Question

I’m doing some graphics programming and I’m using Vertex pools. I’d like to be able to allocate a range out of the pool and use this for drawing.

Whats different from the solution I need than from a C allocator is that I never call malloc. Instead I preallocate the array and then need an object that wraps that up and keeps track of the free space and allocates a range (a pair of begin/end pointers) from the allocation I pass in.

Much thanks.

Answer 1

in general: you’re looking for a memory mangager, which uses a (see wikipedia) memory pool (like the boost::pool as answered by TokenMacGuy). They come in many flavours. Important considerations:

• block size (fixed or variable; number of different block sizes; can the block size usage be predicted (statistically)?
• efficiency (some managers have 2^n block sizes, i.e. for use in network stacks where they search for best fit block; very good performance and no fragementation at the cost of wasting memory)
• administration overhead (I presume that you’ll have many, very small blocks; so the number of ints and pointers maintainted by the memory manager is significant for efficiency)

In case of boost::pool, I think the simple segragated storage is worth a look.
It will allow you to configure a memory pool with many different block sizes for which a best-match is searched for.