Wasmtime GitHub notifications bot (Nov 26 2025 at 05:52): Wasmtime GitHub notifications bot (Nov 26 2025 at 05:52):alexcrichton assigned dicej to issue #12092.
Wasmtime GitHub notifications bot (Nov 26 2025 at 05:52):alexcrichton opened issue #12092:
Applying this diff:
<details>
diff --git a/tests/all/component_model/async.rs b/tests/all/component_model/async.rs index b3e816c758..b1e3bf8d55 100644 --- a/tests/all/component_model/async.rs +++ b/tests/all/component_model/async.rs @@ -1,5 +1,7 @@ use crate::async_functions::{PollOnce, execute_across_threads}; use anyhow::Result; +use std::pin::Pin; +use std::task::{Context, Poll}; use wasmtime::{AsContextMut, Config, component::*}; use wasmtime::{Engine, Store, StoreContextMut, Trap}; use wasmtime_component_util::REALLOC_AND_FREE; @@ -670,3 +672,98 @@ async fn task_deletion() -> Result<()> { Ok(()) } + +#[tokio::test] +#[cfg_attr(miri, ignore)] +async fn cancel_host_future() -> Result<()> { + let mut config = Config::new(); + config.async_support(true); + config.wasm_component_model_async(true); + let engine = Engine::new(&config)?; + + let component = Component::new( + &engine, + r#" +(component + (core module $libc (memory (export "memory") 1)) + (core instance $libc (instantiate $libc)) + (core module $m + (import "" "future.read" (func $future.read (param i32 i32) (result i32))) + (import "" "future.cancel-read" (func $future.cancel-read (param i32) (result i32))) + (memory (export "memory") 1) + + (func (export "run") (param i32) + ;; read/cancel attempt 1 + (call $future.read (local.get 0) (i32.const 100)) + i32.const -1 ;; BLOCKED + i32.ne + if unreachable end + + (call $future.cancel-read (local.get 0)) + i32.const 2 ;; CANCELLED + i32.ne + if unreachable end + + ;; read/cancel attempt 2 + (call $future.read (local.get 0) (i32.const 100)) + i32.const -1 ;; BLOCKED + i32.ne + if unreachable end + + (call $future.cancel-read (local.get 0)) + i32.const 2 ;; CANCELLED + i32.ne + if unreachable end + ) + ) + + (type $f (future u32)) + (core func $future.read (canon future.read $f async (memory $libc "memory"))) + (core func $future.cancel-read (canon future.cancel-read $f)) + + (core instance $i (instantiate $m + (with "" (instance + (export "future.read" (func $future.read)) + (export "future.cancel-read" (func $future.cancel-read)) + )) + )) + + (func (export "run") (param "f" $f) + (canon lift + (core func $i "run") + (memory $libc "memory") + ) + ) +) + "#, + )?; + + let mut store = Store::new(&engine, ()); + let instance = Linker::new(&engine) + .instantiate_async(&mut store, &component) + .await?; + let func = instance.get_typed_func::<(FutureReader<u32>,), ()>(&mut store, "run")?; + let reader = FutureReader::new(&mut store, MyFutureReader); + func.call_async(&mut store, (reader,)).await?; + + return Ok(()); + + struct MyFutureReader; + + impl FutureProducer<()> for MyFutureReader { + type Item = u32; + + fn poll_produce( + self: Pin<&mut Self>, + _cx: &mut Context<'_>, + _store: StoreContextMut<()>, + finish: bool, + ) -> Poll<Result<Option<Self::Item>>> { + if finish { + Poll::Ready(Ok(None)) + } else { + Poll::Pending + } + } + } +}</details>
currently fails with:
$ cargo test --test all cancel_host_future Finished `test` profile [unoptimized + debuginfo] target(s) in 0.10s Running tests/all/main.rs (target/x86_64-unknown-linux-gnu/debug/deps/all-e79d98f84418a5e1) running 1 test test component_model::r#async::cancel_host_future ... FAILED failures: ---- component_model::r#async::cancel_host_future stdout ---- Error: error while executing at wasm backtrace: 0: 0xba - m!<wasm function 2> Caused by: cannot read from future after previous read succeeded failures: component_model::r#async::cancel_host_future test result: FAILED. 0 passed; 1 failed; 0 ignored; 0 measured; 982 filtered out; finished in 0.01s error: test failed, to rerun pass `--test all`where the second
future.readcall is what's failing here
Wasmtime GitHub notifications bot (Nov 26 2025 at 05:52):alexcrichton added the wasm-proposal:component-model-async label to Issue #12092.
