Include config.h so DISABLE_MEMPOOLS actually has an effect. (#96437,
[platform/upstream/glib.git] / gobject / gsignal.c
index 7394de1..3050ded 100644 (file)
  * MT safe
  */
 
+#include <config.h>
+
 #include        "gsignal.h"
 #include        "gbsearcharray.h"
 #include        "gvaluecollector.h"
 #include       "gvaluetypes.h"
 #include       "gboxed.h"
 #include       <string.h> 
+#include       <signal.h>
 
 
 /* pre allocation configurations
  */
 #define        MAX_STACK_VALUES        (16)
 #define HANDLER_PRE_ALLOC       (48)
-#define EMISSION_PRE_ALLOC      (16)
 
 #define REPORT_BUG      "please report occourance circumstances to gtk-devel-list@gnome.org"
 #ifdef G_ENABLE_DEBUG
@@ -129,17 +131,18 @@ static inline void                handler_ref             (Handler         *handler);
 static inline void             handler_unref_R         (guint            signal_id,
                                                         gpointer         instance,
                                                         Handler         *handler);
+static gint                    handler_lists_cmp       (gconstpointer    node1,
+                                                        gconstpointer    node2);
 static inline void             emission_push           (Emission       **emission_list_p,
-                                                        guint            signal_id,
-                                                        GQuark           detail,
-                                                        gpointer         instance,
-                                                        EmissionState   *state_p);
+                                                        Emission        *emission);
 static inline void             emission_pop            (Emission       **emission_list_p,
-                                                        EmissionState   *state_p);
+                                                        Emission        *emission);
 static inline Emission*                emission_find           (Emission        *emission_list,
                                                         guint            signal_id,
                                                         GQuark           detail,
                                                         gpointer         instance);
+static gint                    class_closures_cmp      (gconstpointer    node1,
+                                                        gconstpointer    node2);
 static gint                    signal_key_cmp          (gconstpointer    node1,
                                                         gconstpointer    node2);
 static       gboolean          signal_emit_unlocked_R  (SignalNode      *node,
@@ -147,6 +150,7 @@ static            gboolean          signal_emit_unlocked_R  (SignalNode      *node,
                                                         gpointer         instance,
                                                         GValue          *return_value,
                                                         const GValue    *instance_and_params);
+static const gchar *            type_debug_name         (GType            type);
 
 
 /* --- structures --- */
@@ -175,7 +179,7 @@ struct _SignalNode
   guint              n_params : 8;
   GType                    *param_types; /* mangled with G_SIGNAL_TYPE_STATIC_SCOPE flag */
   GType                     return_type; /* mangled with G_SIGNAL_TYPE_STATIC_SCOPE flag */
-  GClosure          *class_closure;
+  GBSearchArray     *class_closure_bsa;
   SignalAccumulator *accumulator;
   GSignalCMarshaller c_marshaller;
   GHookList         *emission_hooks;
@@ -190,11 +194,11 @@ struct _SignalKey
 
 struct _Emission
 {
-  Emission      *next;
-  guint          signal_id;
-  GQuark        detail;
-  gpointer       instance;
-  EmissionState *state_p;
+  Emission             *next;
+  gpointer              instance;
+  GSignalInvocationHint ihint;
+  EmissionState         state;
+  GType                        chain_type;
 };
 
 struct _HandlerList
@@ -225,16 +229,30 @@ struct _HandlerMatch
   } d;
 };
 
+typedef struct
+{
+  GType     instance_type; /* 0 for default closure */
+  GClosure *closure;
+} ClassClosure;
+
 
 /* --- variables --- */
-static GBSearchArray  g_signal_key_bsa = G_STATIC_BSEARCH_ARRAY_INIT (sizeof (SignalKey),
-                                                                     signal_key_cmp,
-                                                                     G_BSEARCH_ARRAY_ALIGN_POWER2);
+static GBSearchArray *g_signal_key_bsa = NULL;
+static GBSearchConfig g_signal_key_bconfig = G_STATIC_BCONFIG (sizeof (SignalKey),
+                                                              signal_key_cmp,
+                                                              G_BSEARCH_ARRAY_ALIGN_POWER2);
+static GBSearchConfig g_signal_hlbsa_bconfig = G_STATIC_BCONFIG (sizeof (HandlerList),
+                                                                handler_lists_cmp,
+                                                                G_BSEARCH_ARRAY_DEFER_SHRINK);
+static GBSearchConfig g_class_closure_bconfig = G_STATIC_BCONFIG (sizeof (ClassClosure),
+                                                                 class_closures_cmp,
+                                                                 0);
 static GHashTable    *g_handler_list_bsa_ht = NULL;
 static Emission      *g_recursive_emissions = NULL;
 static Emission      *g_restart_emissions = NULL;
+#ifndef DISABLE_MEM_POOLS
 static GTrashStack   *g_handler_ts = NULL;
-static GTrashStack   *g_emission_ts = NULL;
+#endif
 static gulong         g_handler_sequential_number = 1;
 G_LOCK_DEFINE_STATIC (g_signal_mutex);
 #define        SIGNAL_LOCK()           G_LOCK (g_signal_mutex)
@@ -272,7 +290,7 @@ signal_id_lookup (GQuark quark,
       SignalKey *signal_key;
       
       key.itype = type;
-      signal_key = g_bsearch_array_lookup (&g_signal_key_bsa, &key);
+      signal_key = g_bsearch_array_lookup (g_signal_key_bsa, &g_signal_key_bconfig, &key);
       
