diff options
Diffstat (limited to 'src/corelib/thread')
| -rw-r--r-- | src/corelib/thread/qbasicatomic.h | 12 | ||||
| -rw-r--r-- | src/corelib/thread/qmutex.cpp | 100 | ||||
| -rw-r--r-- | src/corelib/thread/qmutex.h | 34 | ||||
| -rw-r--r-- | src/corelib/thread/qmutexpool.cpp | 9 | ||||
| -rw-r--r-- | src/corelib/thread/qmutexpool_p.h | 2 | ||||
| -rw-r--r-- | src/corelib/thread/qthread.cpp | 17 | ||||
| -rw-r--r-- | src/corelib/thread/qthread_unix.cpp | 8 |
7 files changed, 148 insertions, 34 deletions
diff --git a/src/corelib/thread/qbasicatomic.h b/src/corelib/thread/qbasicatomic.h index 9804e60119..dc976819ef 100644 --- a/src/corelib/thread/qbasicatomic.h +++ b/src/corelib/thread/qbasicatomic.h @@ -99,10 +99,8 @@ public: typename Ops::Type _q_value; // Everything below is either implemented in ../arch/qatomic_XXX.h or (as fallback) in qgenericatomic.h -#if QT_DEPRECATED_SINCE(5, 14) - QT_DEPRECATED_VERSION_X_5_14("Use loadRelaxed") T load() const noexcept { return loadRelaxed(); } - QT_DEPRECATED_VERSION_X_5_14("Use storeRelaxed") void store(T newValue) noexcept { storeRelaxed(newValue); } -#endif + T load() const noexcept { return loadRelaxed(); } + void store(T newValue) noexcept { storeRelaxed(newValue); } T loadRelaxed() const noexcept { return Ops::loadRelaxed(_q_value); } void storeRelaxed(T newValue) noexcept { Ops::storeRelaxed(_q_value, newValue); } @@ -240,10 +238,8 @@ public: AtomicType _q_value; -#if QT_DEPRECATED_SINCE(5, 14) - QT_DEPRECATED_VERSION_X_5_14("Use loadRelaxed") Type load() const noexcept { return loadRelaxed(); } - QT_DEPRECATED_VERSION_X_5_14("Use storeRelaxed") void store(Type newValue) noexcept { storeRelaxed(newValue); } -#endif + Type load() const noexcept { return loadRelaxed(); } + void store(Type newValue) noexcept { storeRelaxed(newValue); } Type loadRelaxed() const noexcept { return Ops::loadRelaxed(_q_value); } void storeRelaxed(Type newValue) noexcept { Ops::storeRelaxed(_q_value, newValue); } diff --git a/src/corelib/thread/qmutex.cpp b/src/corelib/thread/qmutex.cpp index bd3a0fa7ba..9e52f286ee 100644 --- a/src/corelib/thread/qmutex.cpp +++ b/src/corelib/thread/qmutex.cpp @@ -147,7 +147,7 @@ public: It is constructed and destroyed with almost no overhead, which means it is fine to have many mutexes as part of other classes. - \sa QMutexLocker, QReadWriteLock, QSemaphore, QWaitCondition + \sa QRecursiveMutex, QMutexLocker, QReadWriteLock, QSemaphore, QWaitCondition */ /*! @@ -156,12 +156,19 @@ public: \value Recursive In this mode, a thread can lock the same mutex multiple times and the mutex won't be unlocked until a corresponding number of unlock() calls - have been made. + have been made. You should use QRecursiveMutex + for this use-case. \value NonRecursive In this mode, a thread may only lock a mutex once. - \sa QMutex() + \sa QMutex(), QRecursiveMutex +*/ + +/*! + \fn QMutex::QMutex() + + Constructs a new mutex. The mutex is created in an unlocked state. */ /*! @@ -205,13 +212,15 @@ QMutex::~QMutex() } /*! \fn void QMutex::lock() + \fn QRecursiveMutex::lock() + Locks the mutex. If another thread has locked the mutex then this call will block until that thread has unlocked it. Calling this function multiple times on the same mutex from the same thread is allowed if this mutex is a - \l{QMutex::Recursive}{recursive mutex}. If this mutex is a - \l{QMutex::NonRecursive}{non-recursive mutex}, this function will + \l{QRecursiveMutex}{recursive mutex}. If this mutex is a + \l{QMutex}{non-recursive mutex}, this function will \e dead-lock when the mutex is locked recursively. \sa unlock() @@ -228,6 +237,7 @@ void QMutex::lock() QT_MUTEX_LOCK_NOEXCEPT } /*! \fn bool QMutex::tryLock(int timeout) + \fn bool QRecursiveMutex::tryLock(int timeout) Attempts to lock the mutex. This function returns \c true if the lock was obtained; otherwise it returns \c false. If another thread has @@ -243,8 +253,8 @@ void