package com.yitong.mobile.common.base.utils;

import java.util.concurrent.Executors;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;

/**
 * 線程池管理 管理整個(gè)項(xiàng)目中所有的線程，所以不能有多個(gè)實(shí)例對(duì)象
 */
public class ThreadPoolManager {

    private static ThreadPoolManager mInstance = new ThreadPoolManager();

    public static ThreadPoolManager getInstance() {
        return mInstance;
    }

    private int corePoolSize;//核心線程池的數(shù)量，同時(shí)能夠執(zhí)行的線程數(shù)量
    private int maximumPoolSize;//最大線程池?cái)?shù)量，表示當(dāng)緩沖隊(duì)列滿的時(shí)候能繼續(xù)容納的等待任務(wù)的數(shù)量
    private long keepAliveTime = 1;//存活時(shí)間
    private TimeUnit unit = TimeUnit.HOURS;
    private ThreadPoolExecutor executor;

    private ThreadPoolManager() {
        /**
         * 給corePoolSize賦值：當(dāng)前設(shè)備可用處理器核心數(shù)*2 + 1,能夠讓cpu的效率得到最大程度執(zhí)行（有研究論證的）
         */
        corePoolSize = Runtime.getRuntime().availableProcessors() * 2 + 1;
        maximumPoolSize = corePoolSize; //雖然maximumPoolSize用不到，但是需要賦值，否則報(bào)錯(cuò)
        executor = new ThreadPoolExecutor(
                corePoolSize, //當(dāng)某個(gè)核心任務(wù)執(zhí)行完畢，會(huì)依次從緩沖隊(duì)列中取出等待任務(wù)
                maximumPoolSize, //5,先corePoolSize,然后new LinkedBlockingQueue<Runnable>(),然后maximumPoolSize,但是它的數(shù)量是包含了corePoolSize的
                keepAliveTime, //表示的是maximumPoolSize當(dāng)中等待任務(wù)的存活時(shí)間
                unit,
                new LinkedBlockingQueue<Runnable>(), //緩沖隊(duì)列，用于存放等待任務(wù)，Linked的先進(jìn)先出
                Executors.defaultThreadFactory(), //創(chuàng)建線程的工廠
                new ThreadPoolExecutor.AbortPolicy() //用來(lái)對(duì)超出maximumPoolSize的任務(wù)的處理策略
        );
    }

    /**
     * 執(zhí)行任務(wù)
     */
    public void execute(Runnable runnable) {
        if (runnable == null) {
            return;
        }
        executor.execute(runnable);
    }

    /**
     * 從線程池中移除任務(wù)
     */
    public void remove(Runnable runnable) {
        if (runnable == null) {
            return;
        }
        executor.remove(runnable);
    }
}