Use ThreadSafe Set instead Issue #1633

data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/executor/DataSourceQuery.java

@@ -946,14 +946,12 @@ private static class OdaQueryCanceller implements ICancellable {
 		private StopSign stop;
 		private DataException exception;
 		private DataSourceQuery dsQuery;
-		private final String id;
 
 		OdaQueryCanceller(PreparedStatement statement, DataSource dataSource, StopSign stop, DataSourceQuery dsQuery) {
 			this.statement = statement;
 			this.stop = stop;
 			this.dataSource = dataSource;
 			this.dsQuery = dsQuery;
-			this.id = java.util.UUID.randomUUID().toString();
 		}
 
 		/**
@@ -1004,11 +1002,6 @@ public void cancel() {
 		public boolean doCancel() {
 			return this.stop.isStopped();
 		}
-
-		@Override
-		public String getId() {
-			return this.id;
-		}
 	}
 
 	/**

data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/impl/CancelManager.java

@@ -14,19 +14,17 @@
  *******************************************************************************/
 package org.eclipse.birt.data.engine.impl;
 
-import java.util.Map;
-import java.util.HashMap;
-import java.util.ArrayList;
-import java.util.List;
+import java.util.Set;
 import java.util.TimerTask;
+import java.util.concurrent.ConcurrentHashMap;
 
 /**
  *
  */
 
 public class CancelManager extends TimerTask {
 	//
-	private Map<String, ICancellable> cancellableMap = new HashMap<>();
+	private final Set<ICancellable> cancellables = ConcurrentHashMap.newKeySet();
 
 	/**
 	 * Constructor
@@ -39,19 +37,15 @@ public CancelManager() {
 	 * @param cancellable
 	 */
 	public void register(ICancellable cancellable) {
-		synchronized (cancellableMap) {
-			cancellableMap.put(cancellable.getId(), cancellable);
-		}
+		cancellables.add(cancellable);
 	}
 
 	/**
 	 *
 	 * @param cancellable
 	 */
 	public void deregister(ICancellable cancellable) {
-		synchronized (cancellableMap) {
-			cancellableMap.remove(cancellable.getId());
-		}
+		cancellables.remove(cancellable);
 	}
 
 	/*
@@ -65,11 +59,7 @@ public void run() {
 	}
 
 	public void doCancel() {
-		List<ICancellable> cancellableCollection = null;
-		synchronized (cancellableMap) {
-			cancellableCollection = new ArrayList<>(cancellableMap.values());
-		}
-		for (ICancellable cancellable : cancellableCollection) {
+		for (ICancellable cancellable : cancellables.toArray(ICancellable[]::new)) {
 			if (cancellable.doCancel()) {
 				cancellable.cancel();
 			}

data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/impl/ICancellable.java

@@ -26,6 +26,4 @@ public interface ICancellable {
 	void cancel();
 
 	DataException collectException();
-
-	String getId();
 }