Struct wasm_tracing_allocator::WasmTracingAllocator

pub struct WasmTracingAllocator<A>(pub A)
 where
    A: GlobalAlloc;

A global allocator that traces the Wasm module's allocations and deallocations.

It wraps some global allocator A that actually implements the allocation and deallocation, and inserts its tracing after each invocation.

Example

Just give it the global allocator A to wrap, and add the #[global_allocator] attribute. The module level documentation has an example of wrapping the default system allocator. Here is an example of wrapping wee_alloc:

// src/lib.rs

use wasm_tracing_allocator::WasmTracingAllocator;
use wee_alloc::WeeAlloc;

#[global_allocator]
static GLOBAL_ALLOCATOR: WasmTracingAllocator<WeeAlloc> =
    WasmTracingAllocator(WeeAlloc::INIT);

Trait Implementations

impl<A: Debug> Debug for WasmTracingAllocator<A> where
    A: GlobalAlloc, 

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

Formats the value using the given formatter.

impl<A> GlobalAlloc for WasmTracingAllocator<A> where
    A: GlobalAlloc, 

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

Allocate memory as described by the given layout.

unsafe fn dealloc(&self, pointer: *mut u8, layout: Layout)

Deallocate 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,
    old_pointer: *mut u8,
    layout: Layout,
    new_size: usize
) -> *mut u8

Shrink or grow a block of memory to the given new_size. The block is described by the given ptr pointer and layout.