Oh, my GoD! Goroutines on D

[Jin]

On Monday, 6 January 2025 at 10:15:39 UTC, Jin wrote:
> I found a bug. I first checked if there was anything in the 
> queue, and if not, I checked if the queue was finalized. 
> Sometimes the queue would fill up between these two steps and I 
> would lose data. I moved the finalization check to the 
> beginning and now everything is stable.

I looked into the core.atomic code and was very disappointed. I 
expected to see memory barriers (necessary for wait-free), but I 
saw a CAS-spinlock there (and this is lock-free):

```d
asm pure nothrow @nogc @trusted
{
       naked;
       push RBX;
       mov R8, RDX;
       mov RAX, [RDX];
       mov RDX, 8[RDX];
       mov RBX, [RCX];
       mov RCX, 8[RCX];
   L1: lock; cmpxchg16b [R8];
       jne L1;
       pop RBX;
       ret;
}
```