/* GObject - GLib Type, Object, Parameter and Signal Library

 * Copyright (C) 2000-2001 Red Hat, Inc.

 * Portions copyright (c) 2006-2009 Nokia Corporation.  All rights reserved.

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2 of the License, or (at your option) any later version.

 *

 * This library is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General

 * Public License along with this library; if not, write to the

 * Free Software Foundation, Inc., 59 Temple Place, Suite 330,

 * Boston, MA 02111-1307, USA.

 *

 * this code is based on the original GtkSignal implementation

 * for the Gtk+ library by Peter Mattis <petm@xcf.berkeley.edu>

 */

/*

 * MT safe

 */

#include "config.h"

#include <string.h>

#include <signal.h>

#include "gsignal.h"

#include "gbsearcharray.h"

#include "gvaluecollector.h"

#include "gvaluetypes.h"

#include "gboxed.h"

#include "gobject.h"

#include "genums.h"

#include "gobjectalias.h"

#ifdef __SYMBIAN32__

#include <glib_global.h>

#include "gobject_wsd.h"

#endif /* __SYMBIAN32__ */

/**

 * SECTION:signals

 * @short_description: A means for customization of object behaviour

 *     and a general purpose notification mechanism

 * @title: Signals

 *

 * The basic concept of the signal system is that of the

 * <emphasis>emission</emphasis> of a signal. Signals are introduced

 * per-type and are identified through strings.  Signals introduced

 * for a parent type are available in derived types as well, so

 * basically they are a per-type facility that is inherited.  A signal

 * emission mainly involves invocation of a certain set of callbacks

 * in precisely defined manner. There are two main categories of such

 * callbacks, per-object 

 * <footnote><para>Although signals can deal with any kind of instantiatable 

 * type, i'm referring to those types as "object types" in the following, 

 * simply because that is the context most users will encounter signals in.

 * </para></footnote>

 * ones and user provided ones.

 * The per-object callbacks are most often referred to as "object method

 * handler" or "default (signal) handler", while user provided callbacks are

 * usually just called "signal handler".

 * The object method handler is provided at signal creation time (this most

 * frequently happens at the end of an object class' creation), while user

 * provided handlers are frequently connected and disconnected to/from a certain

 * signal on certain object instances.

 *

 * A signal emission consists of five stages, unless prematurely stopped:

 * <variablelist>

 * <varlistentry><term></term><listitem><para>

 * 	1 - Invocation of the object method handler for %G_SIGNAL_RUN_FIRST signals

 * </para></listitem></varlistentry>

 * <varlistentry><term></term><listitem><para>

 * 	2 - Invocation of normal user-provided signal handlers (<emphasis>after</emphasis> flag %FALSE)

 * </para></listitem></varlistentry>

 * <varlistentry><term></term><listitem><para>

 * 	3 - Invocation of the object method handler for %G_SIGNAL_RUN_LAST signals

 * </para></listitem></varlistentry>

 * <varlistentry><term></term><listitem><para>

 * 	4 - Invocation of user provided signal handlers, connected with an <emphasis>after</emphasis> flag of %TRUE

 * </para></listitem></varlistentry>

 * <varlistentry><term></term><listitem><para>

 * 	5 - Invocation of the object method handler for %G_SIGNAL_RUN_CLEANUP signals

 * </para></listitem></varlistentry>

 * </variablelist>

 * The user-provided signal handlers are called in the order they were

 * connected in.

 * All handlers may prematurely stop a signal emission, and any number of

 * handlers may be connected, disconnected, blocked or unblocked during

 * a signal emission.

 * There are certain criteria for skipping user handlers in stages 2 and 4

 * of a signal emission.

 * First, user handlers may be <emphasis>blocked</emphasis>, blocked handlers are omitted

 * during callback invocation, to return from the "blocked" state, a

 * handler has to get unblocked exactly the same amount of times

 * it has been blocked before.

 * Second, upon emission of a %G_SIGNAL_DETAILED signal, an additional

 * "detail" argument passed in to g_signal_emit() has to match the detail

 * argument of the signal handler currently subject to invocation.

 * Specification of no detail argument for signal handlers (omission of the

 * detail part of the signal specification upon connection) serves as a

 * wildcard and matches any detail argument passed in to emission.

