[xmlp] the recent garbage collector performance improvements

[bearophile]

Richard Webb:

> Parsing the file with DMD 2.057 takes ~25 seconds
> 
> Parsing the file with DMD 2.058(Git) takes ~6.1 seconds
> 
> Parsing the file with DMD 2.058, with the GC disabled during the 
> LoadFile call, takes ~2.2 seconds.
> 
> 
> For comparison, MSXML6 takes 1.6 seconds to load the same file.

Not too much time ago Python devs have added an heuristic to the Python GC (that is a reference counter + cycle breaker), it "switches off" if it detects the program is allocating many items in a short time. Is it possible to add something similar to the D GC?

Bye,
bearophile