* 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);
+#ifndef NDEBUG
+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 )
p_libvlc_global->i_counter = 0;
p_priv->next = p_priv->prev = p_new;
vlc_mutex_init( &structure_lock );
+#ifndef NDEBUG
+ /* TODO: use the destruction callback to track ref leaks */
+ vlc_threadvar_create( &held_objects, held_objects_destroy );
+#endif
}
else
{
p_priv->pipes[0] = p_priv->pipes[1] = -1;
p_priv->next = VLC_OBJECT (p_libvlc_global);
+#if defined (NDEBUG)
+ /* ... */
+#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;
#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 );
+#ifndef NDEBUG
+ held_objects_destroy( vlc_threadvar_get( &held_objects ) );
+ vlc_threadvar_delete( &held_objects );
+#endif
}
FREENULL( p_this->psz_object_name );
/**
* 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;
}
/**
* 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;
+ return vlc_cond_timedwait( &obj->object_wait, &obj->object_lock, deadline );
}
{
...preprocessing...
- if (vlc_object_wait (self))
- continue;
+ vlc_object_wait (self);
...postprocessing...
}
/**
* 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 )
{
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 );
+
+ if (p_this->i_object_type == VLC_OBJECT_LIBVLC)
+ {
+ vlc_list_t *children = vlc_list_children (p_this);
+ for (int i = 0; i < children->i_count; i++)
+ vlc_object_kill (children->p_values[i].p_object);
+ vlc_list_release (children);
+ }
}
{
libvlc_global_data_t *p_libvlc_global = vlc_global();
vlc_object_t *obj = NULL;
+ 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);
vlc_mutex_lock( &structure_lock );
}
}
obj = NULL;
-
+ 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);
out:
vlc_mutex_unlock( &structure_lock );
return obj;
/* Increment the counter */
internals->i_refcount++;
vlc_spin_unlock( &internals->ref_spin );
+#ifndef NDEBUG
+ /* 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;
+#ifndef NDEBUG
+ /* 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 );
INSERT_ELEM( priv->pp_children, priv->i_children, priv->i_children,
p_this );
+ /* Kill the object if parent is already dead.
+ * Note: We should surely lock parent here, but that would
+ * create quite a few dead lock case. Hopefully, it
+ * is perfectly safe to do it that way. We only risk
+ * receiving kill event twice. But given current API
+ * it is ok. */
+ if( p_this->p_parent->b_die )
+ vlc_object_kill( p_this );
+
vlc_mutex_unlock( &structure_lock );
}
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 )
{
ListChildren( p_list, p_tmp, i_type );
}
}
+
+#ifndef NDEBUG
+# if defined(HAVE_EXECINFO_H) && defined(HAVE_BACKTRACE)
+# include <execinfo.h>
+# endif
+
+void vlc_refcheck (vlc_object_t *obj)
+{
+ static unsigned errors = 0;
+ if (errors > 100)
+ return;
+
+ /* Anyone can use the root object (though it should not exist) */
+ if (obj == VLC_OBJECT (vlc_global ()))
+ return;
+
+ /* Anyone can use its libvlc instance object */
+ if (obj == VLC_OBJECT (obj->p_libvlc))
+ return;
+
+ /* 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);
+
+ for (held_list_t *hlcur = vlc_threadvar_get (&held_objects);
+ hlcur != NULL; hlcur = hlcur->next)
+ if (hlcur->obj == obj)
+ return;
+
+ 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
+
+ if (++errors == 100)
+ fprintf (stderr, "Too many reference errors!\n");
+}
+
+static void held_objects_destroy (void *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
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