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#ifndef QMUTEX_H
#define QMUTEX_H
#include <QtCore/qglobal.h>
#include <QtCore/qatomic.h>
#include <new>
#if QT_HAS_INCLUDE(<chrono>)
# include <chrono>
# include <limits>
#endif
class tst_QMutex;
QT_BEGIN_NAMESPACE
#if !defined(QT_NO_THREAD) || defined(Q_CLANG_QDOC)
#ifdef Q_OS_LINUX
# define QT_MUTEX_LOCK_NOEXCEPT Q_DECL_NOTHROW
#else
# define QT_MUTEX_LOCK_NOEXCEPT
#endif
class QMutexData;
class Q_CORE_EXPORT QBasicMutex
{
public:
// BasicLockable concept
inline void lock() QT_MUTEX_LOCK_NOEXCEPT {
if (!fastTryLock())
lockInternal();
}
// BasicLockable concept
inline void unlock() Q_DECL_NOTHROW {
Q_ASSERT(d_ptr.load()); //mutex must be locked
if (!fastTryUnlock())
unlockInternal();
}
bool tryLock() Q_DECL_NOTHROW {
return fastTryLock();
}
// Lockable concept
bool try_lock() Q_DECL_NOTHROW { return tryLock(); }
bool isRecursive() Q_DECL_NOTHROW; //### Qt6: remove me
bool isRecursive() const Q_DECL_NOTHROW;
private:
inline bool fastTryLock() Q_DECL_NOTHROW {
return d_ptr.testAndSetAcquire(Q_NULLPTR, dummyLocked());
}
inline bool fastTryUnlock() Q_DECL_NOTHROW {
return d_ptr.testAndSetRelease(dummyLocked(), Q_NULLPTR);
}
inline bool fastTryLock(QMutexData *¤t) Q_DECL_NOTHROW {
return d_ptr.testAndSetAcquire(Q_NULLPTR, dummyLocked(), current);
}
inline bool fastTryUnlock(QMutexData *¤t) Q_DECL_NOTHROW {
return d_ptr.testAndSetRelease(dummyLocked(), Q_NULLPTR, current);
}
void lockInternal() QT_MUTEX_LOCK_NOEXCEPT;
bool lockInternal(int timeout) QT_MUTEX_LOCK_NOEXCEPT;
void unlockInternal() Q_DECL_NOTHROW;
QBasicAtomicPointer<QMutexData> d_ptr;
static inline QMutexData *dummyLocked() {
return reinterpret_cast<QMutexData *>(quintptr(1));
}
friend class QMutex;
friend class QMutexData;
};
class Q_CORE_EXPORT QMutex : public QBasicMutex
{
public:
enum RecursionMode { NonRecursive, Recursive };
explicit QMutex(RecursionMode mode = NonRecursive);
~QMutex();
// BasicLockable concept
void lock() QT_MUTEX_LOCK_NOEXCEPT;
bool tryLock(int timeout = 0) QT_MUTEX_LOCK_NOEXCEPT;
// BasicLockable concept
void unlock() Q_DECL_NOTHROW;
// Lockable concept
bool try_lock() QT_MUTEX_LOCK_NOEXCEPT { return tryLock(); }
#if QT_HAS_INCLUDE(<chrono>)
// TimedLockable concept
template <class Rep, class Period>
bool try_lock_for(std::chrono::duration<Rep, Period> duration)
{
return tryLock(convertToMilliseconds(duration));
}
// TimedLockable concept
template<class Clock, class Duration>
bool try_lock_until(std::chrono::time_point<Clock, Duration> timePoint)
{
// Implemented in terms of try_lock_for to honor the similar
// requirement in N4606 § 30.4.1.3 [thread.timedmutex.requirements]/12.
return try_lock_for(timePoint - Clock::now());
}
#endif
bool isRecursive() const Q_DECL_NOTHROW
{ return QBasicMutex::isRecursive(); }
private:
Q_DISABLE_COPY(QMutex)
friend class QMutexLocker;
friend class ::tst_QMutex;
#if QT_HAS_INCLUDE(<chrono>)
template<class Rep, class Period>
static int convertToMilliseconds(std::chrono::duration<Rep, Period> duration)
{
// N4606 § 30.4.1.3.5 [thread.timedmutex.requirements] specifies that a
// duration less than or equal to duration.zero() shall result in a
// try_lock, unlike QMutex's tryLock with a negative duration which
// results in a lock.
