QRunnable Class

The QRunnable class is the base class for all runnable objects. More...

Header: #include <QRunnable>
qmake: QT += core
Since: Qt 4.4

This class was introduced in Qt 4.4.

Public Functions

QRunnable()
virtual ~QRunnable()
bool autoDelete() const
virtual void run() = 0
void setAutoDelete(bool autoDelete)

Static Public Members

QRunnable *create(std::function<void ()> functionToRun)

Detailed Description

The QRunnable class is an interface for representing a task or piece of code that needs to be executed, represented by your reimplementation of the run() function.

You can use QThreadPool to execute your code in a separate thread. QThreadPool deletes the QRunnable automatically if autoDelete() returns true (the default). Use setAutoDelete() to change the auto-deletion flag.

QThreadPool supports executing the same QRunnable more than once by calling QThreadPool::tryStart(this) from within the run() function. If autoDelete is enabled the QRunnable will be deleted when the last thread exits the run function. Calling QThreadPool::start() multiple times with the same QRunnable when autoDelete is enabled creates a race condition and is not recommended.

See also QThreadPool.

Member Function Documentation

QRunnable::QRunnable()

Constructs a QRunnable. Auto-deletion is enabled by default.

See also autoDelete() and setAutoDelete().

[virtual] QRunnable::~QRunnable()

QRunnable virtual destructor.

bool QRunnable::autoDelete() const

Returns true is auto-deletion is enabled; false otherwise.

If auto-deletion is enabled, QThreadPool will automatically delete this runnable after calling run(); otherwise, ownership remains with the application programmer.

See also setAutoDelete() and QThreadPool.

[static] QRunnable *QRunnable::create(std::function<void ()> functionToRun)

Creates a QRunnable that calls functionToRun in run().

Auto-deletion is enabled by default.

This function was introduced in Qt 5.15.

See also run() and autoDelete().

[pure virtual] void QRunnable::run()

Implement this pure virtual function in your subclass.

void QRunnable::setAutoDelete(bool autoDelete)

Enables auto-deletion if autoDelete is true; otherwise auto-deletion is disabled.

If auto-deletion is enabled, QThreadPool will automatically delete this runnable after calling run(); otherwise, ownership remains with the application programmer.

Note that this flag must be set before calling QThreadPool::start(). Calling this function after QThreadPool::start() results in undefined behavior.

See also autoDelete() and QThreadPool.

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