 */

#define REPORT_BUG      "please report occurrence circumstances to gtk-devel-list@gnome.org"

#ifdef	G_ENABLE_DEBUG

#define IF_DEBUG(debug_type, cond)	if ((_g_type_debug_flags & G_TYPE_DEBUG_ ## debug_type) || cond)

#if EMULATOR

PLS(g_trace_instance_signals,gsignal,volatile gpointer )

PLS(g_trap_instance_signals,gsignal,volatile gpointer )

#define g_trace_instance_signals (*FUNCTION_NAME(g_trace_instance_signals,gsignal)())

#define g_trap_instance_signals (*FUNCTION_NAME(g_trap_instance_signals,gsignal)())

#else

static volatile gpointer g_trace_instance_signals = NULL;

static volatile gpointer g_trap_instance_signals = NULL;

#endif /* EMULATOR */

#endif	/* G_ENABLE_DEBUG */

/* --- typedefs --- */

typedef struct _SignalNode   SignalNode;

typedef struct _SignalKey    SignalKey;

typedef struct _Emission     Emission;

typedef struct _Handler      Handler;

typedef struct _HandlerList  HandlerList;

typedef struct _HandlerMatch HandlerMatch;

typedef enum

{

  EMISSION_STOP,

  EMISSION_RUN,

  EMISSION_HOOK,

  EMISSION_RESTART

} EmissionState;

/* --- prototypes --- */

static inline guint		signal_id_lookup	(GQuark		  quark,

							 GType		  itype);

static	      void		signal_destroy_R	(SignalNode	 *signal_node);

static inline HandlerList*	handler_list_ensure	(guint		  signal_id,

							 gpointer	  instance);

static inline HandlerList*	handler_list_lookup	(guint		  signal_id,

							 gpointer	  instance);

static inline Handler*		handler_new		(gboolean	  after);

static	      void		handler_insert		(guint		  signal_id,

							 gpointer	  instance,

							 Handler	 *handler);

static	      Handler*		handler_lookup		(gpointer	  instance,

							 gulong		  handler_id,

							 guint		 *signal_id_p);

static inline HandlerMatch*	handler_match_prepend	(HandlerMatch	 *list,

							 Handler	 *handler,

							 guint		  signal_id);

static inline HandlerMatch*	handler_match_free1_R	(HandlerMatch	 *node,

							 gpointer	  instance);

static	      HandlerMatch*	handlers_find		(gpointer	  instance,

							 GSignalMatchType mask,

							 guint		  signal_id,

							 GQuark		  detail,

							 GClosure	 *closure,

							 gpointer	  func,

							 gpointer	  data,

							 gboolean	  one_and_only);

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,

							 Emission	 *emission);

static inline void		emission_pop		(Emission	**emission_list_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,

							 GQuark		  detail,

							 gpointer	  instance,

							 GValue		 *return_value,

							 const GValue	 *instance_and_params);

static const gchar *            type_debug_name         (GType            type);

/* --- structures --- */

typedef struct

{

  GSignalAccumulator func;

  gpointer           data;

} SignalAccumulator;

typedef struct

{

  GHook hook;

  GQuark detail;

} SignalHook;

#define	SIGNAL_HOOK(hook)	((SignalHook*) (hook))

struct _SignalNode

{

  /* permanent portion */

  guint              signal_id;

  GType              itype;

  const gchar       *name;

  guint              destroyed : 1;

  /* reinitializable portion */

  guint		     test_class_offset : 12;

  guint              flags : 8;

  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 */

  GBSearchArray     *class_closure_bsa;

  SignalAccumulator *accumulator;

  GSignalCMarshaller c_marshaller;

  GHookList         *emission_hooks;

};

#define	MAX_TEST_CLASS_OFFSET	(4096)	/* 2^12, 12 bits for test_class_offset */

#define	TEST_CLASS_MAGIC	(1)	/* indicates NULL class closure, candidate for NOP optimization */

struct _SignalKey

{

  GType  itype;

  GQuark quark;

  guint  signal_id;

};

struct _Emission

{

  Emission             *next;

  gpointer              instance;

  GSignalInvocationHint ihint;

  EmissionState         state;

  GType			chain_type;

};

struct _HandlerList

{

  guint    signal_id;

