bootstrap: load perf_hooks eagerly during bootstrap

nodejs · Jun 8, 2021 · c59009e · c59009e
1 parent f0a70fa
commit c59009e
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Showing 3 changed files with 11 additions and 24 deletions.
diff --git a/lib/internal/bootstrap/node.js b/lib/internal/bootstrap/node.js
@@ -241,10 +241,9 @@ if (!config.noBrowserGlobals) {
 
   defineOperation(globalThis, 'queueMicrotask', queueMicrotask);
 
-  defineLazyGlobal(globalThis, 'performance', () => {
-    const { performance } = require('perf_hooks');
-    return performance;
-  });
+  // https://www.w3.org/TR/hr-time-2/#the-performance-attribute
+  defineReplacableAttribute(globalThis, 'performance',
+                            require('perf_hooks').performance);
 
   // Non-standard extensions:
   defineOperation(globalThis, 'clearImmediate', timers.clearImmediate);
@@ -494,20 +493,12 @@ function defineOperation(target, name, method) {
   });
 }
 
-function defineLazyGlobal(target, name, loader) {
-  let value;
-  let overridden = false;
+// https://heycam.github.io/webidl/#Replaceable
+function defineReplacableAttribute(target, name, value) {
   ObjectDefineProperty(target, name, {
+    writable: true,
     enumerable: true,
     configurable: true,
-    get() {
-      if (value === undefined && !overridden)
-        value = loader();
-      return value;
-    },
-    set(val) {
-      value = val;
-      overridden = true;
-    }
+    value,
   });
 }
diff --git a/lib/internal/event_target.js b/lib/internal/event_target.js
@@ -59,13 +59,7 @@ const kRemoveListener = Symbol('kRemoveListener');
 const kIsNodeStyleListener = Symbol('kIsNodeStyleListener');
 const kTrustEvent = Symbol('kTrustEvent');
 
-// Lazy load perf_hooks to avoid the additional overhead on startup
-let perf_hooks;
-function lazyNow() {
-  if (perf_hooks === undefined)
-    perf_hooks = require('perf_hooks');
-  return perf_hooks.performance.now();
-}
+const { now } = require('internal/perf/utils');
 
 // TODO(joyeecheung): V8 snapshot does not support instance member
 // initializers for now:
@@ -98,7 +92,7 @@ class Event {
     this[kComposed] = !!composed;
     this[kType] = `${type}`;
     this[kDefaultPrevented] = false;
-    this[kTimestamp] = lazyNow();
+    this[kTimestamp] = now();
     this[kPropagationStopped] = false;
     if (options?.[kTrustEvent]) {
       isTrustedSet.add(this);

diff --git a/test/parallel/test-bootstrap-modules.js b/test/parallel/test-bootstrap-modules.js
@@ -79,6 +79,7 @@ const expectedModules = new Set([
   'NativeModule internal/modules/esm/translators',
   'NativeModule internal/process/esm_loader',
   'NativeModule internal/options',
+  'NativeModule internal/perf/event_loop_delay',
   'NativeModule internal/perf/event_loop_utilization',
   'NativeModule internal/perf/nodetiming',
   'NativeModule internal/perf/observe',
@@ -126,6 +127,7 @@ const expectedModules = new Set([
   'NativeModule internal/blob',
   'NativeModule async_hooks',
   'NativeModule path',
+  'NativeModule perf_hooks',
   'NativeModule querystring',
   'NativeModule stream',
   'NativeModule stream/promises',