perf(runtime): short-circuit queue_async_op for Poll::Ready (#15773)

cli/bench/async_ops.js

@@ -0,0 +1,19 @@
+// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
+const queueMicrotask = globalThis.queueMicrotask || process.nextTick;
+let [total, count] = typeof Deno !== "undefined"
+  ? Deno.args
+  : [process.argv[2], process.argv[3]];
+
+total = total ? parseInt(total, 0) : 50;
+count = count ? parseInt(count, 10) : 100000;
+
+async function bench(fun) {
+  const start = Date.now();
+  for (let i = 0; i < count; i++) await fun();
+  const elapsed = Date.now() - start;
+  const rate = Math.floor(count / (elapsed / 1000));
+  console.log(`time ${elapsed} ms rate ${rate}`);
+  if (--total) queueMicrotask(() => bench(fun));
+}
+
+bench(() => Deno.core.opAsync("op_void_async"));

cli/bench/tcp.js

@@ -0,0 +1,22 @@
+// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
+
+const listener = Deno.listen({ port: 4500 });
+const response = new TextEncoder().encode(
+  "HTTP/1.1 200 OK\r\nContent-Length: 12\r\n\r\nHello World\n",
+);
+
+// Accept a connection and write packets as fast as possible.
+async function acceptWrite() {
+  const conn = await listener.accept();
+  try {
+    while (true) {
+      await conn.write(response);
+    }
+  } catch {
+    // Pass
+  }
+  conn.close();
+}
+
+await acceptWrite();
+await acceptWrite();

cli/tests/integration/mod.rs

@@ -928,7 +928,7 @@ async fn test_resolve_dns() {
     let out = String::from_utf8_lossy(&output.stdout);
     assert!(!output.status.success());
     assert!(err.starts_with("Check file"));
-    assert!(err.contains(r#"error: Uncaught (in promise) PermissionDenied: Requires net access to "127.0.0.1:4553""#));
+    assert!(err.contains(r#"error: Uncaught PermissionDenied: Requires net access to "127.0.0.1:4553""#));
     assert!(out.is_empty());
   }
 
@@ -950,7 +950,7 @@ async fn test_resolve_dns() {
     let out = String::from_utf8_lossy(&output.stdout);
     assert!(!output.status.success());
     assert!(err.starts_with("Check file"));
-    assert!(err.contains(r#"error: Uncaught (in promise) PermissionDenied: Requires net access to "127.0.0.1:4553""#));
+    assert!(err.contains(r#"error: Uncaught PermissionDenied: Requires net access to "127.0.0.1:4553""#));
     assert!(out.is_empty());
   }
 

cli/tests/testdata/044_bad_resource.ts.out

@@ -1,2 +1,2 @@
-[WILDCARD]error: Uncaught (in promise) BadResource: Bad resource ID
+[WILDCARD]error: Uncaught [WILDCARD] BadResource: Bad resource ID
 [WILDCARD]

cli/tests/testdata/wasm_unreachable.out

@@ -1,3 +1,3 @@
-error: Uncaught (in promise) RuntimeError: unreachable
+error: Uncaught [WILDCARD] RuntimeError: unreachable
     at <anonymous> (wasm://wasm/d1c677ea:1:41)
     at [WILDCARD]/wasm_unreachable.js:[WILDCARD]

cli/tests/unit/fetch_test.ts

@@ -1202,20 +1202,28 @@ Deno.test({}, function fetchWritableRespProps() {
   assertEquals(new_.headers.get("x-deno"), "foo");
 });
 
-function returnHostHeaderServer(addr: string): Deno.Listener {
+Deno.test(
+  { permissions: { net: true } },
+  async function fetchFilterOutCustomHostHeader(): Promise<
+    void
+  > {
+    const addr = "127.0.0.1:4511";
     const [hostname, port] = addr.split(":");
     const listener = Deno.listen({
       hostname,
       port: Number(port),
     }) as Deno.Listener;
 
+    let httpConn: Deno.HttpConn;
     listener.accept().then(async (conn: Deno.Conn) => {
-    const httpConn = Deno.serveHttp(conn);
+      httpConn = Deno.serveHttp(conn);
 
       await httpConn.nextRequest()
         .then(async (requestEvent: Deno.RequestEvent | null) => {
           const hostHeader = requestEvent?.request.headers.get("Host");
-        const headersToReturn = hostHeader ? { "Host": hostHeader } : undefined;
+          const headersToReturn = hostHeader
+            ? { "Host": hostHeader }
+            : undefined;
 
           await requestEvent?.respondWith(
             new Response("", {
@@ -1224,25 +1232,14 @@ function returnHostHeaderServer(addr: string): Deno.Listener {
             }),
           );
         });
-
-    httpConn.close();
     });
 
-  return listener;
-}
-
-Deno.test(
-  { permissions: { net: true } },
-  async function fetchFilterOutCustomHostHeader(): Promise<
-    void
-  > {
-    const addr = "127.0.0.1:4511";
-    const listener = returnHostHeaderServer(addr);
     const response = await fetch(`http://${addr}/`, {
       headers: { "Host": "example.com" },
     });
     await response.text();
     listener.close();
+    httpConn!.close();
 
     assertEquals(response.headers.get("Host"), addr);
   },

cli/tests/unit/http_test.ts

@@ -45,11 +45,12 @@ async function writeRequestAndReadResponse(conn: Deno.Conn): Promise<string> {
 }
 