  Handler *handlers;

  Handler *tail_before;  /* normal signal handlers are appended here  */

  Handler *tail_after;   /* CONNECT_AFTER handlers are appended here  */

};

struct _Handler

{

  gulong        sequential_number;

  Handler      *next;

  Handler      *prev;

  GQuark	detail;

  guint         ref_count;

  guint         block_count : 16;

#define HANDLER_MAX_BLOCK_COUNT (1 << 16)

  guint         after : 1;

  GClosure     *closure;

};

struct _HandlerMatch

{

  Handler      *handler;

  HandlerMatch *next;

  guint         signal_id;

};

typedef struct

{

  GType     instance_type; /* 0 for default closure */

  GClosure *closure;

} ClassClosure;

/* --- variables --- */

#if EMULATOR

PLS(g_signal_key_bsa,gsignal,GBSearchArray *)

PLS(g_signal_hlbsa_bconfig,gsignal,GBSearchConfig)

PLS(g_class_closure_bconfig,gsignal,GBSearchConfig)

PLS(g_handler_list_bsa_ht,gsignal,GHashTable    *)

PLS(g_recursive_emissions,gsignal,Emission *)

PLS(g_restart_emissions ,gsignal,Emission *)

PLS(g_handler_sequential_number ,gsignal,gulong)

PLS_MACRO(g_signal_mutex,gsignal,GStaticMutex)

PLS(g_n_signal_nodes,gsignal,guint)

PLS(g_signal_nodes ,gsignal,SignalNode   **)

#define g_signal_key_bsa (*FUNCTION_NAME(g_signal_key_bsa,gsignal)())

#define g_signal_hlbsa_bconfig (*FUNCTION_NAME(g_signal_hlbsa_bconfig,gsignal)())

#define g_class_closure_bconfig (*FUNCTION_NAME(g_class_closure_bconfig,gsignal)())

#define g_handler_list_bsa_ht (*FUNCTION_NAME(g_handler_list_bsa_ht,gsignal)())

#define g_recursive_emissions (*FUNCTION_NAME(g_recursive_emissions,gsignal)())

#define g_restart_emissions  (*FUNCTION_NAME(g_restart_emissions ,gsignal)())

#define g_handler_sequential_number  (*FUNCTION_NAME(g_handler_sequential_number ,gsignal)())

#define g__g_signal_mutex_lock (*FUNCTION_NAME_MACRO(g_signal_mutex,gsignal)())

#define g_n_signal_nodes (*FUNCTION_NAME(g_n_signal_nodes,gsignal)())

#define g_signal_nodes (*FUNCTION_NAME(g_signal_nodes,gsignal)())

const GBSearchConfig temp_g_signal_hlbsa_bconfig = {

  sizeof (HandlerList),

  handler_lists_cmp,

  0,

};

 const GBSearchConfig temp_g_class_closure_bconfig = {

  sizeof (ClassClosure),

  class_closures_cmp,

  0,

};

#else

static GBSearchArray *g_signal_key_bsa = NULL;

#endif//EMULATOR

static const GBSearchConfig g_signal_key_bconfig = {

  sizeof (SignalKey),

  signal_key_cmp,

  G_BSEARCH_ARRAY_ALIGN_POWER2,

};

#if (!EMULATOR)

static GBSearchConfig g_signal_hlbsa_bconfig = {

  sizeof (HandlerList),

  handler_lists_cmp,

  0,

};

static GBSearchConfig g_class_closure_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;

static gulong         g_handler_sequential_number = 1;

G_LOCK_DEFINE_STATIC (g_signal_mutex);

#endif//EMULATOR

#define	SIGNAL_LOCK()		G_LOCK (g_signal_mutex)

#define	SIGNAL_UNLOCK()		G_UNLOCK (g_signal_mutex)

/* --- signal nodes --- */

#if (!EMULATOR)

static guint          g_n_signal_nodes = 0;

static SignalNode   **g_signal_nodes = NULL;

#endif /* EMULATOR */

static inline SignalNode*

LOOKUP_SIGNAL_NODE (register guint signal_id)

{

  if (signal_id < g_n_signal_nodes)

    return g_signal_nodes[signal_id];

  else

    return NULL;

