Re:Fast, Safe, and Complete(ish) Web Service in Rust
by zzzcpan on Tuesday March 27, 2018 @05:08PM
(#16692734)
Any process or thread can be descheduled by the OS on top of the stuff it does on its own.
Yielding is a thing from the multithreaded world with synchronous APIs. Asynchronous systems don't yield, they are programmed asynchronously. They have no yielding overhead and can never be slower than yielding threads.
If you are arguing for 1:1 kernel threading against M:N threading (coroutines, goroutines, green threads) that's fine, but multithreading implementations have absolutely nothing to do with asynchronous systems.
Re:Fast, Safe, and Complete(ish) Web Service in Rust
by zbentley on Tuesday March 27, 2018 @06:40PM
(#16693467)
It seems like the two of you disagree fundamentally on what "asynchronous" means in this context.
https://en.wikipedia.org/wiki/Asynchrony_(computer_programmi...
Your asynchronous system can be descheduled by the OS on top of the stuff it does on its own if it runs on a preemptive multitasking OS or hypervisor, which more or less all of them do.
> And it cannot ever be faster than asynchronous, because asynchronous doesn't yield.
The asynchronous system yields doubly, it yields to its own userland scheduler/event loop and it's de-scheduled by the preemptive multitasking OS it runs on top of.