如何在第三方函数调用之前同时运行线程

Question

我做了一个工作线程任务，另一个是我的公共第三方函数。我想同时运行两个线程槽(例如：StartWork(((和我的公共函数(例如：on_pushButton_4_clicked(((，但它们不会。请告诉我如何做到这一点。这是我的代码：

我的线程.cpp

#include "mythread.h"
#include "ui_mythread.h"
Mythread::Mythread(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::Mythread)
{
    ui->setupUi(this);
    //Debug
    this->dumpObjectInfo();
    //myWorker->dumpObjectInfo();
}
Mythread::~Mythread()
{
    myWorker->abort();
    WorkerThread->wait();
    qDebug()<<"Deleting thread and worker in Thread "<<this->QObject::thread()->currentThreadId();
    delete WorkerThread;
    delete myWorker;
    delete ui;
}
void Mythread::on_pushButton_2_clicked()
{
    qDebug() << "stopwork signal emmitted";
    emit stopWorkSignal();
}
void Mythread::on_pushButton_4_clicked()
{
    myWorker = new worker;
    WorkerThread = new QThread;
    myWorker->moveToThread(WorkerThread);
    WorkerThread->start();
    connect(myWorker, SIGNAL(valueChanged(QString)),this, SLOT(myfunc(QString)));
    connect(WorkerThread, SIGNAL(started()), myWorker, SLOT(StartWork()));
    connect(this, SIGNAL(stopWorkSignal()), myWorker, SLOT(abort()));
    qDebug()<<"inside work";
    int i =0;
    while (i<1000)
    {
    qDebug()<<":count *i=========>"<<i;
    i++;
    }
    return;
}
void Mythread::myfunc(QString s)
{
    qDebug()<<"thread TXT"<<s;
    //
    ui->label->setText(s);
}

工人.cpp

#include "worker.h"
#include<QDebug>
#include<mythread.h>
worker::worker(QObject *parent) :
    QObject(parent)
{
    _working =false;
    _abort = false;
}
void worker::do_Work()
{
    qDebug() << "inside do Work";
    qDebug()<<"Starting worker process in Thread   "<<thread()->currentThreadId();
    for (int i = 1; i<100; i ++) {
    // Checks if the process should be aborted
    mutex.lock();
    bool abort = _abort;
    mutex.unlock();
    if (abort) {
        qDebug()<<"Aborting worker process in Thread "<<thread()->currentThreadId();
        break;
    }
    // This will stupidly wait 1 sec doing nothing...
    QEventLoop loop;
    loop.processEvents(QEventLoop::AllEvents);
    QTimer::singleShot(100, &loop, SLOT(quit()));
    loop.exec();
     //Once we're done waiting, value is updated
    emit valueChanged(QString("%1").arg(i++));
    }
    mutex.lock();
    _working = false;
    mutex.unlock();
    qDebug()<<"Worker process finished in Thread "<<thread()->currentThreadId();
    emit finished();
}

void worker::abort()
{
    qDebug()<<"Stop Thread";
    mutex.lock();
    if (_working) {
    _abort = true;
    qDebug()<<"Request worker aborting in Thread "<<thread()->currentThreadId();
    }
    mutex.unlock();
    emit finished();
    //lbl->close();
    //lbl->deleteLater();
}
void worker::StartWork()
{
    qDebug() << "inside StartWork";
    _working = true;
    _abort = false;
    //emit running();
    do_Work();
}

输出如下：

  :count *i=========> 988 
  :count *i=========> 989 
  :count *i=========> 990 
  :count *i=========> 991 
  :count *i=========> 992 
 thread TXT "1" 
 thread TXT "3" 
 thread TXT "5" 
 thread TXT "7" 

Answer 1

几个问题：

• 在启动线程后，您将 QThread：：started 连接到 StartWork((，因此您可能会错过信号。
• 执行 1000 的 while(( 循环是在很短的时间内完成的，因此它很可能会在您有机会向另一个线程发出信号之前运行。
• 最重要的问题是，当你在线程上发出 valueChanged(( 时，它将排队到你的主线程在 myFunc(( 上。

而且你总是可以调用QThread：：currentThread((来查看它是否在正确的线程上运行，它也取决于操作系统来调度你的线程，所以期望看到两个线程的输出不太可能同时发生你尝试的方式。