Chronon Time Travelling Java Debugger - Now in Beta | Hacker News Reader

Chronon Time Travelling Java Debugger - Now in Beta

chrononsystems.com

19 pointssuprgeek6 comments

>What is Chronon?

A revolutionary new technology...

Oh really?

http://www.extremetech.com/article2/0,1558,426529,00.asp

>Java development tool maker VisiComp Inc. on Monday announced a new version of its RetroVue debugger, which it calls a Total Recall debugger for Java. Ron Hughes, CEO of the Felten, Calif., company, said unlike conventional debugging tools, RetroVue keeps track of every operation executed by the program being debugged and thus enables developers to "roll back the clock" to any previous instance in the program's execution and review the state of the program at that point in time.

That's from July 30, 2002. Or how about this:

http://www.lambdacs.com/debugger/

>What if your debugger could go "go backwards in time?" Would that make debugging easier? By simply recording all variable assignments, it is possible to do essentially this. This is the underlying idea for omniscient debugging.

February 18, 2007. (edit: whups, that was just the last update. Evidence of its existence in March 2003: http://www.lambdacs.com/debugger/AADEBUG_Mar_03.pdf )

Really, this isn't all that revolutionary. It's just a new iteration. Better? Quite possibly, but enough with the hyperbole. I wholly agree with the second link, it's a simple concept, and simple to realize. I'd been hoping to find it in debuggers for a couple years before I found the second link, and it's surprising that there are so few instances, but that's probably due to the potentially-very-large memory / disk cost of doing so.

Thanks for the links! I encountered the Omniscient Debugger (2nd link) several years ago, but then lost it somehow...

Watcom IDE could step back in some cases too (for many years now). And that was C code... It did not register the changes though as far as I remember, so you could not step back before x=x-x.

There was also Omnicore's Codeguide and X-Develop products back in the early 2000's. They had a feature called back-in-time debugging.

And how about this from 1995: http://web.media.mit.edu/~lieber/Lieberary/ZStep/ZStep-SoftV...

ZStep 95: A Reversible, Animated Source Code Stepper Henry Lieberman. Christopher Fry

Oh well, nothing new under the sun, and just because it isn't quite as revolutionary as they claim doesn't mean it's not useful.

would love to see benchmarks on speed. instrumenting code can significantly slow it down, yet reproducing production errors can be difficult so this would be cool to run all the time....if it weren't significantly slow, possibly via customization.

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