objects.c

VLC Player Source Code

/*****************************************************************************
 * objects.c: vlc_object_t handling
 *****************************************************************************
 * Copyright (C) 2004-2008 the VideoLAN team
 *
 * Authors: Samuel Hocevar <[e-mail]>
 *
 * 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 contains the functions to handle the vlc_object_t type
 */


/*****************************************************************************
 * Preamble
 *****************************************************************************/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include <vlc_common.h>

#include "../libvlc.h"
#include <vlc_vout.h>
#include <vlc_aout.h>
#include "audio_output/aout_internal.h"

#include <vlc_access.h>
#include <vlc_demux.h>
#include <vlc_stream.h>

#include <vlc_sout.h>
#include "stream_output/stream_output.h"

#include "vlc_interface.h"
#include "vlc_codec.h"
#include "vlc_filter.h"

#include "variables.h"
#ifndef WIN32
# include <unistd.h>
#else
# include <io.h>
# include <fcntl.h>
# include <errno.h> /* ENOSYS */
#endif
#include <assert.h>

/*****************************************************************************
 * Local prototypes
 *****************************************************************************/
static int  DumpCommand( vlc_object_t *, char const *,
                         vlc_value_t, vlc_value_t, void * );

static vlc_object_t * FindObject    ( vlc_object_t *, int, int );
static vlc_object_t * FindObjectName( vlc_object_t *, const char *, int );
static void           PrintObject   ( vlc_object_t *, const char * );
static void           DumpStructure ( vlc_object_t *, int, char * );

static vlc_list_t   * NewList       ( int );
static void           ListReplace   ( vlc_list_t *, vlc_object_t *, int );
/*static void           ListAppend    ( vlc_list_t *, vlc_object_t * );*/
static int            CountChildren ( vlc_object_t *, int );
static void           ListChildren  ( vlc_list_t *, vlc_object_t *, int );

static void vlc_object_destroy( vlc_object_t *p_this );
static void vlc_object_detach_unlocked (vlc_object_t *p_this);

#ifdef LIBVLC_REFCHECK
static vlc_threadvar_t held_objects;
typedef struct held_list_t
{
    struct held_list_t *next;
    vlc_object_t *obj;
} held_list_t;
static void held_objects_destroy (void *);
#endif

/*****************************************************************************
 * Local structure lock
 *****************************************************************************/
static vlc_mutex_t structure_lock;
static unsigned    object_counter = 0;

void *__vlc_custom_create( vlc_object_t *p_this, size_t i_size,
                           int i_type, const char *psz_type )
{
    vlc_object_t *p_new;
    vlc_object_internals_t *p_priv;

    /* NOTE:
     * VLC objects are laid out as follow:
     * - first the LibVLC-private per-object data,
     * - then VLC_COMMON members from vlc_object_t,
     * - finally, the type-specific data (if any).
     *
     * This function initializes the LibVLC and common data,
     * and zeroes the rest.
     */
    p_priv = calloc( 1, sizeof( *p_priv ) + i_size );
    if( p_priv == NULL )
        return NULL;

    assert (i_size >= sizeof (vlc_object_t));
    p_new = (vlc_object_t *)(p_priv + 1);

    p_new->i_object_type = i_type;
    p_new->psz_object_type = psz_type;
    p_new->psz_object_name = NULL;

    p_new->b_die = false;
    p_new->b_error = false;
    p_new->b_dead = false;
    p_new->b_force = false;

    p_new->psz_header = NULL;

    if (p_this)
        p_new->i_flags = p_this->i_flags
            & (OBJECT_FLAGS_NODBG|OBJECT_FLAGS_QUIET|OBJECT_FLAGS_NOINTERACT);

    p_priv->p_vars = calloc( sizeof( variable_t ), 16 );

    if( !p_priv->p_vars )
    {
        free( p_priv );
        return NULL;
    }

    libvlc_global_data_t *p_libvlc_global;
    if( p_this == NULL )
    {
        /* Only the global root object is created out of the blue */
        p_libvlc_global = (libvlc_global_data_t *)p_new;
        p_new->p_libvlc = NULL;

        object_counter = 0; /* reset */
        p_priv->next = p_priv->prev = p_new;
        vlc_mutex_init( &structure_lock );
#ifdef LIBVLC_REFCHECK
        /* TODO: use the destruction callback to track ref leaks */
        vlc_threadvar_create( &held_objects, held_objects_destroy );
#endif
    }
    else
    {
        p_libvlc_global = vlc_global();
        if( i_type == VLC_OBJECT_LIBVLC )
            p_new->p_libvlc = (libvlc_int_t*)p_new;
        else
            p_new->p_libvlc = p_this->p_libvlc;
    }

    vlc_spin_init( &p_priv->ref_spin );
    p_priv->i_refcount = 1;
    p_priv->pf_destructor = NULL;
    p_priv->b_thread = false;
    p_new->p_parent = NULL;
    p_priv->pp_children = NULL;
    p_priv->i_children = 0;

    p_new->p_private = NULL;

    /* Initialize mutexes and condvars */
    vlc_mutex_init( &p_priv->lock );
    vlc_cond_init( p_new, &p_priv->wait );
    vlc_mutex_init( &p_priv->var_lock );
    vlc_spin_init( &p_priv->spin );
    p_priv->pipes[0] = p_priv->pipes[1] = -1;

    p_priv->next = VLC_OBJECT (p_libvlc_global);
#if !defined (LIBVLC_REFCHECK)
    /* ... */
#elif defined (LIBVLC_USE_PTHREAD)
    p_priv->creator_id = pthread_self ();
#elif defined (WIN32)
    p_priv->creator_id = GetCurrentThreadId ();
#endif
    vlc_mutex_lock( &structure_lock );
    p_priv->prev = vlc_internals (p_libvlc_global)->prev;
    vlc_internals (p_libvlc_global)->prev = p_new;
    vlc_internals (p_priv->prev)->next = p_new;
    p_new->i_object_id = object_counter++; /* fetch THEN increment */
    vlc_mutex_unlock( &structure_lock );

    if( i_type == VLC_OBJECT_LIBVLC )
    {
        var_Create( p_new, "list", VLC_VAR_STRING | VLC_VAR_ISCOMMAND );
        var_AddCallback( p_new, "list", DumpCommand, NULL );
        var_Create( p_new, "tree", VLC_VAR_STRING | VLC_VAR_ISCOMMAND );
        var_AddCallback( p_new, "tree", DumpCommand, NULL );
        var_Create( p_new, "vars", VLC_VAR_STRING | VLC_VAR_ISCOMMAND );
        var_AddCallback( p_new, "vars", DumpCommand, NULL );
    }

    return p_new;
}


/**
 * Allocates and initializes a vlc object.
 *
 * @param i_type known object type (all of them are negative integer values),
 *               or object byte size (always positive).
 *
 * @return the new object, or NULL on error.
 */
void * __vlc_object_create( vlc_object_t *p_this, int i_type )
{
    const char   * psz_type;
    size_t         i_size;

    switch( i_type )
    {
        case VLC_OBJECT_INTF:
            i_size = sizeof(intf_thread_t);
            psz_type = "interface";
            break;
        case VLC_OBJECT_DECODER:
            i_size = sizeof(decoder_t);
            psz_type = "decoder";
            break;
        case VLC_OBJECT_PACKETIZER:
            i_size = sizeof(decoder_t);
            psz_type = "packetizer";
            break;
        case VLC_OBJECT_ENCODER:
            i_size = sizeof(encoder_t);
            psz_type = "encoder";
            break;
        case VLC_OBJECT_AOUT:
            i_size = sizeof(aout_instance_t);
            psz_type = "audio output";
            break;
        case VLC_OBJECT_OPENGL:
            i_size = sizeof( vout_thread_t );
            psz_type = "opengl";
            break;
        case VLC_OBJECT_ANNOUNCE:
            i_size = sizeof( announce_handler_t );
            psz_type = "announce";
            break;
        default:
            assert( i_type > 0 ); /* unknown type?! */
            i_size = i_type;
            i_type = VLC_OBJECT_GENERIC;
            psz_type = "generic";
            break;
    }

