Flyingroc.org

My profile

2009-10-12T21:02:00.000-07:00

So many in my team went on this personality profile training (Insights Discovery). As part of it, we got a 22-page personality profile. I thought I'd upload it and let you decide if it's accurate. So here it is; there's at least one thing in there that's absolutely wrong. But in general I thought is was insightful.

Not sure that I learned anything that I didn't know though.

Civ

2009-09-30T21:38:00.001-07:00

If you haven't heard from me lately, it's because I've been playing too much Civilizations Revolution on my iphone. The game is crashy, but that just makes me start over...

Hopefully the game will wear out on me like field runners did ;)

Can Runtime Assertion Checking Work for Concurrency?

2009-09-15T00:40:00.000-07:00

I was reading this article Programs that Test Themselves in Computer magazine (unfortunately, link requires payment to access... Bertrand Meyer has a different but equally fascinating fascinating article which is now free to access: Seven Principles of Software Testing), and noticed that once again, the testing strategy described doesn't work out of the box for concurrent software.

The article describes an end-to-end scenario for automated+manual testing called AutoTest. It has an automated test generation strategy, a mechanism to run these automatically generated tests, and a way to automatically check the tests (pass/fail). They use the trick of runtime assertion checking of postconditions as an oracle (a technique I also used in my thesis). They paint a very attractive picture of testing that fully integrated automated and manually written unit tests that can check their own correctness. Problem is, it doesn't *quite* work for concurrent software.

Issues include:

An automated test generation strategy that is inherently single-threaded
No knob for exploring different schedules when executing the tests (byproduct of the first issue)
Runtime assertion of postconditions don't work in concurrent systems.

The first issue is probably easy to fix, one can imagine a variant of their test generation strategy but on multiple threads. The second can be fixed by running a test multiple times, each with a different thread schedule such as the CHESS tool does. But the last one is quite problematic.

AutoTest relies on the fact that you can evaluate design-by-contract postconditions at runtime to see whether they hold or not. But in concurrent systems, DBC runtime checking is a lot more tricky. Imagine that you have a simple concurrent stack type that had a Push() method: a typical postcondition for a stack would assert that after the Push(), the size of the stack grew by one element. But what if there was a Pop() running concurrently with the Push()--it is now possible that by the time the Push method returns, the stack did not grow at all!

I kind of recall a JML related paper where they try to solve this by putting in safe points--locations inside the code where pre- and postconditions can be checked safely. It wasn't clear to me that this is doable in general. Plus, we now have to muddy the implementation with contract stuff--which isn't very clean at all.

The idea of self-checking software components is certainly very appealing to me, but how do we make it work for concurrency components? Can we make dbc-style runtime checking work? Or do we need something else?

Code coverage for concurrency

2009-09-09T20:16:00.000-07:00

My article with Chris Dern on synchronization coverage is up at MSDN Magazine.

Who could have guessed that someday I'd co-author an article on MSDN Magazine. lol

Taste the Moment

2009-09-05T23:16:00.000-07:00

One good thing about moving to a new neighborhood is the opportunity to explore it. Today, I discovered Taste the Moment restaurant, about a block away from my apartment. It's a real cute place, it feels like you're eating in a dollhouse.

I had brunch there, ordered the eggs benedict, and it was yummy.

Stuffffffff

2009-08-30T01:23:00.000-07:00

You never really realize how much stuff you got until you move.

Most of the boxes are marked "kitchen". The new apartment has a smaller kitchen with fewer storage. Wonder how I'll fare.

Oh well, I guess I'll find out.

Omelette almost totally unlike Julia Child's

2009-08-27T20:44:00.001-07:00

Inspired by the movie, I attempted to make an omelette just like Julia Child made it. I ended up with this sorry looking thing. I think the pan wasn't hot enough, and I kept the eggs in too long. Also, I put too much butter that wasn't that fresh anymore. Oh well, maybe I'll attempt it again after I move :)

Omelette, originally uploaded by flyingroc.

Here's Julia making an omelette, the right way.

Unexpected Lechon

2009-08-24T20:16:00.000-07:00

Yesterday, Joel and I went to the Filipino Community Center in Seattle, because we heard the consul would be there and we could register to vote. But it turned out when we got there around lunch time that they consuls have left for California already. However, the people there were having lunch, and in the typical Filipino fashion, shared their lunch with us, which turned out to be lechon.

It's not the best lechon in the world, not like the kind Anthony Bourdain rhapsodized about. But it was lechon nonetheless, a whole roast pig. A few stragglers were there too--a couple of nuns also missed the voters registration. Oh well, they will do another one in November; not sure whether that qualifies me to vote for the elections next year, tho.

Getting a new lease

2009-08-22T22:25:00.001-07:00

Signed the lease today, moving to a one-bedroom apartment in downtown Redmond. Should save me a few hundred dollars a month in rent. Gotta start packing things up... I should move every couple of years so that I can re-evaluate the stuff that I have.

I'm hoping this blog gets a new lease, too. Gotta have more inane ramblings. So what should I talk about in this blog?

Julie and Julia

2009-08-22T00:05:00.000-07:00

I saw Julie and Julia tonight. Friends at work were joking about how it was a "chick flick". Yeah, it is, but how can I *not* watch a movie about Julia Child? It was a good movie. I am not usually a fan of Meryl Streep, but she did justice to the role here.

After watching the movie, I felt like I should be cooking more. Ah well, perhaps after I move next week.

Here's a video of Julia Child:

"Save up to null on your car insurance"

2009-08-20T20:27:00.001-07:00

LOL just goes to show, they never really read these things. This should remind us all that when dealing with numbers especially floating point, we should be careful about Not-A-Number values. Reminds me of this article by Gary Leavens.

photo, originally uploaded by flyingroc.

