Module Pool_intf

A manual memory manager for a set of mutable tuples.

A pool stores a bounded-size set of tuples, where client code is responsible for explicitly controlling when the pool allocates and frees tuples. One creates a pool of a certain capacity, which returns an empty pool that can hold that many tuples. One then uses new to allocate a tuple, which returns a Pointer.t to the tuple. One then uses get and set along with the pointer to get and set slots of the tuple. Finally, one free's a pointer to the pool's memory for a tuple, making the memory available for subsequent reuse.

The point of Pool is to allocate a single long-lived block of memory (the pool) that lives in the OCaml major heap, and then to reuse the block, rather than continually allocating blocks on the minor heap.

In typical usage, one wraps up a pool with an abstract interface, giving nice names to the tuple slots, and only exposing mutation where desired.

All the usual problems with manual memory allocation are present with pools:

  • one can mistakenly use a pointer after it is freed
  • one can mistakenly free a pointer multiple times
  • one can forget to free a pointer

There is a debugging functor, Pool.Error_check, that is useful for building pools to help debug incorrect pointer usage.


module Int63 = Core_int63
module type S = sig .. end
S is the module type for a pool.
module type Pool = sig .. end