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// Copyright (C) 2023 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 QAUDIOSTATEMACHINEUTILS_P_H
#define QAUDIOSTATEMACHINEUTILS_P_H
//
// W A R N I N G
// -------------
//
// This file is not part of the Qt API. It exists purely as an
// implementation detail. This header file may change from version to
// version without notice, or even be removed.
//
// We mean it.
//
#include "qaudio.h"
QT_BEGIN_NAMESPACE
namespace AudioStateMachineUtils {
using RawState = int;
constexpr RawState DrainingFlag = 1 << 16;
constexpr RawState InProgressFlag = 1 << 17;
constexpr RawState WaitingFlags = DrainingFlag | InProgressFlag;
constexpr bool isWaitingState(RawState state)
{
return (state & WaitingFlags) != 0;
}
constexpr bool isDrainingState(RawState state)
{
return (state & DrainingFlag) != 0;
}
constexpr RawState fromWaitingState(RawState state)
{
return state & ~WaitingFlags;
}
constexpr QAudio::State toAudioState(RawState state)
{
return QAudio::State(fromWaitingState(state));
}
template <typename... States>
constexpr std::pair<RawState, uint32_t> makeStatesSet(QAudio::State first, States... others)
{
return { first, ((1 << first) | ... | (1 << others)) };
}
// ensures compareExchange (testAndSet) operation with opportunity
// to check several states, can be considered as atomic
template <typename T, typename Predicate>
bool multipleCompareExchange(std::atomic<T> &target, T &prevValue, T newValue, Predicate predicate)
{
Q_ASSERT(predicate(prevValue));
do {
if (target.compare_exchange_strong(prevValue, newValue))
return true;
} while (predicate(prevValue));
return false;
}
} // namespace AudioStateMachineUtils
QT_END_NAMESPACE
#endif // QAUDIOSTATEMACHINEUTILS_P_H
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