Skip invisible windows in input list

To reduce traffic sent over binder and the number of copied objects in native code, we decide to remove windows from WindowInfosListener that are not visible because input doesn't need to know about the windows that aren't visible, and invisible windows don't affect the operation of other windows.

Fixes: 305254099
Test: adb shell su root dumpsys SurfaceFlinger
Test: atest LayerSnapshotTest
Flag: EXEMPT bugfix
Change-Id: I1ccc29565ee92277a703d16c07fd1141d6df6862

Author: Wenhui Yang

services/surfaceflinger/FrontEnd/LayerSnapshotBuilder.cpp

@@ -261,20 +261,25 @@ void updateVisibility(LayerSnapshot& snapshot, bool visible) {
     }
     snapshot.isVisible = visible;
 
-    // TODO(b/238781169) we are ignoring this compat for now, since we will have
-    // to remove any optimization based on visibility.
-
-    // For compatibility reasons we let layers which can receive input
-    // receive input before they have actually submitted a buffer. Because
-    // of this we use canReceiveInput instead of isVisible to check the
-    // policy-visibility, ignoring the buffer state. However for layers with
-    // hasInputInfo()==false we can use the real visibility state.
-    // We are just using these layers for occlusion detection in
-    // InputDispatcher, and obviously if they aren't visible they can't occlude
-    // anything.
-    const bool visibleForInput =
-            snapshot.hasInputInfo() ? snapshot.canReceiveInput() : snapshot.isVisible;
-    snapshot.inputInfo.setInputConfig(gui::WindowInfo::InputConfig::NOT_VISIBLE, !visibleForInput);
+    if (FlagManager::getInstance().skip_invisible_windows_in_input()) {
+        snapshot.inputInfo.setInputConfig(gui::WindowInfo::InputConfig::NOT_VISIBLE, !visible);
+    } else {
+        // TODO(b/238781169) we are ignoring this compat for now, since we will have
+        // to remove any optimization based on visibility.
+
+        // For compatibility reasons we let layers which can receive input
+        // receive input before they have actually submitted a buffer. Because
+        // of this we use canReceiveInput instead of isVisible to check the
+        // policy-visibility, ignoring the buffer state. However for layers with
+        // hasInputInfo()==false we can use the real visibility state.
+        // We are just using these layers for occlusion detection in
+        // InputDispatcher, and obviously if they aren't visible they can't occlude
+        // anything.
+        const bool visibleForInput =
+                snapshot.hasInputInfo() ? snapshot.canReceiveInput() : snapshot.isVisible;
+        snapshot.inputInfo.setInputConfig(gui::WindowInfo::InputConfig::NOT_VISIBLE,
+                                          !visibleForInput);
+    }
     LLOGV(snapshot.sequence, "updating visibility %s %s", visible ? "true" : "false",
           snapshot.getDebugString().c_str());
 }
@@ -1260,6 +1265,10 @@ void LayerSnapshotBuilder::forEachInputSnapshot(const ConstVisitor& visitor) con
     for (int i = mNumInterestingSnapshots - 1; i >= 0; i--) {
         LayerSnapshot& snapshot = *mSnapshots[(size_t)i];
         if (!snapshot.hasInputInfo()) continue;
+        if (FlagManager::getInstance().skip_invisible_windows_in_input() &&
+            snapshot.inputInfo.inputConfig.test(gui::WindowInfo::InputConfig::NOT_VISIBLE)) {
+            continue;
+        }
         visitor(snapshot);
     }
 }

services/surfaceflinger/common/FlagManager.cpp

@@ -159,6 +159,7 @@ void FlagManager::dump(std::string& result) const {
     DUMP_READ_ONLY_FLAG(display_config_error_hal);
     DUMP_READ_ONLY_FLAG(connected_display_hdr);
     DUMP_READ_ONLY_FLAG(deprecate_frame_tracker);
+    DUMP_READ_ONLY_FLAG(skip_invisible_windows_in_input);
 
