QMutex: replace QT_MUTEX_LOCK_NOEXCEPT macro with constexpr trait

This says better what it is and I'll use the trait for the unlock
operation.

Change-Id: I46752ca2ee71297d77e5fffdddaa193b6c86dbbc
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
(cherry picked from commit 85ebb9d52a413f205046f864a2823e3f0819ed9e)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
This commit is contained in:
Thiago Macieira 2024-12-31 17:30:25 -03:00 committed by Qt Cherry-pick Bot
parent 993c3fc35b
commit 1290935fab
2 changed files with 34 additions and 24 deletions

View File

@ -332,7 +332,7 @@ QRecursiveMutex::~QRecursiveMutex()
\sa lock(), unlock() \sa lock(), unlock()
*/ */
bool QRecursiveMutex::tryLock(QDeadlineTimer timeout) QT_MUTEX_LOCK_NOEXCEPT bool QRecursiveMutex::tryLock(QDeadlineTimer timeout) noexcept(LockIsNoexcept)
{ {
unsigned tsanFlags = QtTsan::MutexWriteReentrant | QtTsan::TryLock; unsigned tsanFlags = QtTsan::MutexWriteReentrant | QtTsan::TryLock;
QtTsan::mutexPreLock(this, tsanFlags); QtTsan::mutexPreLock(this, tsanFlags);
@ -639,7 +639,7 @@ void QRecursiveMutex::unlock() noexcept
\internal helper for lock() \internal helper for lock()
*/ */
Q_NEVER_INLINE Q_NEVER_INLINE
void QBasicMutex::lockInternal() QT_MUTEX_LOCK_NOEXCEPT void QBasicMutex::lockInternal() noexcept(FutexAlwaysAvailable)
{ {
if (futexAvailable()) { if (futexAvailable()) {
// note we must set to dummyFutexValue because there could be other threads // note we must set to dummyFutexValue because there could be other threads
@ -660,7 +660,7 @@ void QBasicMutex::lockInternal() QT_MUTEX_LOCK_NOEXCEPT
\internal helper for lock(int) \internal helper for lock(int)
*/ */
#if QT_VERSION < QT_VERSION_CHECK(7, 0, 0) #if QT_VERSION < QT_VERSION_CHECK(7, 0, 0)
bool QBasicMutex::lockInternal(int timeout) QT_MUTEX_LOCK_NOEXCEPT bool QBasicMutex::lockInternal(int timeout) noexcept(FutexAlwaysAvailable)
{ {
if (timeout == 0) if (timeout == 0)
return false; return false;
@ -673,7 +673,7 @@ bool QBasicMutex::lockInternal(int timeout) QT_MUTEX_LOCK_NOEXCEPT
\internal helper for tryLock(QDeadlineTimer) \internal helper for tryLock(QDeadlineTimer)
*/ */
Q_NEVER_INLINE Q_NEVER_INLINE
bool QBasicMutex::lockInternal(QDeadlineTimer deadlineTimer) QT_MUTEX_LOCK_NOEXCEPT bool QBasicMutex::lockInternal(QDeadlineTimer deadlineTimer) noexcept(FutexAlwaysAvailable)
{ {
if (deadlineTimer.hasExpired()) if (deadlineTimer.hasExpired())
return false; return false;

