QThread
| Module | Core |
|---|---|
| Include |
|
| CMake |
|
| QMake |
|
QThread has two events: started and finished. QCoro provides
a coroutine-friendly wrapper for QThread - QCoroThread, which allows co_awaiting
those events.
To wrap a QThread object into the QCoroThread wrapper, use qCoro():
QCoroThread qCoro(QThread &);
QCoroThread qCoro(QThread *);
waitForStarted()
Waits for the thread to start. Returns true if the thread is already running
or when the thread starts within the specified timeout. If the thread has already
finished or fails to start within the specified timeout, the coroutine will return
false.
If the timeout is set to -1, the operation will never time out.
See documentation for QThread::started() for details.
QCoro::Task<bool> QCoroThread::waitForStarted(std::chrono::milliseconds timeout);
waitForFinished()
Waits for the thread to finish or until it times out. Returns bool indicating
whether the thread has finished successfuly (true) or timed out (false).
thread to finish. Returns true if the thread has already finished
or if it finishes within the specified timeout. If the thread has not started yet
or fails to stop within the specified timeout the coroutine will return false.
If the timeout is set to -1, the operation will never time out.
See documentation for QThread::finished() for details.
QCoro::Task<bool> QCoroThread::waitForFinished(std::chrono::milliseconds timeout);
QCoro::moveToThread()
A helper coroutine that allows changing the thread context in which the coroutine code is currently being executed.
When co_awaited, the current coroutine will be suspended on the current thread and
immediately resumed again, but in the context of the thread that was passed in as
an argument.
QCoro::Task<> QCoro::moveToThread(QThread *thread);
Examples
#include <QCoroThread>
#include <QThread>
#include <memory>
QCoro::Task<void> MainWindow::processData(const QVector<qint64> &data) {
std::unique_ptr<QThread> thread(QThread::create([data]() {
// Perform some intesive calculation
}));
thread->start();
ui->setState(tr("Processing is starting..."));
co_await qCoro(thread.get()).waitForStarted();
ui->setState(tr("Processing data..."));
co_await qCoro(thread.get()).waitForFinished();
ui->setState(tr("Processing done."));
}