QMutex::lock() QT_MUTEX_LOCK_NOEXCEPT Calling this function multiple times on the same mutex from the same thread is allowed if this mutex is a - \l{QMutex::Recursive}{recursive mutex}. If this mutex is a - \l{QMutex::NonRecursive}{non-recursive mutex}, this function will + \l{QRecursiveMutex}{recursive mutex}. If this mutex is a + \l{QMutex}{non-recursive mutex}, this function will \e always return false when attempting to lock the mutex recursively. @@ -262,6 +272,7 @@ bool QMutex::tryLock(int timeout) QT_MUTEX_LOCK_NOEXCEPT } /*! \fn bool QMutex::try_lock() + \fn bool QRecursiveMutex::try_lock() \since 5.8 Attempts to lock the mutex. This function returns \c true if the lock @@ -275,6 +286,7 @@ bool QMutex::tryLock(int timeout) QT_MUTEX_LOCK_NOEXCEPT */ /*! \fn template <class Rep, class Period> bool QMutex::try_lock_for(std::chrono::duration<Rep, Period> duration) + \fn template <class Rep, class Period> bool QRecursiveMutex::try_lock_for(std::chrono::duration<Rep, Period> duration) \since 5.8 Attempts to lock the mutex. This function returns \c true if the lock @@ -290,8 +302,8 @@ bool QMutex::tryLock(int timeout) QT_MUTEX_LOCK_NOEXCEPT Calling this function multiple times on the same mutex from the same thread is allowed if this mutex is a - \l{QMutex::Recursive}{recursive mutex}. If this mutex is a - \l{QMutex::NonRecursive}{non-recursive mutex}, this function will + \l{QRecursiveMutex}{recursive mutex}. If this mutex is a + \l{QMutex}{non-recursive mutex}, this function will \e always return false when attempting to lock the mutex recursively. @@ -299,6 +311,7 @@ bool QMutex::tryLock(int timeout) QT_MUTEX_LOCK_NOEXCEPT */ /*! \fn template<class Clock, class Duration> bool QMutex::try_lock_until(std::chrono::time_point<Clock, Duration> timePoint) + \fn template<class Clock, class Duration> bool QRecursiveMutex::try_lock_until(std::chrono::time_point<Clock, Duration> timePoint) \since 5.8 Attempts to lock the mutex. This function returns \c true if the lock @@ -314,8 +327,8 @@ bool QMutex::tryLock(int timeout) QT_MUTEX_LOCK_NOEXCEPT Calling this function multiple times on the same mutex from the same thread is allowed if this mutex is a - \l{QMutex::Recursive}{recursive mutex}. If this mutex is a - \l{QMutex::NonRecursive}{non-recursive mutex}, this function will + \l{QRecursiveMutex}{recursive mutex}. If this mutex is a + \l{QMutex}{non-recursive mutex}, this function will \e always return false when attempting to lock the mutex recursively. @@ -323,6 +336,8 @@ bool QMutex::tryLock(int timeout) QT_MUTEX_LOCK_NOEXCEPT */ /*! \fn void QMutex::unlock() + \fn void QRecursiveMutex::unlock() + Unlocks the mutex. Attempting to unlock a mutex in a different thread to the one that locked it results in an error. Unlocking a mutex that is not locked results in undefined behavior. @@ -364,6 +379,58 @@ bool QBasicMutex::isRecursive() const noexcept } /*! + \class QRecursiveMutex + \inmodule QtCore + \since 5.14 + \brief The QRecursiveMutex class provides access serialization between threads. + + \threadsafe + + \ingroup thread + + The QRecursiveMutex class is a mutex, like QMutex, with which it is + API-compatible. It differs from QMutex by accepting lock() calls from + the same thread any number of times. QMutex would deadlock in this situation. + + QRecursiveMutex is much more expensive to construct and operate on, so + use a plain QMutex whenever you can. Sometimes, one public function, + however, calls another public function, and they both need to lock the + same mutex. In this case, you have two options: + + \list + \li Factor the code that needs mutex protection into private functions, + which assume that the mutex is held when they are called, and lock a + plain QMutex in the public functions before you call the private + implementation ones. + \li Or use a recursive mutex, so it doesn't matter that the first public + function has already locked the mutex when the second one