       if (signal_key)
        return signal_key->signal_id;
@@ -288,7 +306,7 @@ signal_id_lookup (GQuark quark,
       SignalKey *signal_key;
 
       key.itype = ifaces[n_ifaces];
-      signal_key = g_bsearch_array_lookup (&g_signal_key_bsa, &key);
+      signal_key = g_bsearch_array_lookup (g_signal_key_bsa, &g_signal_key_bconfig, &key);
 
       if (signal_key)
        {
@@ -302,6 +320,15 @@ signal_id_lookup (GQuark quark,
 }
 
 static gint
+class_closures_cmp (gconstpointer node1,
+                   gconstpointer node2)
+{
+  const ClassClosure *c1 = node1, *c2 = node2;
+  
+  return G_BSEARCH_ARRAY_CMP (c1->instance_type, c2->instance_type);
+}
+
+static gint
 handler_lists_cmp (gconstpointer node1,
                    gconstpointer node2)
 {
@@ -317,15 +344,23 @@ handler_list_ensure (guint    signal_id,
   GBSearchArray *hlbsa = g_hash_table_lookup (g_handler_list_bsa_ht, instance);
   HandlerList key;
   
+  key.signal_id = signal_id;
+  key.handlers = NULL;
   if (!hlbsa)
     {
-      hlbsa = g_bsearch_array_new (sizeof (HandlerList), handler_lists_cmp, G_BSEARCH_ARRAY_DEFER_SHRINK);
+      hlbsa = g_bsearch_array_new (&g_signal_hlbsa_bconfig);
+      hlbsa = g_bsearch_array_insert (hlbsa, &g_signal_hlbsa_bconfig, &key, FALSE);
       g_hash_table_insert (g_handler_list_bsa_ht, instance, hlbsa);
     }
-  key.signal_id = signal_id;
-  key.handlers = NULL;
-  
-  return g_bsearch_array_insert (hlbsa, &key, FALSE);
+  else
+    {
+      GBSearchArray *o = hlbsa;
+
+      hlbsa = g_bsearch_array_insert (o, &g_signal_hlbsa_bconfig, &key, FALSE);
+      if (hlbsa != o)
+       g_hash_table_insert (g_handler_list_bsa_ht, instance, hlbsa);
+    }
+  return g_bsearch_array_lookup (hlbsa, &g_signal_hlbsa_bconfig, &key);
 }
 
 static inline HandlerList*
@@ -337,7 +372,7 @@ handler_list_lookup (guint    signal_id,
   
   key.signal_id = signal_id;
   
-  return hlbsa ? g_bsearch_array_lookup (hlbsa, &key) : NULL;
+  return hlbsa ? g_bsearch_array_lookup (hlbsa, &g_signal_hlbsa_bconfig, &key) : NULL;
 }
 
 static Handler*
@@ -353,7 +388,7 @@ handler_lookup (gpointer instance,
       
       for (i = 0; i < hlbsa->n_nodes; i++)
         {
-          HandlerList *hlist = g_bsearch_array_get_nth (hlbsa, i);
+          HandlerList *hlist = g_bsearch_array_get_nth (hlbsa, &g_signal_hlbsa_bconfig, i);
           Handler *handler;
           
           for (handler = hlist->handlers; handler; handler = handler->next)
@@ -454,7 +489,7 @@ handlers_find (gpointer         instance,
           
           for (i = 0; i < hlbsa->n_nodes; i++)
             {
-              HandlerList *hlist = g_bsearch_array_get_nth (hlbsa, i);
+              HandlerList *hlist = g_bsearch_array_get_nth (hlbsa, &g_signal_hlbsa_bconfig, i);
              SignalNode *node = NULL;
               Handler *handler;
               
@@ -586,36 +621,29 @@ handler_insert (guint    signal_id,
 }
 
 static inline void
-emission_push (Emission     **emission_list_p,
-              guint          signal_id,
-              GQuark         detail,
-              gpointer       instance,
-              EmissionState *state_p)
-{
-  Emission *emission = g_generic_node_alloc (&g_emission_ts,
-                                             sizeof (Emission),
-                                             EMISSION_PRE_ALLOC);
+emission_push (Emission **emission_list_p,
+              Emission  *emission)
+{
   emission->next = *emission_list_p;
-  emission->signal_id = signal_id;
-  emission->detail = detail;
-  emission->instance = instance;
-  emission->state_p = state_p;
   *emission_list_p = emission;
 }
 
 static inline void
-emission_pop (Emission     **emission_list_p,
-             EmissionState *state_p)
+emission_pop (Emission **emission_list_p,
+             Emission  *emission)
 {
-  Emission **loc = emission_list_p, *emission = *loc;
-  
-  while (emission->state_p != state_p)
-    {
-      loc = &emission->next;
-      emission = *loc;
-    }
-  *loc = emission->next;
-  g_generic_node_free (&g_emission_ts, emission);
+  Emission *node, *last = NULL;
+
+  for (node = *emission_list_p; node; last = node, node = last->next)
+    if (node == emission)
+      {
+       if (last)
+         last->next = node->next;
+       else
+         *emission_list_p = node->next;
+       return;
+      }
+  g_assert_not_reached ();
 }
 
 static inline Emission*
@@ -628,12 +656,37 @@ emission_find (Emission *emission_list,
   
   for (emission = emission_list; emission; emission = emission->next)
     if (emission->instance == instance &&
-       emission->signal_id == signal_id &&
-       emission->detail == detail)
+       emission->ihint.signal_id == signal_id &&
+       emission->ihint.detail == detail)
       return emission;
   return NULL;
 }
 
