evas - fix deadlock with sw async rendering calling cbs in post flush
authorCarsten Haitzler (Rasterman) <raster@rasterman.com>
Mon, 17 Aug 2020 12:25:00 +0000 (13:25 +0100)
committerJongmin Lee <jm105.lee@samsung.com>
Thu, 20 Aug 2020 21:03:30 +0000 (06:03 +0900)
post flush doesnt cleanr evas->rendering until after it calls post
flush callbacks. any post flush callback that neexts so access data
and block waiting for an async render tyo be done thus blocks forever.

this adds a 0.2 sec timeout in case so we at last march on with
hiccups instead of totally stalling AND clears evas->rendering before
calling the callbacks.

@fix

src/lib/evas/canvas/evas_render.c

index 0687f8e..4c90840 100644 (file)
@@ -1,5 +1,6 @@
 #include "evas_common_private.h"
 #include "evas_private.h"
+#include <Ecore.h>
 #include <math.h>
 #include <assert.h>
 
@@ -2780,7 +2781,16 @@ _evas_render_cutout_add(Evas_Public_Data *evas, void *context,
 void
 evas_render_rendering_wait(Evas_Public_Data *evas)
 {
-   while (evas->rendering) evas_async_events_process_blocking();
+   double t0 = ecore_time_get();
+   while (evas->rendering)
+     {
+        evas_async_events_process_blocking();
+        if ((ecore_time_get() - t0) > 0.2)
+          {
+             ERR("timeout waiting for async rendering");
+             break;
+          }
+     }
 }
 
 /*
@@ -4000,6 +4010,10 @@ evas_render_wakeup(Evas *eo_e)
      }
    eina_spinlock_release(&(evas->render.lock));
 
+   /* post rendering */
+   _rendering_evases = eina_list_remove_list(_rendering_evases, evas->rendering);
+   evas->rendering = NULL;
+
    /* flush redraws */
    if (haveup)
      {
@@ -4047,10 +4061,6 @@ evas_render_wakeup(Evas *eo_e)
         free(job);
      }
 
-   /* post rendering */
-   _rendering_evases = eina_list_remove_list(_rendering_evases, evas->rendering);
-   evas->rendering = NULL;
-
    post.updated_area = ret_updates;
    _cb_always_call(eo_e, evas, EVAS_CALLBACK_RENDER_POST, &post);
    evas->inside_post_render = EINA_FALSE;