But I prefer the wasmtime webassembly component model approach these days.
Built a plugin system with that, which has one major upside in my book:
No stringly function invocation.
Instead of run_function("my-function-with-typo") I have a instantiated_plugin.my_function call, where I can be sure that if the plugin has been instantiated, it does have that function.
I manually compile a plugin and in my system I can "refresh" a plugin and even say "activate version 1.1 of the plugin" or "activate version 1.2" of the plugin etc.
But that's something I had to build myself and is not built into wasmtime itself.
I assume you wouldn't ship the whole plugin runtime for each plugin that wants to host another plugin?!
Shipping the runtime is another good option, because it means you don't have to worry about runtime versioning.
match Plugin::instantiate_async(&mut store, &component, &linker).await {
Ok(plugin) => {
match plugin
.plugin_guest_oncallback()
.call_ontimedcallback(&mut store, &callback_name)
.await
{
Ok(()) => debug!("Successfully called oncallback for {plugin_path:?}"),
Err(e) => warn!("Failed to call oncallback for {plugin_path:?}: {e}"),
}
}
Err(e) => {
error!("Failed to call oncallback for {plugin_path:?}!: {e}");
}
}
If of course I put a wasm file in the plugin folder that doesn't adhere to that definition, that wasm file isn't considered a plugin.
To elaborate a bit further: wasmtime ships a [bindings generator proc macro](https://docs.wasmtime.dev/api/wasmtime/component/macro.bindg...) that takes a wit and emits all the code wasmtime requires to load a component and use it through those wit interfaces. It doesn’t just check the loaded component for the string names present: it also type checks that all of the types in the component match those given by the wit. So, when you call the export functions above, you can be quite sure all of the bindings for their arguments, and any functions and types they import, all match up to Rust types. And your component can be implemented in any language!
More info: https://github.com/bytecodealliance/wasmtime/issues/8036 Several folks have volunteered work on the C bindings over the last year or two, with this contributor making progress most recently: https://github.com/bytecodealliance/wasmtime/pulls?q=is%3Apr...
Next up I'm hoping to integrate this stuff into a game so you can have hot-reloadable game logic, with the potential for loading and sandboxing user-created mods.