fix: unref stdin read (#23534)

Closes https://github.com/denoland/deno_core/issues/648

Co-authored-by: Matt Mastracci <matthew@mastracci.com>

runtime/tokio_util.rs

@@ -99,7 +99,13 @@ where
   #[cfg(not(tokio_unstable))]
   let join_handle = rt.spawn(future);
 
-  rt.block_on(join_handle).unwrap().into_inner()
+  let r = rt.block_on(join_handle).unwrap().into_inner();
+  // Forcefully shutdown the runtime - we're done executing JS code at this
+  // point, but there might be outstanding blocking tasks that were created and
+  // latered "unrefed". They won't terminate on their own, so we're forcing
+  // termination of Tokio runtime at this point.
+  rt.shutdown_background();
+  r
 }
 
 #[inline(always)]

tests/specs/run/unref_stdin/__test__.jsonc

@@ -0,0 +1,5 @@
+// Regression test for https://github.com/denoland/deno/issues/22453
+{
+  "args": "run main.js",
+  "output": "main.out"
+}

tests/specs/run/unref_stdin/main.js

@@ -0,0 +1,11 @@
+const { core } = Deno[Deno.internal];
+const opPromise = core.read(Deno.stdin.rid, new Uint8Array(10));
+core.unrefOpPromise(opPromise);
+
+async function main() {
+  console.log(1);
+  await opPromise;
+  console.log(2);
+}
+
+main();

tests/specs/run/unref_stdin/main.out

@@ -0,0 +1 @@
+1