A common issue in Python GUI applications is interface 'locking up' during long-running tasks, which can be solved using concurrent execution in PySide6.
PySide6 apps are event-driven, with the GUI thread handling window communication; running tasks synchronously in this thread can freeze the GUI.
Moving long-running tasks to another thread is essential to prevent unresponsiveness; PySide6 provides a simple interface for this.
Preparation involves setting up a stub app to demonstrate multithreading; using events to maintain GUI responsiveness during tasks is impractical.
Utilizing threads and processes in PySide6 allows concurrent execution; threads share memory space, while processes have separate memory space and interpreter.
QRunnable and QThreadPool in PySide6 provide an efficient way to run tasks in other threads, with QThreadPool handling queuing and execution of workers.
Improving QRunnable involves passing custom data into the runner function using __init__(), allowing access to data within the run() slot.
Workers can utilize signals and slots for thread input/output, enabling safe communication from running threads to the GUI thread.
Considerations in multithreading include passing large data back through the GUI thread and potential limitations of the Python GIL.
Using pure Python thread pools like concurrent futures can isolate processing and thread-event handling from the GUI for improved performance.