    return vlc_custom_create( p_this, i_size, i_type, psz_type );
}


/**
 ****************************************************************************
 * Set the destructor of a vlc object
 *
 * This function sets the destructor of the vlc object. It will be called
 * when the object is destroyed when the its refcount reaches 0.
 * (It is called by the internal function vlc_object_destroy())
 *****************************************************************************/
void __vlc_object_set_destructor( vlc_object_t *p_this,
                                  vlc_destructor_t pf_destructor )
{
    vlc_object_internals_t *p_priv = vlc_internals(p_this );
    p_priv->pf_destructor = pf_destructor;
}

/**
 ****************************************************************************
 * Destroy a vlc object (Internal)
 *
 * This function destroys an object that has been previously allocated with
 * vlc_object_create. The object's refcount must be zero and it must not be
 * attached to other objects in any way.
 *****************************************************************************/
static void vlc_object_destroy( vlc_object_t *p_this )
{
    vlc_object_internals_t *p_priv = vlc_internals( p_this );

    /* Objects are always detached beforehand */
    assert( !p_this->p_parent );

    /* Send a kill to the object's thread if applicable */
    vlc_object_kill( p_this );

    /* If we are running on a thread, wait until it ends */
    if( p_priv->b_thread )
    {
        msg_Warn (p_this->p_libvlc, /* do NOT use a dead object for logging! */
                  "%s %d destroyed while thread alive (VLC might crash)",
                  p_this->psz_object_type, p_this->i_object_id);
        vlc_thread_join( p_this );
    }

    /* Call the custom "subclass" destructor */
    if( p_priv->pf_destructor )
        p_priv->pf_destructor( p_this );

    /* Destroy the associated variables, starting from the end so that
     * no memmove calls have to be done. */
    while( p_priv->i_vars )
    {
        var_Destroy( p_this, p_priv->p_vars[p_priv->i_vars - 1].psz_name );
    }

    free( p_priv->p_vars );
    vlc_mutex_destroy( &p_priv->var_lock );

    free( p_this->psz_header );

    if( p_this->p_libvlc == NULL )
    {
#ifndef NDEBUG
        libvlc_global_data_t *p_global = (libvlc_global_data_t *)p_this;

        assert( p_global == vlc_global() );
        /* Test for leaks */
        if (p_priv->next != p_this)
        {
            vlc_object_t *leaked = p_priv->next, *first = leaked;
            do
            {
                /* We are leaking this object */
                fprintf( stderr,
                         "ERROR: leaking object (id:%i, type:%s, name:%s)\n",
                         leaked->i_object_id, leaked->psz_object_type,
                         leaked->psz_object_name );
                /* Dump libvlc object to ease debugging */
                vlc_object_dump( leaked );
                fflush(stderr);
                leaked = vlc_internals (leaked)->next;
            }
            while (leaked != first);

            /* Dump global object to ease debugging */
            vlc_object_dump( p_this );
            /* Strongly abort, cause we want these to be fixed */
            abort();
        }
#endif

        /* We are the global object ... no need to lock. */
        vlc_mutex_destroy( &structure_lock );
#ifdef LIBVLC_REFCHECK
        held_objects_destroy( vlc_threadvar_get( &held_objects ) );
        vlc_threadvar_delete( &held_objects );
#endif
    }

    FREENULL( p_this->psz_object_name );

#if defined(WIN32) || defined(UNDER_CE)
    /* if object has an associated thread, close it now */
    if( p_priv->thread_id )
       CloseHandle(p_priv->thread_id);
#endif

    vlc_spin_destroy( &p_priv->ref_spin );
    vlc_mutex_destroy( &p_priv->lock );
    vlc_cond_destroy( &p_priv->wait );
    vlc_spin_destroy( &p_priv->spin );
    if( p_priv->pipes[1] != -1 )
        close( p_priv->pipes[1] );
    if( p_priv->pipes[0] != -1 )
        close( p_priv->pipes[0] );

    free( p_priv );
}


/** Inter-object signaling */

void __vlc_object_lock( vlc_object_t *obj )