module_t: use GC subsystem instead of objects

Modules have no threads, no variables (!= config items) and
no plugin instances...

src/modules/cache.c

@@ -398,7 +398,7 @@ static int CacheLoadConfig( module_t *p_module, FILE *file )
 
         p_module->p_config[i].b_dirty = false;
 
-        p_module->p_config[i].p_lock = &(vlc_internals(p_module)->lock);
+        p_module->p_config[i].p_lock = &p_module->lock;
 
         if( p_module->p_config[i].i_list )
         {
@@ -586,15 +586,11 @@ void CacheSave( vlc_object_t *p_this )
 
         SAVE_STRING( pp_cache[i]->p_module->psz_filename );
 
-        i_submodule = vlc_internals( pp_cache[i]->p_module )->i_children;
+        i_submodule = pp_cache[i]->p_module->submodule_count;
         SAVE_IMMEDIATE( i_submodule );
-        for( i_submodule = 0;
-             i_submodule < (unsigned)vlc_internals( pp_cache[i]->p_module)->i_children;
-             i_submodule++ )
+        for( module_t *p_module = pp_cache[i]->p_module->submodule;
+             p_module != NULL; p_module = p_module->next )
         {
-            module_t *p_module =
-                (module_t *)vlc_internals( pp_cache[i]->p_module )->pp_children[i_submodule];
-
             SAVE_STRING( p_module->psz_object_name );
             SAVE_STRING( p_module->psz_shortname );
             SAVE_STRING( p_module->psz_longname );
@@ -689,19 +685,23 @@ error:
  *****************************************************************************/
 void CacheMerge( vlc_object_t *p_this, module_t *p_cache, module_t *p_module )
 {
-    int i_submodule;
     (void)p_this;
 
     p_cache->pf_activate = p_module->pf_activate;
     p_cache->pf_deactivate = p_module->pf_deactivate;
     p_cache->handle = p_module->handle;
 
-    for( i_submodule = 0; i_submodule < vlc_internals( p_module )->i_children; i_submodule++ )
+    /* FIXME: This looks too simplistic an algorithm to me. What if the module
+     * file was altered such that the number of order of submodules was
+     * altered... after VLC started -- Courmisch, 09/2008 */
+    module_t *p_child = p_module->submodule,
+             *p_cchild = p_cache->submodule;
+    while( p_child && p_cchild )
     {
-        module_t *p_child = (module_t*)vlc_internals( p_module )->pp_children[i_submodule];
-        module_t *p_cchild = (module_t*)vlc_internals( p_cache )->pp_children[i_submodule];
         p_cchild->pf_activate = p_child->pf_activate;
         p_cchild->pf_deactivate = p_child->pf_deactivate;
+        p_child = p_child->next;
+        p_cchild = p_cchild->next;
     }
 
     p_cache->b_loaded = true;

src/modules/entry.c

@@ -35,40 +35,78 @@
 # define dgettext(d, m) ((char *)(m))
 #endif
 
+static void vlc_module_destruct (gc_object_t *obj)
+{
+    module_t *module = vlc_priv (obj, module_t);
+
+    vlc_mutex_destroy (&module->lock);
+    free (module);
+}
+
 static const char default_name[] = "unnamed";
 
 module_t *vlc_module_create (vlc_object_t *obj)
 {
-    module_t *module =
-        (module_t *)vlc_custom_create (obj, sizeof (module_t),
-                                       VLC_OBJECT_MODULE, "module");
+    module_t *module = malloc (sizeof (*module));
     if (module == NULL)
         return NULL;
 
-    module->b_reentrant = module->b_unloadable = true;
     module->psz_object_name = strdup( default_name );
+    module->next = NULL;
+    module->submodule = NULL;
+    module->parent = NULL;
+    module->submodule_count = 0;
+    vlc_gc_init (module, vlc_module_destruct);
+    vlc_mutex_init (&module->lock);
+
+    module->psz_shortname = NULL;
     module->psz_longname = (char*)default_name;
+    module->psz_help = NULL;
+    for (unsigned i = 0; i < MODULE_SHORTCUT_MAX; i++)
+        module->pp_shortcuts[i] = NULL;
     module->psz_capability = (char*)"";
     module->i_score = 1;
-    module->i_config_items = module->i_bool_items = 0;
-
+    module->i_cpu = 0;
+    module->b_unloadable = true;
+    module->b_reentrant = true;
+    module->b_submodule = false;
+    module->pf_activate = NULL;
+    module->pf_deactivate = NULL;
+    module->p_config = NULL;
+    module->confsize = 0;
+    module->i_config_items = 0;
+    module->i_bool_items = 0;
+    /*module->handle = garbage */
+    module->psz_filename = NULL;
+    module->b_builtin = false;
+    module->b_loaded = false;
+
+    (void)obj;
     return module;
 }
 
