benchmark: add MessagePort benchmark

Add a raw `MessagePort` benchmark that does not ping back and forth
between different threads, unlike the `echo.js` benchmark, as there
are some performance differences between single-threaded and multi-
threaded operation, and a single-threaded Environment can be somewhat
easier to work with when profiling.

PR-URL: #31568
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Denys Otrishko <shishugi@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>

Author: addaleax

benchmark/worker/messageport.js

@@ -0,0 +1,42 @@
+'use strict';
+
+const common = require('../common.js');
+const { MessageChannel } = require('worker_threads');
+const bench = common.createBenchmark(main, {
+  payload: ['string', 'object'],
+  n: [1e6]
+});
+
+function main(conf) {
+  const n = conf.n;
+  let payload;
+
+  switch (conf.payload) {
+    case 'string':
+      payload = 'hello world!';
+      break;
+    case 'object':
+      payload = { action: 'pewpewpew', powerLevel: 9001 };
+      break;
+    default:
+      throw new Error('Unsupported payload type');
+  }
+
+  const { port1, port2 } = new MessageChannel();
+
+  let messages = 0;
+  port2.onmessage = () => {
+    if (messages++ === n) {
+      bench.end(n);
+      port1.close();
+    } else {
+      write();
+    }
+  };
+  bench.start();
+  write();
+
+  function write() {
+    port1.postMessage(payload);
+  }
+}