Stops the currently running event loop.
Calling this function will cause the event loop to stop event processing and the corresponding call to runEventLoop() will return to its caller.
bool shutdown_all_threads = false
|shutdown_all_threads||If true, exits event loops of all threads - false by default. Note that the event loops of all threads are automatically stopped when the main thread exits, so usually there is no need to set shutdown_all_threads to true.|