}

/* --- functions --- */

static inline guint

signal_id_lookup (GQuark quark,

		  GType  itype)

{

  GType *ifaces, type = itype;

  SignalKey key;

  guint n_ifaces;

  key.quark = quark;

  /* try looking up signals for this type and its ancestors */

  do

    {

      SignalKey *signal_key;

      key.itype = type;

      signal_key = g_bsearch_array_lookup (g_signal_key_bsa, &g_signal_key_bconfig, &key);

      if (signal_key)

	return signal_key->signal_id;

      type = g_type_parent (type);

    }

  while (type);

  /* no luck, try interfaces it exports */

  ifaces = g_type_interfaces (itype, &n_ifaces);

  while (n_ifaces--)

    {

      SignalKey *signal_key;

      key.itype = ifaces[n_ifaces];

      signal_key = g_bsearch_array_lookup (g_signal_key_bsa, &g_signal_key_bconfig, &key);

      if (signal_key)

	{

	  g_free (ifaces);

	  return signal_key->signal_id;

	}

    }

  g_free (ifaces);

  return 0;

}

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)

{

  const HandlerList *hlist1 = node1, *hlist2 = node2;

  return G_BSEARCH_ARRAY_CMP (hlist1->signal_id, hlist2->signal_id);

}

static inline HandlerList*

handler_list_ensure (guint    signal_id,

		     gpointer instance)

{

  GBSearchArray *hlbsa = g_hash_table_lookup (g_handler_list_bsa_ht, instance);

  HandlerList key;

  key.signal_id = signal_id;

  key.handlers    = NULL;

  key.tail_before = NULL;

  key.tail_after  = NULL;

  if (!hlbsa)

    {

      hlbsa = g_bsearch_array_create (&g_signal_hlbsa_bconfig);

      hlbsa = g_bsearch_array_insert (hlbsa, &g_signal_hlbsa_bconfig, &key);

      g_hash_table_insert (g_handler_list_bsa_ht, instance, hlbsa);

    }

  else

    {

      GBSearchArray *o = hlbsa;

      hlbsa = g_bsearch_array_insert (o, &g_signal_hlbsa_bconfig, &key);

      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*

handler_list_lookup (guint    signal_id,

		     gpointer instance)

{

  GBSearchArray *hlbsa = g_hash_table_lookup (g_handler_list_bsa_ht, instance);

  HandlerList key;

  key.signal_id = signal_id;

  return hlbsa ? g_bsearch_array_lookup (hlbsa, &g_signal_hlbsa_bconfig, &key) : NULL;

}

static Handler*

handler_lookup (gpointer instance,

		gulong   handler_id,

		guint   *signal_id_p)

{

  GBSearchArray *hlbsa = g_hash_table_lookup (g_handler_list_bsa_ht, instance);

  if (hlbsa)

    {

      guint i;

      for (i = 0; i < hlbsa->n_nodes; i++)

        {

          HandlerList *hlist = g_bsearch_array_get_nth (hlbsa, &g_signal_hlbsa_bconfig, i);

          Handler *handler;

          for (handler = hlist->handlers; handler; handler = handler->next)

            if (handler->sequential_number == handler_id)

              {

                if (signal_id_p)

                  *signal_id_p = hlist->signal_id;

                return handler;

              }

        }

    }

  return NULL;

}

static inline HandlerMatch*

handler_match_prepend (HandlerMatch *list,

		       Handler      *handler,

		       guint	     signal_id)

{

  HandlerMatch *node;

  node = g_slice_new (HandlerMatch);

  node->handler = handler;

  node->next = list;

  node->signal_id = signal_id;

  handler_ref (handler);

  return node;

}

static inline HandlerMatch*

handler_match_free1_R (HandlerMatch *node,

		       gpointer      instance)

{

  HandlerMatch *next = node->next;

  handler_unref_R (node->signal_id, instance, node->handler);

  g_slice_free (HandlerMatch, node);

  return next;

}

static HandlerMatch*

handlers_find (gpointer         instance,

	       GSignalMatchType mask,

	       guint            signal_id,

	       GQuark           detail,

	       GClosure        *closure,

	       gpointer         func,

	       gpointer         data,

	       gboolean         one_and_only)

{

  HandlerMatch *mlist = NULL;

  if (mask & G_SIGNAL_MATCH_ID)

