trap on blocking call in sync task before return #12043
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This implements a spec change (PR pending) such that tasks created for calls to
synchronous exports may not call potentially-blocking imports or return `wait`
or `poll` callback codes prior to returning a value. Specifically, the
following are prohibited in that scenario:
- returning callback-code.{wait,poll}
- sync calling an async import
- sync calling subtask.cancel
- sync calling {stream,future}.{read,write}
- sync calling {stream,future}.cancel-{read,write}
- calling waitable-set.{wait,poll}
- calling thread.suspend
This breaks a number of tests, which will be addressed in follow-up commits:
- The `{tcp,udp}-socket.bind` implementation in `wasmtime-wasi` is implemented
using `Linker::func_wrap_concurrent` and thus assumed to be async, whereas the
WIT interface says they're sync, leading to a type mismatch error at runtime.
Alex and I have discussed this and have a general plan to address it.
- A number of tests in the tests/component-model submodule that points to the
spec repo are failing. Those will presumably be fixed as part of the upcoming
spec PR (although some could be due to bugs in this implementation, in which
case I'll fix them).
- A number of tests in tests/misc_testsuite are failing. I'll address those in
a follow-up commit.
Signed-off-by: Joel Dice <[email protected]>
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`check_blocking` needs access to the current task, but that's not set for post-return functions since those should not be calling _any_ imports at all, so first check for that. Signed-off-by: Joel Dice <[email protected]>
This amounts to adding `async` to any exported component functions that might need to block. Signed-off-by: Joel Dice <[email protected]>
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This implements a spec change (PR pending) such that tasks created for calls to synchronous exports may not call potentially-blocking imports or return
waitorpollcallback codes prior to returning a value. Specifically, the following are prohibited in that scenario:This breaks a number of tests, which will be addressed in follow-up commits:
The
{tcp,udp}-socket.bindimplementation inwasmtime-wasiis implemented usingLinker::func_wrap_concurrentand thus assumed to be async, whereas the WIT interface says they're sync, leading to a type mismatch error at runtime. Alex and I have discussed this and have a general plan to address it.A number of tests in the tests/component-model submodule that points to the spec repo are failing. Those will presumably be fixed as part of the upcoming spec PR (although some could be due to bugs in this implementation, in which case I'll fix them).
A number of tests in tests/misc_testsuite are failing. I'll address those in a follow-up commit.