 
+static void vlc_submodule_destruct (gc_object_t *obj)
+{
+    module_t *module = vlc_priv (obj, module_t);
+    free (module);
+}
+
 module_t *vlc_submodule_create (module_t *module)
 {
     assert (module != NULL);
-    assert (!module->b_submodule); // subsubmodules are not supported
 
-    module_t *submodule =
-        (module_t *)vlc_custom_create (VLC_OBJECT (module), sizeof (module_t),
-                                       VLC_OBJECT_MODULE, "submodule");
+    module_t *submodule = malloc (sizeof (*submodule));
     if (submodule == NULL)
         return NULL;
 
-    vlc_object_attach (submodule, module);
-    submodule->b_submodule = true;
+    memset (submodule, 0, sizeof (*submodule));
+    vlc_gc_init (submodule, vlc_submodule_destruct);
+
+    submodule->next = module->submodule;
+    submodule->parent = module;
+    module->submodule = submodule;
+    module->submodule_count++;
 
     /* Muahahaha! Heritage! Polymorphism! Ugliness!! */
     memcpy (submodule->pp_shortcuts, module->pp_shortcuts,
@@ -80,6 +118,7 @@ module_t *vlc_submodule_create (module_t *module)
     submodule->psz_capability = module->psz_capability;
     submodule->i_score = module->i_score;
     submodule->i_cpu = module->i_cpu;
+    submodule->b_submodule = true;
     return submodule;
 }
 
@@ -220,7 +259,7 @@ module_config_t *vlc_config_create (module_t *module, int type)
 
     memset (tab + confsize, 0, sizeof (tab[confsize]));
     tab[confsize].i_type = type;
-    tab[confsize].p_lock = &(vlc_internals(module)->lock);
+    tab[confsize].p_lock = &module->lock;
 
     if (type & CONFIG_ITEM)
     {

src/modules/modules.c

@@ -131,6 +131,7 @@ void __module_InitBank( vlc_object_t *p_this )
         p_bank->pp_cache = p_bank->pp_loaded_cache = NULL;
         p_bank->b_cache = p_bank->b_cache_dirty =
         p_bank->b_cache_delete = false;
+        p_bank->head = NULL;
 
         /* Everything worked, attach the object */
         p_module_bank = p_bank;
@@ -324,6 +325,56 @@ const char *module_GetHelp( const module_t *m )
     return m->psz_help;
 }
 
+/**
+ * Frees the flat list of VLC modules.
+ * @param list list obtained by module_list_get
+ * @param length number of items on the list
+ * @return nothing.
+ */
+void module_list_free (module_t **list)
+{
+    if (list == NULL)
+        return;
+
+    for (size_t i = 0; list[i] != NULL; i++)
+         module_release (list[i]);
+    free (list);
+}
+
+/**
+ * Gets the flat list of VLC modules.
+ * @param n [OUT] pointer to the number of modules or NULL
+ * @return NULL-terminated table of module pointers
+ *         (release with module_list_free()), or NULL in case of error.
+ */
+module_t **module_list_get (size_t *n)
+{
+    /* TODO: this whole module lookup is quite inefficient */
+    /* Remove this and improve module_Need */
+    module_t **tab = NULL;
+    size_t i = 0;
+
+    for (module_t *mod = p_module_bank->head; mod; mod = mod->next)
+    {
+         module_t **nt;
+         nt  = realloc (tab, (i + 2 + mod->submodule_count) * sizeof (*tab));
+         if (nt == NULL)
+         {
+             module_list_free (tab);
+             return NULL;
+         }
+
+         tab = nt;
+         tab[i++] = module_hold (mod);
+         for (module_t *subm = mod->submodule; subm; subm = subm->next)
+             tab[i++] = module_hold (subm);
+         tab[i] = NULL;
+    }
+    if (n != NULL)
+        *n = i;
+    return tab;
+}
+
 /**
  * module Need
  *
@@ -356,7 +407,6 @@ module_t * __module_Need( vlc_object_t *p_this, const char *psz_capability,
     };
 
     module_list_t *p_list, *p_first, *p_tmp;
-    vlc_list_t *p_all;
 
     int i_which_module, i_index = 0;
 