    {

      HandlerList *hlist = handler_list_lookup (signal_id, instance);

      Handler *handler;

      SignalNode *node = NULL;

      if (mask & G_SIGNAL_MATCH_FUNC)

	{

	  node = LOOKUP_SIGNAL_NODE (signal_id);

	  if (!node || !node->c_marshaller)

	    return NULL;

	}

      mask = ~mask;

      for (handler = hlist ? hlist->handlers : NULL; handler; handler = handler->next)

        if (handler->sequential_number &&

	    ((mask & G_SIGNAL_MATCH_DETAIL) || handler->detail == detail) &&

	    ((mask & G_SIGNAL_MATCH_CLOSURE) || handler->closure == closure) &&

            ((mask & G_SIGNAL_MATCH_DATA) || handler->closure->data == data) &&

	    ((mask & G_SIGNAL_MATCH_UNBLOCKED) || handler->block_count == 0) &&

	    ((mask & G_SIGNAL_MATCH_FUNC) || (handler->closure->marshal == node->c_marshaller &&

					      handler->closure->meta_marshal == 0 &&

					      ((GCClosure*) handler->closure)->callback == func)))

	  {

	    mlist = handler_match_prepend (mlist, handler, signal_id);

	    if (one_and_only)

	      return mlist;

	  }

    }

  else

    {

      GBSearchArray *hlbsa = g_hash_table_lookup (g_handler_list_bsa_ht, instance);

      mask = ~mask;

      if (hlbsa)

        {

          guint i;

          for (i = 0; i < hlbsa->n_nodes; i++)

            {

              HandlerList *hlist = g_bsearch_array_get_nth (hlbsa, &g_signal_hlbsa_bconfig, i);

	      SignalNode *node = NULL;

              Handler *handler;

	      if (!(mask & G_SIGNAL_MATCH_FUNC))

		{

		  node = LOOKUP_SIGNAL_NODE (hlist->signal_id);

		  if (!node->c_marshaller)

		    continue;

		}

              for (handler = hlist->handlers; handler; handler = handler->next)

		if (handler->sequential_number &&

		    ((mask & G_SIGNAL_MATCH_DETAIL) || handler->detail == detail) &&

                    ((mask & G_SIGNAL_MATCH_CLOSURE) || handler->closure == closure) &&

                    ((mask & G_SIGNAL_MATCH_DATA) || handler->closure->data == data) &&

		    ((mask & G_SIGNAL_MATCH_UNBLOCKED) || handler->block_count == 0) &&

		    ((mask & G_SIGNAL_MATCH_FUNC) || (handler->closure->marshal == node->c_marshaller &&

						      handler->closure->meta_marshal == 0 &&

						      ((GCClosure*) handler->closure)->callback == func)))

		  {

		    mlist = handler_match_prepend (mlist, handler, hlist->signal_id);

		    if (one_and_only)

		      return mlist;

		  }

            }

        }

    }

  return mlist;

}

static inline Handler*

handler_new (gboolean after)

{

  Handler *handler = g_slice_new (Handler);

#ifndef G_DISABLE_CHECKS

  if (g_handler_sequential_number < 1)

    g_error (G_STRLOC ": handler id overflow, %s", REPORT_BUG);

#endif

  handler->sequential_number = g_handler_sequential_number++;

  handler->prev = NULL;

  handler->next = NULL;

  handler->detail = 0;

  handler->ref_count = 1;

  handler->block_count = 0;

  handler->after = after != FALSE;

  handler->closure = NULL;

  return handler;

}

static inline void

handler_ref (Handler *handler)

{

  g_return_if_fail (handler->ref_count > 0);

  g_atomic_int_inc ((int *)&handler->ref_count);

}

static inline void

handler_unref_R (guint    signal_id,

		 gpointer instance,

		 Handler *handler)

{

  gboolean is_zero;

  g_return_if_fail (handler->ref_count > 0);

  is_zero = g_atomic_int_dec_and_test ((int *)&handler->ref_count);

  if (G_UNLIKELY (is_zero))

    {

      HandlerList *hlist = NULL;

      if (handler->next)

        handler->next->prev = handler->prev;

      if (handler->prev)    /* watch out for g_signal_handlers_destroy()! */

        handler->prev->next = handler->next;

      else

        {

          hlist = handler_list_lookup (signal_id, instance);

          hlist->handlers = handler->next;

