* objects.c: vlc_object_t handling
*****************************************************************************
* Copyright (C) 2004-2008 the VideoLAN team
- * $Id$
*
* Authors: Samuel Hocevar <sam@zoy.org>
*
# include "config.h"
#endif
-#include <vlc/vlc.h>
+#include <vlc_common.h>
#include "../libvlc.h"
#include <vlc_vout.h>
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 vlc_threadvar_t thread_object;
-void *vlc_custom_create( vlc_object_t *p_this, size_t i_size,
- int i_type, const char *psz_type )
+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;
p_libvlc_global->i_counter = 0;
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_new->p_private = NULL;
/* Initialize mutexes and condvars */
- vlc_mutex_init( &p_new->object_lock );
- vlc_cond_init( p_new, &p_new->object_wait );
+ 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;
switch( i_type )
{
- case VLC_OBJECT_LIBVLC:
- i_size = sizeof(libvlc_int_t);
- psz_type = "libvlc";
- break;
case VLC_OBJECT_INTF:
i_size = sizeof(intf_thread_t);
psz_type = "interface";
break;
- case VLC_OBJECT_DIALOGS:
- i_size = sizeof(intf_thread_t);
- psz_type = "dialogs";
- break;
- case VLC_OBJECT_DEMUX:
- i_size = sizeof(demux_t);
- psz_type = "demux";
- break;
- case VLC_OBJECT_ACCESS:
- i_size = sizeof(access_t);
- psz_type = "access";
- break;
case VLC_OBJECT_DECODER:
i_size = sizeof(decoder_t);
psz_type = "decoder";
i_size = sizeof(encoder_t);
psz_type = "encoder";
break;
- case VLC_OBJECT_FILTER:
- i_size = sizeof(filter_t);
- psz_type = "filter";
- break;
- case VLC_OBJECT_VOUT:
- i_size = sizeof(vout_thread_t);
- psz_type = "video output";
- break;
case VLC_OBJECT_AOUT:
i_size = sizeof(aout_instance_t);
psz_type = "audio output";
break;
- case VLC_OBJECT_SOUT:
- i_size = sizeof(sout_instance_t);
- psz_type = "stream output";
- break;
case VLC_OBJECT_OPENGL:
i_size = sizeof( vout_thread_t );
psz_type = "opengl";
i_size = sizeof( announce_handler_t );
psz_type = "announce";
break;
- case VLC_OBJECT_INTERACTION:
- i_size = sizeof( interaction_t );
- psz_type = "interaction";
- break;
default:
- i_size = i_type > (int)sizeof(vlc_object_t)
- ? i_type : (int)sizeof(vlc_object_t);
+ assert( i_type > 0 ); /* unknown type?! */
+ i_size = i_type;
i_type = VLC_OBJECT_GENERIC;
psz_type = "generic";
break;
/* 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 )
if( p_this->p_libvlc == NULL )
{
+#ifndef NDEBUG
libvlc_global_data_t *p_global = (libvlc_global_data_t *)p_this;
-#ifndef NDEBUG
assert( p_global == vlc_global() );
/* Test for leaks */
- for( vlc_object_t *leaked = p_priv->next;
- leaked != p_this;
- leaked = vlc_internals (leaked)->next )
+ if (p_priv->next != p_this)
{
- /* 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);
- }
+ 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);
- if( p_priv->next != p_this )
- {
- /* Dump libvlc object to ease debugging */
+ /* Dump global object to ease debugging */
vlc_object_dump( p_this );
/* Strongly abort, cause we want these to be fixed */
abort();
/* 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 );
#endif
vlc_spin_destroy( &p_priv->ref_spin );
- vlc_mutex_destroy( &p_this->object_lock );
- vlc_cond_destroy( &p_this->object_wait );
+ 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] );
void __vlc_object_lock( vlc_object_t *obj )
{
- vlc_mutex_lock( &obj->object_lock );
+ vlc_mutex_lock( &(vlc_internals(obj)->lock) );
}
void __vlc_object_unlock( vlc_object_t *obj )
{
- vlc_assert_locked( &obj->object_lock );
- vlc_mutex_unlock( &obj->object_lock );
+ vlc_assert_locked( &(vlc_internals(obj)->lock) );
+ vlc_mutex_unlock( &(vlc_internals(obj)->lock) );
}
#ifdef WIN32
/**
* Waits for the object to be signaled (using vlc_object_signal()).
