wasi-tokio kinda sorta working

crates/wasi-common/tokio/tests/poll_oneoff.rs

@@ -0,0 +1,27 @@
+use anyhow::{Context, Error};
+use std::ops::Deref;
+use wasi_common::{
+    file::{FdFlags, OFlags},
+    sched::{Poll, Userdata},
+    WasiDir, WasiFile,
+};
+use wasi_tokio::{sched::poll_oneoff, Dir, File};
+
+#[tokio::test(flavor = "multi_thread")]
+async fn main() -> Result<(), Error> {
+    let workspace = unsafe { cap_tempfile::tempdir().expect("create tempdir") };
+    workspace.create_dir("d").context("create dir")?;
+    let d = workspace.open_dir("d").context("open dir")?;
+    let d = Dir::from_cap_std(d);
+
+    let mut readable_f = d
+        .open_file(false, "f", OFlags::CREATE, true, false, FdFlags::empty())
+        .await
+        .context("create readable file")?;
+
+    let mut poll = Poll::new();
+    poll.subscribe_read(&mut *readable_f, Userdata::from(123));
+    let poll_events = poll_oneoff(&mut poll).await?;
+
+    Ok(())
+}