        }

      if (instance)

        {

          /*  check if we are removing the handler pointed to by tail_before  */

          if (!handler->after && (!handler->next || handler->next->after))

            {

              if (!hlist)

                hlist = handler_list_lookup (signal_id, instance);

              if (hlist)

                {

                  g_assert (hlist->tail_before == handler); /* paranoid */

                  hlist->tail_before = handler->prev;

                }

            }

          /*  check if we are removing the handler pointed to by tail_after  */

          if (!handler->next)

            {

              if (!hlist)

                hlist = handler_list_lookup (signal_id, instance);

              if (hlist)

                {

                  g_assert (hlist->tail_after == handler); /* paranoid */

                  hlist->tail_after = handler->prev;

                }

            }

        }

      SIGNAL_UNLOCK ();

      g_closure_unref (handler->closure);

      SIGNAL_LOCK ();

      g_slice_free (Handler, handler);

    }

}

static void

handler_insert (guint    signal_id,

		gpointer instance,

		Handler  *handler)

{

  HandlerList *hlist;

  g_assert (handler->prev == NULL && handler->next == NULL); /* paranoid */

  hlist = handler_list_ensure (signal_id, instance);

  if (!hlist->handlers)

    {

      hlist->handlers = handler;

      if (!handler->after)

        hlist->tail_before = handler;

    }

  else if (handler->after)

    {

      handler->prev = hlist->tail_after;

      hlist->tail_after->next = handler;

    }

  else

    {

      if (hlist->tail_before)

        {

          handler->next = hlist->tail_before->next;

          if (handler->next)

            handler->next->prev = handler;

          handler->prev = hlist->tail_before;

          hlist->tail_before->next = handler;

        }

      else /* insert !after handler into a list of only after handlers */

        {

          handler->next = hlist->handlers;

          if (handler->next)

            handler->next->prev = handler;

          hlist->handlers = handler;

        }

      hlist->tail_before = handler;

    }

  if (!handler->next)

    hlist->tail_after = handler;

}

static inline void

emission_push (Emission **emission_list_p,

	       Emission  *emission)

{

  emission->next = *emission_list_p;

  *emission_list_p = emission;

}

static inline void

emission_pop (Emission **emission_list_p,

	      Emission  *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*

emission_find (Emission *emission_list,

	       guint     signal_id,

	       GQuark    detail,

	       gpointer  instance)

{

  Emission *emission;

  for (emission = emission_list; emission; emission = emission->next)

    if (emission->instance == instance &&

	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)

{

  const SignalKey *key1 = node1, *key2 = node2;

  if (key1->itype == key2->itype)

    return G_BSEARCH_ARRAY_CMP (key1->quark, key2->quark);

  else

    return G_BSEARCH_ARRAY_CMP (key1->itype, key2->itype);

}

void

g_signal_init (void)

{

  SIGNAL_LOCK ();

  if (!g_n_signal_nodes)

    {

      /* 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_create (&g_signal_key_bconfig);

      /* invalid (0) signal_id */

      g_n_signal_nodes = 1;

      g_signal_nodes = g_renew (SignalNode*, g_signal_nodes, g_n_signal_nodes);

      g_signal_nodes[0] = NULL;

    }

  SIGNAL_UNLOCK ();

}

void

_g_signals_destroy (GType itype)

{

  guint i;

  SIGNAL_LOCK ();

  for (i = 1; i < g_n_signal_nodes; i++)

    {

      SignalNode *node = g_signal_nodes[i];

      if (node->itype == itype)

        {

          if (node->destroyed)

            g_warning (G_STRLOC ": signal \"%s\" of type `%s' already destroyed",

                       node->name,

                       type_debug_name (node->itype));

          else

	    signal_destroy_R (node);

        }

    }

  SIGNAL_UNLOCK ();

}

/**

 * g_signal_stop_emission:

 * @instance: the object whose signal handlers you wish to stop.

 * @signal_id: the signal identifier, as returned by g_signal_lookup().

 * @detail: the detail which the signal was emitted with.

 *

 * Stops a signal's current emission.

