From cde3928a10627510ae0aee7728e5498a95235482 Mon Sep 17 00:00:00 2001
From: Anatoli Papirovski <anatoli.papirovski@postmates.com>
Date: Thu, 6 Jun 2019 09:18:41 +0200
Subject: [PATCH] process: improve queueMicrotask performance

Optimize the hot code paths of queueMicrotask by
not creating unnecessary objects, not looking up
properties on frozen primordials, etc.

PR-URL: https://github.com/nodejs/node/pull/28093
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Gus Caplan <me@gus.host>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
---
 lib/async_hooks.js                  | 26 +++++++++++++++-----------
 lib/internal/process/task_queues.js |  8 +++-----
 2 files changed, 18 insertions(+), 16 deletions(-)

diff --git a/lib/async_hooks.js b/lib/async_hooks.js
index 3a12a241ea5d5f..0c177055364e41 100644
--- a/lib/async_hooks.js
+++ b/lib/async_hooks.js
@@ -134,15 +134,16 @@ class AsyncResource {
   constructor(type, opts = {}) {
     validateString(type, 'type');
 
-    if (typeof opts === 'number') {
-      opts = { triggerAsyncId: opts, requireManualDestroy: false };
-    } else if (opts.triggerAsyncId === undefined) {
-      opts.triggerAsyncId = getDefaultTriggerAsyncId();
+    let triggerAsyncId = opts;
+    let requireManualDestroy = false;
+    if (typeof opts !== 'number') {
+      triggerAsyncId = opts.triggerAsyncId === undefined ?
+        getDefaultTriggerAsyncId() : opts.triggerAsyncId;
+      requireManualDestroy = !!opts.requireManualDestroy;
     }
 
     // Unlike emitInitScript, AsyncResource doesn't supports null as the
     // triggerAsyncId.
-    const triggerAsyncId = opts.triggerAsyncId;
     if (!Number.isSafeInteger(triggerAsyncId) || triggerAsyncId < -1) {
       throw new ERR_INVALID_ASYNC_ID('triggerAsyncId', triggerAsyncId);
     }
@@ -151,15 +152,14 @@ class AsyncResource {
     this[async_id_symbol] = asyncId;
     this[trigger_async_id_symbol] = triggerAsyncId;
 
-    // This prop name (destroyed) has to be synchronized with C++
-    const destroyed = { destroyed: false };
-    this[destroyedSymbol] = destroyed;
-
     if (initHooksExist()) {
       emitInit(asyncId, type, triggerAsyncId, this);
     }
 
-    if (!opts.requireManualDestroy) {
+    if (!requireManualDestroy) {
+      // This prop name (destroyed) has to be synchronized with C++
+      const destroyed = { destroyed: false };
+      this[destroyedSymbol] = destroyed;
       registerDestroyHook(this, asyncId, destroyed);
     }
   }
@@ -168,6 +168,8 @@ class AsyncResource {
     const asyncId = this[async_id_symbol];
     emitBefore(asyncId, this[trigger_async_id_symbol]);
     try {
+      if (thisArg === undefined)
+        return fn(...args);
       return Reflect.apply(fn, thisArg, args);
     } finally {
       emitAfter(asyncId);
@@ -175,7 +177,9 @@ class AsyncResource {
   }
 
   emitDestroy() {
-    this[destroyedSymbol].destroyed = true;
+    if (this[destroyedSymbol] !== undefined) {
+      this[destroyedSymbol].destroyed = true;
+    }
     emitDestroy(this[async_id_symbol]);
     return this;
   }
diff --git a/lib/internal/process/task_queues.js b/lib/internal/process/task_queues.js
index 1f203c86ed522f..34e925aaf57d08 100644
--- a/lib/internal/process/task_queues.js
+++ b/lib/internal/process/task_queues.js
@@ -128,15 +128,13 @@ function nextTick(callback) {
 }
 
 let AsyncResource;
+const defaultMicrotaskResourceOpts = { requireManualDestroy: true };
 function createMicrotaskResource() {
   // Lazy load the async_hooks module
-  if (!AsyncResource) {
+  if (AsyncResource === undefined) {
     AsyncResource = require('async_hooks').AsyncResource;
   }
-  return new AsyncResource('Microtask', {
-    triggerAsyncId: getDefaultTriggerAsyncId(),
-    requireManualDestroy: true,
-  });
+  return new AsyncResource('Microtask', defaultMicrotaskResourceOpts);
 }
 
 function runMicrotask() {