- * If the object already has a signal pending, this function will return
- * immediately. It is asserted that the caller holds the object lock.
+ * It is assumed that the caller has locked the object. This function will
+ * unlock the object, and lock it again before returning.
+ * If the object was signaled before the caller locked the object, it is
+ * undefined whether the signal will be lost or will wake the process.
*
* @return true if the object is dying and should terminate.
*/
-bool __vlc_object_wait( vlc_object_t *obj )
+void __vlc_object_wait( vlc_object_t *obj )
{
- vlc_assert_locked( &obj->object_lock );
- vlc_cond_wait( &obj->object_wait, &obj->object_lock );
- return obj->b_die;
+ vlc_object_internals_t *priv = vlc_internals( obj );
+ vlc_assert_locked( &priv->lock);
+ vlc_cond_wait( &priv->wait, &priv->lock );
}
/**
* Waits for the object to be signaled (using vlc_object_signal()), or for
- * a timer to expire.
- * If the object already has a signal pending, this function will return
- * immediately. It is asserted that the caller holds the object lock.
+ * a timer to expire. It is asserted that the caller holds the object lock.
*
- * @return negative if the object is dying and should terminate,
- * positive if the the object has been signaled but is not dying,
- * 0 if timeout has been reached.
+ * @return 0 if the object was signaled before the timer expiration, or
+ * ETIMEDOUT if the timer expired without any signal.
*/
int __vlc_object_timedwait( vlc_object_t *obj, mtime_t deadline )
{
- int v;
-
- vlc_assert_locked( &obj->object_lock );
- v = vlc_cond_timedwait( &obj->object_wait, &obj->object_lock, deadline );
- if( v == 0 ) /* signaled */
- return obj->b_die ? -1 : 1;
- return 0;
-}
-
-
-/**
- * Checks whether an object has been "killed".
- * The object lock must be held.
- *
- * Typical code for an object thread could be:
- *
- vlc_object_lock (self);
- ...initialization...
- while (vlc_object_alive (self))
- {
- ...preprocessing...
-
- if (vlc_object_wait (self))
- continue;
-
- ...postprocessing...
- }
- ...deinitialization...
- vlc_object_unlock (self);
- *
- *
- * @return true iff the object has not been killed yet
- */
-bool __vlc_object_alive( vlc_object_t *obj )
-{
- vlc_assert_locked( &obj->object_lock );
- return !obj->b_die;
+ vlc_object_internals_t *priv = vlc_internals( obj );
+ vlc_assert_locked( &priv->lock);
+ return vlc_cond_timedwait( &priv->wait, &priv->lock, deadline );
}
/**
* Signals an object for which the lock is held.
+ * At least one thread currently sleeping in vlc_object_wait() or
+ * vlc_object_timedwait() will wake up, assuming that there is at least one
+ * such thread in the first place. Otherwise, it is undefined whether the
+ * signal will be lost or will wake up one or more thread later.
