On Thursday, 24 October 2013 at 19:53:56 UTC, Andrei Alexandrescu
wrote:
Hello,
I know it's been a long wait. Hopefully it was worth it. The
alpha release of untyped allocators is ready for tire-kicking
and a test drive.
Code:
https://github.com/andralex/phobos/blob/allocator/std/allocator.d
Dox: http://erdani.com/d/phobos-prerelease/std_allocator.html
Warning: this is alpha quality. Unit tests are thin, and there
are no benchmarks. Both would be appreciated, particularly
benchmarks to validate the gains (which I speculate can be very
sizable) of custom-built, special-purpose allocators compared
to traditional allocators.
I acknowledge I'm clearly in no position to evaluate this
design. I have been knocking around it for long enough to have
no idea how easy it is to get into it from the outside, or how
good it is. By all signs I could gather this feels like good
design, and one of the best I've ever put together. The
allocators defined have an archetypal feeling, are flexible
both statically and dynamically, and morph and combine in
infinite ways.
CAllocator and CAllocatorImpl make the link between the static
and dynamic worlds. Once an allocator is assembled out of
pieces and finely tuned, wrapping it in a dynamic API is a snap.
Please destroy! I've literally sweat as I'm sending this :o).
Andrei
Looks good at first glance. A few notes:
- GC.realloc() is nothrow, but you are still catching OOM
exception in GCAllocator.reallocate(). You don't in other methods
(e.g. allocate)
- methods aren't marked as nothrow, they probably should be
- I don't understand how UntypedAllocator.collect() works - since
it is not allowed to store any pointers in it, calling collect()
on it should just free all allocated memory, right? In this case,
it might be best to rename it. It will also be beneficial to pass
proper bitmask attribute to GC.allocate() (e.g. BlkAttr.NO_SCAN).
- Many constants are global lowercase (i.e. platformAlignment,
unbounded etc). It confused me for a bit when I was reading code
("where the hell is this variable coming from?").
Will read the rest later.
