    001    // Copyright 2006, 2007, 2010 The Apache Software Foundation
    002    //
    003    // Licensed under the Apache License, Version 2.0 (the "License");
    004    // you may not use this file except in compliance with the License.
    005    // You may obtain a copy of the License at
    006    //
    007    //     http://www.apache.org/licenses/LICENSE-2.0
    008    //
    009    // Unless required by applicable law or agreed to in writing, software
    010    // distributed under the License is distributed on an "AS IS" BASIS,
    011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    012    // See the License for the specific language governing permissions and
    013    // limitations under the License.
    014
    015    package org.apache.tapestry5.internal.services;
    016
    017    import static org.apache.tapestry5.ioc.internal.util.CollectionFactory.newStack;
    018
    019    import java.util.List;
    020
    021    import org.apache.tapestry5.ioc.internal.util.CollectionFactory;
    022    import org.apache.tapestry5.ioc.util.Stack;
    023    import org.apache.tapestry5.services.Heartbeat;
    024
    025    public class HeartbeatImpl implements Heartbeat
    026    {
    027        private final Stack<List<Runnable>> stack = newStack();
    028
    029        public void begin()
    030        {
    031            List<Runnable> beat = CollectionFactory.newList();
    032
    033            stack.push(beat);
    034        }
    035
    036        public void defer(Runnable command)
    037        {
    038            assert command != null;
    039
    040            stack.peek().add(command);
    041
    042        }
    043
    044        public void end()
    045        {
    046            List<Runnable> beat = stack.pop();
    047
    048            for (Runnable r : beat)
    049                r.run();
    050        }
    051
    052    }