wishes to do so. + \endlist + + \sa QMutex, QMutexLocker, QReadWriteLock, QSemaphore, QWaitCondition +*/ + +/*! + Constructs a new recursive mutex. The mutex is created in an unlocked state. + + \sa lock(), unlock() +*/ +QRecursiveMutex::QRecursiveMutex() + : QMutex() +{ + d_ptr.storeRelaxed(new QRecursiveMutexPrivate); +} + +/*! + Destroys the mutex. + + \warning Destroying a locked mutex may result in undefined behavior. +*/ +QRecursiveMutex::~QRecursiveMutex() +{ + delete static_cast<QRecursiveMutexPrivate*>(d_ptr.fetchAndStoreAcquire(nullptr)); +} + +/*! \class QMutexLocker \inmodule QtCore \brief The QMutexLocker class is a convenience class that simplifies @@ -427,6 +494,17 @@ bool QBasicMutex::isRecursive() const noexcept */ /*! + \fn QMutexLocker::QMutexLocker(QRecursiveMutex *mutex) + \since 5.14 + + Constructs a QMutexLocker and locks \a mutex. The mutex will be + unlocked (unlock() called) when the QMutexLocker is destroyed. + If \a mutex is \nullptr, QMutexLocker does nothing. + + \sa QMutex::lock() +*/ + +/*! \fn QMutexLocker::~QMutexLocker() Destroys the QMutexLocker and unlocks the mutex that was locked diff --git a/src/corelib/thread/qmutex.h b/src/corelib/thread/qmutex.h index 0de0869cb2..c693ff65d8 100644 --- a/src/corelib/thread/qmutex.h +++ b/src/corelib/thread/qmutex.h @@ -62,6 +62,8 @@ QT_BEGIN_NAMESPACE # define QT_MUTEX_LOCK_NOEXCEPT #endif +class QMutex; +class QRecursiveMutex; class QMutexData; class Q_CORE_EXPORT QBasicMutex @@ -120,14 +122,20 @@ private: } friend class QMutex; + friend class QRecursiveMutex; friend class QMutexData; }; class Q_CORE_EXPORT QMutex : public QBasicMutex { public: +#if defined(Q_COMPILER_CONSTEXPR) + constexpr QMutex() = default; +#else + QMutex() { d_ptr.storeRelaxed(nullptr); } +#endif enum RecursionMode { NonRecursive, Recursive }; - explicit QMutex(RecursionMode mode = NonRecursive); + explicit QMutex(RecursionMode mode); ~QMutex(); // BasicLockable concept @@ -164,6 +172,7 @@ public: private: Q_DISABLE_COPY(QMutex) friend class QMutexLocker; + friend class QRecursiveMutex; friend class ::tst_QMutex; #if QT_HAS_INCLUDE(<chrono>) @@ -192,6 +201,24 @@ private: #endif }; +class QRecursiveMutex : private QMutex +{ + // ### Qt 6: make it independent of QMutex + friend class QMutexLocker; +public: + Q_CORE_EXPORT QRecursiveMutex(); + Q_CORE_EXPORT ~QRecursiveMutex(); + + using QMutex::lock; + using QMutex::tryLock; + using QMutex::unlock; + using QMutex::try_lock; +#if QT_HAS_INCLUDE(<chrono>) + using QMutex::try_lock_for; + using QMutex::try_lock_until; +#endif +}; + class Q_CORE_EXPORT QMutexLocker { public: @@ -207,8 +234,11 @@ public: val |= 1; } } + explicit QMutexLocker(QRecursiveMutex *m) QT_MUTEX_LOCK_NOEXCEPT + : QMutexLocker{static_cast<QBasicMutex*>(m)} {} #else QMutexLocker(QMutex *) { } + QMutexLocker(QRecursiveMutex *) {} #endif inline ~QMutexLocker() { unlock(); } @@ -285,6 +315,8 @@ private: Q_DISABLE_COPY(QMutex) }; +class QRecursiveMutex : public QMutex {}; + class Q_CORE_EXPORT QMutexLocker { public: diff --git a/src/corelib/thread/qmutexpool.cpp b/src/corelib/thread/qmutexpool.cpp index 2a02197859..3ece30c01c 100644 --- a/src/corelib/thread/qmutexpool.cpp +++ b/src/corelib/thread/qmutexpool.cpp @@ -104,7 +104,7 @@ QMutexPool::QMutexPool(QMutex::RecursionMode recursionMode, int size) QMutexPool::~QMutexPool() { for (int index = 0; index < mutexes.count(); ++index) - delete mutexes[index].loadRelaxed(); + delete mutexes[index].loadAcquire(); } /*! @@ -129,9 +129,12 @@ QMutex *QMutexPool::createMutex(int index) { // mutex not created, create one QMutex *newMutex = new QMutex(recursionMode); - if (!mutexes[index].testAndSetRelease(0, newMutex)) + if (!mutexes[index].testAndSetRelease(nullptr, newMutex)) { delete newMutex; - return mutexes[index].loadRelaxed(); + return mutexes[index].loadAcquire(); + } else { + return newMutex; + } } /*! diff --git a/src/corelib/thread/qmutexpool_p.h