 #undef DUMP_READ_ONLY_FLAG
 #undef DUMP_SERVER_FLAG
@@ -266,6 +267,7 @@ FLAG_MANAGER_READ_ONLY_FLAG(true_hdr_screenshots, "debug.sf.true_hdr_screenshots
 FLAG_MANAGER_READ_ONLY_FLAG(display_config_error_hal, "");
 FLAG_MANAGER_READ_ONLY_FLAG(connected_display_hdr, "");
 FLAG_MANAGER_READ_ONLY_FLAG(deprecate_frame_tracker, "");
+FLAG_MANAGER_READ_ONLY_FLAG(skip_invisible_windows_in_input, "");
 
 /// Trunk stable server flags ///
 FLAG_MANAGER_SERVER_FLAG(refresh_rate_overlay_on_external_display, "")

services/surfaceflinger/common/include/common/FlagManager.h

@@ -97,6 +97,7 @@ class FlagManager {
     bool display_config_error_hal() const;
     bool connected_display_hdr() const;
     bool deprecate_frame_tracker() const;
+    bool skip_invisible_windows_in_input() const;
 
 protected:
     // overridden for unit tests

services/surfaceflinger/surfaceflinger_flags_new.aconfig

@@ -195,6 +195,17 @@ flag {
   }
  } # single_hop_screenshot
 
+flag {
+  name: "skip_invisible_windows_in_input"
+  namespace: "window_surfaces"
+  description: "Only send visible windows to input list"
+  bug: "305254099"
+  is_fixed_read_only: true
+  metadata {
+    purpose: PURPOSE_BUGFIX
+  }
+ } # skip_invisible_windows_in_input
+
 flag {
   name: "true_hdr_screenshots"
   namespace: "core_graphics"

services/surfaceflinger/tests/unittests/LayerSnapshotTest.cpp

@@ -1551,6 +1551,9 @@ TEST_F(LayerSnapshotTest, propagateDropInputMode) {
 }
 
 TEST_F(LayerSnapshotTest, NonVisibleLayerWithInput) {
+    SET_FLAG_FOR_TEST(com::android::graphics::surfaceflinger::flags::
+                              skip_invisible_windows_in_input,
+                      false);
     LayerHierarchyTestBase::createRootLayer(3);
     setColor(3, {-1._hf, -1._hf, -1._hf});
     UPDATE_AND_VERIFY(mSnapshotBuilder, STARTING_ZORDER);
@@ -1576,6 +1579,39 @@ TEST_F(LayerSnapshotTest, NonVisibleLayerWithInput) {
     EXPECT_TRUE(foundInputLayer);
 }
 
+TEST_F(LayerSnapshotTest, NonVisibleLayerWithInputShouldNotBeIncluded) {
+    SET_FLAG_FOR_TEST(com::android::graphics::surfaceflinger::flags::
+                              skip_invisible_windows_in_input,
+                      true);
+    LayerHierarchyTestBase::createRootLayer(3);
+    setColor(3, {-1._hf, -1._hf, -1._hf});
+    UPDATE_AND_VERIFY(mSnapshotBuilder, STARTING_ZORDER);
+
+    std::vector<TransactionState> transactions;
+    transactions.emplace_back();
+    transactions.back().states.push_back({});
+    transactions.back().states.front().state.what = layer_state_t::eInputInfoChanged;
+    transactions.back().states.front().layerId = 3;
+    transactions.back().states.front().state.windowInfoHandle = sp<gui::WindowInfoHandle>::make();
+    auto inputInfo = transactions.back().states.front().state.windowInfoHandle->editInfo();
+    inputInfo->token = sp<BBinder>::make();
+    hideLayer(3);
+    mLifecycleManager.applyTransactions(transactions);
+
+    update(mSnapshotBuilder);
+
+    bool foundInputLayer = false;
+    mSnapshotBuilder.forEachInputSnapshot([&](const frontend::LayerSnapshot& snapshot) {
+        if (snapshot.uniqueSequence == 3) {
+            EXPECT_TRUE(
+                    snapshot.inputInfo.inputConfig.test(gui::WindowInfo::InputConfig::NOT_VISIBLE));
+            EXPECT_FALSE(snapshot.isVisible);
+            foundInputLayer = true;
+        }
+    });
+    EXPECT_FALSE(foundInputLayer);
+}
+
 TEST_F(LayerSnapshotTest, ForEachSnapshotsWithPredicate) {
     std::vector<uint32_t> visitedUniqueSequences;
     mSnapshotBuilder.forEachSnapshot(