 Deno.test({ permissions: { net: true } }, async function httpServerBasic() {
+  let httpConn: Deno.HttpConn;
   const promise = (async () => {
     const listener = Deno.listen({ port: 4501 });
     const conn = await listener.accept();
     listener.close();
-    const httpConn = Deno.serveHttp(conn);
+    httpConn = Deno.serveHttp(conn);
     const reqEvent = await httpConn.nextRequest();
     assert(reqEvent);
     const { request, respondWith } = reqEvent;
@@ -58,7 +59,6 @@ Deno.test({ permissions: { net: true } }, async function httpServerBasic() {
     await respondWith(
       new Response("Hello World", { headers: { "foo": "bar" } }),
     );
-    httpConn.close();
   })();
 
   const resp = await fetch("http://127.0.0.1:4501/", {
@@ -71,6 +71,8 @@ Deno.test({ permissions: { net: true } }, async function httpServerBasic() {
   const cloneText = await clone.text();
   assertEquals(cloneText, "Hello World");
   await promise;
+
+  httpConn!.close();
 });
 
 // https://github.com/denoland/deno/issues/15107
@@ -88,7 +90,7 @@ Deno.test(
       const { request } = e;
       request.text();
       headers = request.headers;
-      httpConn.close();
+      httpConn!.close();
     })();
 
     const conn = await Deno.connect({ port: 2333 });
@@ -120,7 +122,7 @@ Deno.test(
       await respondWith(new Response("Hello World")); // Closes request
 
       assertThrows(() => request.headers, TypeError, "request closed");
-      httpConn.close();
+      httpConn!.close();
     })();
 
     const conn = await Deno.connect({ port: 2334 });
@@ -138,17 +140,17 @@ Deno.test(
 Deno.test(
   { permissions: { net: true } },
   async function httpServerGetRequestBody() {
+    let httpConn: Deno.HttpConn;
     const promise = (async () => {
       const listener = Deno.listen({ port: 4501 });
       const conn = await listener.accept();
       listener.close();
-      const httpConn = Deno.serveHttp(conn);
+      httpConn = Deno.serveHttp(conn);
       const e = await httpConn.nextRequest();
       assert(e);
       const { request, respondWith } = e;
       assertEquals(request.body, null);
       await respondWith(new Response("", { headers: {} }));
-      httpConn.close();
     })();
 
     const conn = await Deno.connect({ port: 4501 });
@@ -166,6 +168,7 @@ Deno.test(
     conn.close();
 
     await promise;
+    httpConn!.close();
   },
 );
 
@@ -178,23 +181,24 @@ Deno.test(
     writer.write(new TextEncoder().encode("world"));
     writer.close();
 
-    const promise = (async () => {
+    let httpConn: Deno.HttpConn;
     const listener = Deno.listen({ port: 4501 });
+    const promise = (async () => {
       const conn = await listener.accept();
-      const httpConn = Deno.serveHttp(conn);
+      httpConn = Deno.serveHttp(conn);
       const evt = await httpConn.nextRequest();
       assert(evt);
       const { request, respondWith } = evt;
       assert(!request.body);
       await respondWith(new Response(stream.readable));
-      httpConn.close();
-      listener.close();
     })();
 
     const resp = await fetch("http://127.0.0.1:4501/");
     const respBody = await resp.text();
     assertEquals("hello world", respBody);
     await promise;
+    httpConn!.close();
+    listener.close();
   },
 );
 
@@ -240,17 +244,16 @@ Deno.test(
 Deno.test(
   { permissions: { net: true } },
   async function httpServerStreamDuplex() {
-    const promise = (async () => {
+    let httpConn: Deno.HttpConn;
     const listener = Deno.listen({ port: 4501 });
+    const promise = (async () => {
       const conn = await listener.accept();
-      const httpConn = Deno.serveHttp(conn);
+      httpConn = Deno.serveHttp(conn);
       const evt = await httpConn.nextRequest();
       assert(evt);
       const { request, respondWith } = evt;
       assert(request.body);
       await respondWith(new Response(request.body));
-      httpConn.close();
-      listener.close();
     })();
 
     const ts = new TransformStream();
@@ -269,10 +272,13 @@ Deno.test(
     const chunk2 = await reader.read();
     assert(!chunk2.done);
     assertEquals(chunk2.value, new Uint8Array([2]));
+
     await writable.close();
     const chunk3 = await reader.read();
     assert(chunk3.done);
     await promise;
+    httpConn!.close();
+    listener.close();
   },
 );
 
@@ -351,18 +357,17 @@ Deno.test(
 Deno.test(
   { permissions: { net: true } },
   async function httpServerRegressionHang() {
-    const promise = (async () => {
+    let httpConn: Deno.HttpConn;
     const listener = Deno.listen({ port: 4501 });
+    const promise = (async () => {
       const conn = await listener.accept();
-      const httpConn = Deno.serveHttp(conn);
+      httpConn = Deno.serveHttp(conn);
       const event = await httpConn.nextRequest();
       assert(event);
       const { request, respondWith } = event;
       const reqBody = await request.text();
       assertEquals("request", reqBody);
       await respondWith(new Response("response"));
-      httpConn.close();
-      listener.close();
     })();
 
     const resp = await fetch("http://127.0.0.1:4501/", {
@@ -372,6 +377,9 @@ Deno.test(
     const respBody = await resp.text();
     assertEquals("response", respBody);
     await promise;
+
+    httpConn!.close();
+    listener.close();
   },
 );
 
@@ -410,7 +418,7 @@ Deno.test(
         cancelReason!,
       );
       assert(cancelReason!);
-      httpConn.close();
+      httpConn!.close();
       listener.close();
     })();
 