@@ -418,17 +468,17 @@ module_t * __module_Need( vlc_object_t *p_this, const char *psz_capability,
     }
 
     /* Sort the modules and test them */
-    p_all = vlc_list_find( p_this, VLC_OBJECT_MODULE, FIND_ANYWHERE );
-    p_list = malloc( p_all->i_count * sizeof( module_list_t ) );
+    size_t count;
+    module_t **p_all = module_list_get (&count);
+    p_list = malloc( count * sizeof( module_list_t ) );
     p_first = NULL;
     unsigned i_cpu = vlc_CPU();
 
     /* Parse the module list for capabilities and probe each of them */
-    for( i_which_module = 0; i_which_module < p_all->i_count; i_which_module++ )
+    for( i_which_module = 0; i_which_module < count; i_which_module++ )
     {
         int i_shortcut_bonus = 0;
-
-        p_module = (module_t *)p_all->p_values[i_which_module].p_object;
+        p_module = p_all[i_which_module];
 
         /* Test that this module can do what we need */
         if( !module_IsCapable( p_module, psz_capability ) )
@@ -536,12 +586,12 @@ found_shortcut:
     p_tmp = p_first;
     while( p_tmp != NULL )
     {
-        vlc_object_hold( p_tmp->p_module );
+        module_hold( p_tmp->p_module );
         p_tmp = p_tmp->p_next;
     }
 
     /* We can release the list, interesting modules were held */
-    vlc_list_release( p_all );
+    module_list_free (p_all);
 
     /* Parse the linked list and use the first successful module */
     p_tmp = p_first;
@@ -551,7 +601,7 @@ found_shortcut:
         /* Make sure the module is loaded in mem */
         module_t *p_module = p_tmp->p_module;
         if( p_module->b_submodule )
-            p_module = (module_t *)p_module->p_parent;
+            p_module = p_module->parent;
 
         if( !p_module->b_builtin && !p_module->b_loaded )
         {
@@ -572,7 +622,7 @@ found_shortcut:
             break;
         }
 
-        vlc_object_release( p_tmp->p_module );
+        module_release( p_tmp->p_module );
         p_tmp = p_tmp->p_next;
     }
 
@@ -590,7 +640,7 @@ found_shortcut:
     /* Unlock the remaining modules */
     while( p_tmp != NULL )
     {
-        vlc_object_release( p_tmp->p_module );
+        module_release( p_tmp->p_module );
         p_tmp = p_tmp->p_next;
     }
 
@@ -667,7 +717,7 @@ void __module_Unneed( vlc_object_t * p_this, module_t * p_module )
 
     msg_Dbg( p_this, "removing module \"%s\"", p_module->psz_object_name );
 
-    vlc_object_release( p_module );
+    module_release( p_module );
 }
 
 /**
@@ -679,23 +729,24 @@ void __module_Unneed( vlc_object_t * p_this, module_t * p_module )
  */
 module_t *__module_Find( vlc_object_t *p_this, const char * psz_name )
 {
-    vlc_list_t *p_list;
-    int i;
-    p_list = vlc_list_find( p_this, VLC_OBJECT_MODULE, FIND_ANYWHERE );
-    for( i = 0 ; i < p_list->i_count; i++)
+    module_t **list, *module;
+
+    list = module_list_get (NULL);
+    if (!list)
+        return NULL;
+
+    for (size_t i = 0; (module = list[i]) != NULL; i++)
     {
-        module_t *p_module = ((module_t *) p_list->p_values[i].p_object);
-        const char *psz_module_name = p_module->psz_object_name;
+        const char *psz_module_name = module->psz_object_name;
+
         if( psz_module_name && !strcmp( psz_module_name, psz_name ) )
         {
-            /* We can release the list, and return yes */
-            vlc_object_hold( p_module );
-            vlc_list_release( p_list );
-            return p_module;
+            module_hold (module);
+            break;
         }
     }
-    vlc_list_release( p_list );
-    return NULL;
+    module_list_free (list);
+    return module;
 }
 
