GPU: Ensure rendering operations occur within GPU render boundaries.

This is required by the Metal backend to perform flushing of temporary objective-C resources. This is implemented as a global autoreleasepool, and is to ensure consistency such that all rendering operations, whether called via events, or via main loop will be within an autoreleasepool.

Authored by Apple: Michael Parkin-White

Ref T96261

Reviewed By: fclem

Differential Revision: https://developer.blender.org/D15900

source/blender/draw/engines/eevee/eevee_lightcache.c

@@ -591,6 +591,7 @@ static void eevee_lightbake_context_enable(EEVEE_LightBake *lbake)
   if (GPU_use_main_context_workaround() && !BLI_thread_is_main()) {
     GPU_context_main_lock();
     DRW_opengl_context_enable();
+    GPU_render_begin();
     return;
   }
 
@@ -604,10 +605,12 @@ static void eevee_lightbake_context_enable(EEVEE_LightBake *lbake)
   else {
     DRW_opengl_context_enable();
   }
+  GPU_render_begin();
 }
 
 static void eevee_lightbake_context_disable(EEVEE_LightBake *lbake)
 {
+  GPU_render_end();
   if (GPU_use_main_context_workaround() && !BLI_thread_is_main()) {
     DRW_opengl_context_disable();
     GPU_context_main_unlock();

source/blender/draw/engines/workbench/workbench_engine.c

@@ -29,6 +29,8 @@
 
 #include "ED_paint.h"
 
+#include "GPU_context.h"
+
 #include "workbench_engine.h"
 #include "workbench_private.h"
 
@@ -36,6 +38,7 @@
 
 void workbench_engine_init(void *ved)
 {
+  GPU_render_begin();
   WORKBENCH_Data *vedata = ved;
   WORKBENCH_StorageList *stl = vedata->stl;
   WORKBENCH_TextureList *txl = vedata->txl;
@@ -64,6 +67,7 @@ void workbench_engine_init(void *ved)
   workbench_dof_engine_init(vedata);
   workbench_antialiasing_engine_init(vedata);
   workbench_volume_engine_init(vedata);
+  GPU_render_end();
 }
 
 void workbench_cache_init(void *ved)

source/blender/render/intern/engine.cc

@@ -152,6 +152,7 @@ static void engine_depsgraph_free(RenderEngine *engine)
     /* Need GPU context since this might free GPU buffers. */
     const bool use_gpu_context = (engine->type->flag & RE_USE_GPU_CONTEXT);
     if (use_gpu_context) {
+      GPU_render_begin();
       DRW_render_context_enable(engine->re);
     }
 
@@ -160,6 +161,7 @@ static void engine_depsgraph_free(RenderEngine *engine)
 
     if (use_gpu_context) {
       DRW_render_context_disable(engine->re);
+      GPU_render_end();
     }
   }
 }
@@ -756,6 +758,7 @@ static void engine_depsgraph_init(RenderEngine *engine, ViewLayer *view_layer)
     /* Need GPU context since this might free GPU buffers. */
     const bool use_gpu_context = (engine->type->flag & RE_USE_GPU_CONTEXT) && reuse_depsgraph;
     if (use_gpu_context) {
+      GPU_render_begin();
       DRW_render_context_enable(engine->re);
     }
 
@@ -763,6 +766,7 @@ static void engine_depsgraph_init(RenderEngine *engine, ViewLayer *view_layer)
 
     if (use_gpu_context) {
       DRW_render_context_disable(engine->re);
+      GPU_render_end();
     }
   }
   else {
@@ -935,6 +939,7 @@ static void engine_render_view_layer(Render *re,
   if (use_engine) {
     const bool use_gpu_context = (engine->type->flag & RE_USE_GPU_CONTEXT);
     if (use_gpu_context) {
+      GPU_render_begin();
       DRW_render_context_enable(engine->re);
     }
 
@@ -950,6 +955,7 @@ static void engine_render_view_layer(Render *re,
 
     if (use_gpu_context) {
       DRW_render_context_disable(engine->re);
+      GPU_render_end();
     }
   }
 

source/blender/render/intern/pipeline.cc

@@ -2391,6 +2391,9 @@ void RE_RenderAnim(Render *re,
 
 void RE_PreviewRender(Render *re, Main *bmain, Scene *sce)
 {
+  /* Ensure within GPU render boundary. */
+  GPU_render_begin();
+
   Object *camera;
   int winx, winy;
 
@@ -2411,6 +2414,9 @@ void RE_PreviewRender(Render *re, Main *bmain, Scene *sce)
     RE_engine_free(re->engine);
     re->engine = nullptr;
   }
+
+  /* Close GPU render boundary. */
+  GPU_render_end();
 }
 
 /* NOTE: repeated win/disprect calc... solve that nicer, also in compo. */

source/blender/windowmanager/intern/wm_event_system.cc

@@ -56,6 +56,8 @@
 #include "ED_util.h"
 #include "ED_view3d.h"
 
+#include "GPU_context.h"
+
 #include "RNA_access.h"
 
 #include "UI_interface.h"
@@ -484,11 +486,15 @@ static void wm_event_execute_timers(bContext *C)
 
 void wm_event_do_notifiers(bContext *C)
 {
+  /* Ensure insiude render boundary. */
+  GPU_render_begin();
+
   /* Run the timer before assigning `wm` in the unlikely case a timer loads a file, see T80028. */
   wm_event_execute_timers(C);
 
   wmWindowManager *wm = CTX_wm_manager(C);
   if (wm == nullptr) {
+    GPU_render_end();
     return;
   }
 
@@ -691,6 +697,8 @@ void wm_event_do_notifiers(bContext *C)
 
   /* Auto-run warning. */
   wm_test_autorun_warning(C);
+
+  GPU_render_end();
 }
 
 static bool wm_event_always_pass(const wmEvent *event)

source/blender/windowmanager/intern/wm_window.c

@@ -580,6 +580,7 @@ static void wm_window_ghostwindow_add(wmWindowManager *wm,
 
   if (ghostwin) {
     win->gpuctx = GPU_context_create(ghostwin, NULL);
+    GPU_render_begin();
 
     /* needed so we can detect the graphics card below */
     GPU_init();
@@ -621,6 +622,7 @@ static void wm_window_ghostwindow_add(wmWindowManager *wm,
     GPU_clear_color(0.55f, 0.55f, 0.55f, 1.0f);
 
     // GHOST_SetWindowState(ghostwin, GHOST_kWindowStateModified);
+    GPU_render_end();
   }
   else {
     wm_window_set_drawable(wm, prev_windrawable, false);
@@ -1504,6 +1506,7 @@ static bool wm_window_timer(const bContext *C)
 void wm_window_process_events(const bContext *C)
 {
   BLI_assert(BLI_thread_is_main());
+  GPU_render_begin();
 
   bool has_event = GHOST_ProcessEvents(g_system, false); /* `false` is no wait. */
 
@@ -1516,6 +1519,7 @@ void wm_window_process_events(const bContext *C)
    * processing/dispatching but also handling. */
   has_event |= wm_xr_events_handle(CTX_wm_manager(C));
 #endif
+  GPU_render_end();
 
   /* When there is no event, sleep 5 milliseconds not to use too much CPU when idle.
    *