Re:Fuchsia is not Linux
by zaarn on Friday April 13, 2018 @02:35AM
(#16827574)
Linux is async throughout since it can do task switching on blocking.
You're not the only task running.
Or do you expect Linux to pause the system when you read a file until the DMA is answered?
Linux itself is fully async, anything blocking (even interrupts to some extend) will be scheduled to resume when the reason it blocked is gone or alternatively check back regularly to resume.
A program running on Linux can do a lot of things async as mentioned via POSIX AIO. It's not impossible, go seems to do fine on that front too (goroutines are put to sleep when doing blocking syscalls unless you do RawSyscall).
The conclusion that lack of 100% asynchronity means it can't be properly concurrent is also wrong. As evident that sending something to disk also doesn't not halt the kernel.
You're not the only task running.
Or do you expect Linux to pause the system when you read a file until the DMA is answered?
Linux itself is fully async, anything blocking (even interrupts to some extend) will be scheduled to resume when the reason it blocked is gone or alternatively check back regularly to resume.
A program running on Linux can do a lot of things async as mentioned via POSIX AIO. It's not impossible, go seems to do fine on that front too (goroutines are put to sleep when doing blocking syscalls unless you do RawSyscall).
The conclusion that lack of 100% asynchronity means it can't be properly concurrent is also wrong. As evident that sending something to disk also doesn't not halt the kernel.