glass_of_water
Joined 13 years ago
Karma
273
Submissions
100
Member since
Feb 28
Recent submissions
Comment · 1 year ago
I could not agree more. When trying to understand the distinction between "declarative" and "non-declarative" code, I came to the same conclusion: it's all relative.
Comment · 3 years ago
If you find the right organization that uses the funds effectively, what's with donating your wealth as opposed to creating your own charitable organization? Also, I'm sure the tax deduction for donations is exploited when the receiving organization is non-profit in name only, but if the receiving organization really is an effective charity, what's wrong with the donor getting a tax break?
Or is the claim not that one approach is more effective than other in terms of positive impact, but that the wealthy, for their own sake, would be better off founding their own organizations?
Comment · 3 years ago
How do you deal with false negatives when using Hilbert curves for nearest neighbor searches? Based on my limited understanding, points close on space can be far from each other on the curve. Do you use multiple curves or something?
Comment · 4 years ago
A function f(x) whose growth rate at x is proportional to f(x). So anything where growth rate is proportional to the current value.
Comment · 4 years ago
Could you compile to wasm, or is there extra work involved in making that possible? One reason I shied away from learning Common Lisp is that none of the popular implementations seem to run in the browser.
Comment · 4 years ago
If that were true, text books wouldn't contain any diagrams. So I think it's fairly uncontroversial to say that there are cases when text is not the best way to incept ideas. So why should we be confined to just text when writing code? Should we not be free to choose the best tool for the job?
Comment · 5 years ago
Canvas already uses double buffering. OffscreenCanvas lets you issue draw commands from a separate thread.
Comment · 5 years ago
From my understanding, OffscreenCanvas and double buffering are unrelated. OffscreenCanvas just lets you execute draw calls in a separate thread (in a WebWorker). I believe the browser already uses double buffering under the hood for drawing to a canvas element.
Comment · 5 years ago
Oh that's cool, using fork() to create checkpoints. Thank you again for taking the time to explain!
Comment · 5 years ago
As bhackett confirmed, you're right about recording at the system library call level. I wasn't sure if it was more of an analogy or only referred to a version of Replay targeting backend servers written in other languages like Go, especially since the author mentioned hooking into the JS runtime in https://medium.com/replay-io/effective-determinism-54cc91f56.... But it looks like I misunderstood, and their browser product is their generic record/replay library integrated into Firefox, rather than a reimplementation of the same concepts.
Comment · 5 years ago
Thanks for the explanation! Do you ever run into performance issues with replaying from the start on each backward step or is this not really in issue in practice? I imagine for most websites and short replays it's probably fine, but for something like a game with a physics engine it sounds like it would be too expensive and you'd need snapshots or something. I guess that's a super small percentage of the market though.
For question 3 on the ordering, I was imagining the following kind of scenario: one thread maybe calls a system library function to read a cursor position and another calls a system library function to write a cursor position. So even though they're separate functions, they interact with the same state. Do you require users to manually call to the recorder library to give the recorder runtime extra info in this kind of scenario? Sorry if this is a dumb question, I haven't really done any programming at this level.
Comment · 5 years ago
I read the medium post (https://medium.com/replay-io/how-replay-works-5c9c29580c58), which gives an overview of how Replay works, but there are a few things I still don't understand.
1) How does the step backward functionality work? Do you take snapshots every so often of the Javascript environment? How do you handle destructive assignments?
2) Does Replay record actual syscalls made by the browser, or is it recording calls to the browser APIs by the javascript code (which I guess are effectively syscalls from the javascript code's perspective)?
3) The ordered lock technique described in https://medium.com/replay-io/recording-and-replaying-d6102af... makes sure that threads access a given resource in the same order, but what about threads accessing different resources in the same order? e.g. when recording, thread 1 accesses resource A before thread 2 accesses resource B. It seems like the ordered lock technique doesn't help you maintain that ordering in the replay. Is maintaining that kind of ordering across resources not actually necessary most of the time?
Comment · 6 years ago
I had the same issue; I think the error message is wrong. The reason it's not working is that tracking protection is blocking XHR requests to www.reddit.com. If you disable tracking protection or whitelist www.reddit.com it should work.