GC implementation

[Sean Kelly]

Georg Wrede wrote:
> 
> Would it be too hard to have the compiler automatically mark "obvious 
> data" as non-scannable?
> 
> I mean, stuff gotten from streams or files should never contain pointers 
> anyhow. Likewise, the compiler _should_ know whether a large array 
> contains pointers or not. If not, then the entire array might be marked 
> as non-scannable.
> 
> Doing this non-pedantically might gain much speed in GC, without making 
> the program itself much slower. In other words, the compiler should not 
> bother with _every_ item known not to contain pointers, because this 
> would result in a long list of scan/no-scan areas for the GC. But if 
> there was a "lower size" or something like it, then this might actually 
> work as intended.

I think someone actually wrote a GC patch a while back that did this, so 
it's definitely possible with D as-is.  I would like to see this done in 
Phobos before 1.0, and it's on my mental to-do list for Ares as well.


Sean