fixup! perf_hooks: web performance timeline compliance

Author: legendecas

benchmark/perf_hooks/usertiming.js

@@ -8,24 +8,27 @@ const {
 } = require('perf_hooks');
 
 const bench = common.createBenchmark(main, {
-  n: [1e5]
+  n: [1e5],
+  observe: ['all', 'measure'],
 });
 
 function test() {
   performance.mark('a');
-  setImmediate(() => {
-    performance.mark('b');
-    performance.measure('a to b', 'a', 'b');
-  });
+  performance.mark('b');
+  performance.measure('a to b', 'a', 'b');
 }
 
-function main({ n }) {
+function main({ n, observe }) {
+  const entryTypes = observe === 'all' ?
+    [ 'mark', 'measure' ] :
+    [ observe ];
   const obs = new PerformanceObserver(() => {
     bench.end(n);
   });
-  obs.observe({ entryTypes: ['measure'], buffered: true });
+  obs.observe({ entryTypes, buffered: true });
 
   bench.start();
-  for (let i = 0; i < n; i++)
+  performance.mark('start');
+  for (let i = 0; i < 1e5; i++)
     test();
 }

lib/internal/perf/observe.js

@@ -9,6 +9,7 @@ const {
   ArrayPrototypePush,
   ArrayPrototypeSlice,
   ArrayPrototypeSort,
+  Error,
   ObjectDefineProperties,
   ObjectFreeze,
   ObjectKeys,
@@ -32,6 +33,7 @@ const {
 const {
   InternalPerformanceEntry,
   isPerformanceEntry,
+  kBufferNext,
 } = require('internal/perf/performance_entry');
 
 const {
@@ -83,12 +85,17 @@ const kSupportedEntryTypes = ObjectFreeze([
   'mark',
   'measure',
 ]);
-const kTimelineEntryTypes = ObjectFreeze([
-  'mark',
-  'measure',
-]);
 
-const kPerformanceEntryBuffer = new SafeMap();
+// Performance timeline entry Buffers
+const markEntryBuffer = createBuffer();
+const measureEntryBuffer = createBuffer();
+const kMaxPerformanceEntryBuffers = 1e6;
+const kClearPerformanceEntryBuffers = ObjectFreeze({
+  'mark': 'performance.clearMarks',
+  'measure': 'performance.clearMeasures',
+});
+const kWarnedEntryTypes = new SafeMap();
+
 const kObservers = new SafeSet();
 const kPending = new SafeSet();
 let isPending = false;
@@ -238,7 +245,7 @@ class PerformanceObserver {
       maybeIncrementObserverCount(type);
       if (buffered) {
         const entries = filterBufferMapByNameAndType(undefined, type);
-        this[kBuffer].push(...entries);
+        ArrayPrototypePush(this[kBuffer], ...entries);
         kPending.add(this);
         if (kPending.size)
           queuePending();
@@ -307,50 +314,97 @@ function enqueue(entry) {
   }
 
   const entryType = entry.entryType;
-  if (!kTimelineEntryTypes.includes(entryType)) {
+  let buffer;
+  if (entryType === 'mark') {
+    buffer = markEntryBuffer;
+  } else if (entryType === 'measure') {
+    buffer = measureEntryBuffer;
+  } else {
     return;
   }
-  const buffer = getEntryBuffer(entryType);
-  buffer.push(entry);
+
+  const count = buffer.count + 1;
+  buffer.count = count;
+  if (count === 1) {
+    buffer.head = entry;
+    buffer.tail = entry;
+    return;
+  }
+  buffer.tail[kBufferNext] = entry;
+  buffer.tail = entry;
+
+  if (count > kMaxPerformanceEntryBuffers &&
+    !kWarnedEntryTypes.has(entryType)) {
+    kWarnedEntryTypes.set(entryType, true);
+    // No error code for this since it is a Warning
+    // eslint-disable-next-line no-restricted-syntax
+    const w = new Error('Possible perf_hooks memory leak detected. ' +
+                        `${count} ${entryType} entries added to the global ` +
+                        'performance entry buffer. Use ' +
+                        `${kClearPerformanceEntryBuffers[entryType]} to ` +
+                        'clear the buffer.');
+    w.name = 'MaxPerformanceEntryBufferExceededWarning';
+    w.entryType = entryType;
+    w.count = count;
+    process.emitWarning(w);
+  }
 }
 