*/
void __vlc_object_signal_unlocked( vlc_object_t *obj )
{
- vlc_assert_locked (&obj->object_lock);
- vlc_cond_signal( &obj->object_wait );
+ vlc_assert_locked (&(vlc_internals(obj)->lock));
+ vlc_cond_signal( &(vlc_internals(obj)->wait) );
}
*/
void __vlc_object_kill( vlc_object_t *p_this )
{
- vlc_object_internals_t *internals = vlc_internals( p_this );
+ vlc_object_internals_t *priv = vlc_internals( p_this );
int fd;
- vlc_mutex_lock( &p_this->object_lock );
+ vlc_object_lock( p_this );
p_this->b_die = true;
- vlc_spin_lock (&internals->spin);
- fd = internals->pipes[1];
- internals->pipes[1] = -1;
- vlc_spin_unlock (&internals->spin);
+ vlc_spin_lock (&priv->spin);
+ fd = priv->pipes[1];
+ priv->pipes[1] = -1;
+ vlc_spin_unlock (&priv->spin);
if( fd != -1 )
{
close (fd);
}
- if( p_this->i_object_type == VLC_OBJECT_LIBVLC )
- for( int i = 0; i < internals->i_children ; i++ )
- vlc_object_kill( internals->pp_children[i] );
-
vlc_object_signal_unlocked( p_this );
- vlc_mutex_unlock( &p_this->object_lock );
+ /* This also serves as a memory barrier toward vlc_object_alive(): */
+ vlc_object_unlock( p_this );
}
{
libvlc_global_data_t *p_libvlc_global = vlc_global();
vlc_object_t *obj = NULL;
+#ifndef NDEBUG
+ vlc_object_t *caller = vlc_threadobj ();
+ if (caller)
+ msg_Dbg (caller, "uses deprecated vlc_object_get(%d)", i_id);
+ else
+ fprintf (stderr, "main thread uses deprecated vlc_object_get(%d)\n",
+ i_id);
+#endif
vlc_mutex_lock( &structure_lock );
for( obj = vlc_internals (p_libvlc_global)->next;
}
}
obj = NULL;
-
+#ifndef NDEBUG
+ if (caller)
+ msg_Warn (caller, "wants non-existing object %d", i_id);
+ else
+ fprintf (stderr, "main thread wants non-existing object %d\n", i_id);
+#endif
out:
vlc_mutex_unlock( &structure_lock );
return obj;
{
#ifndef NDEBUG
if (i_type == VLC_OBJECT_PLAYLIST)
- msg_Warn (p_this, "using vlc_object_find(VLC_OBJECT_PLAYLIST) "
- "instead of pl_Yield()");
+ msg_Err (p_this, "using vlc_object_find(VLC_OBJECT_PLAYLIST) "
+ "instead of pl_Yield()");
#endif
return vlc_object_find (p_this->p_libvlc, i_type,
(i_mode & ~0x000f)|FIND_CHILD);
/* Increment the counter */
internals->i_refcount++;
vlc_spin_unlock( &internals->ref_spin );
+#ifdef LIBVLC_REFCHECK
+ /* Update the list of referenced objects */
+ /* Using TLS, so no need to lock */
+ /* The following line may leak memory if a thread leaks objects. */
+ held_list_t *newhead = malloc (sizeof (*newhead));
+ held_list_t *oldhead = vlc_threadvar_get (&held_objects);
+ newhead->next = oldhead;
+ newhead->obj = p_this;
+ vlc_threadvar_set (&held_objects, newhead);
+#endif
}
/*****************************************************************************
vlc_object_internals_t *internals = vlc_internals( p_this );
bool b_should_destroy;
+#ifdef LIBVLC_REFCHECK
+ /* Update the list of referenced objects */
+ /* Using TLS, so no need to lock */
+ for (held_list_t *hlcur = vlc_threadvar_get (&held_objects),
+ *hlprev = NULL;
+ hlcur != NULL;
+ hlprev = hlcur, hlcur = hlcur->next)
+ {
+ if (hlcur->obj == p_this)
+ {
+ if (hlprev == NULL)
+ vlc_threadvar_set (&held_objects, hlcur->next);
+ else
+ hlprev->next = hlcur->next;
+ free (hlcur);
+ break;
+ }
+ }
+ /* TODO: what if releasing without references? */
+#endif
+
vlc_spin_lock( &internals->ref_spin );
assert( internals->i_refcount > 0 );
if( end != newval.psz_string )
p_object = vlc_object_get( i_id );
else
- {
/* try using the object's name to find it */
- vlc_object_t *p_libvlc = vlc_object_get( 1 );
- if( p_libvlc )
- {
- /* Look in p_libvlc's children tree */
- p_object = vlc_object_find_name( p_libvlc,
- newval.psz_string,
- FIND_CHILD );
- vlc_object_release( p_libvlc );
- }
- if( !p_object )
- {
- /* If it's not in libvlc, look in libvlc_global (== p_this) */
- p_object = vlc_object_find_name( p_this,
- newval.psz_string,
- FIND_CHILD );
- }
- }
+ p_object = vlc_object_find_name( p_this, newval.psz_string,
+ FIND_ANYWHERE );
if( !p_object )
{
}
}
-#ifndef NDEBUG
+#ifdef LIBVLC_REFCHECK
+# if defined(HAVE_EXECINFO_H) && defined(HAVE_BACKTRACE)
+# include <execinfo.h>
+# endif
+
void vlc_refcheck (vlc_object_t *obj)
{
static unsigned errors = 0;
- vlc_object_t *caller = vlc_threadobj ();
- vlc_object_internals_t *priv = vlc_internals (obj);
- int refs;
-
if (errors > 100)
return;
- if (!caller)
- return; /* main thread, not sure how to handle it */
+ /* Anyone can use the root object (though it should not exist) */
+ if (obj == VLC_OBJECT (vlc_global ()))
+ return;
- /* An object can always access itself without reference! */
- if (caller == obj)
+ /* Anyone can use its libvlc instance object */
+ if (obj == VLC_OBJECT (obj->p_libvlc))
return;
- /* The calling thread is younger than the object.
