Struct basic_allocator::blocklist::BlockList

pub struct BlockList { /* fields omitted */ }

A BlockList is a linked list of "free" blocks in memory.

Each block should be considered "owned" by the BlockList when inserted, and do not hold any sort of payload. They may be split or merged internally.

In this module, thse memory blocks represent freed memory that has not been returned to the OS, and provide a "pool" of available memory for reuse by the allocator.

It maintains a few internal invariants:

• Each block should link to the next, with the last one linking to null.
• Each block should have a pointer < next.
• No two blocks should be precisely adjacent (those should be automatically merged on insertion).

Implementations

impl BlockList

pub const fn header_size() -> usize

pub fn iter(&self) -> BlockIterⓘ

Important traits for BlockIter<'list>

impl<'list> Iterator for BlockIter<'list> type Item = &'list FreeBlock;

pub fn apply<C, R, F: FnMut(&mut FreeBlock, C) -> ApplyState<C, R>>(
    &mut self,
    start: C,
    pred: F
) -> ApplyState<C, R>

Iterate through the blocklist, and apply a function at each step. This allows mutating the list as it is traversed, and replaces IterMut, which cannot be used due to the links between blocks.

Note that any changes to any block's "next" will be followed at the next iteration.

pub fn stats(&self) -> (Validity, Stats)

Check current size of the list, and whether its valid.

pub fn pop_size(&mut self, size: usize) -> Option<Range<NonNull<u8>>>

Find and remove a chunk of size 'size' from the linked list

pub unsafe fn add_block(&mut self, ptr: NonNull<u8>, size: usize)

Add a block to the linked list. Takes ownership of ptr.

Safety

ptr must point to valid, reachable memory of at least size, and ownership of that memory must be transferred to BlockList when this method is called.

pub fn len(&self) -> usize

pub fn is_empty(&self) -> bool

Trait Implementations

impl Default for BlockList

fn default() -> Self

Returns the "default value" for a type.

impl Display for BlockList

fn fmt(&self, f: &mut Formatter) -> Result

Formats the value using the given formatter.

impl<'list> IntoIterator for &'list BlockList

type Item = &'list FreeBlock

The type of the elements being iterated over.

type IntoIter = BlockIter<'list>

Which kind of iterator are we turning this into?

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.