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.
61 lines
2.0 KiB
Rust
61 lines
2.0 KiB
Rust
use std::sync::atomic::{AtomicUsize, Ordering::SeqCst};
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use wasmtime::*;
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#[test]
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fn host_always_has_some_stack() -> anyhow::Result<()> {
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static HITS: AtomicUsize = AtomicUsize::new(0);
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// assume hosts always have at least 512k of stack
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const HOST_STACK: usize = 512 * 1024;
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let mut store = Store::<()>::default();
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// Create a module that's infinitely recursive, but calls the host on each
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// level of wasm stack to always test how much host stack we have left.
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let module = Module::new(
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store.engine(),
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r#"
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(module
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(import "" "" (func $host))
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(func $recursive (export "foo")
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call $host
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call $recursive)
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)
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"#,
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)?;
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let func = Func::wrap(&mut store, test_host_stack);
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let instance = Instance::new(&mut store, &module, &[func.into()])?;
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let foo = instance.get_typed_func::<(), (), _>(&mut store, "foo")?;
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// Make sure that our function traps and the trap says that the call stack
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// has been exhausted.
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let trap = foo.call(&mut store, ()).unwrap_err();
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assert!(
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trap.to_string().contains("call stack exhausted"),
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"{}",
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trap.to_string()
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);
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// Additionally, however, and this is the crucial test, make sure that the
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// host function actually completed. If HITS is 1 then we entered but didn't
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// exit meaning we segfaulted while executing the host, yet still tried to
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// recover from it with longjmp.
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assert_eq!(HITS.load(SeqCst), 0);
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return Ok(());
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fn test_host_stack() {
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HITS.fetch_add(1, SeqCst);
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assert!(consume_some_stack(0, HOST_STACK) > 0);
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HITS.fetch_sub(1, SeqCst);
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}
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#[inline(never)]
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fn consume_some_stack(ptr: usize, stack: usize) -> usize {
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if stack == 0 {
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return ptr;
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}
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let mut space = [0u8; 1024];
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consume_some_stack(space.as_mut_ptr() as usize, stack.saturating_sub(1024))
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}
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}
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