Wasmtime GitHub notifications bot (Nov 26 2025 at 05:52):alexcrichton added the fuzz-bug label to Issue #12092.
Wasmtime GitHub notifications bot (Nov 26 2025 at 16:34):alexcrichton closed issue #12092:
Applying this diff:
<details>
diff --git a/tests/all/component_model/async.rs b/tests/all/component_model/async.rs index b3e816c758..b1e3bf8d55 100644 --- a/tests/all/component_model/async.rs +++ b/tests/all/component_model/async.rs @@ -1,5 +1,7 @@ use crate::async_functions::{PollOnce, execute_across_threads}; use anyhow::Result; +use std::pin::Pin; +use std::task::{Context, Poll}; use wasmtime::{AsContextMut, Config, component::*}; use wasmtime::{Engine, Store, StoreContextMut, Trap}; use wasmtime_component_util::REALLOC_AND_FREE; @@ -670,3 +672,98 @@ async fn task_deletion() -> Result<()> { Ok(()) } + +#[tokio::test] +#[cfg_attr(miri, ignore)] +async fn cancel_host_future() -> Result<()> { + let mut config = Config::new(); + config.async_support(true); + config.wasm_component_model_async(true); + let engine = Engine::new(&config)?; + + let component = Component::new( + &engine, + r#" +(component + (core module $libc (memory (export "memory") 1)) + (core instance $libc (instantiate $libc)) + (core module $m + (import "" "future.read" (func $future.read (param i32 i32) (result i32))) + (import "" "future.cancel-read" (func $future.cancel-read (param i32) (result i32))) + (memory (export "memory") 1) + + (func (export "run") (param i32) + ;; read/cancel attempt 1 + (call $future.read (local.get 0) (i32.const 100)) + i32.const -1 ;; BLOCKED + i32.ne + if unreachable end + + (call $future.cancel-read (local.get 0)) + i32.const 2 ;; CANCELLED + i32.ne + if unreachable end + + ;; read/cancel attempt 2 + (call $future.read (local.get 0) (i32.const 100)) + i32.const -1 ;; BLOCKED + i32.ne + if unreachable end + + (call $future.cancel-read (local.get 0)) + i32.const 2 ;; CANCELLED + i32.ne + if unreachable end + ) + ) + + (type $f (future u32)) + (core func $future.read (canon future.read $f async (memory $libc "memory"))) + (core func $future.cancel-read (canon future.cancel-read $f)) + + (core instance $i (instantiate $m + (with "" (instance + (export "future.read" (func $future.read)) + (export "future.cancel-read" (func $future.cancel-read)) + )) + )) + + (func (export "run") (param "f" $f) + (canon lift + (core func $i "run") + (memory $libc "memory") + ) + ) +) + "#, + )?; + + let mut store = Store::new(&engine, ()); + let instance = Linker::new(&engine) + .instantiate_async(&mut store, &component) + .await?; + let func = instance.get_typed_func::<(FutureReader<u32>,), ()>(&mut store, "run")?; + let reader = FutureReader::new(&mut store, MyFutureReader); + func.call_async(&mut store, (reader,)).await?; + + return Ok(()); + + struct MyFutureReader; + + impl FutureProducer<()> for MyFutureReader { + type Item = u32; + + fn poll_produce( + self: Pin<&mut Self>, + _cx: &mut Context<'_>, + _store: StoreContextMut<()>, + finish: bool, + ) -> Poll<Result<Option<Self::Item>>> { + if finish { + Poll::Ready(Ok(None)) + } else { + Poll::Pending + } + } + } +}</details>
currently fails with:
$ cargo test --test all cancel_host_future Finished `test` profile [unoptimized + debuginfo] target(s) in 0.10s Running tests/all/main.rs (target/x86_64-unknown-linux-gnu/debug/deps/all-e79d98f84418a5e1) running 1 test test component_model::r#async::cancel_host_future ... FAILED failures: ---- component_model::r#async::cancel_host_future stdout ---- Error: error while executing at wasm backtrace: 0: 0xba - m!<wasm function 2> Caused by: cannot read from future after previous read succeeded failures: component_model::r#async::cancel_host_future test result: FAILED. 0 passed; 1 failed; 0 ignored; 0 measured; 982 filtered out; finished in 0.01s error: test failed, to rerun pass `--test all`where the second
future.readcall is what's failing here
Last updated: Dec 06 2025 at 06:05 UTC