Qt
Internal/Contributor docs for the Qt SDK. Note: These are NOT official API docs; those are found at https://doc.qt.io/
Loading...
Searching...
No Matches
QThread Class Reference

#include <qthread.h>

Inherits QObject.

Inherited by AndroidTextureThread, AndroidTextureThread, EventReader, EventReader, FileInfoThread, QAdoptedThread, QCtfServer, QDirectFbInput, QDxgiVSyncThread, QDxgiVSyncThread, QEglFSKmsEventReaderThread, QFFmpeg::ConsumerThread, QFFmpegSurfaceCaptureGrabber::GrabbingThread, QFFmpegSurfaceCaptureGrabber::GrabbingThread, QFileInfoGatherer, QIntegrityHIDManager, QIntegrityHIDManager, QQmlDebugServerThread, QQmlDebugServerThread, QQmlThreadPrivate, QQmlThreadPrivate, QQnxMediaEventThread, QQnxScreenEventThread, QQuickContext2DRenderThread, QQuickPixmapReader, QQuickPixmapReader, QQuickWorkerScriptEngine, QSGRenderThread, QSGRenderThread, QSGSoftwareRenderThread, QSGSoftwareRenderThread, QShGetFileInfoThread, QShGetFileInfoThread, QThreadPoolThread, QThreadPoolThread, QWindowsCaRootFetcherThread, QWindowsCaRootFetcherThread, QWindowsDialogThread, QWindowsDialogThread, QWindowsFileSystemWatcherEngineThread, QWindowsShellExecuteThread, QWindowsShellExecuteThread, QXcbEventQueue, QtDocInstaller, QtWaylandClient::EventThread, QtWaylandClient::EventThread, StdInListener, ThreadedTestHTTPServer, WorkerThread, WorkerThread, WorkerThread, WorkerThread, fulltextsearch::QHelpSearchIndexReader, and fulltextsearch::QHelpSearchIndexWriter.

+ Collaboration diagram for QThread:

Public Types

enum  Priority {
  IdlePriority , LowestPriority , LowPriority , NormalPriority ,
  HighPriority , HighestPriority , TimeCriticalPriority , InheritPriority
}
 
enum class  QualityOfService { Auto , High , Eco }
 

Public Slots

void start (Priority=InheritPriority)
 
void terminate ()
 
void exit (int retcode=0)
 
void quit ()
 
- Public Slots inherited from QObject
void deleteLater ()
 \threadsafe
 

Signals

void started (QPrivateSignal)
 
void finished (QPrivateSignal)
 
- Signals inherited from QObject
void destroyed (QObject *=nullptr)
 This signal is emitted immediately before the object obj is destroyed, after any instances of QPointer have been notified, and cannot be blocked.
 
void objectNameChanged (const QString &objectName, QPrivateSignal)
 This signal is emitted after the object's name has been changed.
 

Public Member Functions

 QThread (QObject *parent=nullptr)
 
 ~QThread ()
 
void setPriority (Priority priority)
 
Priority priority () const
 
bool isFinished () const
 
bool isRunning () const
 
void requestInterruption ()
 
bool isInterruptionRequested () const
 
void setStackSize (uint stackSize)
 
uint stackSize () const
 
QAbstractEventDispatchereventDispatcher () const
 
void setEventDispatcher (QAbstractEventDispatcher *eventDispatcher)
 
bool event (QEvent *event) override
 This virtual function receives events to an object and should return true if the event e was recognized and processed.
 
int loopLevel () const
 
bool isCurrentThread () const noexcept
 
void setServiceLevel (QualityOfService serviceLevel)
 
QualityOfService serviceLevel () const
 
bool wait (QDeadlineTimer deadline=QDeadlineTimer(QDeadlineTimer::Forever))
 
bool wait (unsigned long time)
 This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. time is the time to wait in milliseconds.
 
- Public Member Functions inherited from QObject
Q_INVOKABLE QObject (QObject *parent=nullptr)
 Constructs an object with parent object parent.
 
virtual ~QObject ()
 Destroys the object, deleting all its child objects.
 
virtual bool eventFilter (QObject *watched, QEvent *event)
 Filters events if this object has been installed as an event filter for the watched object.
 
QString objectName () const
 
Q_WEAK_OVERLOAD void setObjectName (const QString &name)
 Sets the object's name to name.
 
void setObjectName (QAnyStringView name)
 This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
 
QBindable< QStringbindableObjectName ()
 
bool isWidgetType () const
 Returns true if the object is a widget; otherwise returns false.
 
bool isWindowType () const
 Returns true if the object is a window; otherwise returns false.
 
bool isQuickItemType () const
 Returns true if the object is a QQuickItem; otherwise returns false.
 
bool signalsBlocked () const noexcept
 Returns true if signals are blocked; otherwise returns false.
 
bool blockSignals (bool b) noexcept
 If block is true, signals emitted by this object are blocked (i.e., emitting a signal will not invoke anything connected to it).
 
