perf_hooks: refactor perf_hooks for snapshot building

- Move Performance and InternalPerformance to a new lib/internal/perf/performance.js - Move now() getMilestoneTimestamp() into lib/internal/perf/utils.js - Rename lib/internal/perf/perf.js to lib/internal/perf/performance_entry.js - Refresh time origin at startup (this means the time origins could differ between snapshot building time and snapshot creation time)
nodejs · joyeecheung · Jun 8, 2021 · Jun 8, 2021 · Jun 8, 2021 · Jun 25, 2021
commit 9064c0d977b3515990c67483fc7e3d75b8561d2d
diff --git a/lib/internal/bootstrap/pre_execution.js b/lib/internal/bootstrap/pre_execution.js
@@ -27,6 +27,7 @@ function prepareMainThreadExecution(expandArgv1 = false) {
   // Patch the process object with legacy properties and normalizations
   patchProcessObject(expandArgv1);
   setupTraceCategoryState();
+  setupPerfHooks();
   setupInspectorHooks();
   setupWarningHandler();
 
@@ -222,6 +223,11 @@ function setupTraceCategoryState() {
   toggleTraceCategoryState(isTraceCategoryEnabled('node.async_hooks'));
 }
 
+function setupPerfHooks() {
+  require('internal/perf/performance').refreshTimeOrigin();
+  require('internal/perf/utils').refreshTimeOrigin();
+}
+
 function setupInspectorHooks() {
   // If Debugger.setAsyncCallStackDepth is sent during bootstrap,
   // we cannot immediately call into JS to enable the hooks, which could
@@ -474,6 +480,7 @@ module.exports = {
   setupCoverageHooks,
   setupWarningHandler,
   setupDebugEnv,
+  setupPerfHooks,
   prepareMainThreadExecution,
   initializeDeprecations,
   initializeESMLoader,

diff --git a/lib/internal/http.js b/lib/internal/http.js
@@ -9,7 +9,7 @@ const {
 
 const { setUnrefTimeout } = require('internal/timers');
 
-const { InternalPerformanceEntry } = require('internal/perf/perf');
+const { InternalPerformanceEntry } = require('internal/perf/performance_entry');
 
 const {
   enqueue,

diff --git a/lib/internal/main/worker_thread.js b/lib/internal/main/worker_thread.js
@@ -18,6 +18,7 @@ const {
   setupInspectorHooks,
   setupWarningHandler,
   setupDebugEnv,
+  setupPerfHooks,
   initializeDeprecations,
   initializeWASI,
   initializeCJSLoader,
@@ -114,6 +115,7 @@ port.on('message', (message) => {
     } = message;
 
     setupTraceCategoryState();
+    setupPerfHooks();
     initializeReport();
     if (manifestSrc) {
       require('internal/process/policy').setup(manifestSrc, manifestURL);

diff --git a/lib/internal/perf/event_loop_utilization.js b/lib/internal/perf/event_loop_utilization.js
@@ -2,7 +2,7 @@
 
 const nodeTiming = require('internal/perf/nodetiming');
 
-const { now } = require('internal/perf/perf');
+const { now } = require('internal/perf/utils');
 
 function eventLoopUtilization(util1, util2) {
   const ls = nodeTiming.loopStart;

diff --git a/lib/internal/perf/nodetiming.js b/lib/internal/perf/nodetiming.js
@@ -3,15 +3,14 @@
 const {
   ObjectDefineProperties,
   ObjectSetPrototypeOf,
-  SafeArrayIterator,
-  SafeSet,
 } = primordials;
 
+const { PerformanceEntry } = require('internal/perf/performance_entry');
+
 const {
-  PerformanceEntry,
-  kReadOnlyAttributes,
   now,
-} = require('internal/perf/perf');
+  getMilestoneTimestamp,
+} = require('internal/perf/utils');
 
 const {
   customInspectSymbol: kInspect,
@@ -29,26 +28,8 @@ const {
     NODE_PERFORMANCE_MILESTONE_ENVIRONMENT
   },
   loopIdleTime,
-  milestones,
-  timeOrigin,
 } = internalBinding('performance');
 
