Ryan Twomey

Web developer and entrepreneur in Woburn, MA.

Dec 13, 2009 11:06pm

Blech. I seem to be coming down with something.

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Dec 12, 2009 12:33am

RT @invotrak Invotrak for the iPhone version 2.0 released to Apple for approval! See the details at http://bit.ly/4F8edd/

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Dec 10, 2009 12:57pm

Sorry to see Lowell go. It’ll be cool to watch him at 1st in Texas though. http://bit.ly/4XcKnZ #redsox

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Dec 8, 2009 3:09pm

Chrome for the Mac is nice but I don’t like using something that’s an afterthought and crippled (no extensions).

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Dec 8, 2009 1:06pm

Trying out Chrome for the Mac. It’ll take a lot for me to switch from Safari though.

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Dec 7, 2009 9:32pm

OH: The hardest kind of person to retrain (ie switch courses) is the Ph.D.

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Dec 7, 2009 3:54pm

RT @TUAW AT&T offers app so you can report crappy service. Huh? http://bit.ly/5qZ3hX [post]

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Dec 7, 2009 12:31pm

What’s up with $AAPL? Down some 12+ points in the last week.

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Dec 5, 2009 3:22pm

Just found a neat trick in photoshop: command click a layer’s icon in the Layers screen to create a selection of it. Great for masks.

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Dec 4, 2009 2:50pm

RT @engadget FusionGarage plans media event to tell its side of the CrunchPad story http://bit.ly/5C9qTw

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Dec 3, 2009 12:47pm

RT @joefiorini here’s how http://to./ was done http://news.ycombinator.com/item?id=974148. pretty neat. (via @ryanbriones)

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Dec 3, 2009 12:47pm

RT @qrush How the… http://to./

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Dec 1, 2009 11:49am

Ugh

Too bad the formatting for that previous entry got all screwed up.  Check out the link to really get a good idea for what’s going on.  The explanation behind that graph is fascinating.

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Dec 1, 2009 11:46am

J is for JVM: Why the ‘J’ in JRuby?

From a post at the Engine Yard blog:

For starters, I’ll say that although Hotspot is a mystery, it does a generally great job at performance. The truth is that dynamic profiling is the path to excellent performance. HotSpot is much more clever than we are. It has the benefit of profile data from the running application to inform itself.

It also has the ability to de-optimize code. As strange as it sounds, this detail ends up being the catalyst to great performance.  When Hotspot does an optimization it puts a cheap guard in front of the optimization to make sure the rationale for the optimization still holds true. If the guard ever fails then it de-optimizes back to a slow path. The reason why this rocks, is that Hotspot can then be super speculative with aggressive optimizations. If the informed bet pays off, it pays off huge. If it doesn’t pay off, it gets reset with additional knowledge for a future potential optimization and some extra cost for trying out the not-quite-right optimization.

Here’s a demonstration of Hotspot in action:



In this graph we’re running a mandelbrot generator many times and plotting the amount of time it takes to generate it each time. If you look at JRuby 1.4.0 on the right side JRuby isclearly smoking Ruby 1.8.7 and doing very well against 1.9.2preview2. If you look at the progression as JRuby starts, you can see that we start slower than 1.8.7 but rapidly pick up steam as Hotspot kicks in.

Very interesting to see the performance of using JRuby (i.e. the Java Virtual Machine with HotSpot) versus a straight Ruby run.

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Nov 30, 2009 12:20pm

OH: blocking an IP range to stop spam is equiv to “We’ve gotten spam from the state of CA so we’ll block email from there”. @cwalcott

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