evas/render: improve evas_render_sync()

Tracking only the async rendering canvases and just waiting for the last one
to finish rendering. This should be enough to sync all canvases since the
render thread orderly executes the commands.

src/lib/evas/canvas/evas_main.c

@@ -16,8 +16,6 @@ EAPI Eina_Bool lockdebug = EINA_FALSE;
 EAPI int lockmax = 0;
 #endif
 
-Eina_List *all_evases = NULL;
-
 static int _evas_init_count = 0;
 int _evas_log_dom_global = -1;
 
@@ -111,9 +109,6 @@ evas_shutdown(void)
    evas_object_image_load_opts_cow = NULL;
    evas_object_image_state_cow = NULL;
 
-   eina_list_free(all_evases);
-   all_evases = NULL;
-
    evas_thread_shutdown();
    _evas_preload_thread_shutdown();
    evas_async_events_shutdown();
@@ -177,8 +172,6 @@ _constructor(Eo *eo_obj, void *class_data, va_list *list EINA_UNUSED)
    EVAS_ARRAY_SET(e, texts_unref_queue);
 
 #undef EVAS_ARRAY_SET
-
-   all_evases = eina_list_append(all_evases, e);
 }
 
 EAPI void
@@ -274,8 +267,6 @@ _destructor(Eo *eo_e, void *_pd, va_list *list EINA_UNUSED)
 
    if (e->engine.module) evas_module_unref(e->engine.module);
 
-   all_evases = eina_list_remove(all_evases, e);
-
    eina_array_flush(&e->delete_objects);
    eina_array_flush(&e->active_objects);
    eina_array_flush(&e->restack_objects);

src/lib/evas/canvas/evas_render.c

@@ -1,6 +1,7 @@
 #include "evas_common_private.h"
 #include "evas_private.h"
 #include <math.h>
+#include <assert.h>
 #ifdef EVAS_CSERVE2
 #include "evas_cs2_private.h"
 #endif
@@ -90,6 +91,8 @@ struct _Render_Updates
 static Eina_Bool
 evas_render_updates_internal(Evas *eo_e, unsigned char make_updates, unsigned char do_draw, Evas_Render_Done_Cb done_func, void *done_data, Eina_Bool do_async);
 
+static Eina_List *_rendering_evases = NULL;
+
 #ifdef EVAS_RENDER_DEBUG_TIMING
 static double
 _time_get()
@@ -1472,19 +1475,20 @@ evas_render_rendering_wait(Evas_Public_Data *evas)
    while (evas->rendering) evas_async_events_process_blocking();
 }
 
-/* syncs ALL async rendering canvases */
+/*
+ * Syncs ALL async rendering canvases. Must be called in the main thread.
+ */
 void
 evas_render_sync(void)
 {
-   Eina_List *l;
-   void *d;
+   Evas_Public_Data *evas;
 
-   EINA_LIST_FOREACH(all_evases, l, d)
-     {
-        Evas_Public_Data *e = d;
-        if (!e->rendering) continue;
-        evas_render_rendering_wait(e);
-     }
+   if (!_rendering_evases) return;
+
+   evas = eina_list_data_get(eina_list_last(_rendering_evases));
+   evas_render_rendering_wait(evas);
+
+   assert(_rendering_evases == NULL);
 }
 
 static Eina_Bool
@@ -1837,6 +1841,7 @@ evas_render_updates_internal(Evas *eo_e,
           {
              eo_ref(eo_e);
              e->rendering = EINA_TRUE;
+             _rendering_evases = eina_list_append(_rendering_evases, e);
 
              evas_thread_queue_flush((Evas_Thread_Command_Cb)done_func, done_data);
           }
@@ -2034,6 +2039,7 @@ evas_render_wakeup(Evas *eo_e)
    eina_array_clean(&e->texts_unref_queue);
 
    /* post rendering */
+   _rendering_evases = eina_list_remove(_rendering_evases, e);
    e->rendering = EINA_FALSE;
 
    post.updated_area = ret_updates;

src/lib/evas/include/evas_private.h

@@ -443,8 +443,6 @@ struct _Evas_Public_Data
    Eina_Bool      rendering : 1;
 };
 
-extern Eina_List *all_evases;
-
 struct _Evas_Layer
 {
    EINA_INLIST;