On 5/26/2011 12:31 AM, Andrei Alexandrescu wrote:
Right now the review queue is empty, and I wonder whether there's some
new stuff ready in people's pipeline. At some point I recall there were
even complaints about the review cycle being too slow!
So, please chime in with components that are ready for the review process.
Thanks,
Andrei
Well, I had put TempAlloc up for review but it didn't seem to actually
get reviewed. TempAlloc is a thread-local segmented stack memory
allocator (defined/detailed in the docs) for efficiently allocating
temporary buffers, matrices, etc. It has the following advantages
compared to allocation on the call stack:
1. Pointers to memory allocated on the TempAlloc stack are still valid
when the function they were allocated from returns. Functions can be
written to create and return data structures on the TempAlloc stack.
2. Since it is a segmented stack, large allocations can be performed
with no danger of stack overflow errors.
It has the following advantages compared to heap allocation:
1. Both allocation and deallocation are extremely fast. Most allocations
consist of verifying enough space is available, incrementing a pointer
and a performing a few cheap bookkeeping operations. Most deallocations
consist decrementing a pointer and performing a few cheap bookkeeping
operations.
2. The segmented stack is thread-local, so synchronization is only
needed when a segment needs to be allocated or freed.
3. Fragmentation is not an issue when allocating memory on the TempAlloc
stack, though it can be an issue when trying to allocate a new segment.
It'd be nice to get this in the next release b/c SciD, which is being
worked on extensively for GSoC, uses it and Don said he wanted to use it
in BigInt.
Code:
https://github.com/dsimcha/TempAlloc/blob/master/tempalloc.d
Docs:
http://cis.jhu.edu/~dsimcha/d/phobos/core_tempalloc.html