@@ -468,22 +476,23 @@ Deno.test(
 Deno.test(
   { permissions: { net: true } },
   async function httpServerEmptyBlobResponse() {
-    const promise = (async () => {
+    let httpConn: Deno.HttpConn;
     const listener = Deno.listen({ port: 4501 });
+    const promise = (async () => {
       const conn = await listener.accept();
-      const httpConn = Deno.serveHttp(conn);
+      httpConn = Deno.serveHttp(conn);
       const event = await httpConn.nextRequest();
       assert(event);
       const { respondWith } = event;
       await respondWith(new Response(new Blob([])));
-      httpConn.close();
-      listener.close();
     })();
 
     const resp = await fetch("http://127.0.0.1:4501/");
     const respBody = await resp.text();
     assertEquals("", respBody);
     await promise;
+    httpConn!.close();
+    listener.close();
   },
 );
 
@@ -633,14 +642,14 @@ Deno.test(
       }).pipeThrough(new TextEncoderStream());
     }
 
+    let httpConn: Deno.HttpConn;
     const listener = Deno.listen({ port: 4501 });
     const finished = (async () => {
       const conn = await listener.accept();
-      const httpConn = Deno.serveHttp(conn);
+      httpConn = Deno.serveHttp(conn);
       const requestEvent = await httpConn.nextRequest();
       const { respondWith } = requestEvent!;
       await respondWith(new Response(periodicStream()));
-      httpConn.close();
     })();
 
     // start a client
@@ -651,6 +660,8 @@ Deno.test(
 
     await finished;
     clientConn.close();
+
+    httpConn!.close();
     listener.close();
   },
 );
@@ -658,11 +669,12 @@ Deno.test(
 Deno.test(
   { permissions: { net: true } },
   async function httpRequestLatin1Headers() {
+    let httpConn: Deno.HttpConn;
     const promise = (async () => {
       const listener = Deno.listen({ port: 4501 });
       const conn = await listener.accept();
       listener.close();
-      const httpConn = Deno.serveHttp(conn);
+      httpConn = Deno.serveHttp(conn);
       const reqEvent = await httpConn.nextRequest();
       assert(reqEvent);
       const { request, respondWith } = reqEvent;
@@ -670,7 +682,6 @@ Deno.test(
       await respondWith(
         new Response("", { headers: { "X-Header-Test": "Æ" } }),
       );
-      httpConn.close();
     })();
 
     const clientConn = await Deno.connect({ port: 4501 });
@@ -688,11 +699,14 @@ Deno.test(
     let responseText = "";
     const buf = new Uint8Array(1024);
     let read;
+
     while ((read = await clientConn.read(buf)) !== null) {
+      httpConn!.close();
       for (let i = 0; i < read; i++) {
         responseText += String.fromCharCode(buf[i]);
       }
     }
+
     clientConn.close();
 
     assert(/\r\n[Xx]-[Hh]eader-[Tt]est: Æ\r\n/.test(responseText));
@@ -704,18 +718,18 @@ Deno.test(
 Deno.test(
   { permissions: { net: true } },
   async function httpServerRequestWithoutPath() {
-    const promise = (async () => {
+    let httpConn: Deno.HttpConn;
     const listener = Deno.listen({ port: 4501 });
+    const promise = (async () => {
       const conn = await listener.accept();
       listener.close();
-      const httpConn = Deno.serveHttp(conn);
+      httpConn = Deno.serveHttp(conn);
       const reqEvent = await httpConn.nextRequest();
       assert(reqEvent);
       const { request, respondWith } = reqEvent;
       assertEquals(new URL(request.url).href, "http://127.0.0.1:4501/");
       assertEquals(await request.text(), "");
       await respondWith(new Response());
-      httpConn.close();
     })();
 
     const clientConn = await Deno.connect({ port: 4501 });
@@ -744,6 +758,7 @@ Deno.test(
     await writeRequest(clientConn);
     clientConn.close();
     await promise;
+    httpConn!.close();
   },
 );
 
@@ -868,11 +883,12 @@ Deno.test(function httpUpgradeWebSocketWithoutUpgradeHeader() {
 Deno.test(
   { permissions: { net: true } },
   async function httpCookieConcatenation() {
+    let httpConn: Deno.HttpConn;
     const promise = (async () => {
       const listener = Deno.listen({ port: 4501 });
       const conn = await listener.accept();
       listener.close();
-      const httpConn = Deno.serveHttp(conn);
+      httpConn = Deno.serveHttp(conn);
       const reqEvent = await httpConn.nextRequest();
       assert(reqEvent);
       const { request, respondWith } = reqEvent;
@@ -880,7 +896,6 @@ Deno.test(
       assertEquals(await request.text(), "");
       assertEquals(request.headers.get("cookie"), "foo=bar; bar=foo");
       await respondWith(new Response("ok"));
-      httpConn.close();
     })();
 
     const resp = await fetch("http://127.0.0.1:4501/", {
@@ -893,6 +908,7 @@ Deno.test(
     const text = await resp.text();
     assertEquals(text, "ok");
     await promise;
+    httpConn!.close();
   },
 );
 