+static inline Emission*
+emission_find_innermost (gpointer instance)
+{
+  Emission *emission, *s = NULL, *c = NULL;
+  
+  for (emission = g_restart_emissions; emission; emission = emission->next)
+    if (emission->instance == instance)
+      {
+       s = emission;
+       break;
+      }
+  for (emission = g_recursive_emissions; emission; emission = emission->next)
+    if (emission->instance == instance)
+      {
+       c = emission;
+       break;
+      }
+  if (!s)
+    return c;
+  else if (!c)
+    return s;
+  else
+    return G_HAVE_GROWING_STACK ? MAX (c, s) : MIN (c, s);
+}
+
 static gint
 signal_key_cmp (gconstpointer node1,
                 gconstpointer node2)
@@ -657,6 +710,7 @@ g_signal_init (void) /* sync with gtype.c */
       
       /* setup handler list binary searchable array hash table (in german, that'd be one word ;) */
       g_handler_list_bsa_ht = g_hash_table_new (g_direct_hash, NULL);
+      g_signal_key_bsa = g_bsearch_array_new (&g_signal_key_bconfig);
       
       /* invalid (0) signal_id */
       g_n_signal_nodes = 1;
@@ -681,7 +735,7 @@ _g_signals_destroy (GType itype)
           if (node->destroyed)
             g_warning (G_STRLOC ": signal \"%s\" of type `%s' already destroyed",
                        node->name,
-                       g_type_name (node->itype));
+                       type_debug_name (node->itype));
           else
            signal_destroy_R (node);
         }
@@ -714,11 +768,11 @@ g_signal_stop_emission (gpointer instance,
       
       if (emission)
         {
-          if (*emission->state_p == EMISSION_HOOK)
+          if (emission->state == EMISSION_HOOK)
             g_warning (G_STRLOC ": emission of signal \"%s\" for instance `%p' cannot be stopped from emission hook",
                        node->name, instance);
-          else if (*emission->state_p == EMISSION_RUN)
-            *emission->state_p = EMISSION_STOP;
+          else if (emission->state == EMISSION_RUN)
+            emission->state = EMISSION_STOP;
         }
       else
         g_warning (G_STRLOC ": no emission of signal \"%s\" to stop for instance `%p'",
@@ -781,7 +835,7 @@ g_signal_add_emission_hook (guint               signal_id,
     }
   hook = g_hook_alloc (node->emission_hooks);
   hook->data = hook_data;
-  hook->func = hook_func;
+  hook->func = (gpointer) hook_func;
   hook->destroy = data_destroy;
   signal_hook = SIGNAL_HOOK (hook);
   signal_hook->detail = detail;
@@ -915,11 +969,11 @@ g_signal_stop_emission_by_name (gpointer     instance,
          
          if (emission)
            {
-             if (*emission->state_p == EMISSION_HOOK)
+             if (emission->state == EMISSION_HOOK)
                g_warning (G_STRLOC ": emission of signal \"%s\" for instance `%p' cannot be stopped from emission hook",
                           node->name, instance);
-             else if (*emission->state_p == EMISSION_RUN)
-               *emission->state_p = EMISSION_STOP;
+             else if (emission->state == EMISSION_RUN)
+               emission->state = EMISSION_STOP;
            }
          else
            g_warning (G_STRLOC ": no emission of signal \"%s\" to stop for instance `%p'",
@@ -973,8 +1027,8 @@ g_signal_list_ids (GType  itype,
   g_return_val_if_fail (n_ids != NULL, NULL);
   
   SIGNAL_LOCK ();
-  keys = g_signal_key_bsa.nodes;
-  n_nodes  = g_signal_key_bsa.n_nodes;
+  keys = G_BSEARCH_ARRAY_NODES (g_signal_key_bsa);
+  n_nodes = g_signal_key_bsa->n_nodes;
   result = g_array_new (FALSE, FALSE, sizeof (guint));
   
   for (i = 0; i < n_nodes; i++)
@@ -1047,40 +1101,6 @@ g_signal_query (guint         signal_id,
 }
 
 guint
-g_signal_new_valist (const gchar       *signal_name,
-                     GType              itype,
-                     GSignalFlags       signal_flags,
-                     GClosure          *class_closure,
-                     GSignalAccumulator accumulator,
-                    gpointer           accu_data,
-                     GSignalCMarshaller c_marshaller,
-                     GType              return_type,
-                     guint              n_params,
-                     va_list            args)
-{
-  GType *param_types;
-  guint i;
-  guint signal_id;
-
-  if (n_params > 0)
-    {
-      param_types = g_new (GType, n_params);
-
-      for (i = 0; i < n_params; i++)
-       param_types[i] = va_arg (args, GType);
-    }
-  else
-    param_types = NULL;
-
-  signal_id = g_signal_newv (signal_name, itype, signal_flags,
-                            class_closure, accumulator, accu_data, c_marshaller,
-                            return_type, n_params, param_types);
-  g_free (param_types);
-
-  return signal_id;
-}
-
-guint
 g_signal_new (const gchar       *signal_name,
              GType               itype,
              GSignalFlags        signal_flags,
@@ -1109,6 +1129,65 @@ g_signal_new (const gchar         *signal_name,
   return signal_id;
 }
 
