From 1711a00c0d23dfd2fb25e6b419b808716cd30007 Mon Sep 17 00:00:00 2001
From: simonla <zengmingyang96@gmail.com>
Date: Fri, 19 Aug 2022 02:45:47 +0800
Subject: [PATCH] Avoid object creation during each frame
 (flutter/engine#35343)

---
 .../android/io/flutter/view/VsyncWaiter.java  | 44 ++++++++++++++-----
 1 file changed, 32 insertions(+), 12 deletions(-)

diff --git a/engine/src/flutter/shell/platform/android/io/flutter/view/VsyncWaiter.java b/engine/src/flutter/shell/platform/android/io/flutter/view/VsyncWaiter.java
index c5021460da8..80f5658dea5 100644
--- a/engine/src/flutter/shell/platform/android/io/flutter/view/VsyncWaiter.java
+++ b/engine/src/flutter/shell/platform/android/io/flutter/view/VsyncWaiter.java
@@ -47,6 +47,7 @@ public class VsyncWaiter {
   private static DisplayListener listener;
   private long refreshPeriodNanos = -1;
   private FlutterJNI flutterJNI;
+  private FrameCallback frameCallback = new FrameCallback(0);
 
   @NonNull
   public static VsyncWaiter getInstance(float fps, @NonNull FlutterJNI flutterJNI) {
@@ -85,22 +86,41 @@ public class VsyncWaiter {
     listener = null;
   }
 
+  private class FrameCallback implements Choreographer.FrameCallback {
+
+    private long cookie;
+
+    FrameCallback(long cookie) {
+      this.cookie = cookie;
+    }
+
+    @Override
+    public void doFrame(long frameTimeNanos) {
+      long delay = System.nanoTime() - frameTimeNanos;
+      if (delay < 0) {
+        delay = 0;
+      }
+      flutterJNI.onVsync(delay, refreshPeriodNanos, cookie);
+      frameCallback = this;
+    }
+  }
+
   private final FlutterJNI.AsyncWaitForVsyncDelegate asyncWaitForVsyncDelegate =
       new FlutterJNI.AsyncWaitForVsyncDelegate() {
+
+        private Choreographer.FrameCallback obtainFrameCallback(final long cookie) {
+          if (frameCallback != null) {
+            frameCallback.cookie = cookie;
+            FrameCallback ret = frameCallback;
+            frameCallback = null;
+            return ret;
+          }
+          return new FrameCallback(cookie);
+        }
+
         @Override
         public void asyncWaitForVsync(long cookie) {
-          Choreographer.getInstance()
-              .postFrameCallback(
-                  new Choreographer.FrameCallback() {
-                    @Override
-                    public void doFrame(long frameTimeNanos) {
-                      long delay = System.nanoTime() - frameTimeNanos;
-                      if (delay < 0) {
-                        delay = 0;
-                      }
-                      flutterJNI.onVsync(delay, refreshPeriodNanos, cookie);
-                    }
-                  });
+          Choreographer.getInstance().postFrameCallback(obtainFrameCallback(cookie));
         }
       };