Windows Embedded Compact is NOT an RTOS... Again!

We just received a report from one of our customers that saw their high priority thread on WEC2013 not being scheduled for a long time, even though that thread was set to the highest priority in the entire system.

They saw behaviour very similar to what we described in this blog post. We investigated here by running our test code to show this bug on a tiny headless kernel with as little drivers included as possible and, to our grand surprise, it indeed showed the bug was back!

The customer was at Wave 5 update level. At GuruCE, we are always updated to the very latest (Wave 7 + March + June 2022) and we also saw the bug regression in WEC2013 (in WEC7 we fixed the issue ourselves at the time and that still worked). Microsoft fixed this bug in WEC2013 somewhere around November 2018 (see this blogpost), but apparently the bug regressed shortly thereafter through an update (Wave 5 or even earlier).

We have reported this issue again to Microsoft and in the mean time we have fixed this issue locally, now both for WEC7 and WEC2013, in our BSPs.

Customers of GuruCE can request this fix immediately through our normal support channels.

Anybody else that wants the fix for both WEC7 and WEC2013 can of course also contact us for support on this and other WEC related issues.

Bug image from Wikimedia Commons with reference to this meme