QThreadthread () const
 Returns the thread in which the object lives.
 
bool moveToThread (QThread *thread QT6_DECL_NEW_OVERLOAD_TAIL)
 Changes the thread affinity for this object and its children and returns true on success.
 
int startTimer (int interval, Qt::TimerType timerType=Qt::CoarseTimer)
 This is an overloaded function that will start a timer of type timerType and a timeout of interval milliseconds.
 
int startTimer (std::chrono::nanoseconds time, Qt::TimerType timerType=Qt::CoarseTimer)
 
void killTimer (int id)
 Kills the timer with timer identifier, id.
 
void killTimer (Qt::TimerId id)
 
template<typename T >
findChild (QAnyStringView aName, Qt::FindChildOptions options=Qt::FindChildrenRecursively) const
 Returns the child of this object that can be cast into type T and that is called name, or \nullptr if there is no such object.
 
template<typename T >
QList< T > findChildren (QAnyStringView aName, Qt::FindChildOptions options=Qt::FindChildrenRecursively) const
 Returns all children of this object with the given name that can be cast to type T, or an empty list if there are no such objects.
 
template<typename T >
findChild (Qt::FindChildOptions options=Qt::FindChildrenRecursively) const
 This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
 
template<typename T >
QList< T > findChildren (Qt::FindChildOptions options=Qt::FindChildrenRecursively) const
 This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
 
const QObjectListchildren () const
 Returns a list of child objects.
 
void setParent (QObject *parent)
 Makes the object a child of parent.
 
void installEventFilter (QObject *filterObj)
 Installs an event filter filterObj on this object.
 
void removeEventFilter (QObject *obj)
 Removes an event filter object obj from this object.
 
QMetaObject::Connection connect (const QObject *sender, const char *signal, const char *member, Qt::ConnectionType type=Qt::AutoConnection) const
 
bool disconnect (const char *signal=nullptr, const QObject *receiver=nullptr, const char *member=nullptr) const
 
bool disconnect (const QObject *receiver, const char *member=nullptr) const
 
void dumpObjectTree () const
 Dumps a tree of children to the debug output.
 
void dumpObjectInfo () const
 Dumps information about signal connections, etc.
 
bool setProperty (const char *name, const QVariant &value)
 Sets the value of the object's name property to value.
 
bool setProperty (const char *name, QVariant &&value)
 
QVariant property (const char *name) const
 Returns the value of the object's name property.
 
QList< QByteArraydynamicPropertyNames () const
 
QBindingStoragebindingStorage ()
 
const QBindingStoragebindingStorage () const
 
QObjectparent () const
 Returns a pointer to the parent object.
 
bool inherits (const char *classname) const
 Returns true if this object is an instance of a class that inherits className or a QObject subclass that inherits className; otherwise returns false.
 

Static Public Member Functions

static Qt::HANDLE currentThreadId () noexcept Q_DECL_PURE_FUNCTION
 
static QThreadcurrentThread ()
 
static bool isMainThread () noexcept
 
static int idealThreadCount () noexcept
 
static void yieldCurrentThread ()
 
template<typename Function , typename... Args>
static QThreadcreate (Function &&f, Args &&... args)
 
static void sleep (unsigned long)
 
static void msleep (unsigned long)
 
static void usleep (unsigned long)
 
static void sleep (std::chrono::nanoseconds nsec)
 
- Static Public Member Functions inherited from QObject
static QMetaObject::Connection connect (const QObject *sender, const char *signal, const QObject *receiver, const char *member, Qt::ConnectionType=Qt::AutoConnection)
 \threadsafe
 
static QMetaObject::Connection connect (const QObject *sender, const QMetaMethod &signal, const QObject *receiver, const QMetaMethod &method, Qt::ConnectionType type=Qt::AutoConnection)
 
template<typename Func1 , typename Func2 >
static QMetaObject::Connection connect (const typename QtPrivate::FunctionPointer< Func1 >::Object *sender, Func1 signal, const typename QtPrivate::ContextTypeForFunctor< Func2 >::ContextType *context, Func2 &&slot, Qt::ConnectionType type=Qt::AutoConnection)
 
template<typename Func1 , typename Func2 >
static QMetaObject::Connection connect (const typename QtPrivate::FunctionPointer< Func1 >::Object *sender, Func1 signal, Func2 &&slot)
 
static bool disconnect (const QObject *sender, const char *signal, const QObject *receiver, const char *member)
 \threadsafe
 
static bool disconnect (const QObject *sender, const QMetaMethod &signal, const QObject *receiver, const QMetaMethod &member)
 
static bool disconnect (const QMetaObject::Connection &)
 Disconnect a connection.
 
