gmain.c

嵌入式下基于MiniGUI的Web Browser

  g_static_mutex_free (&context->mutex);
#endif

  g_ptr_array_free (context->pending_dispatches, TRUE);
  g_free (context->cached_poll_array);
  
  g_mem_chunk_destroy (context->poll_chunk);

#ifdef G_THREADS_ENABLED
  if (g_thread_supported())
    {
#ifndef G_OS_WIN32
      close (context->wake_up_pipe[0]);
      close (context->wake_up_pipe[1]);
#else
      CloseHandle (context->wake_up_semaphore);
#endif
    }
  else
    main_contexts_without_pipe = g_slist_remove (main_contexts_without_pipe, 
						 context);
#endif
  
  g_free (context);
}

/**
 * g_main_context_unref:
 * @context: a #GMainContext
 * 
 * Decreases the reference count on a #GMainContext object by one. If
 * the result is zero, free the context and free all associated memory.
 **/
void
g_main_context_unref (GMainContext *context)
{
  g_return_if_fail (context != NULL);
  g_return_if_fail (context->ref_count > 0); 

  LOCK_CONTEXT (context);
  g_main_context_unref_and_unlock (context);
}

#ifdef G_THREADS_ENABLED
static void 
g_main_context_init_pipe (GMainContext *context)
{
# ifndef G_OS_WIN32
  if (pipe (context->wake_up_pipe) < 0)
    g_error ("Cannot create pipe main loop wake-up: %s\n",
	     g_strerror (errno));
  
  context->wake_up_rec.fd = context->wake_up_pipe[0];
  context->wake_up_rec.events = G_IO_IN;
# else
  context->wake_up_semaphore = CreateSemaphore (NULL, 0, 100, NULL);
  if (context->wake_up_semaphore == NULL)
    g_error ("Cannot create wake-up semaphore: %s",
	     g_win32_error_message (GetLastError ()));
  context->wake_up_rec.fd = (gint) context->wake_up_semaphore;
  context->wake_up_rec.events = G_IO_IN;
#  ifdef G_MAIN_POLL_DEBUG
  g_print ("wake-up semaphore: %#x\n", (guint) context->wake_up_semaphore);
#  endif
# endif
  g_main_context_add_poll_unlocked (context, 0, &context->wake_up_rec);
}

void
g_main_thread_init ()
{
  GSList *curr = main_contexts_without_pipe;
  while (curr)
    {
      g_main_context_init_pipe ((GMainContext *)curr->data);
      curr = curr->next;
    }
  g_slist_free (main_contexts_without_pipe);
  main_contexts_without_pipe = NULL;  
}
#endif /* G_THREADS_ENABLED */

/**
 * g_main_context_new:
 * 
 * Creates a new #GMainContext strcuture
 * 
 * Return value: the new #GMainContext
 **/
GMainContext *
g_main_context_new ()
{
  GMainContext *context = g_new0 (GMainContext, 1);

#ifdef G_THREADS_ENABLED
  g_static_mutex_init (&context->mutex);

  context->owner = NULL;
  context->waiters = NULL;
#endif
      
  context->ref_count = 1;

      context->next_id = 1;
      
      context->source_list = NULL;

#if HAVE_POLL
      context->poll_func = (GPollFunc)poll;
#else
      context->poll_func = g_poll;
#endif

      context->cached_poll_array = NULL;
      context->cached_poll_array_size = 0;
      
      context->pending_dispatches = g_ptr_array_new ();
      
      context->time_is_current = FALSE;

#ifdef G_THREADS_ENABLED
      if (g_thread_supported ())
    g_main_context_init_pipe (context);
  else
    main_contexts_without_pipe = g_slist_prepend (main_contexts_without_pipe, 
						  context);
#endif

  return context;
}

/**
 * g_main_context_default:
 * 
 * Returns the default main context. This is the main context used
 * for main loop functions when a main loop is not explicitly
 * specified.
 * 
 * Return value: the default main context.
 **/
GMainContext *
g_main_context_default (void)
{
  /* Slow, but safe */
  
  G_LOCK (main_loop);

  if (!default_main_context)
    default_main_context = g_main_context_new ();

  G_UNLOCK (main_loop);

  return default_main_context;
}

/* Hooks for adding to the main loop */

/**
 * g_source_new:
 * @source_funcs: structure containing functions that implement
 *                the sources behavior.
 * @struct_size: size of the #GSource structure to create.
 * 
 * Creates a new #GSource structure. The size is specified to
 * allow creating structures derived from #GSource that contain
 * additional data. The size passed in must be at least
 * <literal>sizeof (GSource)</literal>.
 * 
 * The source will not initially be associated with any #GMainContext
 * and must be added to one with g_source_add() before it will be
 * executed.
 * 
 * Return value: the newly-created #GSource.
 **/
GSource *
g_source_new (GSourceFuncs *source_funcs,
	      guint         struct_size)
{
  GSource *source;

  g_return_val_if_fail (source_funcs != NULL, NULL);
  g_return_val_if_fail (struct_size >= sizeof (GSource), NULL);
  
  source = (GSource*) g_malloc0 (struct_size);

  source->source_funcs = source_funcs;
  source->ref_count = 1;
  
  source->priority = G_PRIORITY_DEFAULT;

  source->flags = G_HOOK_FLAG_ACTIVE;

