How to join threads?

[aivarannamaa]

Is there a built-in support for waiting a thread to complete in MicroPython (eg. on ESP32 or RPi Pico)?

If not, then can you recommend a technique for achieving this? Something less ugly than sleeping in a loop and checking a shared flag?

My goal is to recommend a work-around for Thonny users, who get errors when they are using threads (eg. https://github.com/thonny/thonny/issues/1586). When Thonny detects REPL prompt, it thinks the device is idle and it can issue hidden commands (eg. for listing files) without being disturbed. Printing from a thread invalidates this expectation.

I know Thonny should try harder and distinguish the output meant for user from the output from management commands, but for a work-around it would be good if it was possible to organize the user code such that the main thread doesn't return to the prompt before all background threads are done.

[jimmo]

Is there a built-in support for waiting a thread to complete in MicroPython (eg. on ESP32 or RPi Pico)?

Unfortunately not that I'm aware of.

If not, then can you recommend a technique for achieving this? Something less ugly than sleeping in a loop and checking a shared flag?

That's pretty much how join works under the hood but yeah probably a neater solution than using a flag directly is to use a mutex held by the thread and the main thread shouldn't exit until it can acquire the mutex.

[tonygo]

There is some discussion on The Ras Pi Pico Forum but it was a bit above my current experience:
https://www.raspberrypi.org/forums/view ... &p=1808139