Oh, my GoD! Goroutines on D

[Bienlein]

On Saturday, 16 May 2020 at 20:06:47 UTC, mw wrote:
> On Tuesday, 29 March 2016 at 17:10:02 UTC, Jin wrote:
>>
>> http://wiki.dlang.org/Go_to_D
>
> Any performance comparison with Go? esp. in real word scenario?
>
> Can it easily handle hundreds of (go)routines?

Go can easily have some ten thousand green threads. I once did a 
test run to see how many. On a 4 GB machine 80.000 green threads 
aka goroutines were created till out of memory occured.

Communicating sequential processes as in Go relies on being able 
to create a large amount of threads. With a paradigm of threads 
doing blocking takes on channels any application would otherwise 
quickly run out of threads. In D something similar could be done 
using fibers. Using fibers is also the approach chosen in Java 
extending the JVM to have CSP-stye concurrency as in Go, see 
https://www.youtube.com/watch?v=lIq-x_iI-kc

Then you also need continuations. Lets say inside a function a 
blocking take is done on two channels in a row. The first channel 
has some input, the next one has not. In between comes a context 
switch. When switching back the value taken from the first 
channel has to be put back into the context. This is why 
continuations are needed.

Really nice work! Please keep it going :-)