Tag Archives: mace

Kernel Bug

Spent a whole night tracing a strange timer bug: Mace timer did not fire off at correct time on some machines. Specifically, on those machines, timer goes off one second earlier than requested. E.g., if you want it to fire off after 2 second, it actually fires off after 1 second. Strangely, it doesn’t happen to every machines.

Initially I thought it was a problem in Mace code, so I spent the night digging into the timer code. Finally, there’s one function to blame: pthread_cond_timedwait(). It does not behave correctly.

According this this StackOverflow post, this bug is triggered by a Linux kernel bug due to leap second. The problem will be gone after rebooting the machine, and indeed that problematic machine hasn’t been rebooted for more than a year. Well, this is so unexpected.

PLDI Paper Submitted and 700th Commit!

We have just submitted our latest work to PLDI (Programming Language Design and Implementation), a top conference in the programming language area today!
Thanks for every one’s contribution, and it’s great to have six people working on the same paper (i.e. on average, every one just need to write less than two pages) We had some last-minute issue last night, but thankfully we were able to workaround and get the result in time.

Also, we have the 700th changeset committed by Rui Gu today just before the paper submission!