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Leaving Mozilla

robert.ocallahan.org

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Re: Leaving Mozilla

#81

Post by mrdrozdov »

neves wrote: post #4

I've never heard about rr http://rr-project.org/ ), his tool to record program execution and debug it afterwards. The alleged 1.2x slowdown in execution is negligible. The ability to reverse in time is almost a nirvana. I'm sad I didn't have it when I used to program C++. Hope he succeeds in his new endeavor. We'd all win big. Does anyone knows of similar tools for Python and in-browser Javascript?

There is something similar in bpython called rewind. Run a few commands in the repl and then try `ctrl+r`.

Re: Leaving Mozilla

#82

Post by mrdrozdov »

neves wrote: post #4

I've never heard about rr http://rr-project.org/ ), his tool to record program execution and debug it afterwards. The alleged 1.2x slowdown in execution is negligible. The ability to reverse in time is almost a nirvana. I'm sad I didn't have it when I used to program C++. Hope he succeeds in his new endeavor. We'd all win big. Does anyone knows of similar tools for Python and in-browser Javascript?

I wonder how it works. Assuming it must capture state at t=n, and somehow calculate the diff to get to t=n+1. Could theoretically pop diffs to get to any point in the past.

Re: Leaving Mozilla

#83

Post by ArkyBeagle »

yitchelle wrote: post #29
xigency wrote: post #10

Earlier quoted context omitted.

Sounds very similar Green Hills Software's TimeMachine for embedded applications.

My thoughts were very similar to yours. In 1992, when I started out in embedded on a Philips 8051 and debugging it was via an ICE and had direct visibility and control of the 8051. The ICE would be connected to a bonded out version of the 8051 and I was almost able to capture every single clock cycle of 8051's execution. When I hit a failure, I would just replay the trace and see what went wrong. It looks like the fo…

I had access to a Huntsville Microsystems ICe that used a bog-standard - non-bonded-out - 68008 in harness. I had scripting tools that would capture and replay all the registers to back the machine up.

That HMI was a brilliant machine.

It's really the last debug tool I ever used besides AVR, PIC and one ARM JTAG for doing BSP work.

Re: Leaving Mozilla

#84

Post by justinclift »

Reverse debugging has been around for several years, but hasn't seemed to be widely adopted. Which seems kind of unfortunate, as the concept of it looked really useful.

Does rr make reverse debugging much easier than it's previously been in gdb or something? :)

Re: Leaving Mozilla

#85

Post by Shog9 »

jlebar wrote: post #74
kibwen wrote: post #35

Earlier quoted context omitted.

Why is he leaving? That's covered in the OP: he wants to devote his full-time attention to working on rr, a reversible debugger for native code that imposes impressively low overhead, and possibly spin it into a startup.

I think roc would give me a sly smile for pointing out that this doesn't really answer the "why". It's what he's going to do after he leaves. Doesn't quite answer why he's leaving.

Well, it'd be foolish to assume that someone doesn't have multiple reasons for making a dramatic change in their life.

It'd also be foolish to assume that most of those reasons are any of our business.

Robert is an amazing guy, and we're all lucky to have benefited from his work over the years. Now, he's set off on a new adventure, for reasons of his own... And has hinted that he'll continue sharing some of the fruits of his labor.

That's more than enough ;)

Re: Leaving Mozilla

#86

Post by JonathonW »

haberman wrote: post #59
cyphar wrote: post #54

Earlier quoted context omitted.

DTrace doesn't languish. It just doesn't have a Linux port, because of people's contrived rewriting of the history of the GPL.

Let me put it this way. In the last say five years, I can't think of a single article I've come across where someone describes DTrace making their life better (except one I wrote in 2011: http://blog.reverberate.org/2011/05/using-dtrace-on-os-x-to-... ), or a single time anyone I know or work with has even mentioned DTrace. This is a technology that received an innovation award from the Wall Street Journal in 2006. W…

Dtrace isn't completely dead; it's used to great effect as the underlying technology behind Instruments (performance analyzer/visualizer) on OSX.

It never has really managed to catch on as a standalone tool by itself, though. Part of that's the licensing situation on Linux, but I'd hypothesize that part of it is also that it's a pretty complicated tool to use, interpret, and act on-- you don't hear a lot about SystemTap (same concept, GPLed for Linux-friendliness) these days, either.

Re: Leaving Mozilla

#87

Post by shmerl »

davidbanham wrote: post #75
mathattack wrote: post #60

Earlier quoted context omitted.

There's a decent market for selling consulting consulting services on top of open source technology. Being the expert on applying an open source technology to solve specific problems comes with a decent rate card.

You're still selling your labour rather than a product, though. It's possible to be well off doing that, but basically impossible to become ludicrously rich.

He didn't say his goal is to become ludicrously rich. He said he has ideas that Mozilla can't and shouldn't provide resources to realize, so some for profit company would work better for it.

Re: Leaving Mozilla

#88

Post by jamiecollinson »

martindale wrote: post #47
neves wrote: post #4

I've never heard about rr http://rr-project.org/ ), his tool to record program execution and debug it afterwards. The alleged 1.2x slowdown in execution is negligible. The ability to reverse in time is almost a nirvana. I'm sad I didn't have it when I used to program C++. Hope he succeeds in his new endeavor. We'd all win big. Does anyone knows of similar tools for Python and in-browser Javascript?

I'm building something like this for in-browser Javascript, but in a larger context. We're not ready for public consumption yet, but: https://fabric.fm

Interesting! Tried to subscribe but got an error: {"code":-5000}

Re: Leaving Mozilla

#89

Post by elcritch »

ternaryoperator wrote: post #36
mwenge wrote: post #21

Earlier quoted context omitted.

Christians of all denominations actively proselytise - it's a core part of being a Christian, spreading the 'good news'. This distinguishes the Christian ethos from most other mainstream religions which have a weak or non-existent missionary instinct. So no, it's not unusual at all for a Christian to highlight the fact. From the point of view of a Christian in an increasingly secular world it probably feels more nece…

To be clear, only some strains of Christianity are active proselytizing. There are strains that do none at all.

Most strains of Christianity will have some form of proselytizing, though it might be muted. Plus there also tends to be ebbs and flows in the history and culture of such things. It's interesting to note that proselytizing arguably has a very significant (positive) effect on formation of liberal democracies [1].

[1]: http://isites.harvard.edu/fs/docs/icb.topic965299.files/Wood...

Re: Leaving Mozilla

#90

Post by digi_owl »

chris_wot wrote: post #72
haberman wrote: post #59

Earlier quoted context omitted.

Let me put it this way. In the last say five years, I can't think of a single article I've come across where someone describes DTrace making their life better (except one I wrote in 2011: http://blog.reverberate.org/2011/05/using-dtrace-on-os-x-to-... ), or a single time anyone I know or work with has even mentioned DTrace. This is a technology that received an innovation award from the Wall Street Journal in 2006. W…

You really aught to look at Bryan Cantrill's twitter feed then. It happens frequently enough that he notices blog posts and tweets them.

Then again Cantrill has an axe to grind.

In case others are wondering: https://en.wikipedia.org/wiki/Bryan_Cantrill

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