Struct Heap 

pub struct Heap { /* private fields */ }

The simplest possible heap.

Safety

Because it’s the simplest implementation, it does NOT free memory. Any memory you drop cannot be reused (it’s leaked), so avoid dropping anything whenever possible.

It is recommended that you use embedded-alloc

Implementations

impl Heap

pub const fn empty() -> Heap

Create a new UNINITIALIZED heap allocator

You must initialize this heap using the init method before using the allocator.

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

Initializes the heap

This function must be called BEFORE you run any code that makes use of the allocator.

start_addr is the address where the heap will be located.

size is the size of the heap in bytes.

Safety

Obey these or Bad Stuff will happen.

• This function must be called exactly ONCE.
• size > 0

pub fn used(&self) -> usize

Returns an estimate of the amount of bytes in use.

pub fn free(&self) -> usize

Returns an estimate of the amount of bytes available.

Trait Implementations

impl GlobalAlloc for Heap

unsafe fn alloc(&self, layout: Layout) -> *mut u8

Allocates memory as described by the given layout.

unsafe fn dealloc(&self, _ptr: *mut u8, _layout: Layout)

Deallocates the block of memory at the given ptr pointer with the given layout.

unsafe fn alloc_zeroed(&self, layout: Layout) -> *mut u8

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

unsafe fn realloc( &self, ptr: *mut u8, layout: Layout, new_size: usize, ) -> *mut u8

Shrinks or grows a block of memory to the given new_size in bytes. The block is described by the given ptr pointer and layout.