worker: add eventLoopUtilization()

Allow calling eventLoopUtilization() directly on a worker thread:

    const worker = new Worker('./foo.js');
    const elu = worker.performance.eventLoopUtilization();
    setTimeout(() => {
      worker.performance.eventLoopUtilization(elu);
    }, 10);

Add a new performance object on the Worker instance that will hopefully
one day hold all the other performance metrics, such as nodeTiming.

Include benchmarks and tests.

PR-URL: https://github.com/nodejs/node/pull/35664
Reviewed-By: Juan José Arboleda <soyjuanarbol@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Gerhard Stöbich <deb2001-github@yahoo.de>
Reviewed-By: James M Snell <jasnell@gmail.com>

1 files changed, 61 insertions, 0 deletions

diff --git a/benchmark/worker/bench-eventlooputil.js b/benchmark/worker/bench-eventlooputil.js
new file mode 100644
index 0000000000..2d59f9f19e
--- /dev/null
+++ b/benchmark/worker/bench-eventlooputil.js
@@ -0,0 +1,61 @@
+'use strict';
+
+const common = require('../common.js');
+const { Worker, parentPort } = require('worker_threads');
+
+if (process.argv[2] === 'idle cats') {
+  return parentPort.once('message', () => {});
+}
+
+const bench = common.createBenchmark(main, {
+  n: [1e6],
+  method: [
+    'ELU_simple',
+    'ELU_passed',
+  ],
+});
+
+function main({ method, n }) {
+  switch (method) {
+    case 'ELU_simple':
+      benchELUSimple(n);
+      break;
+    case 'ELU_passed':
+      benchELUPassed(n);
+      break;
+    default:
+      throw new Error(`Unsupported method ${method}`);
+  }
+}
+
+function benchELUSimple(n) {
+  const worker = new Worker(__filename, { argv: ['idle cats'] });
+
+  spinUntilIdle(worker, () => {
+    bench.start();
+    for (let i = 0; i < n; i++)
+      worker.performance.eventLoopUtilization();
+    bench.end(n);
+    worker.postMessage('bye');
+  });
+}
+
+function benchELUPassed(n) {
+  const worker = new Worker(__filename, { argv: ['idle cats'] });
+
+  spinUntilIdle(worker, () => {
+    let elu = worker.performance.eventLoopUtilization();
+    bench.start();
+    for (let i = 0; i < n; i++)
+      elu = worker.performance.eventLoopUtilization(elu);
+    bench.end(n);
+    worker.postMessage('bye');
+  });
+}
+
+function spinUntilIdle(w, cb) {
+  const t = w.performance.eventLoopUtilization();
+  if (t.idle + t.active > 0)
+    return process.nextTick(cb);
+  setTimeout(() => spinUntilIdle(w, cb), 1);
+}