fix: reclaim host stream/future transmits when the guest drops its end#13515
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When the guest drops its end of a stream/future while the host consumer/producer is still `HostReady`, the host end was never finalized, so the `TransmitState` and both handles leaked from the concurrent-state table (eventually trapping with "resource table has no free keys"). The `HostReady` arms of `host_drop_reader` and `host_drop_writer` were no-ops; both now `delete_transmit`. `host_drop_writer` only finalizes once the writer is actually `Dropped`. Adds two `component-async-tests` regression tests (one per path) that fail on `main` and pass here. Fixes bytecodealliance#13514. Assisted-by: Claude Code
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Fixes #13514.
When the guest drops its end of a stream/future while the host consumer/producer is still
HostReady, the transmit was never reclaimed. This finalizes the stranded host end so theTransmitStateand both handles are freed.Fix
crates/wasmtime/src/runtime/component/concurrent/futures_and_streams.rs— twoHostReadyarms were no-ops; both now calldelete_transmit(which also drops the host producer/consumer):host_drop_reader(guest dropped the read end → host producer): the read end is alreadyDropped, so finalize unconditionally.host_drop_writer(guest dropped the write end → host consumer): the write end isn't forcedDroppedhere, so finalize only once the writer is actually gone.Tests
Two regression tests in
component-async-tests, driving only the publicStreamReader::pipe/FutureReader::newAPIs:streams::async_host_consumer_drop(+ a minimalhost-consumer-drop-guesttest program) — covershost_drop_writer.streams::async_host_producer_drop(reuses the existingclosed-streamsguest) — covershost_drop_reader.Both fail on
main(leftover concurrent-state entries viaassert_concurrent_state_empty) and pass with this change.Verification
cargo test -p component-async-tests --test test_all→ 82 passed, 0 failed.