@@ -910,7 +926,7 @@ Deno.test({ permissions: { net: true } }, async function httpServerPanic() {
 
   httpConn.nextRequest();
   await client.write(encoder.encode("\r\n\r\n"));
-  httpConn.close();
+  httpConn!.close();
 
   client.close();
   listener.close();
@@ -923,21 +939,23 @@ Deno.test(
     const file = await Deno.open(tmpFile, { write: true, read: true });
     await file.write(new Uint8Array(70 * 1024).fill(1)); // 70kb sent in 64kb + 6kb chunks
     file.close();
-    const promise = (async () => {
+
+    let httpConn: Deno.HttpConn;
     const listener = Deno.listen({ port: 4503 });
+    const promise = (async () => {
       const conn = await listener.accept();
-      const httpConn = Deno.serveHttp(conn);
+      httpConn = Deno.serveHttp(conn);
       const ev = await httpConn.nextRequest();
       const { respondWith } = ev!;
       const f = await Deno.open(tmpFile, { read: true });
       await respondWith(new Response(f.readable, { status: 200 }));
-      httpConn.close();
-      listener.close();
     })();
     const resp = await fetch("http://127.0.0.1:4503/");
     const body = await resp.arrayBuffer();
     assertEquals(body.byteLength, 70 * 1024);
     await promise;
+    httpConn!.close();
+    listener.close();
   },
 );
 
@@ -976,7 +994,7 @@ Deno.test(
     }
 
     assert(didThrow);
-    httpConn.close();
+    httpConn!.close();
     listener.close();
     client.close();
   },
@@ -1018,7 +1036,7 @@ Deno.test(
 
     await respondWith(res).catch((error: Error) => errors.push(error));
 
-    httpConn.close();
+    httpConn!.close();
     listener.close();
 
     assert(errors.length >= 1);
@@ -1047,7 +1065,7 @@ Deno.test(
       )),
     ]);
 
-    httpConn.close();
+    httpConn!.close();
     listener.close();
     clientConn.close();
   },
@@ -1133,10 +1151,11 @@ Deno.test(
     const hostname = "localhost";
     const port = 4501;
 
-    async function server() {
+    let httpConn: Deno.HttpConn;
     const listener = Deno.listen({ hostname, port });
+    async function server() {
       const tcpConn = await listener.accept();
-      const httpConn = Deno.serveHttp(tcpConn);
+      httpConn = Deno.serveHttp(tcpConn);
       const promises = new Array(10).fill(null).map(async (_, i) => {
         const event = await httpConn.nextRequest();
         assert(event);
@@ -1146,8 +1165,6 @@ Deno.test(
         await event.respondWith(response);
       });
       await Promise.all(promises);
-      httpConn.close();
-      listener.close();
     }
 
     async function client() {
@@ -1159,6 +1176,8 @@ Deno.test(
     }
 
     await Promise.all([server(), delay(100).then(client)]);
+    httpConn!.close();
+    listener.close();
   },
 );
 
@@ -1213,16 +1232,15 @@ Deno.test(
     const hostname = "localhost";
     const port = 4501;
 
-    async function server() {
+    let httpConn: Deno.HttpConn;
     const listener = Deno.listen({ hostname, port });
+    async function server() {
       const tcpConn = await listener.accept();
-      const httpConn = Deno.serveHttp(tcpConn);
+      httpConn = Deno.serveHttp(tcpConn);
       const event = await httpConn.nextRequest() as Deno.RequestEvent;
       assert(event.request.body);
       const response = new Response();
       await event.respondWith(response);
-      httpConn.close();
-      listener.close();
     }
 
     async function client() {
@@ -1237,17 +1255,20 @@ Deno.test(
     }
 
     await Promise.all([server(), client()]);
+    httpConn!.close();
+    listener.close();
   },
 );
 
 Deno.test(
   { permissions: { net: true } },
   async function httpServerRespondNonAsciiUint8Array() {
-    const promise = (async () => {
+    let httpConn: Deno.HttpConn;
     const listener = Deno.listen({ port: 4501 });
+    const promise = (async () => {
       const conn = await listener.accept();
       listener.close();
-      const httpConn = Deno.serveHttp(conn);
+      httpConn = Deno.serveHttp(conn);
       const e = await httpConn.nextRequest();
       assert(e);
       const { request, respondWith } = e;
@@ -1255,7 +1276,6 @@ Deno.test(
       await respondWith(
         new Response(new Uint8Array([128]), {}),
       );
-      httpConn.close();
     })();
 
     const resp = await fetch("http://localhost:4501/");
@@ -1264,6 +1284,7 @@ Deno.test(
     assertEquals(new Uint8Array(body), new Uint8Array([128]));
 
     await promise;
+    httpConn!.close();
   },
 );
 
@@ -1276,11 +1297,12 @@ Deno.test(
   async function httpServerOnUnixSocket() {
     const filePath = Deno.makeTempFileSync();
 
+    let httpConn: Deno.HttpConn;
     const promise = (async () => {
       const listener = Deno.listen({ path: filePath, transport: "unix" });
       const conn = await listener.accept();
       listener.close();
-      const httpConn = Deno.serveHttp(conn);
+      httpConn = Deno.serveHttp(conn);
       const reqEvent = await httpConn.nextRequest();
       assert(reqEvent);
       const { request, respondWith } = reqEvent;
@@ -1289,7 +1311,6 @@ Deno.test(
       assertEquals(decodeURIComponent(url.host), filePath);
       assertEquals(url.pathname, "/path/name");
       await respondWith(new Response("", { headers: {} }));
-      httpConn.close();
     })();
 
     // fetch() does not supports unix domain sockets yet https://github.com/denoland/deno/issues/8821
@@ -1307,6 +1328,7 @@ Deno.test(
     conn.close();
 
     await promise;
+    httpConn!.close();
   },
 );
 
@@ -1324,9 +1346,10 @@ Deno.test({
 
     const data = { hello: "deno", now: "with", compressed: "body" };
 
