Is it ok that QueuedConnection start every time a new copy of a function?
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I have an issue or misunderstandig in understanding of how QueuedConnection and QThreads work. I have a controller class which contains a worker object that being moved to a QThread. From main I emit a signal to the controller class which emits signal (QueuedConnection) to the woker object to perform a particular task. In the worker object in a while loop I call QApplication::ProcessEvents() so the signals could be delivered and dispatched to the worker object. But it appears that every time I emit a signal to perform a task a new copy of a function from the worker has been started. Why is it so?
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@MikhailG when a signal queueConnetion type is emited, this signal is inserted at end of queue to be processed when the event loop is able to deliver the signal to slot
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I have an issue or misunderstandig in understanding of how QueuedConnection and QThreads work. I have a controller class which contains a worker object that being moved to a QThread. From main I emit a signal to the controller class which emits signal (QueuedConnection) to the woker object to perform a particular task. In the worker object in a while loop I call QApplication::ProcessEvents() so the signals could be delivered and dispatched to the worker object. But it appears that every time I emit a signal to perform a task a new copy of a function from the worker has been started. Why is it so?
@MikhailG said in Is it ok that QueuedConnection start every time a new copy of a function?:
In the worker object in a while loop I call QApplication::ProcessEvents() so the signals could be delivered and dispatched to the worker object.
This is a very bad idea. Worker object should never try to control event loop of the main thread. Either spin a local event loop to do the waiting, or simply exit the thread when your work is done. Your thread controller can start a new thread / job when it gets the signal to do some work.
But it appears that every time I emit a signal to perform a task a new copy of a function from the worker has been started. Why is it so?
Can you rephrase this question? I don't understand what you mean.
If you mean that every signal emission
emitcauses your slot to execute, then that is exactly what should happen, normal behaviour.(Z(:^
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@MikhailG said in Is it ok that QueuedConnection start every time a new copy of a function?:
In the worker object in a while loop I call QApplication::ProcessEvents() so the signals could be delivered and dispatched to the worker object.
This is a very bad idea. Worker object should never try to control event loop of the main thread. Either spin a local event loop to do the waiting, or simply exit the thread when your work is done. Your thread controller can start a new thread / job when it gets the signal to do some work.
But it appears that every time I emit a signal to perform a task a new copy of a function from the worker has been started. Why is it so?
Can you rephrase this question? I don't understand what you mean.
If you mean that every signal emission
emitcauses your slot to execute, then that is exactly what should happen, normal behaviour.@sierdzio said in Is it ok that QueuedConnection start every time a new copy of a function?:
Can you rephrase this question? I don't understand what you mean.
Well when I emit a signal to the worker object I pass a parameter for debugging purpose. Than I emit another signal with a debug data and I can see in logs for previous call and for current call debug data.
//PrevCall data
"D:/Music"
"D:/Music"
"D:/Music"
"D:/Music"
"D:/Music"
"D:/Music"
"D:/Music"
AWESOME!
//NewCall data
"D:/ISO"
"D:/ISO"
"D:/ISO"
"D:/ISO"
"D:/ISO"
"D:/ISO"
//PrevCall data
"D:/Music"
"D:/Music"
"D:/Music"
"D:/Music" -
@sierdzio said in Is it ok that QueuedConnection start every time a new copy of a function?:
Can you rephrase this question? I don't understand what you mean.
Well when I emit a signal to the worker object I pass a parameter for debugging purpose. Than I emit another signal with a debug data and I can see in logs for previous call and for current call debug data.
//PrevCall data
"D:/Music"
"D:/Music"
"D:/Music"
"D:/Music"
"D:/Music"
"D:/Music"
"D:/Music"
AWESOME!
//NewCall data
"D:/ISO"
"D:/ISO"
"D:/ISO"
"D:/ISO"
"D:/ISO"
"D:/ISO"
//PrevCall data
"D:/Music"
"D:/Music"
"D:/Music"
"D:/Music" -
I have an issue or misunderstandig in understanding of how QueuedConnection and QThreads work. I have a controller class which contains a worker object that being moved to a QThread. From main I emit a signal to the controller class which emits signal (QueuedConnection) to the woker object to perform a particular task. In the worker object in a while loop I call QApplication::ProcessEvents() so the signals could be delivered and dispatched to the worker object. But it appears that every time I emit a signal to perform a task a new copy of a function from the worker has been started. Why is it so?
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@MikhailG do you call
connectmultiple times for the same signal/slot?if so, that would lead to multiply slot calls for one emit
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Hi,
Can you show your code ?
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Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct
