commit 24a356607cd3f7acb916a3453aae90c9f73c3db1
author Pascal Muetschard <pmuetschard@google.com> Wed Aug 17 17:40:30 2022 +0200
committer Pascal Muetschard <pmuetschard@google.com> Tue Aug 23 17:40:57 2022 +0200
tree a2b237d127c05e75f892c0c0e07651493e29dd42
parent 51f38fb6f3858b1431eb63586079a4550795721c

DCL is broken and should not be used.

Use the acceptable instance holder pattern as a replacement.

Change-Id: I2fb29edd48e00ac36a7fb0907a21ae5ca1d5163f

config/preloaded-classes-denylist

diff --git a/config/preloaded-classes-denylist b/config/preloaded-classes-denylist
index 02f2df6..502d8c6 100644
--- a/config/preloaded-classes-denylist
+++ b/config/preloaded-classes-denylist
@@ -9,3 +9,4 @@
 android.net.rtp.AudioStream
 android.net.rtp.RtpStream
 java.util.concurrent.ThreadLocalRandom
+com.android.internal.jank.InteractionJankMonitor$InstanceHolder

core/java/com/android/internal/jank/InteractionJankMonitor.java

diff --git a/core/java/com/android/internal/jank/InteractionJankMonitor.java b/core/java/com/android/internal/jank/InteractionJankMonitor.java
index 6e8a0c7..fc4e041 100644
--- a/core/java/com/android/internal/jank/InteractionJankMonitor.java
+++ b/core/java/com/android/internal/jank/InteractionJankMonitor.java
@@ -293,7 +293,10 @@
             UIINTERACTION_FRAME_INFO_REPORTED__INTERACTION_TYPE__SHADE_CLEAR_ALL,
     };
 
-    private static volatile InteractionJankMonitor sInstance;
+    private static class InstanceHolder {
+        public static final InteractionJankMonitor INSTANCE =
+            new InteractionJankMonitor(new HandlerThread(DEFAULT_WORKER_NAME));
+    }
 
     private final DeviceConfig.OnPropertiesChangedListener mPropertiesChangedListener =
             this::updateProperties;
@@ -385,15 +388,7 @@
      * @return instance of InteractionJankMonitor
      */
     public static InteractionJankMonitor getInstance() {
-        // Use DCL here since this method might be invoked very often.
-        if (sInstance == null) {
-            synchronized (InteractionJankMonitor.class) {
-                if (sInstance == null) {
-                    sInstance = new InteractionJankMonitor(new HandlerThread(DEFAULT_WORKER_NAME));
-                }
-            }
-        }
-        return sInstance;
+        return InstanceHolder.INSTANCE;
     }
 
     /**