+static inline ClassClosure*
+signal_find_class_closure (SignalNode *node,
+                          GType       itype)
+{
+  GBSearchArray *bsa = node->class_closure_bsa;
+  ClassClosure *cc;
+
+  if (bsa)
+    {
+      ClassClosure key;
+
+      /* cc->instance_type is 0 for default closure */
+      
+      key.instance_type = itype;
+      cc = g_bsearch_array_lookup (bsa, &g_class_closure_bconfig, &key);
+      while (!cc && key.instance_type)
+       {
+         key.instance_type = g_type_parent (key.instance_type);
+         cc = g_bsearch_array_lookup (bsa, &g_class_closure_bconfig, &key);
+       }
+    }
+  else
+    cc = NULL;
+  return cc;
+}
+
+static inline GClosure*
+signal_lookup_closure (SignalNode    *node,
+                      GTypeInstance *instance)
+{
+  ClassClosure *cc;
+
+  if (node->class_closure_bsa && node->class_closure_bsa->n_nodes == 1)
+    cc = G_BSEARCH_ARRAY_NODES (node->class_closure_bsa);
+  else
+    cc = signal_find_class_closure (node, G_TYPE_FROM_INSTANCE (instance));
+  return cc ? cc->closure : NULL;
+}
+
+static void
+signal_add_class_closure (SignalNode *node,
+                         GType       itype,
+                         GClosure   *closure)
+{
+  ClassClosure key;
+
+  if (!node->class_closure_bsa)
+    node->class_closure_bsa = g_bsearch_array_new (&g_class_closure_bconfig);
+  key.instance_type = itype;
+  key.closure = g_closure_ref (closure);
+  node->class_closure_bsa = g_bsearch_array_insert (node->class_closure_bsa,
+                                                   &g_class_closure_bconfig,
+                                                   &key,
+                                                   FALSE);
+  g_closure_sink (closure);
+  if (node->c_marshaller && closure && G_CLOSURE_NEEDS_MARSHAL (closure))
+    g_closure_set_marshal (closure, node->c_marshaller);
+}
+
 guint
 g_signal_newv (const gchar       *signal_name,
                GType              itype,
@@ -1146,7 +1225,7 @@ g_signal_newv (const gchar       *signal_name,
     {
       g_warning (G_STRLOC ": signal \"%s\" already exists in the `%s' %s",
                  name,
-                 g_type_name (node->itype),
+                 type_debug_name (node->itype),
                  G_TYPE_IS_INTERFACE (node->itype) ? "interface" : "class ancestry");
       g_free (name);
       SIGNAL_UNLOCK ();
@@ -1156,8 +1235,8 @@ g_signal_newv (const gchar       *signal_name,
     {
       g_warning (G_STRLOC ": signal \"%s\" for type `%s' was previously created for type `%s'",
                  name,
-                 g_type_name (itype),
-                 g_type_name (node->itype));
+                 type_debug_name (itype),
+                 type_debug_name (node->itype));
       g_free (name);
       SIGNAL_UNLOCK ();
       return 0;
@@ -1166,7 +1245,7 @@ g_signal_newv (const gchar       *signal_name,
     if (!G_TYPE_IS_VALUE (param_types[i] & ~G_SIGNAL_TYPE_STATIC_SCOPE))
       {
        g_warning (G_STRLOC ": parameter %d of type `%s' for signal \"%s::%s\" is not a value type",
-                  i + 1, g_type_name (param_types[i] & ~G_SIGNAL_TYPE_STATIC_SCOPE), g_type_name (itype), name);
+                  i + 1, type_debug_name (param_types[i]), type_debug_name (itype), name);
        g_free (name);
        SIGNAL_UNLOCK ();
        return 0;
@@ -1174,7 +1253,7 @@ g_signal_newv (const gchar       *signal_name,
   if (return_type != G_TYPE_NONE && !G_TYPE_IS_VALUE (return_type & ~G_SIGNAL_TYPE_STATIC_SCOPE))
     {
       g_warning (G_STRLOC ": return value of type `%s' for signal \"%s::%s\" is not a value type",
-                g_type_name (return_type & ~G_SIGNAL_TYPE_STATIC_SCOPE), g_type_name (itype), name);
+                type_debug_name (return_type), type_debug_name (itype), name);
       g_free (name);
       SIGNAL_UNLOCK ();
       return 0;
@@ -1183,8 +1262,7 @@ g_signal_newv (const gchar       *signal_name,
       (signal_flags & (G_SIGNAL_RUN_FIRST | G_SIGNAL_RUN_LAST | G_SIGNAL_RUN_CLEANUP)) == G_SIGNAL_RUN_FIRST)
     {
       g_warning (G_STRLOC ": signal \"%s::%s\" has return type `%s' and is only G_SIGNAL_RUN_FIRST",
-                g_type_name (itype), name,
-                g_type_name (return_type & ~G_SIGNAL_TYPE_STATIC_SCOPE));
+                type_debug_name (itype), name, type_debug_name (return_type));
       g_free (name);
       SIGNAL_UNLOCK ();
       return 0;
@@ -1205,10 +1283,10 @@ g_signal_newv (const gchar       *signal_name,
       key.itype = itype;
       key.quark = g_quark_from_string (node->name);
       key.signal_id = signal_id;
-      g_bsearch_array_insert (&g_signal_key_bsa, &key, FALSE);
+      g_signal_key_bsa = g_bsearch_array_insert (g_signal_key_bsa, &g_signal_key_bconfig, &key, FALSE);
       g_strdelimit (node->name, "_", '-');
       key.quark = g_quark_from_static_string (node->name);
-      g_bsearch_array_insert (&g_signal_key_bsa, &key, FALSE);
+      g_signal_key_bsa = g_bsearch_array_insert (g_signal_key_bsa, &g_signal_key_bconfig, &key, FALSE);
     }
   node->destroyed = FALSE;
   