+    let httpConn: Deno.HttpConn;
     async function server() {
       const tcpConn = await listener.accept();
-      const httpConn = Deno.serveHttp(tcpConn);
+      httpConn = Deno.serveHttp(tcpConn);
       const e = await httpConn.nextRequest();
       assert(e);
       const { request, respondWith } = e;
@@ -1335,7 +1358,6 @@ Deno.test({
         headers: { "content-type": "application/json" },
       });
       await respondWith(response);
-      httpConn.close();
       listener.close();
     }
 
@@ -1361,6 +1383,7 @@ Deno.test({
     }
 
     await Promise.all([server(), client()]);
+    httpConn!.close();
   },
 });
 
@@ -1374,9 +1397,10 @@ Deno.test({
 
     const data = { hello: "deno", now: "with", compressed: "body" };
 
+    let httpConn: Deno.HttpConn;
     async function server() {
       const tcpConn = await listener.accept();
-      const httpConn = Deno.serveHttp(tcpConn);
+      httpConn = Deno.serveHttp(tcpConn);
       const e = await httpConn.nextRequest();
       assert(e);
       const { request, respondWith } = e;
@@ -1385,7 +1409,6 @@ Deno.test({
         headers: { "content-type": "application/json" },
       });
       await respondWith(response);
-      httpConn.close();
       listener.close();
     }
 
@@ -1413,6 +1436,7 @@ Deno.test({
     }
 
     await Promise.all([server(), client()]);
+    httpConn!.close();
   },
 });
 
@@ -1423,10 +1447,11 @@ Deno.test({
     const hostname = "localhost";
     const port = 4501;
 
+    let httpConn: Deno.HttpConn;
     async function server() {
       const listener = Deno.listen({ hostname, port });
       const tcpConn = await listener.accept();
-      const httpConn = Deno.serveHttp(tcpConn);
+      httpConn = Deno.serveHttp(tcpConn);
       const e = await httpConn.nextRequest();
       assert(e);
       const { request, respondWith } = e;
@@ -1438,7 +1463,6 @@ Deno.test({
         },
       );
       await respondWith(response);
-      httpConn.close();
       listener.close();
     }
 
@@ -1464,6 +1488,7 @@ Deno.test({
     }
 
     await Promise.all([server(), client()]);
+    httpConn!.close();
   },
 });
 
@@ -1474,10 +1499,11 @@ Deno.test({
     const hostname = "localhost";
     const port = 4501;
 
+    let httpConn: Deno.HttpConn;
     async function server() {
       const listener = Deno.listen({ hostname, port });
       const tcpConn = await listener.accept();
-      const httpConn = Deno.serveHttp(tcpConn);
+      httpConn = Deno.serveHttp(tcpConn);
       const e = await httpConn.nextRequest();
       assert(e);
       const { request, respondWith } = e;
@@ -1492,7 +1518,6 @@ Deno.test({
         },
       );
       await respondWith(response);
-      httpConn.close();
       listener.close();
     }
 
@@ -1518,6 +1543,7 @@ Deno.test({
     }
 
     await Promise.all([server(), client()]);
+    httpConn!.close();
   },
 });
 
@@ -1528,10 +1554,11 @@ Deno.test({
     const hostname = "localhost";
     const port = 4501;
 
+    let httpConn: Deno.HttpConn;
     async function server() {
       const listener = Deno.listen({ hostname, port });
       const tcpConn = await listener.accept();
-      const httpConn = Deno.serveHttp(tcpConn);
+      httpConn = Deno.serveHttp(tcpConn);
       const e = await httpConn.nextRequest();
       assert(e);
       const { request, respondWith } = e;
@@ -1543,7 +1570,6 @@ Deno.test({
         },
       );
       await respondWith(response);
-      httpConn.close();
       listener.close();
     }
 
@@ -1569,6 +1595,7 @@ Deno.test({
     }
 
     await Promise.all([server(), client()]);
+    httpConn!.close();
   },
 });
 
@@ -1579,10 +1606,11 @@ Deno.test({
     const hostname = "localhost";
     const port = 4501;
 
+    let httpConn: Deno.HttpConn;
     async function server() {
       const listener = Deno.listen({ hostname, port });
       const tcpConn = await listener.accept();
-      const httpConn = Deno.serveHttp(tcpConn);
+      httpConn = Deno.serveHttp(tcpConn);
       const e = await httpConn.nextRequest();
       assert(e);
       const { request, respondWith } = e;
@@ -1597,7 +1625,6 @@ Deno.test({
         },
       );
       await respondWith(response);
-      httpConn.close();
       listener.close();
     }
 
@@ -1627,6 +1654,7 @@ Deno.test({
     }
 
     await Promise.all([server(), client()]);
+    httpConn!.close();
   },
 });
 
@@ -1637,10 +1665,11 @@ Deno.test({
     const hostname = "localhost";
     const port = 4501;
 
+    let httpConn: Deno.HttpConn;
     async function server() {
       const listener = Deno.listen({ hostname, port });
       const tcpConn = await listener.accept();
-      const httpConn = Deno.serveHttp(tcpConn);
+      httpConn = Deno.serveHttp(tcpConn);
       const e = await httpConn.nextRequest();
       assert(e);
       const { request, respondWith } = e;
@@ -1655,7 +1684,6 @@ Deno.test({
         },
       );
       await respondWith(response);
-      httpConn.close();
       listener.close();
     }
 
@@ -1684,6 +1712,7 @@ Deno.test({
     }
 
     await Promise.all([server(), client()]);
+    httpConn!.close();
   },
 });
 