template<typename Func1 , typename Func2 >
static bool disconnect (const typename QtPrivate::FunctionPointer< Func1 >::Object *sender, Func1 signal, const typename QtPrivate::FunctionPointer< Func2 >::Object *receiver, Func2 slot)
 
template<typename Func1 >
static bool disconnect (const typename QtPrivate::FunctionPointer< Func1 >::Object *sender, Func1 signal, const QObject *receiver, void **zero)
 

Protected Member Functions

virtual void run ()
 
int exec ()
 
 QThread (QThreadPrivate &dd, QObject *parent=nullptr)
 
- Protected Member Functions inherited from QObject
QObjectsender () const
 Returns a pointer to the object that sent the signal, if called in a slot activated by a signal; otherwise it returns \nullptr.
 
int senderSignalIndex () const
 
int receivers (const char *signal) const
 Returns the number of receivers connected to the signal.
 
bool isSignalConnected (const QMetaMethod &signal) const
 
virtual void timerEvent (QTimerEvent *event)
 This event handler can be reimplemented in a subclass to receive timer events for the object.
 
virtual void childEvent (QChildEvent *event)
 This event handler can be reimplemented in a subclass to receive child events.
 
virtual void customEvent (QEvent *event)
 This event handler can be reimplemented in a subclass to receive custom events.
 
virtual void connectNotify (const QMetaMethod &signal)
 
virtual void disconnectNotify (const QMetaMethod &signal)
 
 QObject (QObjectPrivate &dd, QObject *parent=nullptr)
 

Static Protected Member Functions

static void setTerminationEnabled (bool enabled=true)
 

Friends

class QEventLoopLocker
 
class QCoreApplication
 
class QThreadData
 

Additional Inherited Members

- Protected Attributes inherited from QObject
QScopedPointer< QObjectDatad_ptr
 
- Properties inherited from QObject
QString objectName
 the name of this object
 

Detailed Description

Definition at line 27 of file qthread.h.

Member Enumeration Documentation

◆ Priority

Enumerator
IdlePriority 
LowestPriority 
LowPriority 
NormalPriority 
HighPriority 
HighestPriority 
TimeCriticalPriority 
InheritPriority 

Definition at line 40 of file qthread.h.

◆ QualityOfService

enum class QThread::QualityOfService
strong
Enumerator
Auto 
High 
Eco 

Definition at line 54 of file qthread.h.

Constructor & Destructor Documentation

◆ QThread() [1/2]

QThread::QThread ( QObject * parent = nullptr)
explicit

Definition at line 1004 of file qthread.cpp.

◆ ~QThread()

QThread::~QThread ( )

Definition at line 1011 of file qthread.cpp.

◆ QThread() [2/2]

QThread::QThread ( QThreadPrivate & dd,
QObject * parent = nullptr )
protected

Definition at line 1144 of file qthread.cpp.

Member Function Documentation

◆ create()

template<typename Function , typename... Args>
QThread * QThread::create ( Function && f,
Args &&... args )
staticnodiscard

Definition at line 132 of file qthread.h.

◆ currentThread()

QThread * QThread::currentThread ( )
static

Definition at line 1069 of file qthread.cpp.

◆ currentThreadId()

Qt::HANDLE QThread::currentThreadId ( )
inlinestaticnoexcept

Definition at line 159 of file qthread.h.

◆ event()

bool QThread::event ( QEvent * e)
overridevirtual

This virtual function receives events to an object and should return true if the event e was recognized and processed.

The event() function can be reimplemented to customize the behavior of an object.

Make sure you call the parent event class implementation for all the events you did not handle.

Example:

class MyClass : public QWidget
{
public:
MyClass(QWidget *parent = nullptr);
bool event(QEvent* ev) override
{
if (ev->type() == QEvent::PolishRequest) {
// overwrite handling of PolishRequest if any
doThings();
return true;
} else if (ev->type() == QEvent::Show) {
// complement handling of Show if any
doThings2();
return true;
}
// Make sure the rest of events are handled
return QWidget::event(ev);
}
};
See also
installEventFilter(), timerEvent(), QCoreApplication::sendEvent(), QCoreApplication::postEvent()

Reimplemented from QObject.

Definition at line 1059 of file qthread.cpp.