@@ -1217,9 +1295,7 @@ g_signal_newv (const gchar       *signal_name,
   node->n_params = n_params;
   node->param_types = g_memdup (param_types, sizeof (GType) * n_params);
   node->return_type = return_type;
-  node->class_closure = class_closure ? g_closure_ref (class_closure) : NULL;
-  if (class_closure)
-    g_closure_sink (class_closure);
+  node->class_closure_bsa = NULL;
   if (accumulator)
     {
       node->accumulator = g_new (SignalAccumulator, 1);
@@ -1230,9 +1306,44 @@ g_signal_newv (const gchar       *signal_name,
     node->accumulator = NULL;
   node->c_marshaller = c_marshaller;
   node->emission_hooks = NULL;
-  if (node->c_marshaller && class_closure && G_CLOSURE_NEEDS_MARSHAL (class_closure))
-    g_closure_set_marshal (class_closure, node->c_marshaller);
+  if (class_closure)
+    signal_add_class_closure (node, 0, class_closure);
   SIGNAL_UNLOCK ();
+
+  return signal_id;
+}
+
+guint
+g_signal_new_valist (const gchar       *signal_name,
+                     GType              itype,
+                     GSignalFlags       signal_flags,
+                     GClosure          *class_closure,
+                     GSignalAccumulator accumulator,
+                    gpointer           accu_data,
+                     GSignalCMarshaller c_marshaller,
+                     GType              return_type,
+                     guint              n_params,
+                     va_list            args)
+{
+  GType *param_types;
+  guint i;
+  guint signal_id;
+
+  if (n_params > 0)
+    {
+      param_types = g_new (GType, n_params);
+
+      for (i = 0; i < n_params; i++)
+       param_types[i] = va_arg (args, GType);
+    }
+  else
+    param_types = NULL;
+
+  signal_id = g_signal_newv (signal_name, itype, signal_flags,
+                            class_closure, accumulator, accu_data, c_marshaller,
+                            return_type, n_params, param_types);
+  g_free (param_types);
+
   return signal_id;
 }
 
@@ -1240,14 +1351,14 @@ static void
 signal_destroy_R (SignalNode *signal_node)
 {
   SignalNode node = *signal_node;
-  
+
   signal_node->destroyed = TRUE;
   
   /* reentrancy caution, zero out real contents first */
   signal_node->n_params = 0;
   signal_node->param_types = NULL;
   signal_node->return_type = 0;
-  signal_node->class_closure = NULL;
+  signal_node->class_closure_bsa = NULL;
   signal_node->accumulator = NULL;
   signal_node->c_marshaller = NULL;
   signal_node->emission_hooks = NULL;
@@ -1259,7 +1370,7 @@ signal_destroy_R (SignalNode *signal_node)
     
     for (emission = (node.flags & G_SIGNAL_NO_RECURSE) ? g_restart_emissions : g_recursive_emissions;
          emission; emission = emission->next)
-      if (emission->signal_id == node.signal_id)
+      if (emission->ihint.signal_id == node.signal_id)
         g_critical (G_STRLOC ": signal \"%s\" being destroyed is currently in emission (instance `%p')",
                     node.name, emission->instance);
   }
@@ -1269,7 +1380,18 @@ signal_destroy_R (SignalNode *signal_node)
    */
   SIGNAL_UNLOCK ();
   g_free (node.param_types);
-  g_closure_unref (node.class_closure);
+  if (node.class_closure_bsa)
+    {
+      guint i;
+
+      for (i = 0; i < node.class_closure_bsa->n_nodes; i++)
+       {
+         ClassClosure *cc = g_bsearch_array_get_nth (node.class_closure_bsa, &g_class_closure_bconfig, i);
+
+         g_closure_unref (cc->closure);
+       }
+      g_bsearch_array_destroy (node.class_closure_bsa, &g_class_closure_bconfig);
+    }
   g_free (node.accumulator);
   if (node.emission_hooks)
     {
@@ -1284,13 +1406,98 @@ g_signal_override_class_closure (guint     signal_id,
                                 GType     instance_type,
                                 GClosure *class_closure)
 {
+  SignalNode *node;
+  
+  g_return_if_fail (signal_id > 0);
+  g_return_if_fail (class_closure != NULL);
+  
+  SIGNAL_LOCK ();
+  node = LOOKUP_SIGNAL_NODE (signal_id);
+  if (!g_type_is_a (instance_type, node->itype))
+    g_warning ("%s: type `%s' cannot be overridden for signal id `%u'", G_STRLOC, type_debug_name (instance_type), signal_id);
+  else
+    {
+      ClassClosure *cc = signal_find_class_closure (node, instance_type);
+      
+      if (cc && cc->instance_type == instance_type)
+       g_warning ("%s: type `%s' is already overridden for signal id `%u'", G_STRLOC, type_debug_name (instance_type), signal_id);
+      else
+       signal_add_class_closure (node, instance_type, class_closure);
+    }
+  SIGNAL_UNLOCK ();
 }
 
