/*
 * Copyright 2011 LMAX Ltd.
 *
 * 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 com.lmax.disruptor;

import java.util.concurrent.TimeUnit;

/**
 * Strategy employed for making {@link EventProcessor}s wait on a cursor {@link Sequence}.
 */
public interface WaitStrategy
{
    /**
     * Wait for the given sequence to be available
     *
     * @param sequence to be waited on.
     * @param cursor on which to wait.
     * @param dependents further back the chain that must advance first
     * @param barrier the processor is waiting on.
     * @return the sequence that is available which may be greater than the requested sequence.
     * @throws AlertException if the status of the Disruptor has changed.
     * @throws InterruptedException if the thread is interrupted.
     */
    long waitFor(long sequence, Sequence cursor, Sequence[] dependents, SequenceBarrier barrier)
        throws AlertException, InterruptedException;

    /**
     * Wait for the given sequence to be available with a timeout specified.
     *
     * @param sequence to be waited on.
     * @param cursor on which to wait.
     * @param dependents further back the chain that must advance first
     * @param barrier the processor is waiting on.
     * @param timeout value to abort after.
     * @param sourceUnit of the timeout value.
     * @return the sequence that is available which may be greater than the requested sequence.
     * @throws AlertException if the status of the Disruptor has changed.
     * @throws InterruptedException if the thread is interrupted.
     */
    long waitFor(long sequence, Sequence cursor, Sequence[] dependents, SequenceBarrier barrier, long timeout, TimeUnit sourceUnit)
        throws AlertException, InterruptedException;

    /**
     * Signal those {@link EventProcessor}s waiting that the cursor has advanced.
     */
    void signalAllWhenBlocking();
}