Fe Allocator

This project is an attempt to replicate Tiny Alloc in the EVM

Public interface

For the initial stage, the public interface of the memory pool class will include the following:

- Allocate

Returns a pointer (as a u256) to address in heap space or 0 if allocation failed

- Reallocate

Attempts to adjust the size of the block at the given allocated address to new size or if not possible, attempt to allocate a new block and copies contents of current block (if successful, automatically frees old address). Returns new address if successful or else 0.

- Free

Releases given address or array view back into the pool. Returns true if successful.

- freeAll

Frees all allocated blocks, essentially resets the pool.

- listStats

Returns pool statistics

Coalescing && Splitting

Further optimizations that are being performed under the hood in order to preserve memory space

- Coalescing

The allocator supports coalescing of free memory blocks to minimize fragmentation of the managed address space.

- Splitting

In order to avoid unnecessary growing of the heap top, the allocator can split existing free blocks if the user requests allocating a smaller size than that of a suitable free block available.

Memory layout

Memory pool state

- Free

Pointer to first free block header

- Used

Pointer to first used block header

- Top

Address of next new block header

- End

End address of managed region

- minSplit

Minimum block size allowed for splitting

Single memory block state

- Size

The size of the block (inluding header & padding)

- Next

Pointer to next block of the same type (free, used)

- Data

Data to be held inside the block (depending on how this project pans out, this can be a memory buffer)

Note

this project is still a WIP, the initial stage is not complete