 void
 g_signal_chain_from_overridden (const GValue *instance_and_params,
-                               guint         signal_id,
                                GValue       *return_value)
 {
+  GType chain_type = 0, restore_type = 0;
+  Emission *emission = NULL;
+  GClosure *closure = NULL;
+  guint n_params = 0;
+  gpointer instance;
+  
+  g_return_if_fail (instance_and_params != NULL);
+  instance = g_value_peek_pointer (instance_and_params);
+  g_return_if_fail (G_TYPE_CHECK_INSTANCE (instance));
+  
+  SIGNAL_LOCK ();
+  emission = emission_find_innermost (instance);
+  if (emission)
+    {
+      SignalNode *node = LOOKUP_SIGNAL_NODE (emission->ihint.signal_id);
+      
+      g_assert (node != NULL); /* paranoid */
+      
+      /* we should probably do the same parameter checks as g_signal_emit() here.
+       */
+      if (emission->chain_type != G_TYPE_NONE)
+       {
+         ClassClosure *cc = signal_find_class_closure (node, emission->chain_type);
+         
+         g_assert (cc != NULL);        /* closure currently in call stack */
+
+         n_params = node->n_params;
+         restore_type = cc->instance_type;
+         cc = signal_find_class_closure (node, g_type_parent (cc->instance_type));
+         if (cc && cc->instance_type != restore_type)
+           {
+             closure = cc->closure;
+             chain_type = cc->instance_type;
+           }
+       }
+      else
+       g_warning ("%s: signal id `%u' cannot be chained from current emission stage for instance `%p'", G_STRLOC, node->signal_id, instance);
+    }
+  else
+    g_warning ("%s: no signal is currently being emitted for instance `%p'", G_STRLOC, instance);
+  if (closure)
+    {
+      emission->chain_type = chain_type;
+      SIGNAL_UNLOCK ();
+      g_closure_invoke (closure,
+                       return_value,
+                       n_params + 1,
+                       instance_and_params,
+                       &emission->ihint);
+      SIGNAL_LOCK ();
+      emission->chain_type = restore_type;
+    }
+  SIGNAL_UNLOCK ();
+}
+
+GSignalInvocationHint*
+g_signal_get_invocation_hint (gpointer instance)
+{
+  Emission *emission = NULL;
+  
+  g_return_val_if_fail (G_TYPE_CHECK_INSTANCE (instance), NULL);
+
+  SIGNAL_LOCK ();
+  emission = emission_find_innermost (instance);
+  SIGNAL_UNLOCK ();
+  
+  return emission ? &emission->ihint : NULL;
 }
 
 gulong
@@ -1539,7 +1746,7 @@ g_signal_handlers_destroy (gpointer instance)
       
       for (i = 0; i < hlbsa->n_nodes; i++)
         {
-          HandlerList *hlist = g_bsearch_array_get_nth (hlbsa, i);
+          HandlerList *hlist = g_bsearch_array_get_nth (hlbsa, &g_signal_hlbsa_bconfig, i);
           Handler *handler = hlist->handlers;
          
           while (handler)
@@ -1558,7 +1765,7 @@ g_signal_handlers_destroy (gpointer instance)
                }
             }
         }
-      g_bsearch_array_destroy (hlbsa);
+      g_bsearch_array_destroy (hlbsa, &g_signal_hlbsa_bconfig);
     }
   SIGNAL_UNLOCK ();
 }
@@ -1781,7 +1988,7 @@ g_signal_emitv (const GValue *instance_and_params,
       {
        g_critical ("%s: value for `%s' parameter %u for signal \"%s\" is of type `%s'",
                    G_STRLOC,
-                   g_type_name (node->param_types[i] & ~G_SIGNAL_TYPE_STATIC_SCOPE),
+                   type_debug_name (node->param_types[i]),
                    i,
                    node->name,
                    G_VALUE_TYPE_NAME (param_values + i));
@@ -1794,7 +2001,7 @@ g_signal_emitv (const GValue *instance_and_params,
        {
          g_critical ("%s: return value `%s' for signal \"%s\" is (NULL)",
                      G_STRLOC,
-                     g_type_name (node->return_type & ~G_SIGNAL_TYPE_STATIC_SCOPE),
+                     type_debug_name (node->return_type),
                      node->name);
          SIGNAL_UNLOCK ();
          return;
@@ -1803,7 +2010,7 @@ g_signal_emitv (const GValue *instance_and_params,
        {
          g_critical ("%s: return value `%s' for signal \"%s\" is of type `%s'",
                      G_STRLOC,
-                     g_type_name (node->return_type & ~G_SIGNAL_TYPE_STATIC_SCOPE),
+                     type_debug_name (node->return_type),
                      node->name,
                      G_VALUE_TYPE_NAME (return_value));
          SIGNAL_UNLOCK ();
@@ -1993,9 +2200,8 @@ signal_emit_unlocked_R (SignalNode   *node,
                        GValue       *emission_return,
                        const GValue *instance_and_params)
 {
-  EmissionState emission_state = 0;
   SignalAccumulator *accumulator;
-  GSignalInvocationHint ihint;
+  Emission emission;
   GClosure *class_closure;
   HandlerList *hlist;
   Handler *handler_list = NULL;
@@ -2020,17 +2226,15 @@ signal_emit_unlocked_R (SignalNode   *node,
   signal_id = node->signal_id;
   if (node->flags & G_SIGNAL_NO_RECURSE)
     {
-      Emission *emission = emission_find (g_restart_emissions, signal_id, detail, instance);
+      Emission *node = emission_find (g_restart_emissions, signal_id, detail, instance);
       
