/**
* \file
* This file contains the functions to handle the vlc_object_t type
+ *
+ * Unless otherwise stated, functions in this file are not cancellation point.
+ * All functions in this file are safe w.r.t. deferred cancellation.
*/
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
+static void vlc_object_dump( vlc_object_t *p_this );
/*****************************************************************************
* Local structure lock
*****************************************************************************/
-static vlc_mutex_t structure_lock;
+static vlc_mutex_t structure_lock;
+static unsigned object_counter = 0;
+
+static void close_nocancel (int fd)
+{
+ int canc = vlc_savecancel ();
+ close (fd);
+ vlc_restorecancel (canc);
+}
-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;
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;
-
- 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_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;
+ {
+ p_new->p_libvlc = NULL;
+ vlc_mutex_init( &structure_lock );
+ }
+
+ p_this = p_priv->next = p_priv->prev = p_new;
}
+ else
+ p_new->p_libvlc = p_this->p_libvlc;
vlc_spin_init( &p_priv->ref_spin );
p_priv->i_refcount = 1;
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
+ p_priv->next = p_this;
vlc_mutex_lock( &structure_lock );
- p_priv->prev = vlc_internals (p_libvlc_global)->prev;
- vlc_internals (p_libvlc_global)->prev = p_new;
+ p_priv->prev = vlc_internals (p_this)->prev;
+ vlc_internals (p_this)->prev = p_new;
vlc_internals (p_priv->prev)->next = p_new;
- p_new->i_object_id = p_libvlc_global->i_counter++;
+ p_new->i_object_id = object_counter++; /* fetch THEN increment */
vlc_mutex_unlock( &structure_lock );
if( i_type == VLC_OBJECT_LIBVLC )
{
+ int canc = vlc_savecancel ();
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 );
+ vlc_restorecancel (canc);
}
return p_new;
* 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.
+ *
+ * This function must be called with cancellation disabled (currently).
*****************************************************************************/
static void vlc_object_destroy( vlc_object_t *p_this )
{
/* 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! */
- "object %d destroyed while thread alive (VLC might crash)",
- 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 );
+ /* Any thread must have been cleaned up at this point. */
+ assert( !p_priv->b_thread );
+
/* Destroy the associated variables, starting from the end so that
* no memmove calls have to be done. */
while( p_priv->i_vars )
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 the object was signaled before the caller locked the object, it is
* undefined whether the signal will be lost or will wake the process.
*
+ * This function is a cancellation point. In case of cancellation, the object
+ * will be in locked state.
+ *
* @return true if the object is dying and should terminate.
*/
void __vlc_object_wait( vlc_object_t *obj )
* Waits for the object to be signaled (using vlc_object_signal()), or for
* a timer to expire. It is asserted that the caller holds the object lock.
*
+ * This function is a cancellation point. In case of cancellation, the object
+ * will be in locked state.
+ *
* @return 0 if the object was signaled before the timer expiration, or
* ETIMEDOUT if the timer expired without any signal.
*/
vlc_object_internals_t *priv = vlc_internals( p_this );
int fd;
+ vlc_thread_cancel( p_this );
vlc_object_lock( p_this );
p_this->b_die = true;
if( fd != -1 )
{
msg_Dbg (p_this, "waitpipe: object killed");
- close (fd);
+ close_nocancel (fd);
}
vlc_object_signal_unlocked( p_this );
* vlc_object_yield(), use the pointer as your reference, and call
* vlc_object_release() when you're done.
*/
-void * vlc_object_get( int i_id )
+void * vlc_object_get( libvlc_int_t *p_anchor, int i_id )
{
- 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);
+ int canc = vlc_savecancel ();
+ fprintf (stderr, "Use of deprecated vlc_object_get(%d) ", i_id);
+ vlc_backtrace ();
+ vlc_restorecancel (canc);
#endif
vlc_mutex_lock( &structure_lock );
- for( obj = vlc_internals (p_libvlc_global)->next;
- obj != VLC_OBJECT (p_libvlc_global);
+ for( obj = vlc_internals (p_anchor)->next;
+ obj != VLC_OBJECT (p_anchor);
obj = vlc_internals (obj)->next )
{
if( obj->i_object_id == i_id )
}
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);
+ fprintf (stderr, "Object %d does not exist\n", i_id);
#endif
out:
vlc_mutex_unlock( &structure_lock );
return p_found;
}
+#undef vlc_object_find_name
/**
- ****************************************************************************
- * find a named object and increment its refcount
- *****************************************************************************
- * This function recursively looks for a given object name. i_mode can be one
- * of FIND_PARENT, FIND_CHILD or FIND_ANYWHERE.
- *****************************************************************************/
-void * __vlc_object_find_name( vlc_object_t *p_this, const char *psz_name,
- int i_mode )
+ * Finds a named object and increment its reference count.
+ * Beware that objects found in this manner can be "owned" by another thread,
+ * be of _any_ type, and be attached to any module (if any). With such an
+ * object reference, you can set or get object variables, emit log messages,
+ * and read write-once object parameters (i_object_id, psz_object_type, etc).
+ * You CANNOT cast the object to a more specific object type, and you
+ * definitely cannot invoke object type-specific callbacks with this.
