Multi-threaded plugins problem Topic is solved

[mgugu]

Pi2/Trixie - Domoticz: latest beta
Hi all,
I tested this multi-threaded plugin example :https://github.com/domoticz/domoticz/bl ... hreaded.py
Encountered issues:
- Domoticz hangs undefinitely when I click on update

2026-04-25 10_47_11-Domoticz.jpg (129.03 KiB) Viewed 41917 times

- Restarting domoticz service is very long
Other multithreaded plugins I tested have same kind of issues.
Are there some restrictions in using multi-threaded plugins ?

[jvdz]

Do you get any messages in the log when you test as the OnStop() function should show you whether it is waiting for threads to finish?

[mgugu]

Yes, on another multi-threaded plugin (Domoticz universal GPIO) I get following messages after service restart or hardware update:

Code: Select all

2026-04-25 16:14:58.240  GPIO: GPIO event_loop exited
2026-04-25 16:14:58.242  Error: GPIO: Plugin has 1 Python threads still running.
2026-04-25 16:14:59.243  Error: GPIO: Plugin has 1 Python threads still running.
2026-04-25 16:15:00.244  Error: GPIO: Plugin has 1 Python threads still running.
2026-04-25 16:15:01.244  Error: GPIO: Plugin has 1 Python threads still running.
2026-04-25 16:15:02.245  Error: GPIO: Plugin has 1 Python threads still running.
2026-04-25 16:15:03.245  Error: GPIO: Plugin has 1 Python threads still running.
2026-04-25 16:15:04.246  Error: GPIO: Plugin has 1 Python threads still running.
2026-04-25 16:15:05.247  Error: GPIO: Plugin has 1 Python threads still running.
2026-04-25 16:15:06.247  Error: GPIO: Plugin has 1 Python threads still running.
2026-04-25 16:15:07.248  Error: GPIO: Plugin has 1 Python threads still running.
2026-04-25 16:15:08.248  Error: GPIO: Plugin has 1 Python threads still running.
2026-04-25 16:15:08.249  Error: GPIO: Plugin has 1 Python threads still running.
2026-04-25 16:15:08.249  Error: GPIO: Abandoning wait for Plugin thread shutdown, hang or crash may result.

And the still running thread is Mainthread

[jvdz]

The example plugin you linked does tell the thread to close by supplying a None into the messagequeue: self.messageQueue.put(None), so the thread knowns it needs to stop:

Code: Select all

                Message = self.messageQueue.get(block=True)
                if Message is None:
                    Domoticz.Debug("Exiting message handler")
                    self.messageQueue.task_done()
                    break

Have you done something similar?

[Rik60]

Yes, on another multi-threaded plugin (Domoticz universal GPIO) I get following messages after service restart or hardware update:

Code: Select all

2026-04-25 16:14:58.240  GPIO: GPIO event_loop exited
2026-04-25 16:14:58.242  Error: GPIO: Plugin has 1 Python threads still running.
2026-04-25 16:14:59.243  Error: GPIO: Plugin has 1 Python threads still running.
2026-04-25 16:15:00.244  Error: GPIO: Plugin has 1 Python threads still running.
2026-04-25 16:15:01.244  Error: GPIO: Plugin has 1 Python threads still running.
2026-04-25 16:15:02.245  Error: GPIO: Plugin has 1 Python threads still running.
2026-04-25 16:15:03.245  Error: GPIO: Plugin has 1 Python threads still running.
2026-04-25 16:15:04.246  Error: GPIO: Plugin has 1 Python threads still running.
2026-04-25 16:15:05.247  Error: GPIO: Plugin has 1 Python threads still running.
2026-04-25 16:15:06.247  Error: GPIO: Plugin has 1 Python threads still running.
2026-04-25 16:15:07.248  Error: GPIO: Plugin has 1 Python threads still running.
2026-04-25 16:15:08.248  Error: GPIO: Plugin has 1 Python threads still running.
2026-04-25 16:15:08.249  Error: GPIO: Plugin has 1 Python threads still running.
2026-04-25 16:15:08.249  Error: GPIO: Abandoning wait for Plugin thread shutdown, hang or crash may result.

And the still running thread is Mainthread

Can you check the plugin code:

Code: Select all

                if self.request.wait_edge_events(5):

and change the 5 into 0.2
copilot thinks that this is the problem

[mgugu]

@jvdz, here is the multi-threaded GPIO plugin provided by Rik60, it provides error messages at restart while Multi-threaded Plugin example hangs
@Rik60, changing self.request.wait_edge_events(5) to (0.2) does not change anything.
I submitted the problem to Anthropic AI (also to improve inputs management) and he told me that the plugin is properly coded and the problem comes likely from domoticz mainthread management.

[Rik60]

Perhaps it isn't the this plugin as you wrote. But the change worked for me. Btw, i have seen this error also when other plugin is stopping. Zigbee 4 Domoticz is also showing this error when Domoticz is restarting but i didn't pay attention to it.

[gizmocuz]

@Rik60, yes Zigbee4domoticz has know issues, and are solved when using a new python version, but that is not officially supported

[gizmocuz]

Should be solved when using the latest docker compose beta image (upgraded to python 3.13)