View File

@ -15,12 +15,6 @@ QT_BEGIN_NAMESPACE
#if QT_CONFIG(thread) || defined(Q_QDOC) #if QT_CONFIG(thread) || defined(Q_QDOC)
#if defined(Q_OS_FREEBSD) || defined(Q_OS_LINUX) || defined(Q_OS_WIN) // these platforms use futex
# define QT_MUTEX_LOCK_NOEXCEPT noexcept
#else
# define QT_MUTEX_LOCK_NOEXCEPT
#endif
class QMutex; class QMutex;
class QRecursiveMutex; class QRecursiveMutex;
class QMutexPrivate; class QMutexPrivate;
@ -28,13 +22,22 @@ class QMutexPrivate;
class Q_CORE_EXPORT QBasicMutex class Q_CORE_EXPORT QBasicMutex
{ {
Q_DISABLE_COPY_MOVE(QBasicMutex) Q_DISABLE_COPY_MOVE(QBasicMutex)
protected:
static constexpr bool FutexAlwaysAvailable =
#if defined(Q_OS_FREEBSD) || defined(Q_OS_LINUX) || defined(Q_OS_WIN) // these platforms use futex
true
#else
false
#endif
;
public: public:
constexpr QBasicMutex() constexpr QBasicMutex()
: d_ptr(nullptr) : d_ptr(nullptr)
{} {}
// BasicLockable concept // BasicLockable concept
inline void lock() QT_MUTEX_LOCK_NOEXCEPT { inline void lock() noexcept(FutexAlwaysAvailable) {
QtTsan::mutexPreLock(this, 0u); QtTsan::mutexPreLock(this, 0u);
if (!fastTryLock()) if (!fastTryLock())
@ -82,10 +85,10 @@ private:
return d_ptr.testAndSetRelease(dummyLocked(), nullptr); return d_ptr.testAndSetRelease(dummyLocked(), nullptr);
} }
void lockInternal() QT_MUTEX_LOCK_NOEXCEPT; void lockInternal() noexcept(FutexAlwaysAvailable);
bool lockInternal(QDeadlineTimer timeout) QT_MUTEX_LOCK_NOEXCEPT; bool lockInternal(QDeadlineTimer timeout) noexcept(FutexAlwaysAvailable);
#if QT_VERSION < QT_VERSION_CHECK(7, 0, 0) #if QT_VERSION < QT_VERSION_CHECK(7, 0, 0)
bool lockInternal(int timeout) QT_MUTEX_LOCK_NOEXCEPT; bool lockInternal(int timeout) noexcept(FutexAlwaysAvailable);
#endif #endif
void unlockInternal() noexcept; void unlockInternal() noexcept;
#if QT_CORE_REMOVED_SINCE(6, 9) #if QT_CORE_REMOVED_SINCE(6, 9)
@ -114,7 +117,7 @@ public:
} }
#ifdef Q_QDOC #ifdef Q_QDOC
inline void lock() QT_MUTEX_LOCK_NOEXCEPT; inline void lock() noexcept(FutexAlwaysAvailable);
inline void unlock() noexcept; inline void unlock() noexcept;
bool tryLock() noexcept; bool tryLock() noexcept;
#endif #endif
@ -124,12 +127,12 @@ public:
using QBasicMutex::tryLock; using QBasicMutex::tryLock;
bool tryLock(int timeout) QT_MUTEX_LOCK_NOEXCEPT bool tryLock(int timeout) noexcept(FutexAlwaysAvailable)
{ {
return tryLock(QDeadlineTimer(timeout)); return tryLock(QDeadlineTimer(timeout));
} }
bool tryLock(QDeadlineTimer timeout) QT_MUTEX_LOCK_NOEXCEPT bool tryLock(QDeadlineTimer timeout) noexcept(FutexAlwaysAvailable)
{ {
unsigned tsanFlags = QtTsan::TryLock; unsigned tsanFlags = QtTsan::TryLock;
QtTsan::mutexPreLock(this, tsanFlags); QtTsan::mutexPreLock(this, tsanFlags);
@ -174,6 +177,7 @@ class Q_CORE_EXPORT QRecursiveMutex
// only ever accessed from the thread that owns 'mutex': // only ever accessed from the thread that owns 'mutex':
uint count = 0; uint count = 0;
QMutex mutex; QMutex mutex;
static constexpr bool LockIsNoexcept = noexcept(std::declval<QMutex>().lock());
public: public:
constexpr QRecursiveMutex() = default; constexpr QRecursiveMutex() = default;
@ -181,16 +185,16 @@ public:
// BasicLockable concept // BasicLockable concept
void lock() QT_MUTEX_LOCK_NOEXCEPT void lock() noexcept(LockIsNoexcept)
{ tryLock(QDeadlineTimer(QDeadlineTimer::Forever)); } { tryLock(QDeadlineTimer(QDeadlineTimer::Forever)); }
QT_CORE_INLINE_SINCE(6, 6) QT_CORE_INLINE_SINCE(6, 6)
bool tryLock(int timeout) QT_MUTEX_LOCK_NOEXCEPT; bool tryLock(int timeout) noexcept(LockIsNoexcept);
bool tryLock(QDeadlineTimer timer = {}) QT_MUTEX_LOCK_NOEXCEPT; bool tryLock(QDeadlineTimer timer = {}) noexcept(LockIsNoexcept);
// BasicLockable concept // BasicLockable concept
void unlock() noexcept; void unlock() noexcept;
// Lockable concept // Lockable concept
bool try_lock() QT_MUTEX_LOCK_NOEXCEPT { return tryLock(); } bool try_lock() noexcept(LockIsNoexcept) { return tryLock(); }
// TimedLockable concept // TimedLockable concept
template <class Rep, class Period> template <class Rep, class Period>
@ -208,7 +212,7 @@ public:
}; };
#if QT_CORE_INLINE_IMPL_SINCE(6, 6) #if QT_CORE_INLINE_IMPL_SINCE(6, 6)
bool QRecursiveMutex::tryLock(int timeout) QT_MUTEX_LOCK_NOEXCEPT bool QRecursiveMutex::tryLock(int timeout) noexcept(LockIsNoexcept)
{ {
return tryLock(QDeadlineTimer(timeout)); return tryLock(QDeadlineTimer(timeout));
} }
@ -217,9 +221,15 @@ bool QRecursiveMutex::tryLock(int timeout) QT_MUTEX_LOCK_NOEXCEPT
template <typename Mutex> template <typename Mutex>
class QMutexLocker class QMutexLocker
{ {
#ifdef Q_CC_GHS
// internal compiler error otherwise
static constexpr bool LockIsNoexcept = false;
#else
static constexpr bool LockIsNoexcept = noexcept(std::declval<Mutex>().lock());
#endif
public: public:
Q_NODISCARD_CTOR Q_NODISCARD_CTOR
inline explicit QMutexLocker(Mutex *mutex) QT_MUTEX_LOCK_NOEXCEPT inline explicit QMutexLocker(Mutex *mutex) noexcept(LockIsNoexcept)
{ {
m_mutex = mutex; m_mutex = mutex;
if (Q_LIKELY(mutex)) { if (Q_LIKELY(mutex)) {
@ -254,7 +264,7 @@ public:
m_isLocked = false; m_isLocked = false;
} }
inline void relock() QT_MUTEX_LOCK_NOEXCEPT inline void relock() noexcept(LockIsNoexcept)
{ {
Q_ASSERT(!m_isLocked); Q_ASSERT(!m_isLocked);
m_mutex->lock(); m_mutex->lock();