9364eb1d98
* Compute instance exports on demand. Instead having instances eagerly compute a Vec of Externs, and bumping the refcount for each Extern, compute Externs on demand. This also enables `Instance::get_export` to avoid doing a linear search. This also means that the closure returned by `get0` and friends now holds an `InstanceHandle` to dynamically hold the instance live rather than being scoped to a lifetime. * Compute module imports and exports on demand too. And compute Extern::ty on demand too. * Add a utility function for computing an ExternType. * Add a utility function for looking up a function's signature. * Add a utility function for computing the ValType of a Global. * Rename wasmtime_environ::Export to EntityIndex. This helps differentiate it from other Export types in the tree, and describes what it is. * Fix a typo in a comment. * Simplify module imports and exports. * Make `Instance::exports` return the export names. This significantly simplifies the public API, as it's relatively common to need the names, and this avoids the need to do a zip with `Module::exports`. This also changes `ImportType` and `ExportType` to have public members instead of private members and accessors, as I find that simplifies the usage particularly in cases where there are temporary instances. * Remove `Instance::module`. This doesn't quite remove `Instance`'s `module` member, it gets a step closer. * Use a InstanceHandle utility function. * Don't consume self in the `Func::get*` methods. Instead, just create a closure containing the instance handle and the export for them to call. * Use `ExactSizeIterator` to avoid needing separate `num_*` methods. * Rename `Extern::func()` etc. to `into_func()` etc. * Revise examples to avoid using `nth`. * Add convenience methods to instance for getting specific extern types. * Use the convenience functions in more tests and examples. * Avoid cloning strings for `ImportType` and `ExportType`. * Remove more obviated clone() calls. * Simplify `Func`'s closure state. * Make wasmtime::Export's fields private. This makes them more consistent with ExportType. * Fix compilation error. * Make a lifetime parameter explicit, and use better lifetime names. Instead of 'me, use 'instance and 'module to make it clear what the lifetime is. * More lifetime cleanups.
93 lines
2.7 KiB
Rust
93 lines
2.7 KiB
Rust
//! This is an example of working with mulit-value modules and dealing with
|
|
//! multi-value functions.
|
|
//!
|
|
//! Note that the `Func::wrap*` interfaces cannot be used to return multiple
|
|
//! values just yet, so we need to use the more dynamic `Func::new` and
|
|
//! `Func::call` methods.
|
|
|
|
// You can execute this example with `cargo run --example multi`
|
|
|
|
use anyhow::{format_err, Result};
|
|
use wasmtime::*;
|
|
|
|
fn main() -> Result<()> {
|
|
// Configure our `Store`, but be sure to use a `Config` that enables the
|
|
// wasm multi-value feature since it's not stable yet.
|
|
println!("Initializing...");
|
|
let engine = Engine::new(Config::new().wasm_multi_value(true));
|
|
let store = Store::new(&engine);
|
|
|
|
// Compile.
|
|
println!("Compiling module...");
|
|
let module = Module::from_file(&store, "examples/multi.wat")?;
|
|
|
|
// Create external print functions.
|
|
println!("Creating callback...");
|
|
let callback_type = FuncType::new(
|
|
Box::new([ValType::I32, ValType::I64]),
|
|
Box::new([ValType::I64, ValType::I32]),
|
|
);
|
|
let callback_func = Func::new(&store, callback_type, |_, args, results| {
|
|
println!("Calling back...");
|
|
println!("> {} {}", args[0].unwrap_i32(), args[1].unwrap_i64());
|
|
|
|
results[0] = Val::I64(args[1].unwrap_i64() + 1);
|
|
results[1] = Val::I32(args[0].unwrap_i32() + 1);
|
|
Ok(())
|
|
});
|
|
|
|
// Instantiate.
|
|
println!("Instantiating module...");
|
|
let instance = Instance::new(&module, &[callback_func.into()])?;
|
|
|
|
// Extract exports.
|
|
println!("Extracting export...");
|
|
let g = instance
|
|
.get_func("g")
|
|
.ok_or(format_err!("failed to find export `g`"))?;
|
|
|
|
// Call `$g`.
|
|
println!("Calling export \"g\"...");
|
|
let results = g.call(&[Val::I32(1), Val::I64(3)])?;
|
|
|
|
println!("Printing result...");
|
|
println!("> {} {}", results[0].unwrap_i64(), results[1].unwrap_i32());
|
|
|
|
assert_eq!(results[0].unwrap_i64(), 4);
|
|
assert_eq!(results[1].unwrap_i32(), 2);
|
|
|
|
// Call `$round_trip_many`.
|
|
println!("Calling export \"round_trip_many\"...");
|
|
let round_trip_many = instance
|
|
.get_func("round_trip_many")
|
|
.ok_or(format_err!("failed to find export `round_trip_many`"))?;
|
|
let args = vec![
|
|
Val::I64(0),
|
|
Val::I64(1),
|
|
Val::I64(2),
|
|
Val::I64(3),
|
|
Val::I64(4),
|
|
Val::I64(5),
|
|
Val::I64(6),
|
|
Val::I64(7),
|
|
Val::I64(8),
|
|
Val::I64(9),
|
|
];
|
|
let results = round_trip_many.call(&args)?;
|
|
|
|
println!("Printing result...");
|
|
print!(">");
|
|
for r in results.iter() {
|
|
print!(" {}", r.unwrap_i64());
|
|
}
|
|
println!();
|
|
|
|
assert_eq!(results.len(), 10);
|
|
assert!(args
|
|
.iter()
|
|
.zip(results.iter())
|
|
.all(|(a, r)| a.i64() == r.i64()));
|
|
|
|
Ok(())
|
|
}
|