 
@@ -707,7 +758,7 @@ module_t *__module_Find( vlc_object_t *p_this, const char * psz_name )
  */
 void module_Put( module_t *module )
 {
-    vlc_object_release( module );
+    module_release( module );
 }
 
 
@@ -748,16 +799,17 @@ char ** __module_GetModulesNamesForCapability( vlc_object_t *p_this,
                                                const char *psz_capability,
                                                char ***pppsz_longname )
 {
-    vlc_list_t *p_list;
-    int i, j, count = 0;
+    size_t count = 0;
     char **psz_ret;
 
+    module_t **list = module_list_get (NULL);
+
     /* Do it in two passes : count the number of modules before */
-    p_list = vlc_list_find( p_this, VLC_OBJECT_MODULE, FIND_ANYWHERE );
-    for( i = 0 ; i < p_list->i_count; i++)
+    for (size_t i = 0; list[i]; i++)
     {
-        module_t *p_module = ((module_t *) p_list->p_values[i].p_object);
+        module_t *p_module = list[i];
         const char *psz_module_capability = p_module->psz_capability;
+
         if( psz_module_capability && !strcmp( psz_module_capability, psz_capability ) )
             count++;
     }
@@ -770,15 +822,15 @@ char ** __module_GetModulesNamesForCapability( vlc_object_t *p_this,
         free( psz_ret );
         free( *pppsz_longname );
         *pppsz_longname = NULL;
-        vlc_list_release( p_list );
+        module_list_free (list);
         return NULL;
     }
 
-    j = 0;
-    for( i = 0 ; i < p_list->i_count; i++)
+    for (size_t i = 0, j = 0; list[i]; i++)
     {
-        module_t *p_module = ((module_t *) p_list->p_values[i].p_object);
+        module_t *p_module = list[i];
         const char *psz_module_capability = p_module->psz_capability;
+
         if( psz_module_capability && !strcmp( psz_module_capability, psz_capability ) )
         {
             int k = -1; /* hack to handle submodules properly */
@@ -796,7 +848,7 @@ char ** __module_GetModulesNamesForCapability( vlc_object_t *p_this,
     }
     psz_ret[count] = NULL;
 
-    vlc_list_release( p_list );
+    module_list_free (list);
 
     return psz_ret;
 }
@@ -1192,8 +1244,8 @@ static int AllocatePluginFile( vlc_object_t * p_this, char * psz_file,
 
         /* msg_Dbg( p_this, "plugin \"%s\", %s",
                     p_module->psz_object_name, p_module->psz_longname ); */
-
-        vlc_object_attach( p_module, p_module_bank );
+        p_module->next = p_module_bank->head;
+        p_module_bank->head = p_module;
 
         if( !p_module_bank->b_cache )
             return 0;
@@ -1248,10 +1300,10 @@ static module_t * AllocatePlugin( vlc_object_t * p_this, char * psz_file )
     p_module->b_loaded = true;
 
     /* Initialize the module: fill p_module, default config */
-    if( module_Call( VLC_OBJECT(p_module), p_module ) != 0 )
+    if( module_Call( p_this, p_module ) != 0 )
     {
         /* We couldn't call module_init() */
-        vlc_object_release( p_module );
+        module_release( p_module );
         module_Unload( handle );
         return NULL;
     }
@@ -1274,7 +1326,6 @@ static module_t * AllocatePlugin( vlc_object_t * p_this, char * psz_file )
 static void DupModule( module_t *p_module )
 {
     char **pp_shortcut;
-    int i_submodule;
 
     for( pp_shortcut = p_module->pp_shortcuts ; *pp_shortcut ; pp_shortcut++ )
     {
@@ -1290,10 +1341,8 @@ static void DupModule( module_t *p_module )
     p_module->psz_help = p_module->psz_help ? strdup( p_module->psz_help )
                                             : NULL;
 