  /* NULL/0 initialization for all other fields */
  
  return source;
}

/* Holds context's lock
 */
static void
g_source_list_add (GSource      *source,
		   GMainContext *context)
{
  GSource *tmp_source, *last_source;
  
  last_source = NULL;
  tmp_source = context->source_list;
  while (tmp_source && tmp_source->priority <= source->priority)
    {
      last_source = tmp_source;
      tmp_source = tmp_source->next;
    }

  source->next = tmp_source;
  if (tmp_source)
    tmp_source->prev = source;
  
  source->prev = last_source;
  if (last_source)
    last_source->next = source;
  else
    context->source_list = source;
}

/* Holds context's lock
 */
static void
g_source_list_remove (GSource      *source,
		      GMainContext *context)
{
  if (source->prev)
    source->prev->next = source->next;
  else
    context->source_list = source->next;

  if (source->next)
    source->next->prev = source->prev;

  source->prev = NULL;
  source->next = NULL;
}

/**
 * g_source_attach:
 * @source: a #GSource
 * @context: a #GMainContext (if %NULL, the default context will be used)
 * 
 * Adds a #GSource to a @context so that it will be executed within
 * that context.
 *
 * Return value: the ID for the source within the #GMainContext
 **/
guint
g_source_attach (GSource      *source,
		 GMainContext *context)
{
  guint result = 0;
  GSList *tmp_list;

  g_return_val_if_fail (source->context == NULL, 0);
  g_return_val_if_fail (!SOURCE_DESTROYED (source), 0);
  
  if (!context)
    context = g_main_context_default ();

  LOCK_CONTEXT (context);

  source->context = context;
  result = source->source_id = context->next_id++;

  source->ref_count++;
  g_source_list_add (source, context);

  tmp_list = source->poll_fds;
  while (tmp_list)
    {
      g_main_context_add_poll_unlocked (context, source->priority, tmp_list->data);
      tmp_list = tmp_list->next;
    }

#ifdef G_THREADS_ENABLED
  /* Now wake up the main loop if it is waiting in the poll() */
  g_main_context_wakeup_unlocked (context);
#endif

  UNLOCK_CONTEXT (context);

  return result;
}

static void
g_source_destroy_internal (GSource      *source,
			   GMainContext *context,
			   gboolean      have_lock)
{
  if (!have_lock)
    LOCK_CONTEXT (context);
  
  if (!SOURCE_DESTROYED (source))
    {
      GSList *tmp_list;
      gpointer old_cb_data;
      GSourceCallbackFuncs *old_cb_funcs;
      
      source->flags &= ~G_HOOK_FLAG_ACTIVE;

      old_cb_data = source->callback_data;
      old_cb_funcs = source->callback_funcs;

      source->callback_data = NULL;
      source->callback_funcs = NULL;

      if (old_cb_funcs)
	{
	  UNLOCK_CONTEXT (context);
	  old_cb_funcs->unref (old_cb_data);
	  LOCK_CONTEXT (context);
	}
      
      tmp_list = source->poll_fds;
      while (tmp_list)
	{
	  g_main_context_remove_poll_unlocked (context, tmp_list->data);
	  tmp_list = tmp_list->next;
	}
      
      g_source_unref_internal (source, context, TRUE);
    }

  if (!have_lock)
    UNLOCK_CONTEXT (context);
}

/**
 * g_source_destroy:
 * @source: a #GSource
 * 
 * Removes a source from its #GMainContext, if any, and mark it as
 * destroyed.  The source cannot be subsequently added to another
 * context.
 **/
void
g_source_destroy (GSource *source)
{
  GMainContext *context;
  
  g_return_if_fail (source != NULL);
  
  context = source->context;
  
  if (context)
    g_source_destroy_internal (source, context, FALSE);
  else
    source->flags &= ~G_HOOK_FLAG_ACTIVE;
}

/**
 * g_source_get_id:
 * @source: a #GSource
 * 
 * Returns the numeric ID for a particular source. The ID of a source
 * is unique within a particular main loop context. The reverse
 * mapping from ID to source is done by g_main_context_find_source_by_id().
 *
 * Return value: the ID for the source
 **/
guint
g_source_get_id (GSource *source)
{
  guint result;
  
  g_return_val_if_fail (source != NULL, 0);
  g_return_val_if_fail (source->context != NULL, 0);

