[ISSUE #3199] Two timed task for RequestFutureTable (#3202)

Co-authored-by: Npanzhi33 <wb-pz502261@alibaba-inc.com>

client/src/main/java/org/apache/rocketmq/client/impl/producer/DefaultMQProducerImpl.java

@@ -24,14 +24,14 @@ import java.util.HashSet;
 import java.util.List;
 import java.util.Random;
 import java.util.Set;
-import java.util.Timer;
-import java.util.TimerTask;
 import java.util.concurrent.BlockingQueue;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
 import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
 import java.util.concurrent.LinkedBlockingQueue;
 import java.util.concurrent.RejectedExecutionException;
+import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.ThreadFactory;
 import java.util.concurrent.ThreadPoolExecutor;
 import java.util.concurrent.TimeUnit;
@@ -107,7 +107,12 @@ public class DefaultMQProducerImpl implements MQProducerInner {
     private final RPCHook rpcHook;
     private final BlockingQueue<Runnable> asyncSenderThreadPoolQueue;
     private final ExecutorService defaultAsyncSenderExecutor;
-    private final Timer timer = new Timer("RequestHouseKeepingService", true);
+    private final ScheduledExecutorService scheduledExecutorService = Executors.newSingleThreadScheduledExecutor(new ThreadFactory() {
+        @Override
+        public Thread newThread(Runnable r) {
+            return new Thread(r, "RequestHouseKeepingService");
+        }
+    });
     protected BlockingQueue<Runnable> checkRequestQueue;
     protected ExecutorService checkExecutor;
     private ServiceState serviceState = ServiceState.CREATE_JUST;
@@ -227,7 +232,13 @@ public class DefaultMQProducerImpl implements MQProducerInner {
 
         this.mQClientFactory.sendHeartbeatToAllBrokerWithLock();
 
-        this.timer.scheduleAtFixedRate(new TimerTask() {
+        this.startScheduledTask();
+
+    }
+
+    private void startScheduledTask() {
+        if (RequestFutureTable.getProducerNum().incrementAndGet() == 1) {
+            this.scheduledExecutorService.scheduleAtFixedRate(new Runnable() {
                 @Override
                 public void run() {
                     try {
@@ -236,7 +247,8 @@ public class DefaultMQProducerImpl implements MQProducerInner {
                         log.error("scan RequestFutureTable exception", e);
                     }
                 }
-        }, 1000 * 3, 1000);
+            }, 1000 * 3, 1000, TimeUnit.MILLISECONDS);
+        }
     }
 
     private void checkConfig() throws MQClientException {
@@ -266,7 +278,9 @@ public class DefaultMQProducerImpl implements MQProducerInner {
                 if (shutdownFactory) {
                     this.mQClientFactory.shutdown();
                 }
-                this.timer.cancel();
+                if (RequestFutureTable.getProducerNum().decrementAndGet() == 0) {
+                    scheduledExecutorService.shutdown();
+                }
                 log.info("the producer [{}] shutdown OK", this.defaultMQProducer.getProducerGroup());
                 this.serviceState = ServiceState.SHUTDOWN_ALREADY;
                 break;

client/src/main/java/org/apache/rocketmq/client/producer/RequestFutureTable.java

@@ -22,6 +22,8 @@ import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.atomic.AtomicInteger;
+
 import org.apache.rocketmq.client.common.ClientErrorCode;
 import org.apache.rocketmq.client.exception.RequestTimeoutException;
 import org.apache.rocketmq.client.log.ClientLogger;
@@ -30,6 +32,7 @@ import org.apache.rocketmq.logging.InternalLogger;
 public class RequestFutureTable {
     private static InternalLogger log = ClientLogger.getLog();
     private static ConcurrentHashMap<String, RequestResponseFuture> requestFutureTable = new ConcurrentHashMap<String, RequestResponseFuture>();
+    private static final AtomicInteger producerNum = new AtomicInteger(0);
 
     public static ConcurrentHashMap<String, RequestResponseFuture> getRequestFutureTable() {
         return requestFutureTable;
@@ -59,4 +62,8 @@ public class RequestFutureTable {
             }
         }
     }
+
+    public static AtomicInteger getProducerNum() {
+        return producerNum;
+    }
 }