- * Access could be valid, we would need more accounting. */
- if (caller->i_object_id > obj->i_object_id)
+ /* The thread that created the object holds the initial reference */
+ vlc_object_internals_t *priv = vlc_internals (obj);
+#if defined (LIBVLC_USE_PTHREAD)
+ if (pthread_equal (priv->creator_id, pthread_self ()))
+#elif defined WIN32
+ if (priv->creator_id == GetCurrentThreadId ())
+#else
+ if (0)
+#endif
return;
+ /* A thread can use its own object without references! */
+ vlc_object_t *caller = vlc_threadobj ();
+ if (caller == obj)
+ return;
+#if 0
+ /* The calling thread is younger than the object.
+ * Access could be valid through cross-thread synchronization;
+ * we would need better accounting. */
+ if (caller && (caller->i_object_id > obj->i_object_id))
+ return;
+#endif
+ int refs;
vlc_spin_lock (&priv->ref_spin);
refs = priv->i_refcount;
vlc_spin_unlock (&priv->ref_spin);
- /* Object has more than one reference.
- * The current thread could be holding a valid reference. */
- if (refs > 1)
- return;
-
- /* The parent of an object normally holds the unique reference.
- * As not all objects are threads, it could also be an ancestor. */
- vlc_mutex_lock (&structure_lock);
- for (vlc_object_t *cur = obj; cur != NULL; cur = cur->p_parent)
- if (cur == caller)
- {
- vlc_mutex_unlock (&structure_lock);
+ for (held_list_t *hlcur = vlc_threadvar_get (&held_objects);
+ hlcur != NULL; hlcur = hlcur->next)
+ if (hlcur->obj == obj)
return;
- }
- vlc_mutex_unlock (&structure_lock);
-#if 1
- if (caller->i_object_type == VLC_OBJECT_PLAYLIST)
- return; /* Playlist is too clever, or hopelessly broken. */
+ fprintf (stderr, "The %s %s thread object is accessing...\n"
+ "the %s %s object without references.\n",
+ caller && caller->psz_object_name
+ ? caller->psz_object_name : "unnamed",
+ caller ? caller->psz_object_type : "main",
+ obj->psz_object_name ? obj->psz_object_name : "unnamed",
+ obj->psz_object_type);
+ fflush (stderr);
+
+#ifdef HAVE_BACKTRACE
+ void *stack[20];
+ int stackdepth = backtrace (stack, sizeof (stack) / sizeof (stack[0]));
+ backtrace_symbols_fd (stack, stackdepth, 2);
#endif
- msg_Err (caller, "This thread is accessing...");
- msg_Err (obj, "...this object in a suspicious manner.");
if (++errors == 100)
- msg_Err (caller, "Too many reference errors");
+ fprintf (stderr, "Too many reference errors!\n");
+}
+
+static void held_objects_destroy (void *data)
+{
+ VLC_UNUSED( data );
+ held_list_t *hl = vlc_threadvar_get (&held_objects);
+ vlc_object_t *caller = vlc_threadobj ();
+
+ while (hl != NULL)
+ {
+ held_list_t *buf = hl->next;
+ vlc_object_t *obj = hl->obj;
+
+ fprintf (stderr, "The %s %s thread object leaked a reference to...\n"
+ "the %s %s object.\n",
+ caller && caller->psz_object_name
+ ? caller->psz_object_name : "unnamed",
+ caller ? caller->psz_object_type : "main",
+ obj->psz_object_name ? obj->psz_object_name : "unnamed",
+ obj->psz_object_type);
+ free (hl);
+ hl = buf;
+ }
}
#endif
projects / vlc / blobdiff