2 files changed, 25 insertions, 29 deletions

diff --git a/core/01_core.js b/core/01_core.js
index ab54316e5..4cefb52e9 100644
--- a/core/01_core.js
+++ b/core/01_core.js
@@ -194,8 +194,9 @@
   function opAsync2(name, arg0, arg1) {
     const id = nextPromiseId++;
     let promise = PromisePrototypeThen(setPromise(id), unwrapOpResult);
+    let maybeResult;
     try {
-      ops[name](id, arg0, arg1);
+      maybeResult = ops[name](id, arg0, arg1);
     } catch (err) {
       // Cleanup the just-created promise
       getPromise(id);
@@ -204,14 +205,20 @@
     }
     promise = handleOpCallTracing(name, id, promise);
     promise[promiseIdSymbol] = id;
+    if (typeof maybeResult !== "undefined") {
+      const promise = getPromise(id);
+      promise.resolve(maybeResult);
+    }
+
     return promise;
   }
 
   function opAsync(name, ...args) {
     const id = nextPromiseId++;
     let promise = PromisePrototypeThen(setPromise(id), unwrapOpResult);
+    let maybeResult;
     try {
-      ops[name](id, ...new SafeArrayIterator(args));
+      maybeResult = ops[name](id, ...new SafeArrayIterator(args));
     } catch (err) {
       // Cleanup the just-created promise
       getPromise(id);
@@ -220,6 +227,11 @@
     }
     promise = handleOpCallTracing(name, id, promise);
     promise[promiseIdSymbol] = id;
+    if (typeof maybeResult !== "undefined") {
+      const promise = getPromise(id);
+      promise.resolve(maybeResult);
+    }
+
     return promise;
   }
 
diff --git a/core/runtime.rs b/core/runtime.rs
index ef65d2192..b03f3f7d0 100644
--- a/core/runtime.rs
+++ b/core/runtime.rs
@@ -2437,12 +2437,12 @@ pub fn queue_fast_async_op(
 }
 
 #[inline]
-pub fn queue_async_op(
+pub fn queue_async_op<'s>(
   ctx: &OpCtx,
-  scope: &mut v8::HandleScope,
+  scope: &'s mut v8::HandleScope,
   deferred: bool,
   op: impl Future<Output = (RealmIdx, PromiseId, OpId, OpResult)> + 'static,
-) {
+) -> Option<v8::Local<'s, v8::Value>> {
   let runtime_state = match ctx.runtime_state.upgrade() {
     Some(rc_state) => rc_state,
     // atleast 1 Rc is held by the JsRuntime.
@@ -2459,31 +2459,13 @@ pub fn queue_async_op(
   );
 
   match OpCall::eager(op) {
-    // This calls promise.resolve() before the control goes back to userland JS. It works something
-    // along the lines of:
-    //
-    // function opresolve(promiseId, ...) {
-    //   getPromise(promiseId).resolve(...);
-    // }
-    // const p = setPromise();
-    // op.op_async(promiseId, ...); // Calls `opresolve`
-    // return p;
-    EagerPollResult::Ready((_, promise_id, op_id, mut resp)) if !deferred => {
-      let context_state_rc = JsRealm::state_from_scope(scope);
-      let context_state = context_state_rc.borrow();
-
-      let args = &[
-        v8::Integer::new(scope, promise_id).into(),
-        resp.to_v8(scope).unwrap(),
-      ];
-
+    // If the result is ready we'll just return it straight to the caller, so
+    // we don't have to invoke a JS callback to respond. // This works under the
+    // assumption that `()` return value is serialized as `null`.
+    EagerPollResult::Ready((_, _, op_id, mut resp)) if !deferred => {
+      let resp = resp.to_v8(scope).unwrap();
       ctx.state.borrow_mut().tracker.track_async_completed(op_id);
-
-      let tc_scope = &mut v8::TryCatch::new(scope);
-      let js_recv_cb =
-        context_state.js_recv_cb.as_ref().unwrap().open(tc_scope);
-      let this = v8::undefined(tc_scope).into();
-      js_recv_cb.call(tc_scope, this, args);
+      return Some(resp);
     }
     EagerPollResult::Ready(op) => {
       let ready = OpCall::ready(op);
@@ -2497,6 +2479,8 @@ pub fn queue_async_op(
       state.have_unpolled_ops = true;
     }
   }
+
+  None
 }
 
 #[cfg(test)]