HDDS-4526. Remove false-positive error logs from LeaseManager

hadoop-hdds/common/src/main/java/org/apache/hadoop/ozone/lease/LeaseManager.java

@@ -17,9 +17,6 @@
 
 package org.apache.hadoop.ozone.lease;
 
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
 import java.util.List;
 import java.util.Map;
 import java.util.concurrent.Callable;
@@ -28,6 +25,8 @@
 import java.util.concurrent.Executors;
 
 import static org.apache.hadoop.ozone.lease.Lease.messageForResource;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * LeaseManager is someone who can provide you leases based on your
@@ -46,6 +45,7 @@ public class LeaseManager<T> {
 
   private final String name;
   private final long defaultTimeout;
+  private final Object monitor = new Object();
   private Map<T, Lease<T>> activeLeases;
   private LeaseMonitor leaseMonitor;
   private Thread leaseMonitorThread;
@@ -115,12 +115,14 @@ public synchronized Lease<T> acquire(T resource, long timeout)
     if (LOG.isDebugEnabled()) {
       LOG.debug("Acquiring lease on {} for {} milliseconds", resource, timeout);
     }
-    if(activeLeases.containsKey(resource)) {
+    if (activeLeases.containsKey(resource)) {
       throw new LeaseAlreadyExistException(messageForResource(resource));
     }
     Lease<T> lease = new Lease<>(resource, timeout);
     activeLeases.put(resource, lease);
-    leaseMonitorThread.interrupt();
+    synchronized (monitor) {
+      monitor.notifyAll();
+    }
     return lease;
   }
 
@@ -135,7 +137,7 @@ public synchronized Lease<T> acquire(T resource, long timeout)
   public Lease<T> get(T resource) throws LeaseNotFoundException {
     checkStatus();
     Lease<T> lease = activeLeases.get(resource);
-    if(lease != null) {
+    if (lease != null) {
       return lease;
     }
     throw new LeaseNotFoundException(messageForResource(resource));
@@ -156,7 +158,7 @@ public synchronized void release(T resource)
       LOG.debug("Releasing lease on {}", resource);
     }
     Lease<T> lease = activeLeases.remove(resource);
-    if(lease == null) {
+    if (lease == null) {
       throw new LeaseNotFoundException(messageForResource(resource));
     }
     lease.invalidate();
@@ -171,11 +173,13 @@ public void shutdown() {
     checkStatus();
     LOG.debug("Shutting down LeaseManager service");
     leaseMonitor.disable();
-    leaseMonitorThread.interrupt();
-    for(T resource : activeLeases.keySet()) {
+    synchronized (monitor) {
+      monitor.notifyAll();
+    }
+    for (T resource : activeLeases.keySet()) {
       try {
         release(resource);
-      }  catch(LeaseNotFoundException ex) {
+      } catch (LeaseNotFoundException ex) {
         //Ignore the exception, someone might have released the lease
       }
     }
@@ -187,7 +191,7 @@ public void shutdown() {
    * running.
    */
   private void checkStatus() {
-    if(!isRunning) {
+    if (!isRunning) {
       throw new LeaseManagerNotRunningException("LeaseManager not running.");
     }
   }
@@ -198,16 +202,16 @@ private void checkStatus() {
    */
   private final class LeaseMonitor implements Runnable {
 
-    private volatile boolean monitor = true;
     private final ExecutorService executorService;
+    private volatile boolean running = true;
 
     private LeaseMonitor() {
       this.executorService = Executors.newCachedThreadPool();
     }
 
     @Override
     public void run() {
-      while (monitor) {
+      while (running) {
         LOG.debug("{}-LeaseMonitor: checking for lease expiry", name);
         long sleepTime = Long.MAX_VALUE;
 
@@ -230,12 +234,12 @@ public void run() {
         }
 
         try {
-          if(!Thread.interrupted()) {
-            Thread.sleep(sleepTime);
+          synchronized (monitor) {
+            monitor.wait(sleepTime);
           }
         } catch (InterruptedException e) {
           // This means a new lease is added to activeLeases.
-          LOG.error("Execution was interrupted ", e);
+          LOG.warn("Lease manager is interrupted. Shutting down...", e);
           Thread.currentThread().interrupt();
         }
       }
@@ -246,7 +250,7 @@ public void run() {
      * will stop lease monitor.
      */
     public void disable() {
-      monitor = false;
+      running = false;
     }
   }