Struct wasmtime_jit::CodeMemory

pub struct CodeMemory { /* private fields */ }

Management of executable memory within a MmapVec

This type consumes ownership of a region of memory and will manage the executable permissions of the contained JIT code as necessary.

Implementations

impl CodeMemory

pub fn new(mmap: MmapVec) -> Result<Self>

Creates a new CodeMemory by taking ownership of the provided MmapVec.

The returned CodeMemory manages the internal MmapVec and the publish method is used to actually make the memory executable.

pub fn mmap(&self) -> &MmapVec

Returns a reference to the underlying MmapVec this memory owns.

pub fn text(&self) -> &[u8]

Returns the contents of the text section of the ELF executable this represents.

pub fn dwarf(&self) -> &[u8]

Returns the contents of the ELF_WASMTIME_DWARF section.

pub fn func_name_data(&self) -> &[u8]

Returns the data in the ELF_NAME_DATA section.

pub fn wasm_data(&self) -> &[u8]

Returns the concatenated list of all data associated with this wasm module.

This is used for initialization of memories and all data ranges stored in a Module are relative to the slice returned here.

pub fn address_map_data(&self) -> &[u8]

Returns the encoded address map section used to pass to wasmtime_environ::lookup_file_pos.

pub fn wasmtime_info(&self) -> &[u8]

Returns the contents of the ELF_WASMTIME_INFO section, or an empty slice if it wasn’t found.

pub fn trap_data(&self) -> &[u8]

Returns the contents of the ELF_WASMTIME_TRAPS section, or an empty slice if it wasn’t found.

pub unsafe fn vmtrampoline(&self, loc: FunctionLoc) -> VMTrampoline

Returns a VMTrampoline function pointer for the given function in the text section.

Unsafety

This function is unsafe as there’s no guarantee that the returned function pointer is valid.

pub fn publish(&mut self) -> Result<()>

Publishes the internal ELF image to be ready for execution.

This method can only be called once and will panic if called twice. This will parse the ELF image from the original MmapVec and do everything necessary to get it ready for execution, including:

• Change page protections from read/write to read/execute.
• Register unwinding information with the OS

After this function executes all JIT code should be ready to execute.

Trait Implementations

impl Drop for CodeMemory

fn drop(&mut self)

Executes the destructor for this type.