include/QtCore/qelapsedtimer.h

0001 // Copyright (C) 2016 The Qt Company Ltd.
0002 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
0003
0004 #ifndef QELAPSEDTIMER_H
0005 #define QELAPSEDTIMER_H
0006
0007 #include <QtCore/qcompare.h>
0008 #include <QtCore/qglobal.h>
0009
0010 #include <chrono>
0011
0012 QT_BEGIN_NAMESPACE
0013
0014 class Q_CORE_EXPORT QElapsedTimer
0015 {
0016 public:
0017     enum ClockType {
0018         SystemTime,
0019         MonotonicClock,
0020         TickCounter Q_DECL_ENUMERATOR_DEPRECATED_X(
0021                 "Not supported anymore. Use PerformanceCounter instead."),
0022         MachAbsoluteTime,
0023         PerformanceCounter
0024     };
0025
0026     // similar to std::chrono::*_clock
0027     using Duration = std::chrono::nanoseconds;
0028     using TimePoint = std::chrono::time_point<std::chrono::steady_clock, Duration>;
0029
0030     constexpr QElapsedTimer() = default;
0031
0032     static ClockType clockType() noexcept;
0033     static bool isMonotonic() noexcept;
0034
0035     void start() noexcept;
0036     qint64 restart() noexcept;
0037     void invalidate() noexcept;
0038     bool isValid() const noexcept;
0039
0040     Duration durationElapsed() const noexcept;
0041     qint64 nsecsElapsed() const noexcept;
0042     qint64 elapsed() const noexcept;
0043     bool hasExpired(qint64 timeout) const noexcept;
0044
0045     qint64 msecsSinceReference() const noexcept;
0046     Duration durationTo(const QElapsedTimer &other) const noexcept;
0047     qint64 msecsTo(const QElapsedTimer &other) const noexcept;
0048     qint64 secsTo(const QElapsedTimer &other) const noexcept;
0049     friend bool Q_CORE_EXPORT operator<(const QElapsedTimer &lhs, const QElapsedTimer &rhs) noexcept;
0050
0051 private:
0052     friend bool comparesEqual(const QElapsedTimer &lhs, const QElapsedTimer &rhs) noexcept
0053     {
0054         return lhs.t1 == rhs.t1 && lhs.t2 == rhs.t2;
0055     }
0056     Q_DECLARE_EQUALITY_COMPARABLE(QElapsedTimer)
0057
0058     friend Qt::strong_ordering compareThreeWay(const QElapsedTimer &lhs,
0059                                                const QElapsedTimer &rhs) noexcept
0060     {
0061         return Qt::compareThreeWay(lhs.t1, rhs.t1);
0062     }
0063
0064 #if defined(__cpp_lib_three_way_comparison)
0065     friend std::strong_ordering
0066     operator<=>(const QElapsedTimer &lhs, const QElapsedTimer &rhs) noexcept
0067     {
0068         return compareThreeWay(lhs, rhs);
0069     }
0070 #else
0071     friend bool operator>(const QElapsedTimer &lhs, const QElapsedTimer &rhs) noexcept
0072     {
0073         return is_gt(compareThreeWay(lhs, rhs));
0074     }
0075     friend bool operator<=(const QElapsedTimer &lhs, const QElapsedTimer &rhs) noexcept
0076     {
0077         return is_lteq(compareThreeWay(lhs, rhs));
0078     }
0079     friend bool operator>=(const QElapsedTimer &lhs, const QElapsedTimer &rhs) noexcept
0080     {
0081         return is_gteq(compareThreeWay(lhs, rhs));
0082     }
0083 #endif // defined(__cpp_lib_three_way_comparison)
0084     qint64 t1 = Q_INT64_C(0x8000000000000000);
0085     qint64 t2 = Q_INT64_C(0x8000000000000000);
0086 };
0087
0088 QT_END_NAMESPACE
0089
0090 #endif // QELAPSEDTIMER_H