Struct buddy_system_allocator::Heap

pub struct Heap { /* fields omitted */ }

A heap that uses buddy system

Usage

Create a heap and add a memory region to it:

use buddy_system_allocator::*;
let mut heap = Heap::empty();
unsafe {
    heap.init(begin, size);
    // or
    heap.add_to_heap(begin, end);
}

Methods

impl Heap

pub const fn new() -> Self

Create an empty heap

pub const fn empty() -> Self

Create an empty heap

pub unsafe fn add_to_heap(&mut self, start: usize, end: usize)

Add a range of memory [start, end) to the heap

pub unsafe fn init(&mut self, start: usize, size: usize)

Add a range of memory [start, end) to the heap

pub fn alloc(&mut self, layout: Layout) -> Result<NonNull<u8>, AllocErr>

Alloc a range of memory from the heap satifying layout requirements

pub fn dealloc(&mut self, ptr: NonNull<u8>, layout: Layout)

Dealloc a range of memory from the heap

Trait Implementations

impl Debug for Heap

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

Formats the value using the given formatter.

impl Alloc for Heap

unsafe fn alloc(&mut self, layout: Layout) -> Result<NonNull<u8>, AllocErr>

🔬 This is a nightly-only experimental API. (allocator_api)

Returns a pointer meeting the size and alignment guarantees of layout.

unsafe fn dealloc(&mut self, ptr: NonNull<u8>, layout: Layout)

🔬 This is a nightly-only experimental API. (allocator_api)

Deallocate the memory referenced by ptr.

fn usable_size(&self, layout: &Layout) -> (usize, usize)

🔬 This is a nightly-only experimental API. (allocator_api)

Returns bounds on the guaranteed usable size of a successful allocation created with the specified layout.

unsafe fn realloc(
    &mut self,
    ptr: NonNull<u8>,
    layout: Layout,
    new_size: usize
) -> Result<NonNull<u8>, AllocErr>

🔬 This is a nightly-only experimental API. (allocator_api)

Returns a pointer suitable for holding data described by a new layout with layout’s alignment and a size given by new_size. To accomplish this, this may extend or shrink the allocation referenced by ptr to fit the new layout.

unsafe fn alloc_zeroed(
    &mut self,
    layout: Layout
) -> Result<NonNull<u8>, AllocErr>

🔬 This is a nightly-only experimental API. (allocator_api)

Behaves like alloc, but also ensures that the contents are set to zero before being returned.

unsafe fn alloc_excess(&mut self, layout: Layout) -> Result<Excess, AllocErr>

🔬 This is a nightly-only experimental API. (allocator_api)

Behaves like alloc, but also returns the whole size of the returned block. For some layout inputs, like arrays, this may include extra storage usable for additional data.

unsafe fn realloc_excess(
    &mut self,
    ptr: NonNull<u8>,
    layout: Layout,
    new_size: usize
) -> Result<Excess, AllocErr>

🔬 This is a nightly-only experimental API. (allocator_api)

Behaves like realloc, but also returns the whole size of the returned block. For some layout inputs, like arrays, this may include extra storage usable for additional data.

unsafe fn grow_in_place(
    &mut self,
    ptr: NonNull<u8>,
    layout: Layout,
    new_size: usize
) -> Result<(), CannotReallocInPlace>

🔬 This is a nightly-only experimental API. (allocator_api)

Attempts to extend the allocation referenced by ptr to fit new_size.

unsafe fn shrink_in_place(
    &mut self,
    ptr: NonNull<u8>,
    layout: Layout,
    new_size: usize
) -> Result<(), CannotReallocInPlace>

🔬 This is a nightly-only experimental API. (allocator_api)

Attempts to shrink the allocation referenced by ptr to fit new_size.

fn alloc_one<T>(&mut self) -> Result<NonNull<T>, AllocErr>

🔬 This is a nightly-only experimental API. (allocator_api)

Allocates a block suitable for holding an instance of T.

unsafe fn dealloc_one<T>(&mut self, ptr: NonNull<T>)

🔬 This is a nightly-only experimental API. (allocator_api)

Deallocates a block suitable for holding an instance of T.

fn alloc_array<T>(&mut self, n: usize) -> Result<NonNull<T>, AllocErr>

🔬 This is a nightly-only experimental API. (allocator_api)

Allocates a block suitable for holding n instances of T.

unsafe fn realloc_array<T>(
    &mut self,
    ptr: NonNull<T>,
    n_old: usize,
    n_new: usize
) -> Result<NonNull<T>, AllocErr>

🔬 This is a nightly-only experimental API. (allocator_api)

Reallocates a block previously suitable for holding n_old instances of T, returning a block suitable for holding n_new instances of T.

unsafe fn dealloc_array<T>(
    &mut self,
    ptr: NonNull<T>,
    n: usize
) -> Result<(), AllocErr>

🔬 This is a nightly-only experimental API. (allocator_api)

Deallocates a block suitable for holding n instances of T.