@@ -1694,10 +1723,11 @@ Deno.test({
     const hostname = "localhost";
     const port = 4501;
 
+    let httpConn: Deno.HttpConn;
     async function server() {
       const listener = Deno.listen({ hostname, port });
       const tcpConn = await listener.accept();
-      const httpConn = Deno.serveHttp(tcpConn);
+      httpConn = Deno.serveHttp(tcpConn);
       const e = await httpConn.nextRequest();
       assert(e);
       const { request, respondWith } = e;
@@ -1712,7 +1742,6 @@ Deno.test({
         },
       );
       await respondWith(response);
-      httpConn.close();
       listener.close();
     }
 
@@ -1738,6 +1767,7 @@ Deno.test({
     }
 
     await Promise.all([server(), client()]);
+    httpConn!.close();
   },
 });
 
@@ -1748,10 +1778,11 @@ Deno.test({
     const hostname = "localhost";
     const port = 4501;
 
+    let httpConn: Deno.HttpConn;
     async function server() {
       const listener = Deno.listen({ hostname, port });
       const tcpConn = await listener.accept();
-      const httpConn = Deno.serveHttp(tcpConn);
+      httpConn = Deno.serveHttp(tcpConn);
       const e = await httpConn.nextRequest();
       assert(e);
       const { request, respondWith } = e;
@@ -1766,7 +1797,6 @@ Deno.test({
         },
       );
       await respondWith(response);
-      httpConn.close();
       listener.close();
     }
 
@@ -1792,6 +1822,7 @@ Deno.test({
     }
 
     await Promise.all([server(), client()]);
+    httpConn!.close();
   },
 });
 
@@ -1807,9 +1838,10 @@ Deno.test({
 
     const data = { hello: "deno", now: "with", compressed: "body" };
 
+    let httpConn: Deno.HttpConn;
     async function server() {
       const tcpConn = await listener.accept();
-      const httpConn = Deno.serveHttp(tcpConn);
+      httpConn = Deno.serveHttp(tcpConn);
       const e = await httpConn.nextRequest();
       assert(e);
       const { request, respondWith } = e;
@@ -1825,7 +1857,6 @@ Deno.test({
         { headers: { "content-type": "application/json" } },
       );
       await respondWith(response);
-      httpConn.close();
       listener.close();
     }
 
@@ -1852,6 +1883,7 @@ Deno.test({
     }
 
     await Promise.all([server(), client()]);
+    httpConn!.close();
   },
 });
 
@@ -1867,9 +1899,10 @@ Deno.test({
 
     const data = { hello: "deno", now: "with", compressed: "body" };
 
+    let httpConn: Deno.HttpConn;
     async function server() {
       const tcpConn = await listener.accept();
-      const httpConn = Deno.serveHttp(tcpConn);
+      httpConn = Deno.serveHttp(tcpConn);
       const e = await httpConn.nextRequest();
       assert(e);
       const { request, respondWith } = e;
@@ -1885,7 +1918,6 @@ Deno.test({
         { headers: { "content-type": "application/json" } },
       );
       await respondWith(response);
-      httpConn.close();
       listener.close();
     }
 
@@ -1913,6 +1945,7 @@ Deno.test({
     }
 
     await Promise.all([server(), client()]);
+    httpConn!.close();
   },
 });
 
@@ -1924,10 +1957,11 @@ Deno.test({
     const port = 4501;
     let contentLength: string;
 
+    let httpConn: Deno.HttpConn;
     async function server() {
       const listener = Deno.listen({ hostname, port });
       const tcpConn = await listener.accept();
-      const httpConn = Deno.serveHttp(tcpConn);
+      httpConn = Deno.serveHttp(tcpConn);
       const e = await httpConn.nextRequest();
       assert(e);
       const { request, respondWith } = e;
@@ -1948,7 +1982,6 @@ Deno.test({
         },
       );
       await respondWith(response);
-      httpConn.close();
       listener.close();
     }
 
@@ -1977,6 +2010,7 @@ Deno.test({
     }
 
     await Promise.all([server(), client()]);
+    httpConn!.close();
   },
 });
 
@@ -1988,10 +2022,11 @@ Deno.test({
     const port = 4501;
     let contentLength: string;
 
+    let httpConn: Deno.HttpConn;
     async function server() {
       const listener = Deno.listen({ hostname, port });
       const tcpConn = await listener.accept();
-      const httpConn = Deno.serveHttp(tcpConn);
+      httpConn = Deno.serveHttp(tcpConn);
       const e = await httpConn.nextRequest();
       assert(e);
       const { request, respondWith } = e;
@@ -2007,7 +2042,6 @@ Deno.test({
         },
       );
       await respondWith(response);
-      httpConn.close();
       listener.close();
     }
 
@@ -2037,6 +2071,7 @@ Deno.test({
     }
 
     await Promise.all([server(), client()]);
+    httpConn!.close();
   },
 });
 
@@ -2048,10 +2083,11 @@ Deno.test({
     const port = 4501;
     let contentLength: string;
 
+    let httpConn: Deno.HttpConn;
     async function server() {
       const listener = Deno.listen({ hostname, port });
       const tcpConn = await listener.accept();
-      const httpConn = Deno.serveHttp(tcpConn);
+      httpConn = Deno.serveHttp(tcpConn);
       const e = await httpConn.nextRequest();
       assert(e);
       const { request, respondWith } = e;
@@ -2068,7 +2104,6 @@ Deno.test({
         },
       );
       await respondWith(response);
-      httpConn.close();
       listener.close();
     }
 
