Computing


Debugging MacOS file locking with DTrace

A few days ago, I was stymied at work by a set of tests that had intermittent failures on OSX but not Windows. There was a process which would try to obtain an exclusive lock on a file, using the lock-on-open provided by the BSD/MacOS O_EXLOCK flag to open(2). It also used O_NONBLOCK; if the file was locked by another process, it could be skipped. The process would hold the lock and remove (unlink(2)) the file, before close(2)-ing the descriptor.

Systems We ❤

I had a really great time at Systems We Love 2 weeks ago. It was refreshing to attend a conference that had genuine talks about complicated systems that keep or kept the “world” running. No sponsor-driven drivel and no “here is how to do X” talks that could’ve been summarized by documentation. Ozan Onay has already summarized all the talks, including links to videos, so I don’t have to. A few talks stood out in particular.

The IT Crowd?

(This article was originally published in Entelechy, edition 32, Jan 2012. It is being published here in full with some annotations.) It has continued to surprise me over the last 3.5 years how few information technology students actually bother to use the innovations of information technology to improve their productivity in any manner. More importantly, they are usually unaware of the products themselves. Recently the issue was brought to the fore when Skish Champi pointed out that Zimbra Collaboration Suite had great calendar integration (and I agree), and we as a college are still struggling around with sending meeting emails and reminders.