-function getMilestoneTimestamp(milestoneIdx) {
-  const ns = milestones[milestoneIdx];
-  if (ns === -1)
-    return ns;
-  return ns / 1e6 - timeOrigin;
-}
-
-const readOnlyAttributes = new SafeSet(new SafeArrayIterator([
-  'nodeStart',
-  'v8Start',
-  'environment',
-  'loopStart',
-  'loopExit',
-  'bootstrapComplete',
-]));
-
 class PerformanceNodeTiming {
   constructor() {
     ObjectDefineProperties(this, {
@@ -159,10 +140,6 @@ class PerformanceNodeTiming {
       idleTime: this.idleTime,
     };
   }
-
-  static get [kReadOnlyAttributes]() {
-    return readOnlyAttributes;
-  }
 }
 
 ObjectSetPrototypeOf(

diff --git a/lib/internal/perf/observe.js b/lib/internal/perf/observe.js
@@ -31,7 +31,7 @@ const {
 const {
   InternalPerformanceEntry,
   isPerformanceEntry,
-} = require('internal/perf/perf');
+} = require('internal/perf/performance_entry');
 
 const {
   codes: {
@@ -174,11 +174,13 @@ class PerformanceObserverEntryList {
 }
 
 class PerformanceObserver {
-  [kBuffer] = [];
-  [kEntryTypes] = new SafeSet();
-  [kType] = undefined;
-
   constructor(callback) {
+    // TODO(joyeecheung): V8 snapshot does not support instance member
+    // initializers for now:
+    // https://bugs.chromium.org/p/v8/issues/detail?id=10704
+    this[kBuffer] = [];
+    this[kEntryTypes] = new SafeSet();
+    this[kType] = undefined;
     validateCallback(callback);
     this[kCallback] = callback;
   }

diff --git a/lib/internal/perf/performance.js b/lib/internal/perf/performance.js
@@ -0,0 +1,129 @@
+'use strict';
+
+const {
+  ObjectDefineProperty,
+  ObjectDefineProperties,
+  ObjectSetPrototypeOf,
+  TypeError,
+} = primordials;
+
+const {
+  EventTarget,
+} = require('internal/event_target');
+
+const { now } = require('internal/perf/utils');
+
+const {
+  mark,
+  measure,
+  clearMarks,
+} = require('internal/perf/usertiming');
+
+const eventLoopUtilization = require('internal/perf/event_loop_utilization');
+const nodeTiming = require('internal/perf/nodetiming');
+const timerify = require('internal/perf/timerify');
+const { customInspectSymbol: kInspect } = require('internal/util');
+const { inspect } = require('util');
+
+const {
+  getTimeOriginTimestamp
+} = internalBinding('performance');
+
+class Performance extends EventTarget {
+  constructor() {
+    // eslint-disable-next-line no-restricted-syntax
+    throw new TypeError('Illegal constructor');
+  }
+
+  [kInspect](depth, options) {
+    if (depth < 0) return this;
+
+    const opts = {
+      ...options,
+      depth: options.depth == null ? null : options.depth - 1
+    };
+
+    return `Performance ${inspect({
+      nodeTiming: this.nodeTiming,
+      timeOrigin: this.timeOrigin,
+    }, opts)}`;
+  }
+
+}
+
+function toJSON() {
+  return {
+    nodeTiming: this.nodeTiming,
+    timeOrigin: this.timeOrigin,
+    eventLoopUtilization: this.eventLoopUtilization()
+  };
+}
+
+class InternalPerformance extends EventTarget {}
+InternalPerformance.prototype.constructor = Performance.prototype.constructor;
+ObjectSetPrototypeOf(InternalPerformance.prototype, Performance.prototype);
+
+ObjectDefineProperties(Performance.prototype, {
+  clearMarks: {
+    configurable: true,
+    enumerable: false,
+    value: clearMarks,
+  },
+  eventLoopUtilization: {
+    configurable: true,
+    enumerable: false,
+    value: eventLoopUtilization,
+  },
+  mark: {
+    configurable: true,
+    enumerable: false,
+    value: mark,
+  },
+  measure: {
+    configurable: true,
+    enumerable: false,
+    value: measure,
+  },
+  nodeTiming: {
+    configurable: true,
+    enumerable: false,
+    value: nodeTiming,
+  },
+  now: {
+    configurable: true,
+    enumerable: false,
+    value: now,
+  },
+  timerify: {
+    configurable: true,
+    enumerable: false,
+    value: timerify,
+  },
+  // This would be updated during pre-execution in case
+  // the process is launched from a snapshot.
+  // TODO(joyeecheung): we may want to warn about access to
+  // this during snapshot building.
+  timeOrigin: {
+    configurable: true,
+    enumerable: true,
+    value: getTimeOriginTimestamp(),
+  },
+  toJSON: {
+    configurable: true,
+    enumerable: true,
+    value: toJSON,
+  }
+});
+
+function refreshTimeOrigin() {
+  ObjectDefineProperty(Performance.prototype, 'timeOrigin', {
+    configurable: true,
+    enumerable: true,
+    value: getTimeOriginTimestamp(),
+  });
+}
+
+module.exports = {
+  InternalPerformance,
+  refreshTimeOrigin
+};
diff --git a/lib/internal/perf/perf.js → lib/internal/perf/performance_entry.js b/lib/internal/perf/perf.js → lib/internal/perf/performance_entry.js
@@ -6,10 +6,6 @@ const {
   TypeError,
 } = primordials;
 