@@ -2095,6 +2130,7 @@ Deno.test({
     }
 
     await Promise.all([server(), client()]);
+    httpConn!.close();
   },
 });
 
@@ -2248,7 +2284,7 @@ Deno.test("upgradeHttp unix", {
     const resp = new Response(null, { status: 101 });
     await respondWith(resp);
     await promise;
-    httpConn.close();
+    httpConn!.close();
   })();
 
   await Promise.all([server, client()]);

core/01_core.js

@@ -160,10 +160,11 @@
 
   function opAsync(opName, ...args) {
     const promiseId = nextPromiseId++;
+    let p = setPromise(promiseId);
     const maybeError = ops[opName](promiseId, ...args);
     // Handle sync error (e.g: error parsing args)
     if (maybeError) return unwrapOpResult(maybeError);
-    let p = PromisePrototypeThen(setPromise(promiseId), unwrapOpResult);
+    p = PromisePrototypeThen(p, unwrapOpResult);
     if (opCallTracingEnabled) {
       // Capture a stack trace by creating a new `Error` object. We remove the
       // first 6 characters (the `Error\n` prefix) to get just the stack trace.

core/ops.rs

@@ -28,17 +28,25 @@ use std::task::Poll;
 /// turn of the event loop, which is too late for certain ops.
 pub struct OpCall<T>(MaybeDone<Pin<Box<dyn Future<Output = T>>>>);
 
+pub enum EagerPollResult<T> {
+  Ready(T),
+  Pending(OpCall<T>),
+}
+
 impl<T> OpCall<T> {
   /// Wraps a future, and polls the inner future immediately.
   /// This should be the default choice for ops.
-  pub fn eager(fut: impl Future<Output = T> + 'static) -> Self {
+  pub fn eager(fut: impl Future<Output = T> + 'static) -> EagerPollResult<T> {
     let boxed = Box::pin(fut) as Pin<Box<dyn Future<Output = T>>>;
     let mut inner = maybe_done(boxed);
     let waker = noop_waker();
     let mut cx = Context::from_waker(&waker);
     let mut pinned = Pin::new(&mut inner);
-    let _ = pinned.as_mut().poll(&mut cx);
+    let poll = pinned.as_mut().poll(&mut cx);
-    Self(inner)
+    match poll {
+      Poll::Ready(_) => EagerPollResult::Ready(pinned.take_output().unwrap()),
+      _ => EagerPollResult::Pending(Self(inner)),
+    }
   }
 
   /// Wraps a future; the inner future is polled the usual way (lazily).

core/runtime.rs

@@ -2145,14 +2145,54 @@ impl JsRealm {
 
 #[inline]
 pub fn queue_async_op(
-  scope: &v8::Isolate,
+  state: Rc<RefCell<OpState>>,
+  scope: &mut v8::HandleScope,
+  deferred: bool,
   op: impl Future<Output = (v8::Global<v8::Context>, PromiseId, OpId, OpResult)>
     + 'static,
 ) {
+  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((context, promise_id, op_id, mut resp))
+      if !deferred =>
+    {
+      let args = &[
+        v8::Integer::new(scope, promise_id).into(),
+        resp.to_v8(scope).unwrap(),
+      ];
+
+      let realm = JsRealm::new(context);
+      let js_recv_cb_handle =
+        realm.state(scope).borrow().js_recv_cb.clone().unwrap();
+      state.borrow().tracker.track_async_completed(op_id);
+
+      let tc_scope = &mut v8::TryCatch::new(scope);
+      let js_recv_cb = js_recv_cb_handle.open(tc_scope);
+      let this = v8::undefined(tc_scope).into();
+      js_recv_cb.call(tc_scope, this, args);
+    }
+    EagerPollResult::Ready(op) => {
+      let ready = OpCall::ready(op);
       let state_rc = JsRuntime::state(scope);
       let mut state = state_rc.borrow_mut();
-  state.pending_ops.push(OpCall::eager(op));
+      state.pending_ops.push(ready);
       state.have_unpolled_ops = true;
+    }
+    EagerPollResult::Pending(op) => {
+      let state_rc = JsRuntime::state(scope);
+      let mut state = state_rc.borrow_mut();
+      state.pending_ops.push(op);
+      state.have_unpolled_ops = true;
+    }
+  }
 }
 
 #[cfg(test)]
@@ -2194,7 +2234,7 @@ pub mod tests {
     dispatch_count: Arc<AtomicUsize>,
   }
 
-  #[op]
+  #[op(deferred)]
   async fn op_test(
     rc_op_state: Rc<RefCell<OpState>>,
     control: u8,
@@ -2255,41 +2295,6 @@ pub mod tests {
     (runtime, dispatch_count)
   }
 
-  #[test]
-  fn test_dispatch() {
-    let (mut runtime, dispatch_count) = setup(Mode::Async);
-    runtime
-      .execute_script(
-        "filename.js",
-        r#"
-        let control = 42;
-        Deno.core.opAsync("op_test", control);
-        async function main() {
-          Deno.core.opAsync("op_test", control);
-        }
-        main();
-        "#,
-      )
-      .unwrap();
-    assert_eq!(dispatch_count.load(Ordering::Relaxed), 2);
-  }
-
-  #[test]
-  fn test_op_async_promise_id() {
-    let (mut runtime, _dispatch_count) = setup(Mode::Async);
-    runtime
-      .execute_script(
-        "filename.js",
-        r#"
-        const p = Deno.core.opAsync("op_test", 42);
-        if (p[Symbol.for("Deno.core.internalPromiseId")] == undefined) {
-          throw new Error("missing id on returned promise");
-        }
-        "#,
-      )
-      .unwrap();
-  }
-
   #[test]
   fn test_ref_unref_ops() {
     let (mut runtime, _dispatch_count) = setup(Mode::Async);
@@ -2344,6 +2349,41 @@ pub mod tests {
     }
   }
 
