Qt QThreadPool线程池的实现

#include "widget.h"
#include "ui_widget.h"
#include <QRunnable>
#include <QThreadPool>
#include <QDebug>
#include <QMutex>
#include <QList>

QList<int> g_list;
QMutex g_mutex;

class MyRunnable : public QRunnable
{
public:
    void run() override
    {
        while(true)
        {
            g_mutex.lock();
            if(g_list.size() == 0)
            {
                g_mutex.unlock();
                break;
            }
            qDebug() << "Task running in thread:" << QThread::currentThread() << "deal num "<<g_list.first();
            g_list.pop_front();
            g_mutex.unlock();
        }
        qDebug() << "Task running in thread:" << QThread::currentThread() << "finished ";
    }
};

Widget::Widget(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::Widget)
{
    ui->setupUi(this);

    for(int i=0;i<20;i++)
    {
        g_list.append(i);
    }

    QThreadPool::globalInstance()->setMaxThreadCount(4);

    for (int i = 0; i < 4; ++i)
    {
        MyRunnable *r = new MyRunnable();
        r->setAutoDelete(true);
        QThreadPool::globalInstance()->start(r);

    }
}

Widget::~Widget()
{
    delete ui;
}