Fix race condition and bad memory access highlighting render tiles

Is was possible that interface will be refreshed at thesame time
as render engine will start freeing render parts.

Not sure if we can get away without RW mutex here, seems we need
one way of synchronization or another..

3 files changed, 15 insertions, 2 deletions

diff --git a/source/blender/render/intern/include/render_types.h b/source/blender/render/intern/include/render_types.h
index 8d92fb9eec9..a53ff302475 100644
--- a/source/blender/render/intern/include/render_types.h
+++ b/source/blender/render/intern/include/render_types.h
@@ -194,6 +194,7 @@ struct Render
 	struct Object *camera_override;
 	unsigned int lay, layer_override;
 	
+	ThreadRWMutex partsmutex;
 	ListBase parts;
 	
 	/* render engine */
diff --git a/source/blender/render/intern/source/external_engine.c b/source/blender/render/intern/source/external_engine.c
index 4e63a9918e1..557fcb01778 100644
--- a/source/blender/render/intern/source/external_engine.c
+++ b/source/blender/render/intern/source/external_engine.c
@@ -375,9 +375,12 @@ void RE_engine_get_current_tiles(Render *re, int *total_tiles_r, rcti **tiles_r)
 	rcti *tiles = NULL;
 	int allocation_size = 0, allocation_step = BLENDER_MAX_THREADS;
 
+	BLI_rw_mutex_lock(&re->partsmutex, THREAD_LOCK_READ);
+
 	if (re->engine && (re->engine->flag & RE_ENGINE_HIGHLIGHT_TILES) == 0) {
 		*total_tiles_r = 0;
 		*tiles_r = NULL;
+		BLI_rw_mutex_unlock(&re->partsmutex);
 		return;
 	}
 
@@ -404,7 +407,7 @@ void RE_engine_get_current_tiles(Render *re, int *total_tiles_r, rcti **tiles_r)
 			total_tiles++;
 		}
 	}
-
+	BLI_rw_mutex_unlock(&re->partsmutex);
 	*total_tiles_r = total_tiles;
 	*tiles_r = tiles;
 }
@@ -478,6 +481,8 @@ bool RE_bake_engine(
 	engine->tile_y = 0;
 	engine->flag &= ~RE_ENGINE_RENDERING;
 
+	BLI_rw_mutex_lock(&re->partsmutex, THREAD_LOCK_WRITE);
+
 	/* re->engine becomes zero if user changed active render engine during render */
 	if (!persistent_data || !re->engine) {
 		RE_engine_free(engine);
@@ -485,6 +490,7 @@ bool RE_bake_engine(
 	}
 
 	RE_parts_free(re);
+	BLI_rw_mutex_unlock(&re->partsmutex);
 
 	if (BKE_reports_contain(re->reports, RPT_ERROR))
 		G.is_break = true;
@@ -663,6 +669,8 @@ int RE_engine_render(Render *re, int do_all)
 
 	render_result_free_list(&engine->fullresult, engine->fullresult.first);
 
+	BLI_rw_mutex_lock(&re->partsmutex, THREAD_LOCK_WRITE);
+
 	/* re->engine becomes zero if user changed active render engine during render */
 	if (!persistent_data || !re->engine) {
 		RE_engine_free(engine);
@@ -682,6 +690,7 @@ int RE_engine_render(Render *re, int do_all)
 	}
 
 	RE_parts_free(re);
+	BLI_rw_mutex_unlock(&re->partsmutex);
 
 	if (BKE_reports_contain(re->reports, RPT_ERROR))
 		G.is_break = true;
diff --git a/source/blender/render/intern/source/pipeline.c b/source/blender/render/intern/source/pipeline.c
index 21ca7924fa0..b397db7c31b 100644
--- a/source/blender/render/intern/source/pipeline.c
+++ b/source/blender/render/intern/source/pipeline.c
@@ -385,6 +385,7 @@ Render *RE_NewRender(const char *name)
 		BLI_addtail(&RenderGlobal.renderlist, re);
 		BLI_strncpy(re->name, name, RE_MAXNAME);
 		BLI_rw_mutex_init(&re->resultmutex);
+		BLI_rw_mutex_init(&re->partsmutex);
 		re->eval_ctx = MEM_callocN(sizeof(EvaluationContext), "re->eval_ctx");
 		re->eval_ctx->mode = DAG_EVAL_RENDER;
 	}
@@ -423,6 +424,7 @@ void RE_FreeRender(Render *re)
 		RE_engine_free(re->engine);
 
 	BLI_rw_mutex_end(&re->resultmutex);
+	BLI_rw_mutex_end(&re->partsmutex);
 
 	BLI_freelistN(&re->r.layers);
 	
@@ -1268,8 +1270,9 @@ static void threaded_tile_processor(Render *re)
 
 	/* unset threadsafety */
 	g_break = 0;
-	
+	BLI_rw_mutex_lock(&re->partsmutex, THREAD_LOCK_WRITE);
 	RE_parts_free(re);
+	BLI_rw_mutex_unlock(&re->partsmutex);
 	re->viewplane = viewplane; /* restore viewplane, modified by pano render */
 }