◆ eventDispatcher()

QAbstractEventDispatcher * QThread::eventDispatcher ( ) const
Since
5.0

Returns a pointer to the event dispatcher object for the thread. If no event dispatcher exists for the thread, this function returns \nullptr.

Definition at line 1180 of file qthread.cpp.

◆ exec()

int QThread::exec ( )
protected

Definition at line 1021 of file qthread.cpp.

◆ exit

void QThread::exit ( int retcode = 0)
slot

Definition at line 1043 of file qthread.cpp.

◆ finished

void QThread::finished ( QPrivateSignal )
signal

◆ idealThreadCount()

int QThread::idealThreadCount ( )
staticnoexcept

Definition at line 1079 of file qthread.cpp.

◆ isCurrentThread()

bool QThread::isCurrentThread ( ) const
noexcept

Definition at line 1074 of file qthread.cpp.

◆ isFinished()

bool QThread::isFinished ( ) const

Definition at line 1089 of file qthread.cpp.

◆ isInterruptionRequested()

bool QThread::isInterruptionRequested ( ) const

Definition at line 1105 of file qthread.cpp.

◆ isMainThread()

static bool QThread::isMainThread ( )
staticnoexcept

◆ isRunning()

bool QThread::isRunning ( ) const

Definition at line 1094 of file qthread.cpp.

◆ loopLevel()

int QThread::loopLevel ( ) const

◆ msleep()

void QThread::msleep ( unsigned long msecs)
static

Definition at line 585 of file qthread_unix.cpp.

◆ priority()

Priority QThread::priority ( ) const

◆ quit

void QThread::quit ( )
slot

Definition at line 1038 of file qthread.cpp.

◆ requestInterruption()

void QThread::requestInterruption ( )

Definition at line 1100 of file qthread.cpp.

◆ run()

◆ serviceLevel()

QualityOfService QThread::serviceLevel ( ) const

◆ setEventDispatcher()

void QThread::setEventDispatcher ( QAbstractEventDispatcher * eventDispatcher)
Since
5.0

Sets the event dispatcher for the thread to eventDispatcher. This is only possible as long as there is no event dispatcher installed for the thread yet.

An event dispatcher is automatically created for the main thread when \l QCoreApplication is instantiated and on start() for auxiliary threads.

This method takes ownership of the object.

Definition at line 1198 of file qthread.cpp.

◆ setPriority()

void QThread::setPriority ( Priority priority)

◆ setServiceLevel()

void QThread::setServiceLevel ( QualityOfService serviceLevel)

◆ setStackSize()

void QThread::setStackSize ( uint stackSize)

Definition at line 1162 of file qthread.cpp.

◆ setTerminationEnabled()

void QThread::setTerminationEnabled ( bool enabled = true)
staticprotected

Definition at line 1110 of file qthread.cpp.

◆ sleep() [1/2]

void QThread::sleep ( std::chrono::nanoseconds nsec)
static

Definition at line 595 of file qthread_unix.cpp.

◆ sleep() [2/2]

void QThread::sleep ( unsigned long secs)
static

Definition at line 580 of file qthread_unix.cpp.

◆ stackSize()

uint QThread::stackSize ( ) const

Definition at line 1167 of file qthread.cpp.

◆ start

void QThread::start ( Priority priority = InheritPriority)
slot

Definition at line 1026 of file qthread.cpp.

◆ started

void QThread::started ( QPrivateSignal )
signal

◆ terminate

void QThread::terminate ( )
slot

Definition at line 1033 of file qthread.cpp.

◆ usleep()

void QThread::usleep ( unsigned long usecs)
static

Definition at line 590 of file qthread_unix.cpp.

◆ wait() [1/2]

bool QThread::wait ( QDeadlineTimer deadline = QDeadlineTimer(QDeadlineTimer::Forever))

Definition at line 1053 of file qthread.cpp.

◆ wait() [2/2]

bool QThread::wait ( unsigned long time)
inline

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. time is the time to wait in milliseconds.

If time is ULONG_MAX, then the wait will never timeout.

Definition at line 95 of file qthread.h.

◆ yieldCurrentThread()

void QThread::yieldCurrentThread ( )
static

Definition at line 1084 of file qthread.cpp.

Friends And Related Symbol Documentation

◆ QCoreApplication

friend class QCoreApplication
friend

Definition at line 127 of file qthread.h.

◆ QEventLoopLocker

friend class QEventLoopLocker
friend

Definition at line 122 of file qthread.h.

◆ QThreadData

friend class QThreadData
friend

Definition at line 128 of file qthread.h.


The documentation for this class was generated from the following files: