qtconcurrentrun.h

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// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
#ifndef QTCONCURRENT_RUN_H
#define QTCONCURRENT_RUN_H
 
#if 0
#pragma qt_class(QtConcurrentRun)
#endif
 
#include <QtConcurrent/qtconcurrentcompilertest.h>
 
#if !defined(QT_NO_CONCURRENT) || defined(Q_QDOC)
 
#include <QtConcurrent/qtconcurrentrunbase.h>
#include <QtConcurrent/qtconcurrentstoredfunctioncall.h>
 
QT_BEGIN_NAMESPACE
 
#ifdef Q_QDOC
 
typedef int Function;
 
namespace QtConcurrent {
 
    template <typename T>
    QFuture<T> run(Function function, ...);
 
    template <typename T>
    QFuture<T> run(QThreadPool *pool, Function function, ...);
 
} // namespace QtConcurrent
 
#else
 
namespace QtConcurrent {
 
#define QTCONCURRENT_RUN_NODISCARD
    Q_NODISCARD_X("Use QThreadPool::start(Callable&&) if you don't need the returned QFuture")
 
template <class Function, class ...Args>
QTCONCURRENT_RUN_NODISCARD
auto run(QThreadPool *pool, Function &&f, Args &&...args)
{
    DecayedTuple<Function, Args...> tuple { std::forward<Function>(f),
                                            std::forward<Args>(args)... };
    return TaskResolver<std::decay_t<Function>, std::decay_t<Args>...>::run(
                std::move(tuple), TaskStartParameters { pool });
}
 
template <class Function, class ...Args>
QTCONCURRENT_RUN_NODISCARD
auto run(QThreadPool *pool, std::reference_wrapper<const Function> &&functionWrapper,
         Args &&...args)
{
    return run(pool, std::forward<const Function>(functionWrapper.get()),
               std::forward<Args>(args)...);
}
 
template <class Function, class ...Args>
QTCONCURRENT_RUN_NODISCARD
auto run(Function &&f, Args &&...args)
{
    return run(QThreadPool::globalInstance(), std::forward<Function>(f),
               std::forward<Args>(args)...);
}
 
// overload with a Promise Type hint, takes thread pool
template <class PromiseType, class Function, class ...Args>
QTCONCURRENT_RUN_NODISCARD
auto run(QThreadPool *pool, Function &&f, Args &&...args)
{
    return (new StoredFunctionCallWithPromise<Function, PromiseType, Args...>(
                std::forward<Function>(f), std::forward<Args>(args)...))->start(pool);
}
 
// overload with a Promise Type hint, uses global thread pool
template <class PromiseType, class Function, class ...Args>
QTCONCURRENT_RUN_NODISCARD
auto run(Function &&f, Args &&...args)
{
    return run<PromiseType>(QThreadPool::globalInstance(), std::forward<Function>(f),
                            std::forward<Args>(args)...);
}
 
#undef QTCONCURRENT_RUN_NODISCARD
 
} //namespace QtConcurrent
 
#endif // Q_QDOC
 
QT_END_NAMESPACE
 
#endif // QT_NO_CONCURRENT
 
#endif