Reduce unnecessary overhead of always-true predicate lambda
Currently compiler always generates new class as
$$ExternalSyntheticLambda* on every invocation place.
And a new instance will be always created on invocation no matter
whether the lambda is capturing arguments or not.
By using an explicit shared instance, it can reduce synthetic class
and method generation. Also reduce 4 instructions per invocation:
new-instance, invoke-direct, check-cast, invoke-static.
Bug: 163976519
Test: CtsWindowManagerDeviceActivity
Change-Id: I71a89713d64f0605faf6045ba44389a8eb47f3d5
diff --git a/services/core/java/com/android/server/wm/ActivityRecord.java b/services/core/java/com/android/server/wm/ActivityRecord.java
index e814f17..bd1ba00 100644
--- a/services/core/java/com/android/server/wm/ActivityRecord.java
+++ b/services/core/java/com/android/server/wm/ActivityRecord.java
@@ -11109,7 +11109,7 @@
* Otherwise, return the creation time of the top window.
*/
long getLastWindowCreateTime() {
- final WindowState window = getWindow(win -> true);
+ final WindowState window = getWindow(alwaysTruePredicate());
return window != null && window.mAttrs.type != TYPE_BASE_APPLICATION
? window.getCreateTime()
: createTime;
diff --git a/services/core/java/com/android/server/wm/DisplayContent.java b/services/core/java/com/android/server/wm/DisplayContent.java
index c9a5e71..a5853c0 100644
--- a/services/core/java/com/android/server/wm/DisplayContent.java
+++ b/services/core/java/com/android/server/wm/DisplayContent.java
@@ -2755,7 +2755,7 @@
@Nullable
Task getTopRootTask() {
- return getRootTask(t -> true);
+ return getRootTask(alwaysTruePredicate());
}
/**
diff --git a/services/core/java/com/android/server/wm/TaskDisplayArea.java b/services/core/java/com/android/server/wm/TaskDisplayArea.java
index 2c27b98..eff8315 100644
--- a/services/core/java/com/android/server/wm/TaskDisplayArea.java
+++ b/services/core/java/com/android/server/wm/TaskDisplayArea.java
@@ -223,7 +223,7 @@
@VisibleForTesting
Task getTopRootTask() {
- return getRootTask(t -> true);
+ return getRootTask(alwaysTruePredicate());
}
@Nullable
diff --git a/services/core/java/com/android/server/wm/WindowContainer.java b/services/core/java/com/android/server/wm/WindowContainer.java
index d70ca02..edbba92 100644
--- a/services/core/java/com/android/server/wm/WindowContainer.java
+++ b/services/core/java/com/android/server/wm/WindowContainer.java
@@ -116,6 +116,7 @@
import com.android.server.wm.SurfaceAnimator.Animatable;
import com.android.server.wm.SurfaceAnimator.AnimationType;
import com.android.server.wm.SurfaceAnimator.OnAnimationFinishedCallback;
+import com.android.server.wm.utils.AlwaysTruePredicate;
import java.io.PrintWriter;
import java.lang.ref.WeakReference;
@@ -2019,29 +2020,34 @@
callback, boundary, includeBoundary, traverseTopToBottom, boundaryFound);
}
+ @SuppressWarnings("unchecked")
+ static <T> Predicate<T> alwaysTruePredicate() {
+ return (Predicate<T>) AlwaysTruePredicate.INSTANCE;
+ }
+
ActivityRecord getActivityAbove(ActivityRecord r) {
- return getActivity((above) -> true, r,
+ return getActivity(alwaysTruePredicate(), r /* boundary */,
false /*includeBoundary*/, false /*traverseTopToBottom*/);
}
ActivityRecord getActivityBelow(ActivityRecord r) {
- return getActivity((below) -> true, r,
+ return getActivity(alwaysTruePredicate(), r /* boundary */,
false /*includeBoundary*/, true /*traverseTopToBottom*/);
}
ActivityRecord getBottomMostActivity() {
- return getActivity((r) -> true, false /*traverseTopToBottom*/);
+ return getActivity(alwaysTruePredicate(), false /* traverseTopToBottom */);
}
ActivityRecord getTopMostActivity() {
- return getActivity((r) -> true, true /*traverseTopToBottom*/);
+ return getActivity(alwaysTruePredicate(), true /* traverseTopToBottom */);
}
ActivityRecord getTopActivity(boolean includeFinishing, boolean includeOverlays) {
// Break down into 4 calls to avoid object creation due to capturing input params.
if (includeFinishing) {
if (includeOverlays) {
- return getActivity((r) -> true);
+ return getActivity(alwaysTruePredicate());
}
return getActivity((r) -> !r.isTaskOverlay());
} else if (includeOverlays) {
@@ -2220,21 +2226,17 @@
}
}
- Task getTaskAbove(Task t) {
- return getTask(
- (above) -> true, t, false /*includeBoundary*/, false /*traverseTopToBottom*/);
- }
-
Task getTaskBelow(Task t) {
- return getTask((below) -> true, t, false /*includeBoundary*/, true /*traverseTopToBottom*/);
+ return getTask(alwaysTruePredicate(), t /* boundary */,
+ false /* includeBoundary */, true /* traverseTopToBottom */);
}
Task getBottomMostTask() {
- return getTask((t) -> true, false /*traverseTopToBottom*/);
+ return getTask(alwaysTruePredicate(), false /* traverseTopToBottom */);
}
Task getTopMostTask() {
- return getTask((t) -> true, true /*traverseTopToBottom*/);
+ return getTask(alwaysTruePredicate(), true /* traverseTopToBottom */);
}
Task getTask(Predicate<Task> callback) {
diff --git a/services/core/java/com/android/server/wm/utils/AlwaysTruePredicate.java b/services/core/java/com/android/server/wm/utils/AlwaysTruePredicate.java
new file mode 100644
index 0000000..49dcb6c
--- /dev/null
+++ b/services/core/java/com/android/server/wm/utils/AlwaysTruePredicate.java
@@ -0,0 +1,33 @@
+/*
+ * Copyright (C) 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.wm.utils;
+
+import java.util.function.Predicate;
+
+/** A simple Predicate to avoid synthetic allocation of lambda expression "o -> true". */
+public class AlwaysTruePredicate implements Predicate<Object> {
+
+ public static final AlwaysTruePredicate INSTANCE = new AlwaysTruePredicate();
+
+ private AlwaysTruePredicate() {
+ }
+
+ @Override
+ public boolean test(Object o) {
+ return true;
+ }
+}