Struct wasmi::FuncInstance
source · pub struct FuncInstance(_);Expand description
Runtime representation of a function.
Functions are the unit of organization of code in WebAssembly. Each function takes a sequence of values as parameters and either optionally return a value or trap. Functions can call other function including itself (i.e recursive calls are allowed) and imported functions (i.e functions defined in another module or by the host environment).
Functions can be defined either:
- by a wasm module,
- by the host environment and passed to a wasm module as an import.
See more in
Externals.
Implementations§
source§impl FuncInstance
impl FuncInstance
sourcepub fn alloc_host(signature: Signature, host_func_index: usize) -> FuncRef
pub fn alloc_host(signature: Signature, host_func_index: usize) -> FuncRef
Allocate a function instance for a host function.
When this function instance will be called by the wasm code,
the instance of Externals will be invoked by calling invoke_index
with specified host_func_index here.
This call will be made with the signature provided here.
sourcepub fn signature(&self) -> &Signature
pub fn signature(&self) -> &Signature
Returns signature of this function instance.
This function instance can only be called with matching signatures.
sourcepub fn invoke<E: Externals>(
func: &FuncRef,
args: &[RuntimeValue],
externals: &mut E
) -> Result<Option<RuntimeValue>, Trap>
pub fn invoke<E: Externals>(
func: &FuncRef,
args: &[RuntimeValue],
externals: &mut E
) -> Result<Option<RuntimeValue>, Trap>
sourcepub fn invoke_resumable<'args>(
func: &FuncRef,
args: &'args [RuntimeValue]
) -> Result<FuncInvocation<'args>, Trap>
pub fn invoke_resumable<'args>(
func: &FuncRef,
args: &'args [RuntimeValue]
) -> Result<FuncInvocation<'args>, Trap>
Invoke the function, get a resumable handle. This handle can then be used to start_execution. If a
Host trap happens, caller can use resume_execution to feed the expected return value back in, and then
continue the execution.
This is an experimental API, and this functionality may not be available in other WebAssembly engines.
Errors
Returns Err if args types is not match function signature.