qinxian/gist:5771879

## gistfile1.java
/*
 * Copyright 2011 LMAX Ltd. and qinxian
 *
 * 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.
 *
 * Written by qinxian.
 */
package com.lmax.disruptor;


/**
 * Yielding strategy that uses a Thread.yield() for {@link com.lmax.disruptor.EventProcessor}s waiting on a barrier
 * after an initially spinning.
 *
 * This strategy is a good compromise between performance and CPU resource without incurring significant latency spikes.
 */
public final class ModestLockWaitStrategy implements WaitStrategy
{
    private static final int SPIN_TRIES = 100;

    @Override
    public long waitFor(final long sequence, Sequence cursor, final Sequence dependentSequence, final SequenceBarrier barrier)
        throws AlertException, InterruptedException
    {
        long availableSequence;
        int counter = SPIN_TRIES;

        while ((availableSequence = dependentSequence.get()) < sequence)
        {
            counter = applyWaitMethod(barrier, counter);
        }

        return availableSequence;
    }

    @Override
    public void signalAllWhenBlocking()
    {
    }

    private int applyWaitMethod(final SequenceBarrier barrier, int counter)
        throws AlertException
    {
        barrier.checkAlert();

        if ((counter&1)==1)
        {
            Thread.yield();
        }

        return --counter;
    }
}
	/*
	* Copyright 2011 LMAX Ltd. and qinxian
	*
	* 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.
	*
	* Written by qinxian.
	*/
	package com.lmax.disruptor;


	/**
	* Yielding strategy that uses a Thread.yield() for {@link com.lmax.disruptor.EventProcessor}s waiting on a barrier
	* after an initially spinning.
	*
	* This strategy is a good compromise between performance and CPU resource without incurring significant latency spikes.
	*/
	public final class ModestLockWaitStrategy implements WaitStrategy
	{
	private static final int SPIN_TRIES = 100;

	@Override
	public long waitFor(final long sequence, Sequence cursor, final Sequence dependentSequence, final SequenceBarrier barrier)
	throws AlertException, InterruptedException
	{
	long availableSequence;
	int counter = SPIN_TRIES;

	while ((availableSequence = dependentSequence.get()) < sequence)
	{
	counter = applyWaitMethod(barrier, counter);
	}

	return availableSequence;
	}

	@Override
	public void signalAllWhenBlocking()
	{
	}

	private int applyWaitMethod(final SequenceBarrier barrier, int counter)
	throws AlertException
	{
	barrier.checkAlert();

	if ((counter&1)==1)
	{
	Thread.yield();
	}

	return --counter;
	}
	}