C++Qt QFileSystemWatcher文件上传两次

我遇到问题，文件被上传两次到服务器。

我在Windows XP上使用C++Qt中的QFileSystemWatcher类在文件夹更改时发送文件。文件很小（1-12kb）。

应用程序通过在文件夹发生更改时扫描文件夹来发送文件（根据directoryChanged信号），循环浏览文件并发送我需要的文件。服务器以一个xml文件作为响应，该文件返回到同一文件夹中，供另一个应用程序处理

显然，在一些系统上，几乎同时有两个非常快的目录更改信号，并且有两个速度非常快的文件上传。

服务器正在运行Apache和PHP，在PHP端有一个简单的MUTEX，但我只想找到问题的根源，这个问题似乎在Qt端。我对使用另一个类、另一个库或直接的C++持开放态度。

这里有一些代码，我剥离了所有不相关的内容：

this->w = new QFileSystemWatcher();
this->w->addPath("C:/POSERA/MaitreD/DATA/INT");
QStringList directoryList = w->directories();
Q_FOREACH(QString directory, directoryList)
{
    qDebug() << "Watching Main Directory name: " << directory << endl;
}
DirectoryWatcher* dw = new DirectoryWatcher;
QObject::connect( this->w, SIGNAL(directoryChanged(const QString&)),
                  dw, SLOT(directoryChanged(const QString&)));

和DirectoryWatcher.cpp:

DirectoryWatcher::DirectoryWatcher(QWidget* parent) : QWidget(parent)
{
    lockSend = false;
}
void DirectoryWatcher::directoryChanged(const QString& str)
{
    directoryLastChanged = str;
    QByteArray byteArray = str.toUtf8();
    const char* cString = byteArray.constData();
    sendChangedFiles(cString);
}
void DirectoryWatcher::sendChangedFiles(const char* path)
{
    DIR *dir;
    struct dirent *ent;
    if ((dir = opendir (path)) != NULL)
    {
        QString str;
        while ((ent = readdir (dir)) != NULL)
        {
            str = QString("%1/%2").arg(path, ent->d_name);
            QFileInfo info(str);
            if (lockSend == false &&
               (info.completeSuffix() == "xml" || info.completeSuffix() == "XML") &&
               (info.baseName() != "") &&
               (!info.baseName().startsWith("REDM")) &&
               (!info.baseName().startsWith("REFT")))
            {
                // reset the counter.
                this->resendCounter = 0;
                sendFileAndAccept(str.toUtf8().constData());
            }
        }
        closedir (dir);
    }
    else
    {
        qDebug() << "Could not open directory" << endl;
    }
}
class QNetworkRequest;
class QNetworkReply;
void DirectoryWatcher::sendFileAndAccept(const char* path)
{
    // increment the resend counter
    this->resendCounter++;
    QFileInfo fileInfo(path);
    QNetworkAccessManager * mgr = new QNetworkAccessManager(this);
    connect(mgr,SIGNAL(finished(QNetworkReply*)),
            this,SLOT(saveResponse(QNetworkReply*)));
    connect(mgr,SIGNAL(finished(QNetworkReply*)),
            mgr,SLOT(deleteLater())); // @todo delete later
    QHttpMultiPart *multiPart = new QHttpMultiPart(QHttpMultiPart::FormDataType);
    QHttpPart filePart;
    filePart.setHeader(QNetworkRequest::ContentTypeHeader, QVariant("text/xml")); // @todo test
    filePart.setHeader(QNetworkRequest::ContentDispositionHeader, QVariant("form-data; name="someFile"; filename="" + fileInfo.baseName() + ".xml""));
    currentFileSent = fileInfo.baseName();
    QFile *file = new QFile(path);
    file->open(QIODevice::ReadOnly);
    filePart.setBodyDevice(file);
    file->setParent(multiPart); // we cannot delete the file now, so delete it with the multiPart
    multiPart->append(filePart);
    // POST request
    QNetworkReply *reply = mgr->post(QNetworkRequest(QUrl(XXXXXX)), multiPart);
    multiPart->setParent(reply); // delete the multiPart with the reply
    // lock
    lockSend = true;
}
void DirectoryWatcher::saveResponse(QNetworkReply *rep) {
    // get the response
    QByteArray bts = rep->readAll();
    QString str(bts);
    // compute new path
    QString partName = currentFileSent.mid(1, currentFileSent.length());
    QString newPath = QString("%1/A%2.xml").arg(directoryLastChanged, partName);
    qDebug() << "new path: " << newPath << endl;
    switch (rep->error()) {
        case QNetworkReply::NoError: {
            qDebug() << "NO ERROR" << endl;
            // save response to a file.
            QFile file(newPath);
            file.open(QIODevice::WriteOnly | QIODevice::Text);
            QTextStream out(&file);
            out << str;
            file.close();
            break;
        }
        default:
//        case QNetworkReply::TimeoutError :
//        case QNetworkReply::HostNotFoundError :
            qDebug() << "NETWORK REPLY ERROR" << endl;
            // resend the file if the counter is < 10
            if (this->resendCounter < 5) {
                // delay by n sec
                QTime dieTime = QTime::currentTime().addSecs(1);
                while( QTime::currentTime() < dieTime )
                    QCoreApplication::processEvents(QEventLoop::AllEvents, 100);
                sendFileAndAccept(this->lastPathSent.toStdString().c_str());
            } else {
                // after 10 attempts, we're probably sure that the network is down
                // save the file somewhere and generate a default one to prevent timeouts.
                qDebug() << "Saving file for later..." << endl;
                if (!saveFileForLater(lastPathSent.toStdString().c_str())) {
                    qDebug() << "ERROR SAVING FILE, CHECK IF FOLDER EXISTS AND THE PERMISSIONS." << endl;
                }
                // generate a default one to prevent timeouts.
                qDebug() << "Generate a default file..." << endl;
                // ...
            }
            break;
    }
    // unlock
    lockSend = false;
    rep->deleteLater(); // prevent memory leak
}
bool DirectoryWatcher::saveFileForLater(const char* pathToRequestFile) {
    QFile file(pathToRequestFile);
    if (!file.open(QIODevice::ReadOnly | QIODevice::Text)) {
        qDebug() << "readonly and text" << endl;
        return false;
    }
    QString path(pathToRequestFile);
    QFileInfo fileinfo(path);
    QString newPath = "C:\data\offline\" + fileinfo.fileName();
    return file.copy(newPath);
}

谢谢你的帮助。