Struct wiggle::wasmtime::WasmtimeGuestMemory

pub struct WasmtimeGuestMemory<'a> { /* fields omitted */ }

Lightweight wasmtime::Memory wrapper so we can implement the wiggle::GuestMemory trait on it.

Implementations

impl<'a> WasmtimeGuestMemory<'a>

pub fn new(mem: &'a mut [u8]) -> Self

Trait Implementations

impl GuestMemory for WasmtimeGuestMemory<'_>

fn base(&self) -> (*mut u8, u32)

Returns the base allocation of this guest memory, located in host memory.

fn has_outstanding_borrows(&self) -> bool

Indicates whether any outstanding borrows are known to the GuestMemory. This function must be false in order for it to be safe to recursively call into a WebAssembly module, or to manipulate the WebAssembly memory by any other means.

fn is_shared_borrowed(&self, r: Region) -> bool

Check if a region of linear memory has any shared borrows.

fn is_mut_borrowed(&self, r: Region) -> bool

Check if a region of linear memory is exclusively borrowed. This is called during any GuestPtr::read or GuestPtr::write operation to ensure that wiggle is not reading or writing a region of memory which Rust believes it has exclusive access to.

fn shared_borrow(&self, r: Region) -> Result<BorrowHandle, GuestError>

Shared borrow a region of linear memory. This is used when constructing a GuestSlice or GuestStr. Those types will give Rust & (shared reference) access to the region of linear memory.

fn mut_borrow(&self, r: Region) -> Result<BorrowHandle, GuestError>

Exclusively borrow a region of linear memory. This is used when constructing a GuestSliceMut or GuestStrMut. Those types will give Rust &mut access to the region of linear memory, therefore, the GuestMemory impl must guarantee that at most one BorrowHandle is issued to a given region, GuestMemory::has_outstanding_borrows is true for the duration of the borrow, and that GuestMemory::is_mut_borrowed of any overlapping region is false for the duration of the borrow.

fn shared_unborrow(&self, h: BorrowHandle)

Unborrow a previously borrowed shared region. As long as GuestSlice and GuestStr are implemented correctly, a shared BorrowHandle should only be unborrowed once.

fn mut_unborrow(&self, h: BorrowHandle)

Unborrow a previously borrowed mutable region. As long as GuestSliceMut and GuestStrMut are implemented correctly, a mut BorrowHandle should only be unborrowed once.

fn validate_size_align(
    &self,
    offset: u32,
    align: usize,
    len: u32
) -> Result<*mut u8, GuestError>

Validates a guest-relative pointer given various attributes, and returns the corresponding host pointer.

fn ptr<'a, T>(&'a self, offset: T::Pointer) -> GuestPtr<'a, T> where
    Self: Sized,
    T: ?Sized + Pointee, 

Convenience method for creating a GuestPtr at a particular offset.