Uh oh!
There was an error while loading.Please reload this page.
- Notifications
You must be signed in to change notification settings - Fork32k
Description
Bug report
Bug description:
Actual behavior
Having a Thread running which is waiting for a user cli input lets a newely started multiprocessing Process hang until the user provides the cli input for the Thread once.
The target method of the Process will not get called until the input is provided.
After the user has provided the input for the thread, the target of the Process beginns executing.
Regardless if the Thread is now waiting for further user input, the target of the Process continues running.
Expected behavior
I would expect the target of the Process to begin executing directly whenstart gets called, regardless of any Thread waiting for user input.
Minimal example
fromthreadingimportThreadfrommultiprocessingimportProcessimporttimedefthread_worker():whileTrue:input()print(f"Thread:{time.time_ns()}")time.sleep(1)defprocess_worker():whileTrue:print(f"Process:{time.time_ns()}")time.sleep(1)defmain():t=Thread(target=thread_worker)t.start()p=Process(target=process_worker)p.start()whileTrue:print(f"Parent:{time.time_ns()}")time.sleep(1)if__name__=='__main__':main()
Parent: 1744127459390331500Parent: 1744127460391104200Parent: 1744127461391702600Parent: 1744127462391891200Parent: 1744127463391976800<-- User pressed <Enter> hereThread: 1744127463907895600Process: 1744127464027620700Parent: 1744127464392826400Process: 1744127465027796400Parent: 1744127465393627600Process: 1744127466028309500Parent: 1744127466394346500Process: 1744127467028522100Parent: 1744127467395162900<-- User pressed <Enter> hereThread: 1744127468003765700Process: 1744127468029055500Parent: 1744127468395581600Process: 1744127469029577600Parent: 1744127469395885500Process: 1744127470030224200Parent: 1744127470396392600Process: 1744127471030760100Parent: 1744127471396828100I find it unexpected that before the first<-- User pressed <Enter> here there is no output of the Process.
CPython versions tested on:
3.12
Operating systems tested on:
Windows