b/src/corelib/thread/qmutexpool_p.h index 1a47231abc..00710199b8 100644 --- a/src/corelib/thread/qmutexpool_p.h +++ b/src/corelib/thread/qmutexpool_p.h @@ -68,7 +68,7 @@ public: inline QMutex *get(const void *address) { int index = uint(quintptr(address)) % mutexes.count(); - QMutex *m = mutexes[index].loadRelaxed(); + QMutex *m = mutexes[index].loadAcquire(); if (m) return m; else diff --git a/src/corelib/thread/qthread.cpp b/src/corelib/thread/qthread.cpp index 1eac7db11d..280c785049 100644 --- a/src/corelib/thread/qthread.cpp +++ b/src/corelib/thread/qthread.cpp @@ -73,8 +73,8 @@ QThreadData::~QThreadData() // crashing during QCoreApplicationData's global static cleanup we need to // safeguard the main thread here.. This fix is a bit crude, but it solves // the problem... - if (this->thread == QCoreApplicationPrivate::theMainThread) { - QCoreApplicationPrivate::theMainThread = 0; + if (this->thread.loadAcquire() == QCoreApplicationPrivate::theMainThread.loadAcquire()) { + QCoreApplicationPrivate::theMainThread.storeRelease(nullptr); QThreadData::clearCurrentThreadData(); } @@ -85,8 +85,8 @@ QThreadData::~QThreadData() // because this destructor is still running (the _ref sub-object has not // been destroyed) and there's no reentrancy. The refcount will become // negative, but that's acceptable. - QThread *t = thread; - thread = 0; + QThread *t = thread.loadAcquire(); + thread.storeRelease(nullptr); delete t; for (int i = 0; i < postEventList.size(); ++i) { @@ -171,6 +171,11 @@ QThreadPrivate::QThreadPrivate(QThreadData *d) // to 128K. #ifdef Q_OS_INTEGRITY stackSize = 128 * 1024; +#elif defined(Q_OS_RTEMS) + static bool envStackSizeOk = false; + static const int envStackSize = qEnvironmentVariableIntValue("QT_DEFAULT_THREAD_STACK_SIZE", &envStackSizeOk); + if (envStackSizeOk) + stackSize = envStackSize; #endif #if defined (Q_OS_WIN) @@ -393,7 +398,7 @@ QThread *QThread::currentThread() { QThreadData *data = QThreadData::current(); Q_ASSERT(data != 0); - return data->thread; + return data->thread.loadAcquire(); } /*! @@ -980,7 +985,7 @@ bool QThread::event(QEvent *event) void QThread::requestInterruption() { - if (this == QCoreApplicationPrivate::theMainThread) { + if (this == QCoreApplicationPrivate::theMainThread.loadAcquire()) { qWarning("QThread::requestInterruption has no effect on the main thread"); return; } diff --git a/src/corelib/thread/qthread_unix.cpp b/src/corelib/thread/qthread_unix.cpp index 89efbff6aa..38e9c1c3ec 100644 --- a/src/corelib/thread/qthread_unix.cpp +++ b/src/corelib/thread/qthread_unix.cpp @@ -141,7 +141,7 @@ static void destroy_current_thread_data(void *p) pthread_setspecific(current_thread_data_key, p); QThreadData *data = static_cast<QThreadData *>(p); if (data->isAdopted) { - QThread *thread = data->thread; + QThread *thread = data->thread.loadAcquire(); Q_ASSERT(thread); QThreadPrivate *thread_p = static_cast<QThreadPrivate *>(QObjectPrivate::get(thread)); Q_ASSERT(!thread_p->finished); @@ -253,8 +253,8 @@ QThreadData *QThreadData::current(bool createIfNecessary) data->deref(); data->isAdopted = true; data->threadId.storeRelaxed(to_HANDLE(pthread_self())); - if (!QCoreApplicationPrivate::theMainThread) - QCoreApplicationPrivate::theMainThread = data->thread.loadRelaxed(); + if (!QCoreApplicationPrivate::theMainThread.loadAcquire()) + QCoreApplicationPrivate::theMainThread.storeRelease(data->thread.loadRelaxed()); } return data; } @@ -285,7 +285,7 @@ QAbstractEventDispatcher *QThreadPrivate::createEventDispatcher(QThreadData *dat else return new QEventDispatcherUNIX; #elif !defined(QT_NO_GLIB) - const bool isQtMainThread = data->thread == QCoreApplicationPrivate::mainThread(); + const bool isQtMainThread = data->thread.loadAcquire() == QCoreApplicationPrivate::mainThread(); if (qEnvironmentVariableIsEmpty("QT_NO_GLIB") && (isQtMainThread || qEnvironmentVariableIsEmpty("QT_NO_THREADED_GLIB")) && QEventDispatcherGlib::versionSupported()) |