7a1b7cdf92
Implement Wasmtime's new API as designed by RFC 11. This is quite a large commit which has had lots of discussion externally, so for more information it's best to read the RFC thread and the PR thread.
34 lines
1.2 KiB
Rust
34 lines
1.2 KiB
Rust
//! Example of limiting a WebAssembly function's runtime using "fuel consumption".
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// You can execute this example with `cargo run --example fuel`
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use anyhow::Result;
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use wasmtime::*;
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fn main() -> Result<()> {
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let mut config = Config::new();
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config.consume_fuel(true);
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let engine = Engine::new(&config)?;
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let mut store = Store::new(&engine, ());
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store.add_fuel(10_000)?;
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let module = Module::from_file(store.engine(), "examples/fuel.wat")?;
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let instance = Instance::new(&mut store, &module, &[])?;
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// Invoke `fibonacci` export with higher and higher numbers until we exhaust our fuel.
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let fibonacci = instance.get_typed_func::<i32, i32, _>(&mut store, "fibonacci")?;
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for n in 1.. {
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let fuel_before = store.fuel_consumed().unwrap();
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let output = match fibonacci.call(&mut store, n) {
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Ok(v) => v,
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Err(_) => {
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println!("Exhausted fuel computing fib({})", n);
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break;
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}
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};
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let fuel_consumed = store.fuel_consumed().unwrap() - fuel_before;
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println!("fib({}) = {} [consumed {} fuel]", n, output, fuel_consumed);
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store.add_fuel(fuel_consumed)?;
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}
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Ok(())
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}
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