if (duration <= duration.zero())
return 0;
// when converting from 'duration' to milliseconds, make sure that
// the result is not shorter than 'duration':
std::chrono::milliseconds wait = std::chrono::duration_cast<std::chrono::milliseconds>(duration);
if (wait < duration)
wait += std::chrono::milliseconds(1);
Q_ASSERT(wait >= duration);
const auto ms = wait.count();
const auto maxInt = (std::numeric_limits<int>::max)();
return ms < maxInt ? int(ms) : maxInt;
}
#endif
};
class Q_CORE_EXPORT QMutexLocker
{
public:
#ifndef Q_CLANG_QDOC
inline explicit QMutexLocker(QBasicMutex *m) QT_MUTEX_LOCK_NOEXCEPT
{
Q_ASSERT_X((reinterpret_cast<quintptr>(m) & quintptr(1u)) == quintptr(0),
"QMutexLocker", "QMutex pointer is misaligned");
val = quintptr(m);
if (Q_LIKELY(m)) {
// call QMutex::lock() instead of QBasicMutex::lock()
static_cast<QMutex *>(m)->lock();
val |= 1;
}
}
#else
QMutexLocker(QMutex *) { }
#endif
inline ~QMutexLocker() { unlock(); }
inline void unlock() Q_DECL_NOTHROW
{
if ((val & quintptr(1u)) == quintptr(1u)) {
val &= ~quintptr(1u);
mutex()->unlock();
}
}
inline void relock() QT_MUTEX_LOCK_NOEXCEPT
{
if (val) {
if ((val & quintptr(1u)) == quintptr(0u)) {
mutex()->lock();
val |= quintptr(1u);
}
}
}
#if defined(Q_CC_MSVC)
#pragma warning( push )
#pragma warning( disable : 4312 ) // ignoring the warning from /Wp64
#endif
inline QMutex *mutex() const
{
return reinterpret_cast<QMutex *>(val & ~quintptr(1u));
}
#if defined(Q_CC_MSVC)
#pragma warning( pop )
#endif
private:
Q_DISABLE_COPY(QMutexLocker)
quintptr val;
};
#else // QT_NO_THREAD && !Q_CLANG_QDOC
class Q_CORE_EXPORT QMutex
{
public:
enum RecursionMode { NonRecursive, Recursive };
inline explicit QMutex(RecursionMode mode = NonRecursive) Q_DECL_NOTHROW { Q_UNUSED(mode); }
inline void lock() Q_DECL_NOTHROW {}
inline bool tryLock(int timeout = 0) Q_DECL_NOTHROW { Q_UNUSED(timeout); return true; }
inline bool try_lock() Q_DECL_NOTHROW { return true; }
inline void unlock() Q_DECL_NOTHROW {}
inline bool isRecursive() const Q_DECL_NOTHROW { return true; }
#if QT_HAS_INCLUDE(<chrono>)
template <class Rep, class Period>
inline bool try_lock_for(std::chrono::duration<Rep, Period> duration) Q_DECL_NOTHROW
{
Q_UNUSED(duration);
return true;
}
template<class Clock, class Duration>
inline bool try_lock_until(std::chrono::time_point<Clock, Duration> timePoint) Q_DECL_NOTHROW
{
Q_UNUSED(timePoint);
return true;
}
#endif
private:
Q_DISABLE_COPY(QMutex)
};
class Q_CORE_EXPORT QMutexLocker
{
public:
inline explicit QMutexLocker(QMutex *) Q_DECL_NOTHROW {}
inline ~QMutexLocker() Q_DECL_NOTHROW {}
inline void unlock() Q_DECL_NOTHROW {}
void relock() Q_DECL_NOTHROW {}
inline QMutex *mutex() const Q_DECL_NOTHROW { return Q_NULLPTR; }
private:
Q_DISABLE_COPY(QMutexLocker)
};
typedef QMutex QBasicMutex;
#endif // QT_NO_THREAD && !Q_CLANG_QDOC
QT_END_NAMESPACE
#endif // QMUTEX_H