Threads and Linux (again!)

I have an application that reads webcam data on one thread, and passes the resulting bitmap to the main loop for display (cut down version attached)

The application works fine on Windows10, but not on Linux (Raspberry Pi).

The suggestion in the link below is to use PostEvent (which I have done as well using CallAfter and pubsub) but the result is still the same, Windows works and Linux gives:

“[xcb] Unknown request in queue while dequeuing…”

Any suggestions as to where I might be going wrong, or whether additional synchronisation is necessary, would be much appreciated

Many thanks

Phil Evans

LINK:

Could it be that TheClipboard object cannot be used with Threading on Linux?

https://groups.google.com/d/msg/wxpython-users/_S0zEBRxI5w/9v2sz7A_AQAJ

zampleD_02.py (2.83 KB)

If you receive an error pointing to XInitThreads has not been called, then the hack Ed Hynan provided in the link you mentioned, solved it for me.

Cheers

Claudia

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Am Donnerstag, 26. Oktober 2017 17:17:12 UTC+2 schrieb phil evans:

I have an application that reads webcam data on one thread, and passes the resulting bitmap to the main loop for display (cut down version attached)

The application works fine on Windows10, but not on Linux (Raspberry Pi).

The suggestion in the link below is to use PostEvent (which I have done as well using CallAfter and pubsub) but the result is still the same, Windows works and Linux gives:

“[xcb] Unknown request in queue while dequeuing…”

Any suggestions as to where I might be going wrong, or whether additional synchronisation is necessary, would be much appreciated

Many thanks

Phil Evans

LINK:

Could it be that TheClipboard object cannot be used with Threading on Linux?

https://groups.google.com/d/msg/wxpython-users/_S0zEBRxI5w/9v2sz7A_AQAJ

Thank you Claudia

I’d focused on the PostEvent comments, rather than Ed’s - which has fixed the problem

My Raspberry Pi is now happily displaying wifi camera images in my app

cheers

Phil