Struct EspHeap

pub struct EspHeap { /* private fields */ }

A memory allocator

In addition to what Rust’s memory allocator can do it allows to allocate memory in regions satisfying specific needs.

Implementations

impl EspHeap

pub const fn empty() -> Self

Crate a new UNINITIALIZED heap allocator

pub unsafe fn add_region(&self, region: HeapRegion)

Add a memory region to the heap

heap_bottom is a pointer to the location of the bottom of the heap.

size is the size of the heap in bytes.

You can add up to three regions per allocator.

Note that:

• Memory is allocated from the first suitable memory region first

• The heap grows “upwards”, towards larger addresses. Thus end_addr must be larger than start_addr

• The size of the heap is (end_addr as usize) - (start_addr as usize). The allocator won’t use the byte at end_addr.

Safety

• The supplied memory region must be available for the entire program (a 'static lifetime).
• The supplied memory region must be exclusively available to the heap only, no aliasing.
• size > 0.

pub fn used(&self) -> usize

Returns an estimate of the amount of bytes in use in all memory regions.

pub fn stats(&self) -> HeapStats

Return usage stats for the Heap.

Note: HeapStats directly implements [Display], so this function can be called from within println!() to pretty-print the usage of the heap.

pub fn free(&self) -> usize

Returns an estimate of the amount of bytes available.

pub fn free_caps(&self, capabilities: EnumSet<MemoryCapability>) -> usize

The free heap satisfying the given requirements

pub unsafe fn alloc_caps( &self, capabilities: EnumSet<MemoryCapability>, layout: Layout, ) -> *mut u8

Allocate memory in a region satisfying the given requirements.

Safety

This function is unsafe because undefined behavior can result if the caller does not ensure that layout has non-zero size.

The allocated block of memory may or may not be initialized.

Trait Implementations

impl GlobalAlloc for EspHeap

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.