AA vs __gshared

[IchorDev]

On Friday, 28 July 2023 at 11:15:31 UTC, Steven Schveighoffer 
wrote:
> All `__gshared` does is give you storage that is accessible 
> from all threads,

"All __gshared does is give you [a live bomb, ready to go off at 
any moment]"
!!

On Friday, 28 July 2023 at 14:10:16 UTC, Kagamin wrote:
> Your error is using allocating the object with malloc. Since gc 
> doesn't see your AA, the AA is freed and you get UAF.

Friend, I think you nailed it. After adding this I haven't been 
able to reproduce the segfault again:
```d
this(long n){
	(){
		cache = new typeof(cache);
		assert(cache);
		import core.memory;
		core.memory.GC.addRoot(cast(void*)cache);
	}();
	// ...
```
It did always happen at random, so perhaps I haven't spent enough 
time testing it yet, but I've gone far longer without it 
segfaulting than ever before.