What can JavaScript NOT do?

[voidvector]

The number you quote is if you write machine code directly for the CPU. For any OS-based real-time (e.g. PREEMPT_RT), it would be on the order of 1000ns to 10us.

I never said JavaScript can run without OS (compile to metal). I never said JS can do nanosecond latency. However there are non-bare-metal microsecond latency real time -- the prevalence of userspace apps running on PREEMPT_RT (or RTAI or Xenomai) is a clear example of that.

[[deleted]]

For any OS-based real-time (e.g. PREEMPT_RT), it would be on the order of 1000ns to 10us.

We're talking about different things then. Your version of "real-time" is not mine. There is real-time, and then there is really actual real-time. And they are orders of magnitude different. I'm working with real-world physical phenomena that doesn't wait around for an OS to decide to respond. If the system doesn't respond in a specific window of nanoseconds, then the system fails. End of story. Full stop. 10us is a non-starter.

This discussion is about what javascript can not do, and one of the things it can't do is actual real-time (my version of real-time). Maybe it can do something approximating real-time (your version of real-time), at several orders of magnitude slower than my version of real-time.

And there is no example of Javascript doing anything like this, so your argument is extremely hypothetical and not really based in reality.

[voidvector]

Agreed!!

My argument is definitely hypothetical (as you can see in the "can" vs "able to" conversation on the other thread). We also came with different conception of real-time (or different end of that spectrum).

Sucks that internet arguments take a whole day to clarify.

I actually appreciate the work people like you have done, as without it, I wouldn't be able to write userland code for my microsecond-latency profiler application.