X-Git-Url: https://gerrit.onap.org/r/gitweb?a=blobdiff_plain;f=datarouter-node%2Fsrc%2Fmain%2Fjava%2Forg%2Fonap%2Fdmaap%2Fdatarouter%2Fnode%2FTaskList.java;h=a77277f29f354cc49e0cc963fc8d2af58f915c07;hb=c87a3bf443d1d71389da4cda76adbddcac26e7a2;hp=33e4f801a965377b005ef97b147f066a8e8ba5ca;hpb=8cbe8a88bc6dfe8673a33a017fe6a5a3e7ce86c3;p=dmaap%2Fdatarouter.git

diff --git a/datarouter-node/src/main/java/org/onap/dmaap/datarouter/node/TaskList.java b/datarouter-node/src/main/java/org/onap/dmaap/datarouter/node/TaskList.java
index 33e4f801..a77277f2 100644
--- a/datarouter-node/src/main/java/org/onap/dmaap/datarouter/node/TaskList.java
+++ b/datarouter-node/src/main/java/org/onap/dmaap/datarouter/node/TaskList.java
@@ -24,63 +24,54 @@
 
 package org.onap.dmaap.datarouter.node;
 
-import java.util.*;
+import java.util.HashSet;
+import java.util.Iterator;
 
 /**
- * Manage a list of tasks to be executed when an event occurs.
- * This makes the following guarantees:
+ * Manage a list of tasks to be executed when an event occurs. This makes the following guarantees:
  * <ul>
  * <li>Tasks can be safely added and removed in the middle of a run.</li>
  * <li>No task will be returned more than once during a run.</li>
  * <li>No task will be returned when it is not, at that moment, in the list of tasks.</li>
  * <li>At the moment when next() returns null, all tasks on the list have been returned during the run.</li>
- * <li>Initially and once next() returns null during a run, next() will continue to return null until startRun() is called.
+ * <li>Initially and once next() returns null during a run, next() will continue to return null until startRun() is
+ * called.
  * </ul>
  */
-public class TaskList {
+class TaskList {
+
     private Iterator<Runnable> runlist;
-    private HashSet<Runnable> tasks = new HashSet<Runnable>();
+    private HashSet<Runnable> tasks = new HashSet<>();
     private HashSet<Runnable> togo;
     private HashSet<Runnable> sofar;
     private HashSet<Runnable> added;
     private HashSet<Runnable> removed;
 
-    /**
-     * Construct a new TaskList
-     */
-    public TaskList() {
-    }
-
     /**
      * Start executing the sequence of tasks.
      */
-    public synchronized void startRun() {
-        sofar = new HashSet<Runnable>();
-        added = new HashSet<Runnable>();
-        removed = new HashSet<Runnable>();
-        togo = new HashSet<Runnable>(tasks);
+    synchronized void startRun() {
+        sofar = new HashSet<>();
+        added = new HashSet<>();
+        removed = new HashSet<>();
+        togo = new HashSet<>(tasks);
         runlist = togo.iterator();
     }
 
     /**
-     * Get the next task to execute
+     * Get the next task to execute.
      */
-    public synchronized Runnable next() {
+    synchronized Runnable next() {
         while (runlist != null) {
             if (runlist.hasNext()) {
                 Runnable task = runlist.next();
-                if (removed.contains(task)) {
-                    continue;
+                if (addTaskToSoFar(task)) {
+                    return task;
                 }
-                if (sofar.contains(task)) {
-                    continue;
-                }
-                sofar.add(task);
-                return (task);
             }
-            if (added.size() != 0) {
+            if (!added.isEmpty()) {
                 togo = added;
-                added = new HashSet<Runnable>();
+                added = new HashSet<>();
                 removed.clear();
                 runlist = togo.iterator();
                 continue;
@@ -97,7 +88,7 @@ public class TaskList {
     /**
      * Add a task to the list of tasks to run whenever the event occurs.
      */
-    public synchronized void addTask(Runnable task) {
+    synchronized void addTask(Runnable task) {
         if (runlist != null) {
             added.add(task);
             removed.remove(task);
@@ -108,11 +99,22 @@ public class TaskList {
     /**
      * Remove a task from the list of tasks to run whenever the event occurs.
      */
-    public synchronized void removeTask(Runnable task) {
+    synchronized void removeTask(Runnable task) {
         if (runlist != null) {
             removed.add(task);
             added.remove(task);
         }
         tasks.remove(task);
     }
+
+    private boolean addTaskToSoFar(Runnable task) {
+        if (removed.contains(task)) {
+            return false;
+        }
+        if (sofar.contains(task)) {
+            return false;
+        }
+        sofar.add(task);
+        return true;
+    }
 }