QtHelpers.h

//
//  Created by Bradley Austin Davis on 2017/06/29
//  Copyright 2013-2015 High Fidelity, Inc.
//  Copyright 2023 Overte e.V.
//
//  Distributed under the Apache License, Version 2.0.
//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
//  SPDX-License-Identifier: Apache-2.0
//
 
#pragma once
#ifndef hifi_Shared_QtHelpers_h
#define hifi_Shared_QtHelpers_h
 
#include <QtCore/QObject>
#include <QtCore/QLoggingCategory>
#include <QtCore/QThread>
 
#include "../Profile.h"
 
#if defined(Q_OS_WIN)
// Enable event queue debugging
#define DEBUG_EVENT_QUEUE
#endif
 
class QLoggingCategory;
const QLoggingCategory& thread_safety();
 
namespace hifi { namespace qt {
void addBlockingForbiddenThread(const QString& name, QThread* thread = nullptr);
QString isBlockingForbiddenThread(QThread* currentThread);
 
bool blockingInvokeMethod(
    const char* function,
    QObject *obj, const char *member,
    QGenericReturnArgument ret,
    QGenericArgument val0 = QGenericArgument(Q_NULLPTR),
    QGenericArgument val1 = QGenericArgument(),
    QGenericArgument val2 = QGenericArgument(),
    QGenericArgument val3 = QGenericArgument(),
    QGenericArgument val4 = QGenericArgument(),
    QGenericArgument val5 = QGenericArgument(),
    QGenericArgument val6 = QGenericArgument(),
    QGenericArgument val7 = QGenericArgument(),
    QGenericArgument val8 = QGenericArgument(),
    QGenericArgument val9 = QGenericArgument());
 
bool blockingInvokeMethod(
    const char* function,
    QObject *obj, const char *member,
    QGenericArgument val0 = QGenericArgument(Q_NULLPTR),
    QGenericArgument val1 = QGenericArgument(),
    QGenericArgument val2 = QGenericArgument(),
    QGenericArgument val3 = QGenericArgument(),
    QGenericArgument val4 = QGenericArgument(),
    QGenericArgument val5 = QGenericArgument(),
    QGenericArgument val6 = QGenericArgument(),
    QGenericArgument val7 = QGenericArgument(),
    QGenericArgument val8 = QGenericArgument(),
    QGenericArgument val9 = QGenericArgument());
 
// handling unregistered functions
template <typename Func, typename ReturnType>
typename std::enable_if<!std::is_convertible<Func, const char*>::value, bool>::type
blockingInvokeMethod(const char* callingFunction, QObject* context, Func function, ReturnType* retVal) {
    auto currentThread = QThread::currentThread();
    if (currentThread == qApp->thread()) {
        qCWarning(thread_safety) << "BlockingQueuedConnection invoked on main thread from " << callingFunction;
        return QMetaObject::invokeMethod(context, function, Qt::BlockingQueuedConnection, retVal);
    }
 
    QString forbiddenThread = isBlockingForbiddenThread(currentThread);
    if (!forbiddenThread.isEmpty()) {
        qCWarning(thread_safety) << "BlockingQueuedConnection invoked on forbidden thread " << forbiddenThread;
    }
 
    PROFILE_RANGE(app, callingFunction);
    return QMetaObject::invokeMethod(context, function, Qt::BlockingQueuedConnection, retVal);
}
 
template <typename Func>
typename std::enable_if<!std::is_convertible<Func, const char*>::value, bool>::type
blockingInvokeMethod(const char* callingFunction, QObject* context, Func function) {
    auto currentThread = QThread::currentThread();
    if (currentThread == qApp->thread()) {
        qCWarning(thread_safety) << "BlockingQueuedConnection invoked on main thread from " << callingFunction;
        return QMetaObject::invokeMethod(context, function, Qt::BlockingQueuedConnection);
    }
 
    QString forbiddenThread = isBlockingForbiddenThread(currentThread);
    if (!forbiddenThread.isEmpty()) {
        qCWarning(thread_safety) << "BlockingQueuedConnection invoked on forbidden thread " << forbiddenThread;
    }
 
    PROFILE_RANGE(app, callingFunction);
    return QMetaObject::invokeMethod(context, function, Qt::BlockingQueuedConnection);
}
 
// Inspecting of the qt event queue
// requres access to private Qt datastructures
// Querying the event queue should be done with
// care as it could lock the threadData->postEventList.mutex
// The code uses a tryLock to avoid the possability of a
// deadlock during a call to this code, although that is unlikely
// When getEventQueueSize fails to get the lock, it returns -1
#ifdef DEBUG_EVENT_QUEUE
    int getEventQueueSize(QThread* thread);
    void dumpEventQueue(QThread* thread);
#endif // DEBUG_EVENT_QUEUE
 
} }
 
#define BLOCKING_INVOKE_METHOD(obj, member, ...) \
    ::hifi::qt::blockingInvokeMethod(__FUNCTION__, obj, member, ##__VA_ARGS__)
 
#endif