The cost of software error

2009-08-12T21:46:00.000-07:00

It's about $500 Million for Social Security. What's the likelihood that two people have the same name and birth date? And what's the likelihood that one of them is a felon?

The lead plaintiff in the class-action suit, Rosa Martinez, 52, of Redwood City, Calif., was cut off from her $870 monthly disability benefit check in January 2008 because the system had flagged an outstanding drug warrant in 1980 for a Rosa Martinez from Miami. An investigation showed that the warrant was for a different Rosa Martinez. Martinez tried for months to convince officials that she was innocent but failed.

(via slashdot)

Back from vacation

2009-07-25T07:12:00.000-07:00

My wonderful vacation was punctured by a tragic event. My nephew Tyler, born with a congenital heart defect, passed away after surgery. Angel and Tom are heartbroken, but determined to persevere with life, I think. I'm praying for them.

Aside from that tragedy though, my vacation was great. I got to spend time with my family and friends. Got to go home to my home town of Cotabato City, got through singing on stage at my father's birthday without any scars, and even spent a day at the beach (Pearl Farm beach resort).

And all the food! It seems that just as one meal is ending, another one is about to start. In many ways, our lives in the Philippines is one of incredible luxury. We have maids to wash our clothes, cook our food, and clean our house. We have a driver to chauffeur us around. Food is cheap *and* good. If only we could fix government corruption, traffic, and pollution.

Now it's back to work, hopefully with renewed vigor and passion. I considered not coming back to the US and decided not to give Shaun a heart attack :P. Thanks to everyone who made the trip so wonderful. To the friends I didn't get to meet, let's do it next time!

Strange cooking dream

2009-06-15T09:26:00.001-07:00

So I dreamt I was in a cooking competition, where I was helping out my cousin Anjing. In my dream, I accidentally threw out the risotto, and couldn't figure out how to brew a simple pot of coffee. Hm, what could this mean?!?!

I'm still here

2009-06-04T23:01:00.001-07:00

I think I might have some form of blogger's block. You guys have anything interesting to talk about?

Where the bugs are

2009-05-25T23:46:00.000-07:00

I've only skimmed the original paper, but this article is intriguing--"...in their study, the top 20 per cent of the largest programs contained over 60 per cent of the bugs."

I've felt like longer functions are more bug-prone per line of code than shorter ones, and this study seems to confirm that intuition.

Condo hunting

2009-05-17T22:13:00.000-07:00

Went to look at condos today. There are some pretty nice places out there. But given my current financial state, anything I buy would make my budget extremely tight.

On the one hand, it's a bit of a "waste" to spend all that money on rent when I can use it to pay toward my own place. On the other hand, is it really a smart idea to deplete my savings given the current economic climate? Maybe I can ask Suze if I can afford it!

Data visualization example

2009-05-05T21:40:00.000-07:00

It is difficult for us people to visualize large numbers. And I still have problems with intuitively projecting "exponential growth" even if I deal with it every day.

Weekends pass by so quickly

2009-05-03T17:57:00.000-07:00

And I always find I haven't done half of what I wanted to do. Even when I just wanted to do nothing.

The travails of shoe shopping

2009-04-25T21:24:00.000-07:00

I have small wide feet, and they're hard to find shoes for. So the annual shopping for a pair of "leather shoes" and a pair of "rubber shoes" went the usual way--frustrating. Shoes that I liked didn't fit, and shoes that fit were horrible. So finally decided to see if online shopping might be better. I ordered two pairs of shoes from endless.com. One pair looked really good, but were so narrow that I had to return them.

Thankfully, the other one, a pair of Teva hiking shoes actually fit. So now I feel ready to climb Mount St. Helens.

Shoe shopping online verdict: still frustrating, but possible.

In Remembrance

2009-04-15T21:53:00.001-07:00

It was some of the saddest times of my years at Tech. But I was never prouder of the Hokie nation.

800px-2007_Virginia_Tech_massacre_candlelight_vigil_4, originally uploaded by shizhao.

Clouds over Vancouver

2009-04-12T20:37:00.000-07:00

What would have been a perfectly nice, if cloudy weekend was marred by someone breaking into my car and stealing my GPS, ipod cables, and a sweater(!). When Anjing said we had to call the Royal Canadian Mounted Police, I was imagining some guy on horseback galloping into the garage... but alas we just had to give the details of the theft through the phone.

Other than having to have my window repaired, it was a fun weekend; we went to Granville Island, and then went to Richmond to take a peek at the Olympic oval. On Sunday went to Easter Mass at a church with so many Filipinos, it was like having mass at home. Vancouver definitely has a lot more Asian feel to it than Seattle. We had Dimsum--it was good, about as good as you'd get in Hong Kong, I'd say (which is pretty dang good).

I'm looking forward to visiting again, hopefully then it won't be so stressful with the car and all. This is the second time someone broke into my car in two years! I feel so violated.

Coming back to Seattle, I had to navigate the old fashioned way--with directions printed out from Google maps, and looking at the signs.

In Vancouver

2009-04-10T23:37:00.000-07:00

"What's your status in the US?" The Canadian immigration officer said. It took me a second to realize she wasn't talking about my Facebook status. Anyway, I'm here in Vancouver to visit cousin Anjing for Easter weekend. It's a 2.5 hour drive or so from Seattle to Vancouver. It was an uneventful drive (I love my car!).

Pretty excited finally get to travel here...

Cockroach allergies cause asthma attacks?

2009-04-07T20:13:00.000-07:00

The NYT article says so. It could be the reason why my asthma is so much better controlled here in the US.

Back

2009-04-05T23:06:00.000-07:00

I'm back home, it was a good trip. Here's me presenting at the conference. Pooja insisted on taking the picture :P.

There is some deep thinking going on in software testing research, glad I was able to go.