fluencelabs/wasm-bindgen
1
0
Fork 0
mirror of https://github.com/fluencelabs/wasm-bindgen synced 2025-06-14 13:31:22 +00:00
Code Issues Projects Releases Wiki Activity

Changing wasm-in-wasm example to be async (#1903)

Browse Source
This commit is contained in:
Pauan
2019-12-09 18:44:49 +01:00
committed by Alex Crichton
parent 057c9157b3
commit b71b136fe8
2 changed files with 13 additions and 16 deletions
Download Patch File Download Diff File Expand all files Collapse all files

1
examples/wasm-in-wasm/Cargo.toml
View File

@ -10,3 +10,4 @@ crate-type = ["cdylib"]
[dependencies] [dependencies]
wasm-bindgen = "0.2.55" wasm-bindgen = "0.2.55"
js-sys = "0.3.32" js-sys = "0.3.32"
wasm-bindgen-futures = "0.4.5"

28
examples/wasm-in-wasm/src/lib.rs
View File

@ -1,6 +1,7 @@
use js_sys::{Function, Object, Reflect, Uint8Array, WebAssembly}; use js_sys::{Function, Object, Reflect, WebAssembly};
use wasm_bindgen::prelude::*; use wasm_bindgen::prelude::*;
use wasm_bindgen::JsCast; use wasm_bindgen::JsCast;
use wasm_bindgen_futures::{spawn_local, JsFuture};
// lifted from the `console_log` example // lifted from the `console_log` example
#[wasm_bindgen] #[wasm_bindgen]
@ -15,24 +16,12 @@ macro_rules! console_log {
const WASM: &[u8] = include_bytes!("add.wasm"); const WASM: &[u8] = include_bytes!("add.wasm");
#[wasm_bindgen(start)] async fn run_async() -> Result<(), JsValue> {
pub fn run() -> Result<(), JsValue> {
console_log!("instantiating a new wasm module directly"); console_log!("instantiating a new wasm module directly");
// Note that `Uint8Array::view` is somewhat dangerous (hence the let a = JsFuture::from(WebAssembly::instantiate_buffer(WASM, &Object::new())).await?;
// `unsafe`!). This is creating a raw view into our module's let b: WebAssembly::Instance = Reflect::get(&a, &"instance".into())?.dyn_into()?;
// `WebAssembly.Memory` buffer, but if we allocate more pages for ourself
// (aka do a memory allocation in Rust) it'll cause the buffer to change,
// causing the `Uint8Array` to be invalid.
//
// As a result, after `Uint8Array::view` we have to be very careful not to
// do any memory allocations before it's dropped.
let a = unsafe {
let array = Uint8Array::view(WASM);
WebAssembly::Module::new(array.as_ref())?
};
let b = WebAssembly::Instance::new(&a, &Object::new())?;
let c = b.exports(); let c = b.exports();
let add = Reflect::get(c.as_ref(), &"add".into())? let add = Reflect::get(c.as_ref(), &"add".into())?
@ -51,3 +40,10 @@ pub fn run() -> Result<(), JsValue> {
Ok(()) Ok(())
} }
#[wasm_bindgen(start)]
pub fn run() {
spawn_local(async {
run_async().await.unwrap_throw();
});
}