-const {
-  timeOrigin,
-} = internalBinding('performance');
-
 const {
   customInspectSymbol: kInspect,
 } = require('internal/util');
@@ -21,12 +17,6 @@ const kType = Symbol('kType');
 const kStart = Symbol('kStart');
 const kDuration = Symbol('kDuration');
 const kDetail = Symbol('kDetail');
-const kReadOnlyAttributes = Symbol('kReadOnlyAttributes');
-
-function now() {
-  const hr = process.hrtime();
-  return (hr[0] * 1000 + hr[1] / 1e6) - timeOrigin;
-}
 
 function isPerformanceEntry(obj) {
   return obj?.[kName] !== undefined;
@@ -88,7 +78,5 @@ ObjectSetPrototypeOf(
 module.exports = {
   InternalPerformanceEntry,
   PerformanceEntry,
-  kReadOnlyAttributes,
   isPerformanceEntry,
-  now,
 };
diff --git a/lib/internal/perf/timerify.js b/lib/internal/perf/timerify.js
@@ -9,10 +9,8 @@ const {
   Symbol,
 } = primordials;
 
-const {
-  InternalPerformanceEntry,
-  now,
-} = require('internal/perf/perf');
+const { InternalPerformanceEntry } = require('internal/perf/performance_entry');
+const { now } = require('internal/perf/utils');
 
 const {
   validateFunction,

diff --git a/lib/internal/perf/usertiming.js b/lib/internal/perf/usertiming.js
@@ -3,16 +3,13 @@
 const {
   ObjectKeys,
   SafeMap,
+  SafeSet,
+  SafeArrayIterator,
 } = primordials;
 
-const {
-  InternalPerformanceEntry,
-  kReadOnlyAttributes,
-  now,
-} = require('internal/perf/perf');
-
+const { InternalPerformanceEntry } = require('internal/perf/performance_entry');
+const { now } = require('internal/perf/utils');
 const { enqueue } = require('internal/perf/observe');
-
 const nodeTiming = require('internal/perf/nodetiming');
 
 const {
@@ -31,8 +28,15 @@ const {
 } = require('internal/errors');
 
 const marks = new SafeMap();
-const nodeTimingReadOnlyAttributes =
-  nodeTiming.constructor[kReadOnlyAttributes];
+
+const nodeTimingReadOnlyAttributes = new SafeSet(new SafeArrayIterator([
+  'nodeStart',
+  'v8Start',
+  'environment',
+  'loopStart',
+  'loopExit',
+  'bootstrapComplete',
+]));
 
 function getMark(name) {
   if (name === undefined) return;

diff --git a/lib/internal/perf/utils.js b/lib/internal/perf/utils.js
@@ -0,0 +1,33 @@
+'use strict';
+
+const binding = internalBinding('performance');
+const {
+  milestones,
+  getTimeOrigin,
+} = binding;
+
+// TODO(joyeecheung): we may want to warn about access to
+// this during snapshot building.
+let timeOrigin = getTimeOrigin();
+
+function now() {
+  const hr = process.hrtime();
+  return (hr[0] * 1000 + hr[1] / 1e6) - timeOrigin;
+}
+
+function getMilestoneTimestamp(milestoneIdx) {
+  const ns = milestones[milestoneIdx];
+  if (ns === -1)
+    return ns;
+  return ns / 1e6 - timeOrigin;
+}
+
+function refreshTimeOrigin() {
+  timeOrigin = getTimeOrigin();
+}
+
+module.exports = {
+  now,
+  getMilestoneTimestamp,
+  refreshTimeOrigin
+};