/*
 * Copyright 2006 the original author or authors.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.wamblee.socketproxy; 

public class Barrier {

    private int _countLeft;

    public Barrier( int aCount ) {
        _countLeft = aCount;
    }

    public synchronized void block( ) {
        _countLeft--;
        if ( _countLeft < 0 ) {
            throw new IllegalStateException(
                    "Barrier count became negative, programming error" );
        }
        notifyAll( );
        while ( _countLeft > 0 ) {
            waitUninterruptable( );
        }
    }

    private void waitUninterruptable( ) {
        try {
            wait( );
        } catch ( InterruptedException e ) {
            // ignore.
        }
    }

}