X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fmisc%2Fobjects.c;h=96214c14d0710889a451e8df0252bc433da03894;hb=ba8f5af2374314a1aac064c1d12a76779e0de8bc;hp=36f9159d1c7e879499f89823d97e6328772f4332;hpb=debed14afc143e80839ba97b92ea5be332c4ed51;p=vlc diff --git a/src/misc/objects.c b/src/misc/objects.c index 36f9159d1c..96214c14d0 100644 --- a/src/misc/objects.c +++ b/src/misc/objects.c @@ -2,7 +2,6 @@ * objects.c: vlc_object_t handling ***************************************************************************** * Copyright (C) 2004-2008 the VideoLAN team - * $Id$ * * Authors: Samuel Hocevar * @@ -34,7 +33,7 @@ # include "config.h" #endif -#include +#include #include "../libvlc.h" #include @@ -82,14 +81,23 @@ 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 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; @@ -143,6 +151,10 @@ void *vlc_custom_create( vlc_object_t *p_this, size_t i_size, 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 { @@ -164,13 +176,20 @@ void *vlc_custom_create( vlc_object_t *p_this, size_t i_size, 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; @@ -207,26 +226,10 @@ void * __vlc_object_create( vlc_object_t *p_this, int i_type ) 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"; @@ -239,22 +242,10 @@ void * __vlc_object_create( vlc_object_t *p_this, int i_type ) 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"; @@ -263,13 +254,9 @@ void * __vlc_object_create( vlc_object_t *p_this, int i_type ) 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; @@ -314,7 +301,12 @@ static void vlc_object_destroy( vlc_object_t *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 ) @@ -334,9 +326,9 @@ static void vlc_object_destroy( vlc_object_t *p_this ) 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 */ if (p_priv->next != p_this) @@ -365,6 +357,10 @@ static void vlc_object_destroy( vlc_object_t *p_this ) /* 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 ); @@ -376,8 +372,8 @@ static void vlc_object_destroy( vlc_object_t *p_this ) #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] ); @@ -392,13 +388,13 @@ static void vlc_object_destroy( vlc_object_t *p_this ) 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 @@ -520,78 +516,47 @@ int __vlc_object_waitpipe( vlc_object_t *obj ) /** * 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) ); } @@ -601,16 +566,16 @@ void __vlc_object_signal_unlocked( vlc_object_t *obj ) */ 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 ) { @@ -618,12 +583,9 @@ void __vlc_object_kill( vlc_object_t *p_this ) 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 ); } @@ -640,7 +602,15 @@ void * vlc_object_get( 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); +#endif vlc_mutex_lock( &structure_lock ); for( obj = vlc_internals (p_libvlc_global)->next; @@ -654,7 +624,12 @@ void * vlc_object_get( int 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); +#endif out: vlc_mutex_unlock( &structure_lock ); return obj; @@ -683,8 +658,8 @@ void * __vlc_object_find( vlc_object_t *p_this, int i_type, int i_mode ) { #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); @@ -762,6 +737,16 @@ void __vlc_object_yield( vlc_object_t *p_this ) /* 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 } /***************************************************************************** @@ -773,6 +758,27 @@ 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 ); @@ -1012,25 +1018,9 @@ static int DumpCommand( vlc_object_t *p_this, char const *psz_cmd, 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 ) { @@ -1471,57 +1461,96 @@ static void ListChildren( vlc_list_t *p_list, vlc_object_t *p_this, int i_type ) } } -#ifndef NDEBUG +#ifdef LIBVLC_REFCHECK +# if defined(HAVE_EXECINFO_H) && defined(HAVE_BACKTRACE) +# include +# 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