure_lock );
 392     p_this->i_refcount++;
 393     vlc_mutex_unlock( &p_this->p_vlc->structure_lock );
 394 }
 395
 396 /*****************************************************************************
 397  * vlc_object_release: decrement an object refcount
 398  *****************************************************************************/
 399 void __vlc_object_release( vlc_object_t *p_this )
 400 {
 401     vlc_mutex_lock( &p_this->p_vlc->structure_lock );
 402     p_this->i_refcount--;
 403     vlc_mutex_unlock( &p_this->p_vlc->structure_lock );
 404 }
 405
 406 /*****************************************************************************
 407  * vlc_object_attach: attach object to a parent object
 408  *****************************************************************************
 409  * This function sets p_this as a child of p_parent, and p_parent as a parent
 410  * of p_this. This link can be undone using vlc_object_detach.
 411  *****************************************************************************/
 412 void __vlc_object_attach( vlc_object_t *p_this, vlc_object_t *p_parent )
 413 {
 414     vlc_mutex_lock( &p_this->p_vlc->structure_lock );
 415
 416     /* Attach the parent to its child */
 417     p_this->p_parent = p_parent;
 418
 419     /* Attach the child to its parent */
 420     p_parent->i_children++;
 421     p_parent->pp_children = (vlc_object_t **)realloc( p_parent->pp_children,
 422                                p_parent->i_children * sizeof(vlc_object_t *) );
 423     p_parent->pp_children[p_parent->i_children - 1] = p_this;
 424
 425     /* Climb up the tree to see whether we are connected with the root */
 426     if( p_parent->b_attached )
 427     {
 428         set_attachment_flag( p_this, VLC_TRUE );
 429     }
 430
 431     vlc_mutex_unlock( &p_this->p_vlc->structure_lock );
 432 }
 433
 434 /*****************************************************************************
 435  * vlc_object_detach: detach object from its parent
 436  *****************************************************************************
 437  * This function removes all links between an object and its parent.
 438  *****************************************************************************/
 439 void __vlc_object_detach( vlc_object_t *p_this )
 440 {
 441     vlc_mutex_lock( &p_this->p_vlc->structure_lock );
 442     if( !p_this->p_parent )
 443     {
 444         msg_Err( p_this, "object is not attached" );
 445         vlc_mutex_unlock( &p_this->p_vlc->structure_lock );
 446         return;
 447     }
 448
 449     /* Climb up the tree to see whether we are connected with the root */
 450     if( p_this->p_parent->b_attached )
 451     {
 452         set_attachment_flag( p_this, VLC_FALSE );
 453     }
 454
 455     vlc_object_detach_inner( p_this );
 456     vlc_mutex_unlock( &p_this->p_vlc->structure_lock );
 457 }
 458
 459 static void vlc_object_detach_inner( vlc_object_t *p_this )
 460 {
 461     vlc_object_t *p_parent = p_this->p_parent;
 462     int i_index, i;
 463
 464     /* Remove p_this's parent */
 465     p_this->p_parent = NULL;
 466
 467     /* Remove all of p_parent's children which are p_this */
 468     for( i_index = p_parent->i_children ; i_index-- ; )
 469     {
 470         if( p_parent->pp_children[i_index] == p_this )
 471         {
 472             p_parent->i_children--;
 473             for( i = i_index ; i < p_parent->i_children ; i++ )
 474             {
 475                 p_parent->pp_children[i] = p_parent->pp_children[i+1];
 476             }
 477         }
 478     }
 479
 480     if( p_parent->i_children )
 481     {
 482         p_parent->pp_children = (vlc_object_t **)realloc( p_parent->pp_children,
 483                                p_parent->i_children * sizeof(vlc_object_t *) );
 484     }
 485     else
 486     {
 487         free( p_parent->pp_children );
 488         p_parent->pp_children = NULL;
 489     }
 490 }
 491
 492 /*****************************************************************************
 493  * set_attachment_flag: recursively set the b_attached flag of a subtree.
 494  *****************************************************************************
 495  * This function is used by the attach and detach functions to propagate
 496  * the b_attached flag in a subtree.
