remove CallbackCode::Poll

[dicej]

As of WebAssembly/component-model#578, that code no longer exists. Instead, we can emulate it via a combination of CallbackCode::Yield and waitable-set.poll.

I'm working on a PR to make the corresponding changes to Wasmtime, and needed this to make the tests pass.

[dicej]

wit-bindgen-go will also need to be updated. I'll do that in another PR.

[alexcrichton]

Can you look into the CI failure before merging? Looks like the C generator needs to be adjusted since some behavior changed, and it also looks like there's a panic in Wasmtime itself

[dicej]

Can you look into the CI failure before merging? Looks like the C generator needs to be adjusted since some behavior changed, and it also looks like there's a panic in Wasmtime itself

I went ahead and updated the C and Go generators, and the tests are green when I run them locally using the branch from bytecodealliance/wasmtime#12182. I suspect we'll need to get that merged before CI is green here.

[alexcrichton]

@dicej for this:

  Caused by:
      command execution failed
      command: "wasmtime" "-W" "component-model-async" "--invoke=run()" "/home/runner/work/wit-bindgen/wit-bindgen/target/artifacts/cancel-import/composed-runner.rs-test.rs.wasm"
      status: signal: 6 (SIGABRT) (core dumped)
      stdout:
        test cancelling an import in progress
        
      stderr:
        
        thread 'main' (9800) panicked at crates/wasmtime/src/runtime/component/concurrent.rs:1777:17:
        assertion failed: task.event.is_none()
        note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

that's pretty bad in that it's a build of Wasmtime today which will panic with a given input. Is that fixed by your PR to wasmtime, caused recently, and/or worth investigation?

It's a bad thing that the fuzzer I wrote isn't uncovering this since it means that it's not exploring the space well enough

[dicej]

I'll look into it.

[alexcrichton]

That panic was fixed by bytecodealliance/wasmtime#12190 and of the three remaining failures:

cancel-import

Details

------ Failure: cancel-import --------
  runner: tests/runtime-async/async/cancel-import/runner.c
  compiled runner: /home/runner/work/wit-bindgen/wit-bindgen/target/artifacts/cancel-import/runner-c.wasm
  test: tests/runtime-async/async/cancel-import/test.rs
  compiled test: /home/runner/work/wit-bindgen/wit-bindgen/target/artifacts/cancel-import/test-rust.wasm
  error: failed to run `cancel-import`
  
  Caused by:
      command execution failed
      command: "wasmtime" "-W" "component-model-async" "--invoke=run()" "/home/runner/work/wit-bindgen/wit-bindgen/target/artifacts/cancel-import/composed-runner.c-test.rs.wasm"
      status: exit status: 134
      stderr:
        Error: failed to run main module `/home/runner/work/wit-bindgen/wit-bindgen/target/artifacts/cancel-import/composed-runner.c-test.rs.wasm`
        
        Caused by:
            0: error while executing at wasm backtrace:
                   0:    0x15f - <unknown>!<wasm function 6>
                   1:   0x18a5 - runner-c.core.wasm!test_backpressure_set
                   2:   0x13de - runner-c.core.wasm!exports_runner_run
                   3:   0x18ba - runner-c.core.wasm!__wasm_export_exports_runner_run
               note: using the `WASMTIME_BACKTRACE_DETAILS=1` environment variable may show more debugging information
            1: wasm trap: wasm `unreachable` instruction executed

Details

------ Failure: cancel-import --------
  runner: tests/runtime-async/async/cancel-import/runner.rs
  compiled runner: /home/runner/work/wit-bindgen/wit-bindgen/target/artifacts/cancel-import/runner-rust.wasm
  test: tests/runtime-async/async/cancel-import/test.rs
  compiled test: /home/runner/work/wit-bindgen/wit-bindgen/target/artifacts/cancel-import/test-rust.wasm
  error: failed to run `cancel-import`
  
  Caused by:
      command execution failed
      command: "wasmtime" "-W" "component-model-async" "--invoke=run()" "/home/runner/work/wit-bindgen/wit-bindgen/target/artifacts/cancel-import/composed-runner.rs-test.rs.wasm"
      status: exit status: 134
      stdout:
        test cancelling an import in progress
        test cancelling an import before it starts
        test cancelling an import in the started state
        
      stderr:
        Error: failed to run main module `/home/runner/work/wit-bindgen/wit-bindgen/target/artifacts/cancel-import/composed-runner.rs-test.rs.wasm`
        
