From d407ebf101437b864b4b2e9ddc9bd2daf74525a8 Mon Sep 17 00:00:00 2001
From: markgui <markgui@tencent.com>
Date: Thu, 29 Jul 2021 21:00:32 +0800
Subject: [PATCH] HDDS-5513. Race condition upon dn restart at prefinalization.

---
 .../common/statemachine/DatanodeStateMachine.java         | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/hadoop-hdds/container-service/src/main/java/org/apache/hadoop/ozone/container/common/statemachine/DatanodeStateMachine.java b/hadoop-hdds/container-service/src/main/java/org/apache/hadoop/ozone/container/common/statemachine/DatanodeStateMachine.java
index 56ab9a63ba71..488c7bc03655 100644
--- a/hadoop-hdds/container-service/src/main/java/org/apache/hadoop/ozone/container/common/statemachine/DatanodeStateMachine.java
+++ b/hadoop-hdds/container-service/src/main/java/org/apache/hadoop/ozone/container/common/statemachine/DatanodeStateMachine.java
@@ -88,7 +88,7 @@ public class DatanodeStateMachine implements Closeable {
   private final ReportManager reportManager;
   private long commandsHandled;
   private final AtomicLong nextHB;
-  private Thread stateMachineThread = null;
+  private volatile Thread stateMachineThread = null;
   private Thread cmdProcessThread = null;
   private final ReplicationSupervisor supervisor;
 
@@ -476,7 +476,7 @@ public void startDaemon() {
    * be sent by datanode.
    */
   public void triggerHeartbeat() {
-    if (stateMachineThread != null) {
+    if (stateMachineThread != null && isDaemonStarted()) {
       stateMachineThread.interrupt();
     }
   }
@@ -517,6 +517,10 @@ public synchronized void stopDaemon() {
     }
   }
 
+  public boolean isDaemonStarted() {
+    return this.getContext().getExecutionCount() > 0;
+  }
+
   /**
    *
    * Check if the datanode state machine daemon is stopped.