QT - Thread (3) 2개의 클래스 객체를 스레드로 실행시키기

서론

MainWindow에서 2개의 객체를 동시에 실행시켜보자.

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흐름도

 

1. 클래스간의 헤더 파일에서 slots 함수와 signal을 선언 및 cpp파일에서 slots 함수 구현을 해준다.

 

- 슬롯 함수

void Custom::doWork()
{
    for(int i=0; i<5; i++){
        QThread::sleep(1);
        qDebug() << "[Custom] in thread : " << QThread::currentThread();
    }
    emit workFinished();
}

 

2. mainwindow.cpp 파일에서 signal과 slots 함수를 연결해준다.

    worker->moveToThread(workerThread);
    custom->moveToThread(customThread);

    connect(workerThread, SIGNAL(started()), worker, SLOT(doWork()));
    connect(customThread, SIGNAL(started()), custom, SLOT(doWork()));

    connect(worker, SIGNAL(workFinished()), this, SLOT(on_workFinished()));
    connect(custom, SIGNAL(workFinished()), this, SLOT(on_workFinished()));

    connect(worker, SIGNAL(workFinished()), workerThread, SLOT(quit()));
    connect(custom, SIGNAL(workFinished()), customThread, SLOT(quit()));

    connect(workerThread, SIGNAL(finished()), worker, SLOT(deleteLater()));
    connect(customThread, SIGNAL(finished()), custom, SLOT(deleteLater()));

    connect(workerThread, SIGNAL(finished()), workerThread, SLOT(deleteLater()));
    connect(customThread, SIGNAL(finished()), customThread, SLOT(deleteLater()));

그러면 그림과 같이 실행 순서를 알 수 있다.

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전체 코드

Mainwindow

mainwindow.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include "worker.h"
#include "custom.h"
#include <QMainWindow>
#include <QThread>
#include <QDebug>

QT_BEGIN_NAMESPACE
namespace Ui { class MainWindow; }
QT_END_NAMESPACE

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    MainWindow(QWidget *parent = nullptr);
    ~MainWindow();

private:
    Ui::MainWindow *ui;
    QThread *workerThread;
    QThread *customThread;
    Worker *worker;
    Custom *custom;

private slots:
    void on_startButton_clicked();
    void on_workFinished();
};
#endif // MAINWINDOW_H

 

mainwindow.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"

#include <QThread>
#include <QDebug>


MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::MainWindow)
    , workerThread(new QThread(this))
    , customThread(new QThread(this))
    , worker(new Worker)
    , custom(new Custom)
{
    ui->setupUi(this);

    worker->moveToThread(workerThread);
    custom->moveToThread(customThread);

    connect(workerThread, SIGNAL(started()), worker, SLOT(doWork()));
    connect(customThread, SIGNAL(started()), custom, SLOT(doWork()));

    connect(worker, SIGNAL(workFinished()), this, SLOT(on_workFinished()));
    connect(custom, SIGNAL(workFinished()), this, SLOT(on_workFinished()));

    connect(worker, SIGNAL(workFinished()), workerThread, SLOT(quit()));
    connect(custom, SIGNAL(workFinished()), customThread, SLOT(quit()));

    connect(workerThread, SIGNAL(finished()), worker, SLOT(deleteLater()));
    connect(customThread, SIGNAL(finished()), custom, SLOT(deleteLater()));

    connect(workerThread, SIGNAL(finished()), workerThread, SLOT(deleteLater()));
    connect(customThread, SIGNAL(finished()), customThread, SLOT(deleteLater()));
}

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


void MainWindow::on_startButton_clicked()
{
    workerThread->start();
    customThread->start();
}

void MainWindow::on_workFinished()
{
    qDebug() << "Work finished in thread : " << QThread::currentThread();
}

worker

worker.h

#ifndef WORKER_H
#define WORKER_H

#include <QObject>

class Worker : public QObject
{
    Q_OBJECT
public:
    explicit Worker(QObject *parent = nullptr);

public slots:
    void doWork();

signals:
    void workFinished();
};

#endif // WORKER_H

 

worker.cpp

#include "worker.h"
#include <QThread>
#include <QDebug>


Worker::Worker(QObject *parent)
    : QObject{parent}
{

}

void Worker::doWork()
{
    for(int i=0; i<5; i++){
        QThread::sleep(1);
        qDebug() << "[Worker] in thread : " << QThread::currentThread();
    }
    emit workFinished();
}

Custom

custom.h

#ifndef CUSTOM_H
#define CUSTOM_H

#include <QObject>

class Custom : public QObject
{
    Q_OBJECT
public:
    explicit Custom(QObject *parent = nullptr);

public slots:
    void doWork();

signals:
    void workFinished();

};

#endif // CUSTOM_H

 

custom.cpp

#include "custom.h"
#include <QThread>
#include <QDebug>

Custom::Custom(QObject *parent)
    : QObject{parent}
{

}

void Custom::doWork()
{
    for(int i=0; i<5; i++){
        QThread::sleep(1);
        qDebug() << "[Custom] in thread : " << QThread::currentThread();
    }
    emit workFinished();
}

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결과