Remove dedicated support for boundary constraint in heap allocator

[Sebastian Huber]

Some time ago a dedicated support for a boundary constraint was added to the first fit heap allocator. The use case for this is the libbsd (new network stack) which needs this for the bus space allocator:

​https://www.freebsd.org/cgi/man.cgi?query=bus_dma

It turned out that this feature is rarely used. It makes the first fit heap allocator implementation considerably more complex. It is also not a standard allocator feature which makes it more difficult to replace the first fit heap allocator with something else, e.g. TLSF.

The boundary constraint can be also satisfied by an allocator which supports only the alignment constraint via:

if (boundary > alignment) {
	assert(alignment == 0 || boundary % alignment == 0);
	alignment = boundary;
}

[Chris Johns]

TLSF provides tlsf_memalign(). I think this ticket can be closed and the requirement for an aligned allocation call for any new allocators be made.

[Sebastian Huber]

This ticket refers to the first fit allocator. Removing the boundary support would simplify the implementation a bit. We should replace the first fit allocator with TLSF, so this ticket is probably obsolete.

[Chris Johns]

Replying to Sebastian Huber:

This ticket refers to the first fit allocator. Removing the boundary support would simplify the implementation a bit. We should replace the first fit allocator with TLSF, so this ticket is probably obsolete.

I agree and thanks and that was my view. Please close if you think it would be covered in the other ticket.