 *

 * This will prevent the default method from running, if the signal was

 * %G_SIGNAL_RUN_LAST and you connected normally (i.e. without the "after"

 * flag).

 *

 * Prints a warning if used on a signal which isn't being emitted.

 */

EXPORT_C void

g_signal_stop_emission (gpointer instance,

                        guint    signal_id,

			GQuark   detail)

{

  SignalNode *node;

  g_return_if_fail (G_TYPE_CHECK_INSTANCE (instance));

  g_return_if_fail (signal_id > 0);

  SIGNAL_LOCK ();

  node = LOOKUP_SIGNAL_NODE (signal_id);

  if (node && detail && !(node->flags & G_SIGNAL_DETAILED))

    {

      g_warning ("%s: signal id `%u' does not support detail (%u)", G_STRLOC, signal_id, detail);

      SIGNAL_UNLOCK ();

      return;

    }

  if (node && g_type_is_a (G_TYPE_FROM_INSTANCE (instance), node->itype))

    {

      Emission *emission_list = node->flags & G_SIGNAL_NO_RECURSE ? g_restart_emissions : g_recursive_emissions;

      Emission *emission = emission_find (emission_list, signal_id, detail, instance);

      if (emission)

        {

          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 == EMISSION_RUN)

            emission->state = EMISSION_STOP;

        }

      else

        g_warning (G_STRLOC ": no emission of signal \"%s\" to stop for instance `%p'",

                   node->name, instance);

    }

  else

    g_warning ("%s: signal id `%u' is invalid for instance `%p'", G_STRLOC, signal_id, instance);

  SIGNAL_UNLOCK ();

}

static void

signal_finalize_hook (GHookList *hook_list,

		      GHook     *hook)

{

  GDestroyNotify destroy = hook->destroy;

  if (destroy)

    {

      hook->destroy = NULL;

      SIGNAL_UNLOCK ();

      destroy (hook->data);

      SIGNAL_LOCK ();

    }

}

#if EMULATOR

PLS(seq_hook_id ,g_signal_add_emission_hook ,gulong)

#define seq_hook_id  (*FUNCTION_NAME(seq_hook_id ,g_signal_add_emission_hook)())

#endif /* EMULATOR */

/**

 * g_signal_add_emission_hook:

 * @signal_id: the signal identifier, as returned by g_signal_lookup().

 * @detail: the detail on which to call the hook.

 * @hook_func: a #GSignalEmissionHook function.

 * @hook_data: user data for @hook_func.

 * @data_destroy: a #GDestroyNotify for @hook_data.

 *

 * Adds an emission hook for a signal, which will get called for any emission

 * of that signal, independent of the instance. This is possible only

 * for signals which don't have #G_SIGNAL_NO_HOOKS flag set.

 *

 * Returns: the hook id, for later use with g_signal_remove_emission_hook().

 */

EXPORT_C gulong

g_signal_add_emission_hook (guint               signal_id,

			    GQuark              detail,

			    GSignalEmissionHook hook_func,

			    gpointer            hook_data,

			    GDestroyNotify      data_destroy)

{

  #if !(EMULATOR)

  static gulong seq_hook_id = 1;

  #endif /* EMULATOR */

  SignalNode *node;

  GHook *hook;

  SignalHook *signal_hook;

  g_return_val_if_fail (signal_id > 0, 0);

  g_return_val_if_fail (hook_func != NULL, 0);

  SIGNAL_LOCK ();

  node = LOOKUP_SIGNAL_NODE (signal_id);

  if (!node || node->destroyed)

    {

      g_warning ("%s: invalid signal id `%u'", G_STRLOC, signal_id);

      SIGNAL_UNLOCK ();

      return 0;

    }

  if (node->flags & G_SIGNAL_NO_HOOKS) 

    {

      g_warning ("%s: signal id `%u' does not support emission hooks (G_SIGNAL_NO_HOOKS flag set)", G_STRLOC, signal_id);

      SIGNAL_UNLOCK ();

      return 0;

    }

  if (detail && !(node->flags & G_SIGNAL_DETAILED))

    {

      g_warning ("%s: signal id `%u' does not support detail (%u)", G_STRLOC, signal_id, detail);

      SIGNAL_UNLOCK ();

      return 0;

    }

  if (!node->emission_hooks)

    {