With WebAssembly/WASI#193 merged, WASI is moving
to make `poll_oneoff` with no arguments an error. Even though that's in
ephemeral and not yet in a snapshot, we can start to anticipate it in
libc:
 - Remove the `pause` function, since WASI has no signals and thus no
   way to ever wake it up short of having the host terminate it.
 - Make `poll` and `pselect` return `ENOTSUP` in the case of having no
   events to wait for.

With WebAssembly/WASI#193 merged, WASI is moving
to make `poll_oneoff` with no arguments an error. Even though that's in
ephemeral and not yet in a snapshot, we can start to anticipate it in
libc:
 - Remove the `pause` function, since WASI has no signals and thus no
   way to ever wake it up short of having the host terminate it.
 - Make `poll` and `pselect` return `ENOTSUP` in the case of having no
   events to wait for.

We adhere to WebAssembly/WASI#193.

We adhere to WebAssembly/WASI#193.

* Return EINVAL in poll_oneoff with no events.

We adhere to WebAssembly/WASI#193.

* Add a test for empty poll.

With WebAssembly/WASI#193 merged, WASI is moving
to make `poll_oneoff` with no arguments an error. Even though that's in
ephemeral and not yet in a snapshot, we can start to anticipate it in
libc:
 - Remove the `pause` function, since WASI has no signals and thus no
   way to ever wake it up short of having the host terminate it.
 - Make `poll` and `pselect` return `ENOTSUP` in the case of having no
   events to wait for.

With WebAssembly/WASI#193 merged, WASI is moving
to make `poll_oneoff` with no arguments an error. Even though that's in
ephemeral and not yet in a snapshot, we can start to anticipate it in
libc:
 - Remove the `pause` function, since WASI has no signals and thus no
   way to ever wake it up short of having the host terminate it.
 - Make `poll` and `pselect` return `ENOTSUP` in the case of having no
   events to wait for.

With WebAssembly/WASI#193 merged, WASI is moving
to make `poll_oneoff` with no arguments an error. Even though that's in
ephemeral and not yet in a snapshot, we can start to anticipate it in
libc:
 - Remove the `pause` function, since WASI has no signals and thus no
   way to ever wake it up short of having the host terminate it.
 - Make `poll` and `pselect` return `ENOTSUP` in the case of having no
   events to wait for.

With WebAssembly/WASI#193 merged, WASI is moving
to make `poll_oneoff` with no arguments an error. Even though that's in
ephemeral and not yet in a snapshot, we can start to anticipate it in
libc:
 - Remove the `pause` function, since WASI has no signals and thus no
   way to ever wake it up short of having the host terminate it.
 - Make `poll` and `pselect` return `ENOTSUP` in the case of having no
   events to wait for.

* Avoid calling `poll_oneoff` with zero subscriptions.

With WebAssembly/WASI#193 merged, WASI is moving
to make `poll_oneoff` with no arguments an error. Even though that's in
ephemeral and not yet in a snapshot, we can start to anticipate it in
libc:
 - Remove the `pause` function, since WASI has no signals and thus no
   way to ever wake it up short of having the host terminate it.
 - Make `poll` and `pselect` return `ENOTSUP` in the case of having no
   events to wait for.

* Remove `pause` from the defined-symbols.txt list.

* Fix __wasilibc_unmodified_upstream markers.

* Check for zero subscriptions, rather than zero events.

Make `poll` and `pselect` return `ENOTSUP` when asked to poll on zero
subscriptions, rather than when the systerm returns zero events.

While here, drop the `__wasilibc_unmodified_upstream` markers, which
were already pretty noisy here, and would be significantly worse with
this change.

* Add comments about the subtle relationship between nfds and nsubscriptions.

* Rewrite the comment.

* Fix code quotes.

…mbly#193)

`poll` with no subscriptions is effectively an infinite hang. Since wasm
has no signals, use cases which involve waking up a libc `pause` call, which
is implemented in terms of a poll with no subscriptions, aren't applicable.
So all `pause` can do is suspend the program until the host environment
terminates it.

One situation where that's useful is in debugging, as it's sometimes useful
to be able to suspend a process in place so that it can be inspected by a
debugger. However, that doesn't require a fully infinite suspend; a suspend
with a long timeout is adequate.

Making the no-subscriptions case an error can help catch cases where
applications unintentionally enter infinite loops.

…mbly#193)

`poll` with no subscriptions is effectively an infinite hang. Since wasm
has no signals, use cases which involve waking up a libc `pause` call, which
is implemented in terms of a poll with no subscriptions, aren't applicable.
So all `pause` can do is suspend the program until the host environment
terminates it.

One situation where that's useful is in debugging, as it's sometimes useful
to be able to suspend a process in place so that it can be inspected by a
debugger. However, that doesn't require a fully infinite suspend; a suspend
with a long timeout is adequate.

Making the no-subscriptions case an error can help catch cases where
applications unintentionally enter infinite loops.

…-wit-0.3.0-rc-2025-09-16

Revert "Update 0.3.0 WIT definitions to 0.3.0-rc-2025-09-16"

…mbly#193)

`poll` with no subscriptions is effectively an infinite hang. Since wasm
has no signals, use cases which involve waking up a libc `pause` call, which
is implemented in terms of a poll with no subscriptions, aren't applicable.
So all `pause` can do is suspend the program until the host environment
terminates it.

One situation where that's useful is in debugging, as it's sometimes useful
to be able to suspend a process in place so that it can be inspected by a
debugger. However, that doesn't require a fully infinite suspend; a suspend
with a long timeout is adequate.

Making the no-subscriptions case an error can help catch cases where
applications unintentionally enter infinite loops.