async.cpp

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/*
 * Copyright (C) 2018-2025 QuasarApp.
 * Distributed under the lgplv3 software license, see the accompanying
 * Everyone is permitted to copy and distribute verbatim copies
 * of this license document, but changing it is not allowed.
*/
 
#include "async.h"
 
#include <QCoreApplication>
#include <QDateTime>
#include <QThread>
#include <QDebug>
#include <quasarapp.h>
#include <thread>
#include <chrono>
#include <qaglobalutils.h>
 
// Private implementation of waitFor functions.
#define waitPrivate(CONDITION, TIMEOUT) \
    auto curmsec = QDateTime::currentMSecsSinceEpoch() + TIMEOUT; \
    while (curmsec > QDateTime::currentMSecsSinceEpoch() && !CONDITION) { \
        QCoreApplication::processEvents(); \
    } \
    QCoreApplication::processEvents(); \
    return CONDITION; \
 
 
#define freazePrivate(CONDITION, TIMEOUT) \
    auto curmsec = QDateTime::currentMSecsSinceEpoch() + TIMEOUT; \
    while (curmsec > QDateTime::currentMSecsSinceEpoch() && !CONDITION) { \
        std::this_thread::sleep_for(std::chrono::microseconds(1)); \
    } \
    return CONDITION; \
 
namespace QH {
 
Async::Async(QThread *thread):
    QObject() {
 
    threadAnalize(thread);
    moveToThread(thread);
}
 
Async::~Async() {
 
}
 
void Async::asyncHandler(Job job,
                         bool *endOfWork,
                         bool *resultOfWork) const {
 
    bool result = job();
 
    if (endOfWork && resultOfWork)
        *resultOfWork = result;
 
    if (endOfWork) {
        *endOfWork = true;
    }
}
 
void Async::threadAnalize(QThread *thread) {
    debug_assert(thread, "Async object must be initialized with a valid work thread");
}
 
bool Async::waitFor(bool *condition, int timeout, bool freaze) const {
    if (!condition)
        return false;
 
    if (freaze) {
        freazePrivate(*condition, timeout)
    } else {
        waitPrivate(*condition, timeout)
    }
}
 
bool Async::asyncLauncher(const Async::Job &job, bool await, bool freaze) const {
 
    if (QThread::currentThread() == thread()) {
        return job();
    }
 
    if (!thread()->isRunning()) {
 
        qCritical() << "The work threand of the async object is not running";
 
        return false;
    }
 
    if (!await) {
        return  QMetaObject::invokeMethod(const_cast<Async*>(this),
                                          "asyncHandler",
                                          Qt::QueuedConnection,
                                          Q_ARG(QH::Async::Job, std::move(job)));
    }
 
    bool workOfEnd = false, workResult = false;
 
    bool invockeResult = QMetaObject::invokeMethod(const_cast<Async*>(this),
                                                   "asyncHandler",
                                                   Qt::QueuedConnection,
                                                   Q_ARG(QH::Async::Job, std::move(job)),
                                                   Q_ARG(bool*, &workOfEnd),
                                                   Q_ARG(bool*, &workResult));
 
 
    if (!invockeResult)
        return false;
 
    if (!waitFor(&workOfEnd, WAIT_TIME, freaze)) {
        return false;
    }
 
    return workResult;
}
 
bool Async::waitFor(const std::function<bool ()> &condition, int timeout, bool freaze) const {
    if (freaze) {
        freazePrivate(condition(), timeout)
    } else {
        waitPrivate(condition(), timeout)
    }
 
}
 
}