On 10/25/13 7:23 AM, Manu wrote:
1. I'm still sad there are no allocAligned() functions or something of
that type to request explicit alignment with allocations. I'm not sure
there is sufficient support for requesting alignment with allocations.
The set-able alignment property approach seems a little weird (and only
seemed to be supported on one allocator?).
Woke up this morning with the following idea.
1. We add two optional API functions:
void[] alignedAllocate(size_t, uint);
bool alignedReallocate(ref void[], size_t, uint);
These would satisfy aligned allocation requests. The pointer thus
allocated should be deallocated the usual way (there is no
alignedDeallocate).
2. We make alignment a statically-known enum and delete all code that
allows it to be get and set at runtime.
Consequences:
1. The API gets larger due to the two new APIs. However, that is offset
(probably more than enough) by the removal the option to set the
alignment at runtime, which currently is causing severe ripple effects.
I think the result will be a simpler overall design and implementation.
2. HeapBlock should be able to implement the two functions. All regions
should be able to implement the first.
3. Mallocator could also implement these on Posix:
http://man7.org/linux/man-pages/man3/posix_memalign.3.html. However,
Windows requires a specific call for deallocating aligned memory. To
accommodate both portably, we leave Mallocator as is and create
AlignedMallocator that uses the _aligned_* family on Windows and the
respective functions on Posix. On Windows, allocate() requests would
pass a default of platformSize (i.e. 16 I suspect) to _aligned_malloc.
Is this satisfactory for everyone?
Andrei