 497  *****************************************************************************/
 498 static void set_attachment_flag( vlc_object_t *p_this, vlc_bool_t b_attached )
 499 {
 500     int i_index;
 501
 502     for( i_index = p_this->i_children ; i_index-- ; )
 503     {
 504         set_attachment_flag( p_this->pp_children[i_index], b_attached );
 505     }
 506
 507     p_this->b_attached = b_attached;
 508 }
 509
 510 /*****************************************************************************
 511  * vlc_dumpstructure: print the current vlc structure
 512  *****************************************************************************
 513  * This function prints an ASCII tree showing the connections between vlc
 514  * objects, and additional information such as their refcount, thread ID,
 515  * address, etc.
 516  *****************************************************************************/
 517 void __vlc_dumpstructure( vlc_object_t *p_this )
 518 {
 519     char psz_foo[2 * MAX_DUMPSTRUCTURE_DEPTH + 1];
 520
 521     vlc_mutex_lock( &p_this->p_vlc->structure_lock );
 522     psz_foo[0] = '|';
 523     vlc_dumpstructure_inner( p_this, 0, psz_foo );
 524     vlc_mutex_unlock( &p_this->p_vlc->structure_lock );
 525 }
 526
 527 static void vlc_dumpstructure_inner( vlc_object_t *p_this,
 528                                      int i_level, char *psz_foo )
 529 {
 530     int i;
 531     char i_back = psz_foo[i_level];
 532     char psz_children[20], psz_refcount[20], psz_thread[20], psz_name[50];
 533
 534     psz_name[0] = '\0';
 535     if( p_this->psz_object_name )
 536     {
 537         snprintf( psz_name, 50, " \"%s\"", p_this->psz_object_name );
 538         psz_name[48] = '\"';
 539         psz_name[49] = '\0';
 540     }
 541
 542     psz_children[0] = '\0';
 543     switch( p_this->i_children )
 544     {
 545         case 0:
 546             break;
 547         case 1:
 548             strcpy( psz_children, ", 1 child" );
 549             break;
 550         default:
 551             snprintf( psz_children, 20,
 552                       ", %i children", p_this->i_children );
 553             psz_children[19] = '\0';
 554             break;
 555     }
 556
 557     psz_refcount[0] = '\0';
 558     if( p_this->i_refcount )
 559     {
 560         snprintf( psz_refcount, 20, ", refcount %i", p_this->i_refcount );
 561         psz_refcount[19] = '\0';
 562     }
 563
 564     psz_thread[0] = '\0';
 565     if( p_this->b_thread )
 566     {
 567         snprintf( psz_thread, 20, " (thread %d)", (int)p_this->thread_id );
 568         psz_thread[19] = '\0';
 569     }
 570
 571     psz_foo[i_level] = '\0';
 572     msg_Info( p_this, "%so %s %p%s%s%s%s", psz_foo, p_this->psz_object_type,
 573               p_this, psz_name, psz_thread, psz_refcount, psz_children );
 574     psz_foo[i_level] = i_back;
 575
 576     if( i_level / 2 >= MAX_DUMPSTRUCTURE_DEPTH )
 577     {
 578         msg_Warn( p_this, "structure tree is too deep" );
 579         return;
 580     }
 581
 582     for( i = 0 ; i < p_this->i_children ; i++ )
 583     {
 584         if( i_level )
 585         {
 586             psz_foo[i_level-1] = ' ';
 587
 588             if( psz_foo[i_level-2] == '`' )
 589             {
 590                 psz_foo[i_level-2] = ' ';
 591             }
 592         }
 593
 594         if( i == p_this->i_children - 1 )
 595         {
 596             psz_foo[i_level] = '`';
 597         }
 598         else
 599         {
 600             psz_foo[i_level] = '|';
 601         }
 602
 603         psz_foo[i_level+1] = '-';
 604         psz_foo[i_level+2] = '\0';
 605
 606         vlc_dumpstructure_inner( p_this->pp_children[i], i_level + 2, psz_foo );
 607     }
 608 }
 609