add_full


Description:

[ CCode ( cname = "clutter_threads_add_idle_full" ) ]
[ Version ( since = "0.4" ) ]
public uint add_full (int priority, owned SourceFunc func)

Adds a function to be called whenever there are no higher priority events pending.

If the function returns false it is automatically removed from the list of event sources and will not be called again.

This function can be considered a thread-safe variant of add_full: it will call function while holding the Clutter lock. It is logically equivalent to the following implementation:

static gboolean
idle_safe_callback (gpointer data)
{
SafeClosure *closure = data;
gboolean res = FALSE;

// mark the critical section //

clutter_threads_enter();

// the callback does not need to acquire the Clutter
/ lock itself, as it is held by the this proxy handler
//
res = closure->callback (closure->data);

clutter_threads_leave();

return res;
}
static gulong
add_safe_idle (GSourceFunc callback,
gpointer data)
{
SafeClosure *closure = g_new0 (SafeClosure, 1);

closure->callback = callback;
closure->data = data;

return g_idle_add_full (G_PRIORITY_DEFAULT_IDLE,
idle_safe_callback,
closure,
g_free)
}

This function should be used by threaded applications to make sure that func is emitted under the Clutter threads lock and invoked from the same thread that started the Clutter main loop. For instance, it can be used to update the UI using the results from a worker thread:

static gboolean
update_ui (gpointer data)
{
SomeClosure *closure = data;

// it is safe to call Clutter API from this function because
/ it is invoked from the same thread that started the main
/ loop and under the Clutter thread lock
//
clutter_label_set_text (CLUTTER_LABEL (closure->label),
closure->text);

g_object_unref (closure->label);
g_free (closure);

return FALSE;
}

// within another thread //
closure = g_new0 (SomeClosure, 1);
// always take a reference on GObject instances //
closure->label = g_object_ref (my_application->label);
closure->text = g_strdup (processed_text_to_update_the_label);

clutter_threads_add_idle_full (G_PRIORITY_HIGH_IDLE,
update_ui,
closure,
NULL);

Parameters:

priority

the priority of the timeout source. Typically this will be in the range between DEFAULT_IDLE and HIGH_IDLE

func

function to call

data

data to pass to the function

notify

functio to call when the idle source is removed

Returns:

the ID (greater than 0) of the event source.


Package: clutter-1.0



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