+  #[test]
+  fn test_dispatch() {
+    let (mut runtime, dispatch_count) = setup(Mode::Async);
+    runtime
+      .execute_script(
+        "filename.js",
+        r#"
+        let control = 42;
+        Deno.core.opAsync("op_test", control);
+        async function main() {
+          Deno.core.opAsync("op_test", control);
+        }
+        main();
+        "#,
+      )
+      .unwrap();
+    assert_eq!(dispatch_count.load(Ordering::Relaxed), 2);
+  }
+
+  #[test]
+  fn test_op_async_promise_id() {
+    let (mut runtime, _dispatch_count) = setup(Mode::Async);
+    runtime
+      .execute_script(
+        "filename.js",
+        r#"
+        const p = Deno.core.opAsync("op_test", 42);
+        if (p[Symbol.for("Deno.core.internalPromiseId")] == undefined) {
+          throw new Error("missing id on returned promise");
+        }
+        "#,
+      )
+      .unwrap();
+  }
+
   #[test]
   fn test_dispatch_no_zero_copy_buf() {
     let (mut runtime, dispatch_count) = setup(Mode::AsyncZeroCopy(false));

ext/web/timers.rs

@@ -93,7 +93,7 @@ pub fn op_timer_handle(state: &mut OpState) -> ResourceId {
 
 /// Waits asynchronously until either `millis` milliseconds have passed or the
 /// [`TimerHandle`] resource given by `rid` has been canceled.
-#[op]
+#[op(deferred)]
 pub async fn op_sleep(
   state: Rc<RefCell<OpState>>,
   millis: u64,

ext/websocket/lib.rs

@@ -420,7 +420,7 @@ pub async fn op_ws_send(
   Ok(())
 }
 
-#[op]
+#[op(deferred)]
 pub async fn op_ws_close(
   state: Rc<RefCell<OpState>>,
   rid: ResourceId,

ops/lib.rs

@@ -51,6 +51,7 @@ struct MacroArgs {
   is_unstable: bool,
   is_v8: bool,
   must_be_fast: bool,
+  deferred: bool,
 }
 
 impl syn::parse::Parse for MacroArgs {
@@ -62,7 +63,7 @@ impl syn::parse::Parse for MacroArgs {
     let vars: Vec<_> = vars.iter().map(Ident::to_string).collect();
     let vars: Vec<_> = vars.iter().map(String::as_str).collect();
     for var in vars.iter() {
-      if !["unstable", "v8", "fast"].contains(var) {
+      if !["unstable", "v8", "fast", "deferred"].contains(var) {
         return Err(syn::Error::new(
           input.span(),
           "Ops expect #[op] or #[op(unstable)]",
@@ -73,6 +74,7 @@ impl syn::parse::Parse for MacroArgs {
       is_unstable: vars.contains(&"unstable"),
       is_v8: vars.contains(&"v8"),
       must_be_fast: vars.contains(&"fast"),
+      deferred: vars.contains(&"deferred"),
     })
   }
 }
@@ -84,6 +86,7 @@ pub fn op(attr: TokenStream, item: TokenStream) -> TokenStream {
     is_unstable,
     is_v8,
     must_be_fast,
+    deferred,
   } = margs;
   let func = syn::parse::<syn::ItemFn>(item).expect("expected a function");
   let name = &func.sig.ident;
@@ -110,7 +113,7 @@ pub fn op(attr: TokenStream, item: TokenStream) -> TokenStream {
   let asyncness = func.sig.asyncness.is_some();
   let is_async = asyncness || is_future(&func.sig.output);
   let v8_body = if is_async {
-    codegen_v8_async(&core, &func, margs, asyncness)
+    codegen_v8_async(&core, &func, margs, asyncness, deferred)
   } else {
     codegen_v8_sync(&core, &func, margs)
   };
@@ -173,6 +176,7 @@ fn codegen_v8_async(
   f: &syn::ItemFn,
   margs: MacroArgs,
   asyncness: bool,
+  deferred: bool,
 ) -> TokenStream2 {
   let MacroArgs { is_v8, .. } = margs;
   let special_args = f
@@ -256,7 +260,7 @@ fn codegen_v8_async(
     };
 
     #pre_result
-    #core::_ops::queue_async_op(scope, async move {
+    #core::_ops::queue_async_op(state, scope, #deferred, async move {
       let result = #result_fut
       #result_wrapper
       (context, promise_id, op_id, #core::_ops::to_op_result(get_class, result))

runtime/js/40_testing.js

@@ -147,6 +147,7 @@
         // cleared can actually be removed from resource table, otherwise
         // false positives may occur (https://github.com/denoland/deno/issues/4591)
         await opSanitizerDelay();
+        await opSanitizerDelay();
       }
 
       if (shouldSkipSanitizers(desc)) return;

runtime/ops/web_worker.rs

@@ -39,7 +39,7 @@ fn op_worker_post_message(
   Ok(())
 }
 
-#[op]
+#[op(deferred)]
 async fn op_worker_recv_message(
   state: Rc<RefCell<OpState>>,
 ) -> Result<Option<JsMessageData>, AnyError> {