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Thoughts on Microsoft's Time-Travel Debugger

robert.ocallahan.org

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Re: Thoughts on Microsoft's Time-Travel Debugger

#71

Post by timmisiak »

bcherny wrote: post #68
SteveJS wrote: post #65

Earlier quoted context omitted.

TDD allows you to recreate a full memory snapshot at an arbitrary point during the recorded execution. A regular debugger cannot tell you what was in a register or memory location previous to what is currently there now. TTD does allow that.

So: - Without TTD, I can inspect values in the call stack where I set a breakpoint - With TTD, I can inspect values in my whole program, and can jump back/forward in time to see how those values changed Is that right?

Yup, you got it. Not just jumping back and forward, but seeking to points in time when memory changed. For instance... have some memory that got corrupted? With normal debugging you're probably out of luck unless you get some hints as to where it got corrupted. With TTD, you just set a memory access breakpoint and "run in reverse" until the memory is modified. It pinpoints the exact point in time where the memory got corrupted.

Re: Thoughts on Microsoft's Time-Travel Debugger

#72

Post by [deleted] »

j_s wrote: post #60
badminton1 wrote: post #3

What I personally do not enjoy as a developer about MS products is that eventually they hit end of life and you are left hanging. With open source stuff, if the project is used enough there will always be some maintainer.

The main problem with Microsoft in the past is that they didn't make money except by selling more software licenses. Things have begun to change with the cloud stuff, but the mentality is still there in the dev tools and frameworks - instead of "if it ain't broke, don't fix it" it winds up being "every time we move the cheese we make more money". Microsoft's incentives still don't quite align with their developer/cus…

[deleted]

Re: Thoughts on Microsoft's Time-Travel Debugger

#74

Post by testfailure »

versteegen wrote: post #22

Awesome, I hadn't heard of TTD. It's great to see reverse-debugging get serious attention rr sounds fantastic... unfortunately, I can't use it because AMD CPUs aren't supported (they simply don't have adequate performance counters; it's not rr's fault). With the exception of Ryzen, but even there, the performance counters apparently aren't entirely reliable (meaning sometimes the debugger will go haywire)

not sure if undodb supports these... they do x86 and arm though so maybe?

Re: Thoughts on Microsoft's Time-Travel Debugger

#75

Post by zastrowm »

j_s wrote: post #63
zastrowm wrote: post #57

Earlier quoted context omitted.

> even the drug-pusher-like "Community" (first hit is free, unless/until you're making money) edition. I mean, yeah it's not free-for-all, but "first hit is free" is kind of unfair. A company is not allowed to use it if they have more than "(a) more than 250 PCs or users or (b) one million U.S. dollars... in annual revenues" [1], and if it doesn't meet that criteria, it's usage is limited to 5 concurrent instances. M…

In case there's any confusion whether or not I agree with you, here's the very next thing I wrote: > It is perfectly reasonable​ on their part as a company selling dev tools to do this The Community edition licensing terms are, at best, awkward. I personally would have the hardest time with the 250 user limit - can I publish a free mobile app without fear this restriction might kick in? It is not as blatant as the Bi…

Yep, it's annoying to have those limitations, but I sort of understand why. They could make their message a lot clearer though.

> I personally would have the hardest time with the 250 user limit

From the document, the text is "more than 250 PCs or users", so my understanding is that a company is limited if it has >= 250 computer users, not 250 customers. E.g. you could have a million free app users and it would be fine.

That fact that I had to preface that with "my understanding is that" means that the document is fuzzy, which is annoying, but at least further documents[2] can clarify a bit:

> - Any individual developer can use Visual Studio Community, to create their own free or paid apps. > - In non-enterprise organizations up to 5 users can use Visual Studio Community. In enterprise organizations (meaning those with >250 PCs or > $1M in annual revenue) no use is permitted for employees as well as contractors beyond... [the exceptions as noted].

[2]: https://www.visualstudio.com/wp-content/uploads/2017/03/Visu...

So you (as an individual not as part of a company) could create a paid or mobile app and have as many users as you want and make as much as you can. If you're a company, then you need to be under 250 PCs, and <= 5 Visual Studio users and you're still good. Exceed those numbers and you have to pay up.

Re: Thoughts on Microsoft's Time-Travel Debugger

#76

Post by sctb »

201709User wrote: post #45
maxdo wrote: post #15

Redux also has sort of time traveling :)

Replaying a chain of well-defined events. How impressive.

Since it seems as though you won't post civilly and substantively, we've banned this account.

https://news.ycombinator.com/newsguidelines.html

Re: Thoughts on Microsoft's Time-Travel Debugger

#77

Post by euroclydon »

KirinDave wrote: post #50
euroclydon wrote: post #33

Earlier quoted context omitted.

Thanks for sharing that. Interesting what constitutes a military breakthrough these days. A real nation-state with a military-industrial complex would just shoot that thing down.

It's might become harder than you think. Especially modern stuff. I've been talking with a lot of hobbyist drone owners lately and several folks are working on fascinating projects using a fleet of semi-autonomous lightweight fixed wing and quad drones along with modern autonomous aircraft techniques. These things are small (you could hold them one handed on a crowded bus), fast (even the quads break 140mph), can be…

Interesting, but I’m sure there are significant efforts in anti-drone technology.
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