This change brings in a new approach to managing address space.
It wraps the Pal with a power of two reservation system, that
guarantees all returned blocks are naturally aligned to their size. It
either lets the Pal perform aligned requests, or over allocates and
splits into power of two blocks.
This changes the implementation of the open enclacve pal to support
aligned allocations. This reduces the amount of memory required for
the initial reservation as the large allocator doesn't have to
overallocate to get alignment.
PALOpenEnclave object is lazily constructed. I couldn't
figure out a straight-forward way to pass the heap bounds to
the constructor of PALOpenEnclave object.
As an alternative, store the bounds in inline static variables of
the PALOpenEnclave class and set them via static setup_initial_range
function.
- two_alloc_types/alloc1.cc
Define oe_allocator_init to forward base, end values to
PALOpenEnclave::setup_inital_range
- two_alloc_types/main.cc
Use oe_allocator_init function to set up heap range.
- fixed_region/fixed_region.cc
Initialize heap range via call to PALOpenEnclave::setup_inital_range.
Signed-off-by: Anand Krishnamoorthi <anakrish@microsoft.com>
The Pal should include address.h, this was masked as other Pals included
it, but are only included for simulating OE scenarios, rather than
the actual build for OE.
If the external thread statics are used, then
we don't need to include some C++ runtime
concepts. This refactoring moves some global initialization under
conditional compilation.
The PAL API previously allowed for returning more memory than asked for.
This was when the PAL performed the alignment work, now this is done in
large alloc, so removing from the PAL.
The PAL can now advertise that it supports aligned allocation. If it
does not, then the memory provider will do the alignment for it.
This change still leaves the PAL responsible for systematic testing, but
it should now be much easier to lift that out.
This does not deallocate memory until the OS tells us that we are short
on memory, then tries to decommit all of the cached chunks (except for
the first page, used for the linked lists).
Nowhere near enough testing to commit to master yet!