        Caused by:
            0: error while executing at wasm backtrace:
                   0:    0x15f - <unknown>!<wasm function 6>
                   1:   0xa38d - runner-rust.core.wasm!runner::my::test::i::backpressure_set::h2060865164350232
                   2:   0x80ef - runner-rust.core.wasm!<runner::Component as runner::Guest>::run::{{closure}}::h3a912066a6a93712
                   3:   0xa9da - runner-rust.core.wasm!runner::_export_run_cabi::{{closure}}::h8ec0ebf2c9707799
                   4:   0xd249 - runner-rust.core.wasm!<core::pin::Pin<P> as core::future::future::Future>::poll::hffbc3a02412fa779
                   5:   0xbca7 - runner-rust.core.wasm!<futures_util::stream::futures_unordered::FuturesUnordered<Fut> as futures_core::stream::Stream>::poll_next::h650942f11319f698
                   6:   0xcefe - runner-rust.core.wasm!futures_util::stream::stream::StreamExt::poll_next_unpin::h5f577b7bd8cf4e0e
                   7:   0xd876 - runner-rust.core.wasm!wit_bindgen::rt::async_support::spawn::Tasks::poll_next::h34689c3d090b9f2e
                   8:   0xdb6a - runner-rust.core.wasm!wit_bindgen::rt::async_support::FutureState::callback::{{closure}}::h30de2b0f178d6460
                   9:   0xda94 - runner-rust.core.wasm!wit_bindgen::rt::async_support::FutureState::with_p3_task_set::hb9db4ba65c26e22f
                  10:   0xf2e0 - runner-rust.core.wasm!wit_bindgen::rt::async_support::FutureState::callback::h28f7868390c04f8a
                  11:   0xf8d3 - runner-rust.core.wasm!wit_bindgen::rt::async_support::callback::h724652dc7db47a40
                  12:   0x2375 - runner-rust.core.wasm!wit_bindgen::rt::async_support::start_task::h702ede5ea975899b
                  13:   0x10d9 - runner-rust.core.wasm!runner::_export_run_cabi::hc4207119b724a9e2
                  14:   0x10a7 - runner-rust.core.wasm![async-lift]run
               note: using the `WASMTIME_BACKTRACE_DETAILS=1` environment variable may show more debugging information
            1: wasm trap: wasm `unreachable` instruction executed

I think these are related to reentrance checks changing? Maybe the tests are invalid now?

ping-pong

Details

``` ------ Failure: ping-pong -------- runner: tests/runtime-async/async/ping-pong/runner.c compiled runner: /home/runner/work/wit-bindgen/wit-bindgen/target/artifacts/ping-pong/runner-c.wasm test: tests/runtime-async/async/ping-pong/test.rs compiled test: /home/runner/work/wit-bindgen/wit-bindgen/target/artifacts/ping-pong/test-rust.wasm error: failed to run `ping-pong`

Caused by:
command execution failed
command: "wasmtime" "-W" "component-model-async" "--invoke=run()" "/home/runner/work/wit-bindgen/wit-bindgen/target/artifacts/ping-pong/composed-runner.c-test.rs.wasm"
status: exit status: 134
stderr:
Assertion failed: RUNNER_SUBTASK_STATE(status) == RUNNER_SUBTASK_STARTED (tests/runtime-async/async/ping-pong/runner.c: exports_runner_run: 50)
Error: failed to run main module /home/runner/work/wit-bindgen/wit-bindgen/target/artifacts/ping-pong/composed-runner.c-test.rs.wasm

    Caused by:
        0: error while executing at wasm backtrace:
               0:   0x4925 - runner-c.core.wasm!abort
               1:   0x4a4a - runner-c.core.wasm!__assert_fail
               2:   0x151e - runner-c.core.wasm!exports_runner_run
               3:   0x1b41 - runner-c.core.wasm!__wasm_export_exports_runner_run
           note: using the `WASMTIME_BACKTRACE_DETAILS=1` environment variable may show more debugging information
        1: wasm trap: wasm `unreachable` instruction executed

</details>

I think this is a case where the C test just neesd to be updated

[dicej]

The remaining failures not addressed by bytecodealliance/wasmtime#12190 are fixed by bytecodealliance/wasmtime#12182, i.e. the tests all pass when using that branch of Wasmtime, where waitable-set.poll no longer yields. There's a chicken-and-egg problem in that the new wit-bindgen code won't work correctly with Wasmtime main, and the Wasmtime PR won't work with wit-bindgen main.

[alexcrichton]

Would it be possible to update the tests to pass here, with wasmtime-as-is, and then once the wasmtime changes land re-update the tests here?

[dicej]

Would it be possible to update the tests to pass here, with wasmtime-as-is, and then once the wasmtime changes land re-update the tests here?

Sure. Would it be acceptable for me to just outright remove the offending test files and then add them back later?

[alexcrichton]

I'd prefer to keep them if it's not too much work. For ping-pong what I'd expect is minor adjustments to the expectations on the C side of things, but for cancel-import I'm not actually sure what to expect and/or how removing poll is going to fix/affect those tests

[alexcrichton]

Talked with Joel a bit offline, we'll merge with failing tests for now and get it working again once Wasmtime changes are merged