commit 854ce1c4a87980c79025a9c958911ce35015eb34
author Vishnu Nair <vishnun@google.com> Sat Aug 19 15:00:13 2023 -0700
committer Vishnu Nair <vishnun@google.com> Mon Aug 21 08:27:33 2023 -0700
tree e6d99a35ce4e9d294fb382101d1627c4aa738522
parent 606d9d074646c04bd966ccd752ade0b796748216

[sf] Set visible regions change flag when layer starts drawing

If a layer state changes so it has a buffer or an effect like
color then, update the flags to indicate that visiblity of a
snapshot has changed. This will mark the visible regions
flag in CE args and force CE to rebuild its layer stack.
Without this flag, there was a scenario where CE
would get a null snapshot and crash.

Also crash early with traces if we ever pass a null snapshot to
CE.

Test: presubmit
Bug: 238781169, 295069311, 294889236
Change-Id: I355502fbe7f1be38c46a5ed25233b6b07c6b4eeb

services/surfaceflinger/FrontEnd/RequestedLayerState.cpp

diff --git a/services/surfaceflinger/FrontEnd/RequestedLayerState.cpp b/services/surfaceflinger/FrontEnd/RequestedLayerState.cpp
index a5d5563..8a39cd6 100644
--- a/services/surfaceflinger/FrontEnd/RequestedLayerState.cpp
+++ b/services/surfaceflinger/FrontEnd/RequestedLayerState.cpp
@@ -150,7 +150,7 @@
 
     const bool hadSideStream = sidebandStream != nullptr;
     const layer_state_t& clientState = resolvedComposerState.state;
-    const bool hadBlur = hasBlur();
+    const bool hadSomethingToDraw = hasSomethingToDraw();
     uint64_t clientChanges = what | layer_state_t::diff(clientState);
     layer_state_t::merge(clientState);
     what = clientChanges;
@@ -228,11 +228,10 @@
                     RequestedLayerState::Changes::VisibleRegion;
         }
     }
-    if (what & (layer_state_t::eBackgroundBlurRadiusChanged | layer_state_t::eBlurRegionsChanged)) {
-        if (hadBlur != hasBlur()) {
-            changes |= RequestedLayerState::Changes::Visibility |
-                    RequestedLayerState::Changes::VisibleRegion;
-        }
+
+    if (hadSomethingToDraw != hasSomethingToDraw()) {
+        changes |= RequestedLayerState::Changes::Visibility |
+                RequestedLayerState::Changes::VisibleRegion;
     }
     if (clientChanges & layer_state_t::HIERARCHY_CHANGES)
         changes |= RequestedLayerState::Changes::Hierarchy;
@@ -579,6 +578,12 @@
     return externalTexture && externalTexture->getUsage() & GRALLOC_USAGE_PROTECTED;
 }
 
+bool RequestedLayerState::hasSomethingToDraw() const {
+    return externalTexture != nullptr || sidebandStream != nullptr || shadowRadius > 0.f ||
+            backgroundBlurRadius > 0 || blurRegions.size() > 0 ||
+            (color.r >= 0.0_hf && color.g >= 0.0_hf && color.b >= 0.0_hf);
+}
+
 void RequestedLayerState::clearChanges() {
     what = 0;
     changes.clear();