virtual-allocator
Python allocator for a virtual memory range. This package only implements the allocation of a memory range, the actual memory access must be implemented separately. So no use-after-free errors can be handled.
The allocator implements the allocate, free and resize methods which each return a new MemoryRegion object.
from virtual_allocator import AllocationPolicy, Allocator, MemoryRange
alloc = Allocator(
address=0,
size=256,
block_size=16,
alignment=32,
allocation_policy=AllocationPolicy.BEST_FIT
)
mem_ranges = [alloc.allocate(64) for _ in range(3)]
assert mem_ranges == [
MemoryRange(address=0, size=64, is_free=False, padding=0),
MemoryRange(address=64, size=64, is_free=False, padding=0),
MemoryRange(address=128, size=64, is_free=False, padding=0),
MemoryRange(address=196, size=64, is_free=True, padding=0),
]
alloc.free(mem_ranges[1])
assert mem_ranges == [
MemoryRange(address=0, size=64, is_free=False, padding=0),
MemoryRange(address=64, size=64, is_free=True, padding=0),
MemoryRange(address=128, size=64, is_free=False, padding=0),
MemoryRange(address=196, size=64, is_free=True, padding=0),
]Allocation policies
The allocator class supports two allocation policies, FIRST_FIT and BEST_FIT.
-
FIRST_FITallocation allocates new regions into the lowest free region -
BEST_FITallocation will allocate new regions into the free region which will create the smallest leftover memory range