  LOCK_CONTEXT (source->context);
  result = source->source_id;
  UNLOCK_CONTEXT (source->context);
  
  return result;
}

/**
 * g_source_get_context:
 * @source: a #GSource
 * 
 * Gets the #GMainContext with which the source is associated.
 * Calling this function on a destroyed source is an error.
 * 
 * Return value: the #GMainContext with which the source is associated,
 *               or %NULL if the context has not yet been added
 *               to a source.
 **/
GMainContext *
g_source_get_context (GSource *source)
{
  g_return_val_if_fail (!SOURCE_DESTROYED (source), NULL);

  return source->context;
}

/**
 * g_source_add_poll:
 * @source:a #GSource 
 * @fd: a #GPollFD structure holding information about a file
 *      descriptor to watch.
 * 
 * Adds a file descriptor to the set of file descriptors polled for
 * this source. This is usually combined with g_source_new() to add an
 * event source. The event source's check function will typically test
 * the @revents field in the #GPollFD struct and return %TRUE if events need
 * to be processed.
 **/
void
g_source_add_poll (GSource *source,
		   GPollFD *fd)
{
  GMainContext *context;
  
  g_return_if_fail (source != NULL);
  g_return_if_fail (fd != NULL);
  g_return_if_fail (!SOURCE_DESTROYED (source));
  
  context = source->context;

  if (context)
    LOCK_CONTEXT (context);
  
  source->poll_fds = g_slist_prepend (source->poll_fds, fd);

  if (context)
    {
      g_main_context_add_poll_unlocked (context, source->priority, fd);
      UNLOCK_CONTEXT (context);
    }
}

/**
 * g_source_remove_poll:
 * @source:a #GSource 
 * @fd: a #GPollFD structure previously passed to g_source_poll().
 * 
 * Removes a file descriptor from the set of file descriptors polled for
 * this source. 
 **/
void
g_source_remove_poll (GSource *source,
		      GPollFD *fd)
{
  GMainContext *context;
  
  g_return_if_fail (source != NULL);
  g_return_if_fail (fd != NULL);
  g_return_if_fail (!SOURCE_DESTROYED (source));
  
  context = source->context;

  if (context)
    LOCK_CONTEXT (context);
  
  source->poll_fds = g_slist_remove (source->poll_fds, fd);

  if (context)
    {
      g_main_context_remove_poll_unlocked (context, fd);
      UNLOCK_CONTEXT (context);
    }
}

/**
 * g_source_set_callback_indirect:
 * @source: the source
 * @callback_data: pointer to callback data "object"
 * @callback_funcs: functions for reference counting @callback_data
 *                  and getting the callback and data
 * 
 * Sets the callback function storing the data as a refcounted callback
 * "object". This is used to implement g_source_set_callback_closure()
 * and internally. Note that calling g_source_set_callback_indirect() assumes
 * an initial reference count on @callback_data, and thus
 * @callback_funcs->unref will eventually be called once more
 * than @callback_funcs->ref.
 **/
void
g_source_set_callback_indirect (GSource              *source,
				gpointer              callback_data,
				GSourceCallbackFuncs *callback_funcs)
{
  GMainContext *context;
  gpointer old_cb_data;
  GSourceCallbackFuncs *old_cb_funcs;
  
  g_return_if_fail (source != NULL);
  g_return_if_fail (callback_funcs != NULL || callback_data == NULL);

  context = source->context;

  if (context)
    LOCK_CONTEXT (context);

  old_cb_data = source->callback_data;
  old_cb_funcs = source->callback_funcs;

  source->callback_data = callback_data;
  source->callback_funcs = callback_funcs;
  
  if (context)
    UNLOCK_CONTEXT (context);
  
  if (old_cb_funcs)
    old_cb_funcs->unref (old_cb_data);
}

static void
g_source_callback_ref (gpointer cb_data)
{
  GSourceCallback *callback = cb_data;

  callback->ref_count++;
}


static void
g_source_callback_unref (gpointer cb_data)
{
  GSourceCallback *callback = cb_data;

  callback->ref_count--;
  if (callback->ref_count == 0)
    {
      if (callback->notify)
	callback->notify (callback->data);
      g_free (callback);
    }
}

static void
g_source_callback_get (gpointer     cb_data,
		       GSource     *source, 
		       GSourceFunc *func,
		       gpointer    *data)
{
  GSourceCallback *callback = cb_data;

  *func = callback->func;
  *data = callback->data;
}

static GSourceCallbackFuncs g_source_callback_funcs = {
  g_source_callback_ref,
  g_source_callback_unref,
  g_source_callback_get,
};

/**
 * g_source_set_callback:
 * @source: the source
 * @func: a callback function
 * @data: the data to pass to callback function