1 files changed, 78 insertions, 0 deletions
diff --git a/bench/callbacks-overhead.mjs b/bench/callbacks-overhead.mjs
new file mode 100644
index 000000000..65171145c
--- /dev/null
+++ b/bench/callbacks-overhead.mjs
@@ -0,0 +1,78 @@
+const iterations = 1_000;
+
+export var report = {
+  async: 0,
+  callback: 0,
+  sync: 0,
+  then: 0,
+};
+
+const tests = {
+  callback(n, cb) {
+    if (n === iterations) return cb();
+    tests.callback(1 + n, () => cb());
+  },
+
+  sync(n) {
+    if (n === iterations) return;
+
+    tests.sync(1 + n);
+  },
+
+  async async(n) {
+    if (n === iterations) return;
+
+    await tests.async(1 + n);
+  },
+
+  then(n) {
+    if (n === iterations) return;
+    return Promise.resolve(1 + n).then(tests.then);
+  },
+};
+
+async function test(log) {
+  {
+    const a = performance.now();
+    await tests.async(0);
+    if (log)
+      console.log(
+        `async/await: ${(report.async = (performance.now() - a).toFixed(4))}ms`
+      );
+  }
+
+  {
+    const a = performance.now();
+    tests.callback(0, function () {
+      if (log)
+        console.log(
+          `callback: ${(report.callback = (performance.now() - a).toFixed(
+            4
+          ))}ms`
+        );
+    });
+  }
+
+  {
+    const a = performance.now();
+    await tests.then(0);
+    if (log)
+      console.log(
+        `then: ${(report.then = (performance.now() - a).toFixed(4))}ms`
+      );
+  }
+
+  {
+    const a = performance.now();
+    tests.sync(0);
+    if (log)
+      console.log(
+        `sync: ${(report.sync = (performance.now() - a).toFixed(4))}ms`
+      );
+  }
+}
+
+let warmup = 10;
+while (warmup--) await test();
+
+await test(true);