Project Loom VirtualThreads hang

[Alan Bateman]

On 29/12/2022 22:25, robert engels wrote:
> I also found, Thread.onSpinWait().
>
> The default implementation is empty, but I wonder if there should be 
> an implementation for VThreads that functions the same as 
> Thread.yield()...

Thread.onSpinWait is for spin or busy waiting in low-level code, say 
when spinning for some variable to change. It is compiled to a pause 
instruction (or isb or the equivalent for the processor, maybe even a 
nop) so it's measured in CPU cycles. This could be a different order of 
magnitude to a Thread.yield that might be a few hundred nanoseconds in 
the best case and appropriate when there isn't any work to do and useful 
to give up the processor.  This is an area where the API docs could 
provide some guidance.

-Alan