-    for( i_submodule = 0; i_submodule < vlc_internals( p_module )->i_children; i_submodule++ )
-    {
-        DupModule( (module_t*)vlc_internals( p_module )->pp_children[ i_submodule ] );
-    }
+    for (module_t *subm = p_module->submodule; subm; subm = subm->next)
+        DupModule (subm);
 }
 
 /*****************************************************************************
@@ -1304,12 +1353,9 @@ static void DupModule( module_t *p_module )
 static void UndupModule( module_t *p_module )
 {
     char **pp_shortcut;
-    int i_submodule;
 
-    for( i_submodule = 0; i_submodule < vlc_internals( p_module )->i_children; i_submodule++ )
-    {
-        UndupModule( (module_t*)vlc_internals( p_module )->pp_children[ i_submodule ] );
-    }
+    for (module_t *subm = p_module->submodule; subm; subm = subm->next)
+        UndupModule (subm);
 
     for( pp_shortcut = p_module->pp_shortcuts ; *pp_shortcut ; pp_shortcut++ )
     {
@@ -1349,18 +1395,20 @@ static int AllocateBuiltinModule( vlc_object_t * p_this,
         /* With a well-written module we shouldn't have to print an
          * additional error message here, but just make sure. */
         msg_Err( p_this, "failed calling entry point in builtin module" );
-        vlc_object_release( p_module );
+        module_release( p_module );
         return -1;
     }
 
     /* Everything worked fine ! The module is ready to be added to the list. */
     p_module->b_builtin = true;
+    /* LOCK */
+    p_module->next = p_module_bank->head;
+    p_module_bank->head = p_module;
+    /* UNLOCK */
 
     /* msg_Dbg( p_this, "builtin \"%s\", %s",
                 p_module->psz_object_name, p_module->psz_longname ); */
 
-    vlc_object_attach( p_module, p_module_bank );
-
     return 0;
 }
 
@@ -1373,9 +1421,6 @@ static void DeleteModule( module_t * p_module, bool b_detach )
 {
     assert( p_module );
 
-    if( b_detach )
-        vlc_object_detach( p_module );
-
     /* We free the structures that we strdup()ed in Allocate*Module(). */
 #ifdef HAVE_DYNAMIC_PLUGINS
     if( !p_module->b_builtin )
@@ -1390,13 +1435,13 @@ static void DeleteModule( module_t * p_module, bool b_detach )
 #endif
 
     /* Free and detach the object's children */
-    while( vlc_internals( p_module )->i_children )
+    while (p_module->submodule)
     {
-        vlc_object_t *p_this = vlc_internals( p_module )->pp_children[0];
-        vlc_object_detach( p_this );
-        vlc_object_release( p_this );
+        module_t *submodule = p_module->submodule;
+        p_module->submodule = submodule->next;
+        module_release (submodule);
     }
 
     config_Free( p_module );
-    vlc_object_release( p_module );
+    module_release( p_module );
 }

src/modules/modules.h

@@ -56,6 +56,8 @@ struct module_bank_t
 
     int            i_loaded_cache;
     module_cache_t **pp_loaded_cache;
+
+    module_t       *head;
 };
 
 /*****************************************************************************
@@ -98,7 +100,13 @@ typedef shl_t module_handle_t;
  */
 struct module_t
 {
-    VLC_COMMON_MEMBERS
+    char       *psz_object_name;
+    module_t   *next;
+    module_t   *submodule;
+    module_t   *parent;
+    unsigned    submodule_count;
+    gc_object_t vlc_gc_data;
+    vlc_mutex_t lock;
 
     /*
      * Variables set by the module to identify itself
@@ -141,6 +149,16 @@ struct module_t
     bool          b_loaded;        /* Set to true if the dll is loaded */
 };
 
+static inline module_t *module_hold (module_t *m)
+{
+    vlc_hold (&m->vlc_gc_data);
+    return m;
+}
+
+static inline void module_release (module_t *m)
+{
+    vlc_release (&m->vlc_gc_data);
+}
 
 #define module_InitBank(a)     __module_InitBank(VLC_OBJECT(a))
 void  __module_InitBank        ( vlc_object_t * );