 function clearEntriesFromBuffer(type, name) {
+  let buffer;
+  if (type === 'mark') {
+    buffer = markEntryBuffer;
+  } else if (type === 'measure') {
+    buffer = measureEntryBuffer;
+  } else {
+    return;
+  }
   if (name === undefined) {
-    kPerformanceEntryBuffer.delete(type);
+    resetBuffer(buffer);
     return;
   }
-  let buffer = getEntryBuffer(type);
-  buffer = ArrayPrototypeFilter(
-    buffer,
-    (entry) => entry.name !== name);
-  kPerformanceEntryBuffer.set(type, buffer);
-}
 
-function getEntryBuffer(type) {
-  let buffer = kPerformanceEntryBuffer.get(type);
-  if (buffer === undefined) {
-    buffer = [];
-    kPerformanceEntryBuffer.set(type, buffer);
+  let head = null;
+  let tail = null;
+  for (let entry = buffer.head; entry !== null; entry = entry[kBufferNext]) {
+    if (entry.name !== name) {
+      head = head ?? entry;
+      tail = entry;
+      continue;
+    }
+    if (tail === null) {
+      continue;
+    }
+    tail[kBufferNext] = entry[kBufferNext];
   }
-  return buffer;
+  buffer.head = head;
+  buffer.tail = tail;
 }
 
 function filterBufferMapByNameAndType(name, type) {
   let bufferList;
-  if (type !== undefined) {
-    bufferList = kPerformanceEntryBuffer.get(type) ?? [];
+  if (type === 'mark') {
+    bufferList = [markEntryBuffer];
+  } else if (type === 'measure') {
+    bufferList = [measureEntryBuffer];
+  } else if (type !== undefined) {
+    // Unrecognized type;
+    return [];
   } else {
-    bufferList = ArrayFrom(kPerformanceEntryBuffer.values());
+    bufferList = [markEntryBuffer, measureEntryBuffer];
   }
   return ArrayPrototypeFlatMap(bufferList,
                                (buffer) => filterBufferByName(buffer, name));
 }
 
 function filterBufferByName(buffer, name) {
-  if (name === undefined) {
-    return buffer;
+  const arr = [];
+  for (let entry = buffer.head; entry !== null; entry = entry[kBufferNext]) {
+    if (name === undefined || entry.name === name) {
+      ArrayPrototypePush(arr, entry);
+    }
   }
-  return ArrayPrototypeFilter(buffer, (it) => it.name === name);
+  return arr;
 }
 
 function observerCallback(name, type, startTime, duration, details) {
@@ -398,6 +452,20 @@ function hasObserver(type) {
   return observerCounts[observerType] > 0;
 }
 
+function createBuffer() {
+  return {
+    head: null,
+    tail: null,
+    count: 0,
+  };
+}
+
+function resetBuffer(buffer) {
+  buffer.head = null;
+  buffer.tail = null;
+  buffer.count = 0;
+}
+
 module.exports = {
   PerformanceObserver,
   enqueue,

lib/internal/perf/performance_entry.js

@@ -17,6 +17,7 @@ const kType = Symbol('kType');
 const kStart = Symbol('kStart');
 const kDuration = Symbol('kDuration');
 const kDetail = Symbol('kDetail');
+const kBufferNext = Symbol('kBufferNext');
 
 function isPerformanceEntry(obj) {
   return obj?.[kName] !== undefined;
@@ -67,6 +68,7 @@ class InternalPerformanceEntry {
     this[kStart] = start;
     this[kDuration] = duration;
     this[kDetail] = detail;
+    this[kBufferNext] = null;
   }
 }
 
@@ -79,4 +81,5 @@ module.exports = {
   InternalPerformanceEntry,
   PerformanceEntry,
   isPerformanceEntry,
+  kBufferNext,
 };