wasmtime::Instance Class Reference

A WebAssembly instance. More...

#include <wasmtime.hh>

Public Member Functions
	Instance (wasmtime_instance_t instance)
	Creates a new instance from the raw underlying C API representation.
std::optional< Extern >	get (Store::Context cx, std::string_view name)
	Load an instance's export by name. More...
std::optional< std::pair< std::string_view, Extern > >	get (Store::Context cx, size_t idx)
	Load an instance's export by index. More...

Static Public Member Functions
static TrapResult< Instance >	create (Store::Context cx, const Module &m, const std::vector< Extern > &imports)
	Instantiates the module m with the provided imports More...

Detailed Description

A WebAssembly instance.

This class represents a WebAssembly instance, created by instantiating a module. An instance is the collection of items exported by the module, which can be accessed through the Store that owns the instance.

Note that this type does not itself own any resources. It points to resources owned within a Store and the Store must be passed in as the first argument to the functions defined on Instance. Note that if the wrong Store is passed in then the process will be aborted.

Examples

externref.cc, interrupt.cc, linking.cc, and memory.cc.

Member Function Documentation

create()

static TrapResult< Instance > wasmtime::Instance::create ( Store::Context  cx, const Module &  m, const std::vector< Extern > &  imports  )

inlinestatic

Instantiates the module m with the provided imports

Parameters

cx	the store in which to instantiate the provided module
m	the module to instantiate
imports	the list of imports to use to instantiate the module

This imports parameter is expected to line up 1:1 with the imports required by the m. The type of m can be inspected to determine in which order to provide the imports. Note that this is a relatively low-level API and it's generally recommended to use Linker instead for name-based instantiation.

This function can return an error if any of the imports have the wrong type, or if the wrong number of imports is provided.

get() [1/2]

std::optional< std::pair< std::string_view, Extern > > wasmtime::Instance::get ( Store::Context  cx, size_t  idx  )

inline

Load an instance's export by index.

This function will look for the idxth export of this instance. This will return both the name of the export as well as the exported item itself.

get() [2/2]

std::optional< Extern > wasmtime::Instance::get ( Store::Context  cx, std::string_view  name  )

inline

Load an instance's export by name.

This function will look for an export named name on this instance and, if found, return it as an Extern.

Examples

externref.cc, interrupt.cc, linking.cc, and memory.cc.

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The documentation for this class was generated from the following file:

• include/wasmtime.hh