[BUG][PeerTaskInstancePriorityQueue]poll implemented in PriorityQueue

dolphinscheduler-service/src/main/java/org/apache/dolphinscheduler/service/queue/PeerTaskInstancePriorityQueue.java

@@ -23,6 +23,7 @@ import org.apache.dolphinscheduler.service.exceptions.TaskPriorityQueueException
 import java.util.Comparator;
 import java.util.Iterator;
 import java.util.PriorityQueue;
+import java.util.concurrent.TimeUnit;
 
 /**
  * Task instances priority queue implementation
@@ -61,6 +62,22 @@ public class PeerTaskInstancePriorityQueue implements TaskPriorityQueue<TaskInst
         return queue.poll();
     }
 
+    /**
+     * poll task info with timeout
+     * @param timeout
+     * @param unit
+     * @return
+     * @throws TaskPriorityQueueException
+     * @throws InterruptedException
+     */
+    @Override
+    public TaskInstance poll(long timeout, TimeUnit unit) throws TaskPriorityQueueException, InterruptedException {
+        if (queue.isEmpty()) {
+            unit.sleep(timeout);
+        }
+        return queue.poll();
+    }
+
     /**
      * peek taskInfo
      *