| // Copyright 2006, 2009 The Apache Software Foundation |
| // |
| // 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.apache.tapestry5.ioc.internal.util; |
| |
| import java.util.ArrayList; |
| import java.util.List; |
| import org.apache.tapestry5.ioc.Invokable; |
| |
| import java.util.concurrent.TimeUnit; |
| |
| public class ConcurrentTarget |
| { |
| private final ConcurrentBarrier barrier = new ConcurrentBarrier(); |
| |
| private int counter; |
| |
| // Used to check if read locks accumulate when a read lock method calls another read lock method |
| public int readCounter() |
| { |
| return barrier.withRead(new Invokable<Integer>() |
| { |
| public Integer invoke() |
| { |
| return getCounter(); |
| } |
| }); |
| } |
| |
| public int getCounter() |
| { |
| return barrier.withRead(new Invokable<Integer>() |
| { |
| public Integer invoke() |
| { |
| return counter; |
| } |
| }); |
| } |
| |
| public void incrementCounter() |
| { |
| barrier.withWrite(new Runnable() |
| { |
| public void run() |
| { |
| counter++; |
| } |
| }); |
| } |
| |
| public void setCounter(final int counter) |
| { |
| barrier.withWrite(new Runnable() |
| { |
| public void run() |
| { |
| ConcurrentTarget.this.counter = counter; |
| } |
| }); |
| } |
| |
| public void incrementIfNonNegative() |
| { |
| barrier.withRead(new Runnable() |
| { |
| public void run() |
| { |
| if (counter >= 0) |
| incrementCounter(); |
| } |
| }); |
| } |
| |
| public void incrementViaRunnable() |
| { |
| barrier.withRead(new Runnable() |
| { |
| public void run() |
| { |
| Runnable r = new Runnable() |
| { |
| public void run() |
| { |
| incrementCounter(); |
| } |
| }; |
| |
| r.run(); |
| } |
| }); |
| } |
| |
| public void incrementCounterHard() |
| { |
| barrier.withWrite(new Runnable() |
| { |
| public void run() |
| { |
| counter = getCounter() + 1; |
| } |
| }); |
| } |
| |
| public boolean tryIncrementCounter() |
| { |
| return barrier.tryWithWrite(new Runnable() |
| { |
| public void run() |
| { |
| counter++; |
| } |
| }, 20, TimeUnit.MILLISECONDS); |
| } |
| |
| public boolean tryIncrementCounterHard() |
| { |
| return barrier.tryWithWrite(new Runnable() |
| { |
| public void run() |
| { |
| counter = getCounter() + 1; |
| } |
| }, 20, TimeUnit.MILLISECONDS); |
| } |
| |
| public boolean tryIncrementIfNonNegative() |
| { |
| final List<Boolean> result = new ArrayList<Boolean>(); |
| barrier.withRead(new Runnable() |
| { |
| public void run() |
| { |
| if (counter >= 0) |
| result.add(tryIncrementCounter()); |
| } |
| }); |
| return result.get(0); |
| } |
| |
| |
| public void withRead(Runnable runnable) |
| { |
| barrier.withRead(runnable); |
| } |
| } |