[Bf-blender-cvs] [f4b7d575510] master: Fix T72175: DrawManager Crash Large Objects

[Jeroen Bakker]

Commit: f4b7d57551061350216048d5d30b9b674f741c28
Author: Jeroen Bakker
Date:   Thu Dec 5 08:14:32 2019 +0100
Branches: master
https://developer.blender.org/rBf4b7d57551061350216048d5d30b9b674f741c28

Fix T72175: DrawManager Crash Large Objects

Introduced by 9c337fcfe2a4 mistaken that `MeshExtract.use_threading` set
to false means that no threading is used at all. This is not the case it
will still perform threading for large objects, it will only run the
different subtasks in serial.

Fixed by scheduling the `lines_loose` in the task_pool after the rest
have been executed. This is cleaner than the previous implementation as
it sticks more to the actual design.

===================================================================

M	source/blender/draw/intern/draw_cache_extract_mesh.c

===================================================================

diff --git a/source/blender/draw/intern/draw_cache_extract_mesh.c b/source/blender/draw/intern/draw_cache_extract_mesh.c
index 06c2bfc301a..7d0cb7c7076 100644
--- a/source/blender/draw/intern/draw_cache_extract_mesh.c
+++ b/source/blender/draw/intern/draw_cache_extract_mesh.c
@@ -4483,20 +4483,22 @@ void mesh_buffer_cache_create_requested(MeshBatchCache *cache,
   EXTRACT(ibo, edituv_points);
   EXTRACT(ibo, edituv_fdots);
 
-#undef EXTRACT
-
   /* TODO(fclem) Ideally, we should have one global pool for all
    * objects and wait for finish only before drawing when buffers
    * need to be ready. */
   BLI_task_pool_work_and_wait(task_pool);
-  BLI_task_pool_free(task_pool);
+
+  /* The next task(s) rely on the result of the tasks above. */
 
   /* The `lines_loose` is a sub buffer from `ibo.lines`.
-   * We don't use the extract mechanism due to potential synchronization issues.*/
-  if (mbc.ibo.lines_loose) {
-    extract_task_create(NULL, mr, &extract_lines_loose, mbc.ibo.lines_loose, task_counters);
-  }
+   * We schedule it here due to potential synchronization issues.*/
+  EXTRACT(ibo, lines_loose);
 
+  BLI_task_pool_work_and_wait(task_pool);
+
+#undef EXTRACT
+
+  BLI_task_pool_free(task_pool);
   MEM_freeN(task_counters);
 
   mesh_render_data_free(mr);