Qt::AutoConnection 信号从不同于接收者的thread发出时是queued 方式触发

qoject.cpp中的代码：

static void queued_activate(QObject *sender, int signal, QObjectPrivate::Connection *c, void **argv)
{
    if (!c->argumentTypes && c->argumentTypes != &DIRECT_CONNECTION_ONLY) {
        QMetaMethod m = sender->metaObject()->method(signal);
        int *tmp = queuedConnectionTypes(m.parameterTypes());
        if (!tmp) // cannot queue arguments
            tmp = &DIRECT_CONNECTION_ONLY;
        if (!c->argumentTypes.testAndSetOrdered(0, tmp)) {
            if (tmp != &DIRECT_CONNECTION_ONLY)
                delete [] tmp;
        }
    }
    if (c->argumentTypes == &DIRECT_CONNECTION_ONLY) // cannot activate
        return;
    int nargs = 1; // include return type
    while (c->argumentTypes[nargs-1])
        ++nargs;
    int *types = (int *) qMalloc(nargs*sizeof(int));
    Q_CHECK_PTR(types);
    void **args = (void **) qMalloc(nargs*sizeof(void *));
    Q_CHECK_PTR(args);
    types[0] = 0; // return type
    args[0] = 0; // return value
    for (int n = 1; n < nargs; ++n)
        args[n] = QMetaType::construct((types[n] = c->argumentTypes[n-1]), argv[n]);
    QCoreApplication::postEvent(c->receiver, new QMetaCallEvent(c->method_offset,
                                                                c->method_relative,
                                                                c->callFunction,
                                                                sender, signal, nargs,
                                                                types, args));
}

void QMetaObject::activate(QObject *sender, const QMetaObject *m, int local_signal_index,
                           void **argv)

。。。。

QObject * const receiver = c->receiver;
const bool receiverInSameThread = currentThreadId == receiver->d_func()->threadData->threadId;

// determine if this connection should be sent immediately or
// put into the event queue
if ((c->connectionType == Qt::AutoConnection && !receiverInSameThread)
    || (c->connectionType == Qt::QueuedConnection)) {
    queued_activate(sender, signal_absolute_index, c, argv ? argv : empty_argv);
    continue;