Common allocation sizes for Lua

[Thomas Harning <harningt@...>]

Just wondering... are there any common allocation sizes for Lua that  
could perhaps take advantage of a memory pool (like boost's.. only  
coded in C instead)?

Boost's memory pool template class has the interesting property that  
it stores the free list interleaved in the data such that you end up  
w/ structures like this.
NEXTFREE -> A
A FREE->B
B FREE->D
C DATA
D FREE->NULL (requires another memory block)
E DATA
F DATA

Allocating requires simple ptr arithmetic that can be carried over  
such that multiple items can be allocated to handle arrays of data  
that are larger than a unit size.

Example Malloc:

ret = *nextfree; // ret = A
nextfree = *ret; // nextfree = B
return ret

Example free (non-ordered... ordered would be used if you want to do  
arrays of data w/ O(N) rather than O(N^2) or high fail-rate
//freed = A
*freed = *nextfree; // A => B
nextfree = freed;   // nextfree = A


Has anybody seen any library like this already for C?  I've generally  
only seen linked-list style implementations that require separate  
storage.

Also... has anybody seen a way to calculate the LCM at compile-time  
for C?  This is the way that the boost pool gets its allocation unit- 
size to get a safe alignment...
At compile-time, i suppose a union w/  { void*, DATATYPE, size_t }  /*  
size_t for the end of the structure to handle linking to the next  
major block */ would get me proper alignment right... run-time would  
require runtime LCM anyways.....

To see what I'm looking at as theory/impl reference:
http://www.boost.org/doc/libs/1_36_0/libs/pool/doc/concepts.html
http://www.boost.org/doc/libs/1_36_0/libs/pool/doc/implementation/alignment.html