/*
 * Copyright 2016 The Netty Project
 *
 * The Netty Project licenses this file to you 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 io.netty.channel;

import io.netty.util.IntSupplier;

Select strategy interface.
Provides the ability to control the behavior of the select loop. For example a blocking select
operation can be delayed or skipped entirely if there are events to process immediately.
/**
 * Select strategy interface.
 *
 * Provides the ability to control the behavior of the select loop. For example a blocking select
 * operation can be delayed or skipped entirely if there are events to process immediately.
 */
public interface SelectStrategy {

    
Indicates a blocking select should follow.
/**
     * Indicates a blocking select should follow.
     */
    int SELECT = -1;
    
Indicates the IO loop should be retried, no blocking select to follow directly.
/**
     * Indicates the IO loop should be retried, no blocking select to follow directly.
     */
    int CONTINUE = -2;

    
The SelectStrategy can be used to steer the outcome of a potential select call. 
Params:
selectSupplier – The supplier with the result of a select result.
hasTasks – true if tasks are waiting to be processed.
Returns:
SELECT if the next step should be blocking select CONTINUE if the next step should be to not select but rather jump back to the IO loop and try again. Any value >= 0 is treated as an indicator that work needs to be done./**
     * The {@link SelectStrategy} can be used to steer the outcome of a potential select
     * call.
     *
     * @param selectSupplier The supplier with the result of a select result.
     * @param hasTasks true if tasks are waiting to be processed.
     * @return {@link #SELECT} if the next step should be blocking select {@link #CONTINUE} if
     *         the next step should be to not select but rather jump back to the IO loop and try
     *         again. Any value >= 0 is treated as an indicator that work needs to be done.
     */
    int calculateStrategy(IntSupplier selectSupplier, boolean hasTasks) throws Exception;
}