cogl: Simplify poll_renderer_get_info

As the only info we can pass now is whether we have any idle
closures. Removes the timeout handling which is now is always set to
either 0 or -1 based on whether we have idle closures

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3887>

cogl/cogl/cogl-glib-source.c

@@ -46,12 +46,8 @@ static gboolean
 cogl_glib_source_prepare (GSource *source, int *timeout)
 {
   CoglGLibSource *cogl_source = (CoglGLibSource *) source;
-  int64_t cogl_timeout;
 
-  cogl_poll_renderer_get_info (cogl_source->renderer,
+  if (!cogl_poll_renderer_has_idle_closures (cogl_source->renderer))
-                               &cogl_timeout);
-
-  if (cogl_timeout == -1)
     {
       *timeout = -1;
       cogl_source->expiration_time = -1;
@@ -59,9 +55,8 @@ cogl_glib_source_prepare (GSource *source, int *timeout)
   else
     {
       /* Round up to ensure that we don't try again too early */
-      *timeout = (cogl_timeout + 999) / 1000;
+      *timeout = 999 / 1000;
-      cogl_source->expiration_time = (g_source_get_time (source) +
+      cogl_source->expiration_time = g_source_get_time (source);
-                                      cogl_timeout);
     }
 
   return *timeout == 0;

cogl/cogl/cogl-glib-source.h

@@ -46,11 +46,7 @@ G_BEGIN_DECLS
  * @priority: The priority of the #GSource
  *
  * Creates a #GSource which handles Cogl's internal system event
- * processing. This can be used as a convenience instead of
+ * processing.
- * cogl_poll_renderer_get_info() and cogl_poll_renderer_dispatch() in
- * applications that are already using the GLib main loop. After this
- * is called the #GSource should be attached to the main loop using
- * g_source_attach().
  *
  * Applications that manually connect to a #CoglRenderer before they
  * create a #CoglContext should instead use
@@ -74,11 +70,7 @@ cogl_glib_source_new (CoglContext *context,
  * @priority: The priority of the #GSource
  *
  * Creates a #GSource which handles Cogl's internal system event
- * processing. This can be used as a convenience instead of
+ * processing
- * cogl_poll_renderer_get_info() and cogl_poll_renderer_dispatch() in
- * applications that are already using the GLib main loop. After this
- * is called the #GSource should be attached to the main loop using
- * g_source_attach().
  *
  * Return value: a new #GSource
  */

cogl/cogl/cogl-poll.c

@@ -37,17 +37,12 @@
 #include "cogl/cogl-renderer-private.h"
 #include "cogl/winsys/cogl-winsys-private.h"
 
-void
+gboolean
-cogl_poll_renderer_get_info (CoglRenderer *renderer,
+cogl_poll_renderer_has_idle_closures (CoglRenderer *renderer)
-                             int64_t *timeout)
 {
-  g_return_if_fail (COGL_IS_RENDERER (renderer));
+  g_return_val_if_fail (COGL_IS_RENDERER (renderer), FALSE);
-  g_return_if_fail (timeout != NULL);
 
-  *timeout = -1;
+  return !_cogl_list_empty (&renderer->idle_closures);
-
-  if (!_cogl_list_empty (&renderer->idle_closures))
-    *timeout = 0;
 }
 
 void

cogl/cogl/cogl-poll.h

@@ -65,29 +65,11 @@ G_BEGIN_DECLS
 
 
 /**
- * cogl_poll_renderer_get_info:
+ * cogl_poll_renderer_has_idle_closures:
  * @renderer: A #CoglRenderer
- * @timeout: A return location for the maximum length of time to wait
- *           in microseconds, or -1 to wait indefinitely.
- *
- * Is used to integrate Cogl with an application mainloop that is based
- * on the unix poll(2) api (or select() or something equivalent). This
- * api should be called whenever an application is about to go idle so
- * that Cogl has a chance to describe what file descriptor events it
- * needs to be woken up for.
- *
- * If your application is using the Glib mainloop then you
- * should jump to the cogl_glib_source_new() api as a more convenient
- * way of integrating Cogl with the mainloop.
- *
- * @timeout will contain a maximum amount of time to wait in
- * microseconds before the application should wake up or -1 if the
- * application should wait indefinitely. This can also be 0 if
- * Cogl needs to be woken up immediately.
  */
-COGL_EXPORT void
+COGL_EXPORT gboolean
-cogl_poll_renderer_get_info (CoglRenderer *renderer,
+cogl_poll_renderer_has_idle_closures (CoglRenderer *renderer);
-                             int64_t *timeout);
 
 /**
  * cogl_poll_renderer_dispatch: