Published on 4 March 2010
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Typical Wednesday. One of my meetings for today was a conference call where I expected to remain mainly in listening mode. So I attempted some of my own work during the call, making good use of the speaker and mute button. I am male, but can usually handle two things at once.

But during the course of that one hour session, I got two cell phone calls, five urgent emails, IMs from four co-workers, and many more questions than expected from the call. It came to a few dozen separate topics, far exceeding my "two plus or minus seven" capacity. Postponing non-urgent interruptions helps, but increases my backlog queue length. Yet responding "on demand" often leads to dropped interrupts and increased interrupt latency. It can be tough to maintain the balance.

Careful thoughtwork requires focus and concentration, and interruptions can quickly wreck that. I was reminded of Larry Constantine's classic essay, Irksome Interruptions. In it, he wittily suggests that programmers adopt the nomenclature of CPU interrupt handling to deal with this problem. It's a geeky way to go about things, but handled this way, an "interrupt request" becomes short enough not to derail a thought process. Want to chat with someone who might be busy at task?  Just ask "IRQ?" (pronounced "irk?"). If it's a good time, they'll "ACK" you, which buys a moment to "save state" before "servicing your interrupt."  If it's a bad time, they can just answer "NAK" (negative acknowledge), and you know to try later, with no harm done (no thought process wrecked). And someone who has developed a habit of frequent interruptions might be labeled IRQsome.

Constantine wrote his essay before our work environments had so many more interrupt request lines to service. Multiple IMs and chat rooms, multiple phones, and emails arriving at high rates add to classic face-to-face interruptions. And the economy was better then (and engineer-to-workload ratio higher), so folks weren't pulled in so many different directions. Yet his suggestions are compelling, and I do exchange "irq"s, "ack"s, and "nak"s (over IM) with one co-worker who has also read the old essay. The classic instant messaging "yt?" also works, provided one is willing to answer "n" or "no" when not prepared to be mentally there.