-      if (emission)
+      if (node)
        {
-         *emission->state_p = EMISSION_RESTART;
+         node->state = EMISSION_RESTART;
          SIGNAL_UNLOCK ();
          return return_value_altered;
        }
     }
-  ihint.signal_id = node->signal_id;
-  ihint.detail = detail;
   accumulator = node->accumulator;
   if (accumulator)
     {
@@ -2041,9 +2245,14 @@ signal_emit_unlocked_R (SignalNode   *node,
     }
   else
     return_accu = emission_return;
-  emission_push ((node->flags & G_SIGNAL_NO_RECURSE) ? &g_restart_emissions : &g_recursive_emissions,
-                signal_id, detail, instance, &emission_state);
-  class_closure = node->class_closure;
+  emission.instance = instance;
+  emission.ihint.signal_id = node->signal_id;
+  emission.ihint.detail = detail;
+  emission.ihint.run_type = 0;
+  emission.state = 0;
+  emission.chain_type = G_TYPE_NONE;
+  emission_push ((node->flags & G_SIGNAL_NO_RECURSE) ? &g_restart_emissions : &g_recursive_emissions, &emission);
+  class_closure = signal_lookup_closure (node, instance);
   
  EMIT_RESTART:
   
@@ -2055,27 +2264,29 @@ signal_emit_unlocked_R (SignalNode   *node,
   if (handler_list)
     handler_ref (handler_list);
   
-  ihint.run_type = G_SIGNAL_RUN_FIRST;
+  emission.ihint.run_type = G_SIGNAL_RUN_FIRST;
   
   if ((node->flags & G_SIGNAL_RUN_FIRST) && class_closure)
     {
-      emission_state = EMISSION_RUN;
-      
+      emission.state = EMISSION_RUN;
+
+      emission.chain_type = G_TYPE_FROM_INSTANCE (instance);
       SIGNAL_UNLOCK ();
       g_closure_invoke (class_closure,
                        return_accu,
                        node->n_params + 1,
                        instance_and_params,
-                       &ihint);
-      if (!accumulate (&ihint, emission_return, &accu, accumulator) &&
-         emission_state == EMISSION_RUN)
-       emission_state = EMISSION_STOP;
+                       &emission.ihint);
+      if (!accumulate (&emission.ihint, emission_return, &accu, accumulator) &&
+         emission.state == EMISSION_RUN)
+       emission.state = EMISSION_STOP;
       SIGNAL_LOCK ();
+      emission.chain_type = G_TYPE_NONE;
       return_value_altered = TRUE;
       
-      if (emission_state == EMISSION_STOP)
+      if (emission.state == EMISSION_STOP)
        goto EMIT_CLEANUP;
-      else if (emission_state == EMISSION_RESTART)
+      else if (emission.state == EMISSION_RESTART)
        goto EMIT_RESTART;
     }
   
@@ -2084,7 +2295,7 @@ signal_emit_unlocked_R (SignalNode   *node,
       gboolean need_destroy, was_in_call, may_recurse = TRUE;
       GHook *hook;
 
-      emission_state = EMISSION_HOOK;
+      emission.state = EMISSION_HOOK;
       hook = g_hook_first_valid (node->emission_hooks, may_recurse);
       while (hook)
        {
@@ -2092,12 +2303,12 @@ signal_emit_unlocked_R (SignalNode   *node,
          
          if (!signal_hook->detail || signal_hook->detail == detail)
            {
-             GSignalEmissionHook hook_func = hook->func;
+             GSignalEmissionHook hook_func = (GSignalEmissionHook) hook->func;
              
              was_in_call = G_HOOK_IN_CALL (hook);
              hook->flags |= G_HOOK_FLAG_IN_CALL;
               SIGNAL_UNLOCK ();
-             need_destroy = !hook_func (&ihint, node->n_params + 1, instance_and_params, hook->data);
+             need_destroy = !hook_func (&emission.ihint, node->n_params + 1, instance_and_params, hook->data);
              SIGNAL_LOCK ();
              if (!was_in_call)
                hook->flags &= ~G_HOOK_FLAG_IN_CALL;
@@ -2107,7 +2318,7 @@ signal_emit_unlocked_R (SignalNode   *node,
          hook = g_hook_next_valid (node->emission_hooks, hook, may_recurse);
        }
       
-      if (emission_state == EMISSION_RESTART)
+      if (emission.state == EMISSION_RESTART)
        goto EMIT_RESTART;
     }
   
@@ -2115,7 +2326,7 @@ signal_emit_unlocked_R (SignalNode   *node,
     {
       Handler *handler = handler_list;
       
-      emission_state = EMISSION_RUN;
+      emission.state = EMISSION_RUN;
       handler_ref (handler);
       do
        {
@@ -2135,14 +2346,14 @@ signal_emit_unlocked_R (SignalNode   *node,
                                return_accu,
                                node->n_params + 1,
                                instance_and_params,
-                               &ihint);
-             if (!accumulate (&ihint, emission_return, &accu, accumulator) &&
-                 emission_state == EMISSION_RUN)
-               emission_state = EMISSION_STOP;
+                               &emission.ihint);
+             if (!accumulate (&emission.ihint, emission_return, &accu, accumulator) &&
+                 emission.state == EMISSION_RUN)
+               emission.state = EMISSION_STOP;
              SIGNAL_LOCK ();
              return_value_altered = TRUE;
              
-             tmp = emission_state == EMISSION_RUN ? handler->next : NULL;
+             tmp = emission.state == EMISSION_RUN ? handler->next : NULL;
            }
          else
            tmp = handler->next;
@@ -2155,33 +2366,35 @@ signal_emit_unlocked_R (SignalNode   *node,
        }
       while (handler);
       