+ *
+ * @param p_this object to search from
+ * @param psz_name name of the object to search for
+ * @param i_mode search direction: FIND_PARENT, FIND_CHILD or FIND_ANYWHERE.
+ *
+ * @return a matching object (must be released by the caller),
+ * or NULL on error.
+ */
+vlc_object_t *vlc_object_find_name( vlc_object_t *p_this,
+ const char *psz_name, int i_mode )
{
vlc_object_t *p_found;
/* 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
}
/*****************************************************************************
- * decrement an object refcount
+ * Decrement an object refcount
* And destroy the object if its refcount reach zero.
*****************************************************************************/
void __vlc_object_release( vlc_object_t *p_this )
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( b_should_destroy )
{
+#ifndef NDEBUG
+ if( VLC_OBJECT(p_this->p_libvlc) == p_this )
+ {
+ /* Test for leaks */
+ vlc_object_t *leaked = internals->next;
+ while( leaked != 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 object to ease debugging */
+ vlc_object_dump( leaked );
+ fflush(stderr);
+ leaked = vlc_internals (leaked)->next;
+ }
+
+ if( internals->next != p_this )
+ /* Dump libvlc object to ease debugging */
+ vlc_object_dump( p_this );
+ }
+#endif
/* Remove the object from object list
* so that it cannot be encountered by vlc_object_get() */
vlc_internals (internals->next)->prev = internals->prev;
if( b_should_destroy )
{
+ int canc;
+
free( internals->pp_children );
internals->pp_children = NULL;
internals->i_children = 0;
+ canc = vlc_savecancel ();
vlc_object_destroy( p_this );
+ vlc_restorecancel (canc);
}
}
* not be shared across LibVLC instances. In the mean time, this ugly
* hack is brought to you by Courmisch. */
if (i_type == VLC_OBJECT_MODULE)
- return vlc_list_find ((vlc_object_t *)vlc_global ()->p_module_bank,
+ return vlc_list_find ((vlc_object_t *)p_module_bank,
i_type, FIND_CHILD);
return vlc_list_find (p_this->p_libvlc, i_type, FIND_CHILD);
static int DumpCommand( vlc_object_t *p_this, char const *psz_cmd,
vlc_value_t oldval, vlc_value_t newval, void *p_data )
{
+ libvlc_int_t *p_libvlc = p_this->p_libvlc;
+
(void)oldval; (void)p_data;
if( *psz_cmd == 'l' )
{
- vlc_object_t *root = VLC_OBJECT (vlc_global ()), *cur = root;
+ vlc_object_t *cur = VLC_OBJECT (p_libvlc);
vlc_mutex_lock( &structure_lock );
do
PrintObject (cur, "");
cur = vlc_internals (cur)->next;
}
- while (cur != root);
+ while (cur != VLC_OBJECT(p_libvlc));
vlc_mutex_unlock( &structure_lock );
}
else
{
char *end;
int i_id = strtol( newval.psz_string, &end, 0 );
- if( end != newval.psz_string )
- p_object = vlc_object_get( i_id );
+ if( !*end )
+ p_object = vlc_object_get( p_libvlc, i_id );
else
/* try using the object's name to find it */
p_object = vlc_object_find_name( p_this, newval.psz_string,
char psz_foo[2 * MAX_DUMPSTRUCTURE_DEPTH + 1];
if( !p_object )
- p_object = p_this->p_libvlc ? VLC_OBJECT(p_this->p_libvlc) : p_this;
+ p_object = VLC_OBJECT(p_this->p_libvlc);
psz_foo[0] = '|';
DumpStructure( p_object, 0, psz_foo );
if( p_var->psz_text )
printf( ", %s", p_var->psz_text );
printf( ")" );
+ if( p_var->i_type & VLC_VAR_HASCHOICE )
+ printf( ", has choices" );
if( p_var->i_type & VLC_VAR_ISCOMMAND )
printf( ", command" );
if( p_var->i_entries )
/*****************************************************************************
* dump an object. (Debug function)
*****************************************************************************/
-void __vlc_object_dump( vlc_object_t *p_this )
+static void vlc_object_dump( vlc_object_t *p_this )
{
- vlc_mutex_lock( &structure_lock );
char psz_foo[2 * MAX_DUMPSTRUCTURE_DEPTH + 1];
psz_foo[0] = '|';
+
+ vlc_assert_locked( &structure_lock );
DumpStructure( p_this, 0, psz_foo );
- vlc_mutex_unlock( &structure_lock );
}
/* Following functions are local */
char psz_children[20], psz_refcount[20], psz_thread[30], psz_name[50],
psz_parent[20];
+ int canc = vlc_savecancel ();
memset( &psz_name, 0, sizeof(psz_name) );
if( p_this->psz_object_name )
{
p_this->i_object_id, p_this->psz_object_type,
psz_name, psz_thread, psz_refcount, psz_children,
psz_parent );
+ vlc_restorecancel (canc);
}
static void DumpStructure( vlc_object_t *p_this, int i_level, char *psz_foo )
ListChildren( p_list, p_tmp, i_type );
}
}
-
-#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;
- 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)
-{
- 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