-      if (emission_state == EMISSION_STOP)
+      if (emission.state == EMISSION_STOP)
        goto EMIT_CLEANUP;
-      else if (emission_state == EMISSION_RESTART)
+      else if (emission.state == EMISSION_RESTART)
        goto EMIT_RESTART;
     }
   
-  ihint.run_type = G_SIGNAL_RUN_LAST;
+  emission.ihint.run_type = G_SIGNAL_RUN_LAST;
   
   if ((node->flags & G_SIGNAL_RUN_LAST) && class_closure)
     {
-      emission_state = EMISSION_RUN;
+      emission.state = EMISSION_RUN;
       
+      emission.chain_type = G_TYPE_FROM_INSTANCE (instance);
       SIGNAL_UNLOCK ();
       g_closure_invoke (class_closure,
                        return_accu,
                        node->n_params + 1,
                        instance_and_params,
-                       &ihint);
-      if (!accumulate (&ihint, emission_return, &accu, accumulator) &&
-         emission_state == EMISSION_RUN)
-       emission_state = EMISSION_STOP;
+                       &emission.ihint);
+      if (!accumulate (&emission.ihint, emission_return, &accu, accumulator) &&
+         emission.state == EMISSION_RUN)
+       emission.state = EMISSION_STOP;
       SIGNAL_LOCK ();
+      emission.chain_type = G_TYPE_NONE;
       return_value_altered = TRUE;
       
-      if (emission_state == EMISSION_STOP)
+      if (emission.state == EMISSION_STOP)
        goto EMIT_CLEANUP;
-      else if (emission_state == EMISSION_RESTART)
+      else if (emission.state == EMISSION_RESTART)
        goto EMIT_RESTART;
     }
   
@@ -2189,7 +2402,7 @@ signal_emit_unlocked_R (SignalNode   *node,
     {
       Handler *handler = handler_list;
       
-      emission_state = EMISSION_RUN;
+      emission.state = EMISSION_RUN;
       handler_ref (handler);
       do
        {
@@ -2203,14 +2416,14 @@ signal_emit_unlocked_R (SignalNode   *node,
                                return_accu,
                                node->n_params + 1,
                                instance_and_params,
-                               &ihint);
-             if (!accumulate (&ihint, emission_return, &accu, accumulator) &&
-                 emission_state == EMISSION_RUN)
-               emission_state = EMISSION_STOP;
+                               &emission.ihint);
+             if (!accumulate (&emission.ihint, emission_return, &accu, accumulator) &&
+                 emission.state == EMISSION_RUN)
+               emission.state = EMISSION_STOP;
              SIGNAL_LOCK ();
              return_value_altered = TRUE;
              
-             tmp = emission_state == EMISSION_RUN ? handler->next : NULL;
+             tmp = emission.state == EMISSION_RUN ? handler->next : NULL;
            }
          else
            tmp = handler->next;
@@ -2222,22 +2435,23 @@ signal_emit_unlocked_R (SignalNode   *node,
        }
       while (handler);
       
-      if (emission_state == EMISSION_STOP)
+      if (emission.state == EMISSION_STOP)
        goto EMIT_CLEANUP;
-      else if (emission_state == EMISSION_RESTART)
+      else if (emission.state == EMISSION_RESTART)
        goto EMIT_RESTART;
     }
   
  EMIT_CLEANUP:
   
-  ihint.run_type = G_SIGNAL_RUN_CLEANUP;
+  emission.ihint.run_type = G_SIGNAL_RUN_CLEANUP;
   
   if ((node->flags & G_SIGNAL_RUN_CLEANUP) && class_closure)
     {
       gboolean need_unset = FALSE;
       
-      emission_state = EMISSION_STOP;
+      emission.state = EMISSION_STOP;
       
+      emission.chain_type = G_TYPE_FROM_INSTANCE (instance);
       SIGNAL_UNLOCK ();
       if (node->return_type != G_TYPE_NONE && !accumulator)
        {
@@ -2248,19 +2462,20 @@ signal_emit_unlocked_R (SignalNode   *node,
                        node->return_type != G_TYPE_NONE ? &accu : NULL,
                        node->n_params + 1,
                        instance_and_params,
-                       &ihint);
+                       &emission.ihint);
       if (need_unset)
        g_value_unset (&accu);
       SIGNAL_LOCK ();
+      emission.chain_type = G_TYPE_NONE;
       
-      if (emission_state == EMISSION_RESTART)
+      if (emission.state == EMISSION_RESTART)
        goto EMIT_RESTART;
     }
   
   if (handler_list)
     handler_unref_R (signal_id, instance, handler_list);
   
-  emission_pop ((node->flags & G_SIGNAL_NO_RECURSE) ? &g_restart_emissions : &g_recursive_emissions, &emission_state);
+  emission_pop ((node->flags & G_SIGNAL_NO_RECURSE) ? &g_restart_emissions : &g_recursive_emissions, &emission);
   SIGNAL_UNLOCK ();
   if (accumulator)
     g_value_unset (&accu);
@@ -2268,6 +2483,17 @@ signal_emit_unlocked_R (SignalNode   *node,
   return return_value_altered;
 }
 
+static const gchar*
+type_debug_name (GType type)
+{
+  if (type)
+    {
+      const char *name = g_type_name (type & ~G_SIGNAL_TYPE_STATIC_SCOPE);
+      return name ? name : "<unknown>";
+    }
+  else
+    return "<invalid>";
+}
 
 /* --- compile standard marshallers --- */
 #include       "gobject.h"