Optimize performance.mark and performance.measure (#52429)

Summary: Pull Request resolved: https://github.com/facebook/react-native/pull/52429 Changelog: [internal] This implements a significant optimization for `performance.mark` and `performance.measure`. After these changes, they take 1/3 of the time they took before. We've seen these methods show up too often in traces (in the Hermes sampling profiler) so this should significantly reduce their overhead. I found out that most of the time spent in `performance.mark` and `performance.measure` was creating the `PerformanceMark` and `PerformanceMeasure` instances returned by those methods. I applied the same playbook I did for `ReactNativeElement` (avoiding private fields and `super()` calls, which yielded these wins. * Before | (index) | Task name | Latency average (ns) | Latency median (ns) | Throughput average (ops/s) | Throughput median (ops/s) | Samples | | ------- | --------------------------------------------------------- | -------------------- | ------------------- | -------------------------- | ------------------------- | ------- | | 0 | 'mark (default)' | '5579.80 ± 0.32%' | '5479.00' | '181368 ± 0.02%' | '182515' | 179218 | | 1 | 'mark (with custom startTime)' | '5759.72 ± 0.99%' | '5648.00' | '176162 ± 0.02%' | '177054' | 173620 | | 2 | 'measure (with start and end timestamps)' | '6506.38 ± 0.34%' | '6390.00' | '155503 ± 0.02%' | '156495' | 153696 | | 3 | 'measure (with mark names)' | '6770.94 ± 0.72%' | '6620.00' | '149833 ± 0.03%' | '151057' | 147691 | | 4 | 'clearMarks' | '785.89 ± 0.07%' | '771.00' | '1291356 ± 0.01%' | '1297017' | 1272442 | | 5 | 'clearMeasures' | '777.98 ± 0.06%' | '761.00' | '1303362 ± 0.01%' | '1314060' | 1285383 | | 6 | 'mark + clearMarks' | '5995.34 ± 1.37%' | '5779.00' | '171874 ± 0.03%' | '173040' | 166797 | | 7 | 'measure + clearMeasures (with start and end timestamps)' | '7040.28 ± 0.57%' | '6830.00' | '145289 ± 0.03%' | '146413' | 142040 | | 8 | 'measure + clearMeasures (with mark names)' | '7184.43 ± 0.40%' | '6990.00' | '141809 ± 0.03%' | '143062' | 139190 | * After | (index) | Task name | Latency average (ns) | Latency median (ns) | Throughput average (ops/s) | Throughput median (ops/s) | Samples | | ------- | --------------------------------------------------------- | -------------------- | ------------------- | -------------------------- | ------------------------- | ------- | | 0 | 'mark (default)' | '1678.19 ± 0.73%' | '1633.00' | '607139 ± 0.01%' | '612370' | 595882 | | 1 | 'mark (with custom startTime)' | '1920.23 ± 1.30%' | '1843.00' | '538217 ± 0.01%' | '542594' | 520772 | | 2 | 'measure (with start and end timestamps)' | '2651.72 ± 0.94%' | '2554.00' | '388312 ± 0.02%' | '391543' | 377114 | | 3 | 'measure (with mark names)' | '2815.84 ± 0.75%' | '2744.00' | '362303 ± 0.02%' | '364431' | 355134 | | 4 | 'clearMarks' | '743.82 ± 0.06%' | '731.00' | '1363190 ± 0.01%' | '1367989' | 1344417 | | 5 | 'clearMeasures' | '776.69 ± 0.07%' | '761.00' | '1306563 ± 0.01%' | '1314060' | 1287512 | | 6 | 'mark + clearMarks' | '2043.97 ± 1.26%' | '1973.00' | '504750 ± 0.01%' | '506842' | 489801 | | 7 | 'measure + clearMeasures (with start and end timestamps)' | '3048.39 ± 0.87%' | '2965.00' | '335285 ± 0.02%' | '337268' | 328042 | | 8 | 'measure + clearMeasures (with mark names)' | '3132.75 ± 0.80%' | '3065.00' | '324365 ± 0.02%' | '326264' | 319209 | Reviewed By: huntie Differential Revision: D77790874 fbshipit-source-id: baf7aca07d281fef4373956d125c63f006fab592
2025-11-01 09:14:26 +00:00 · 2025-07-07 06:42:23 -07:00
parent 74c03b67e3
commit 9005d93e32
2 changed files with 80 additions and 24 deletions
@@ -29,10 +29,14 @@ export type PerformanceEntryJSON = {
 };

 export class PerformanceEntry {
-  #name: string;
-  #entryType: PerformanceEntryType;
-  #startTime: DOMHighResTimeStamp;
-  #duration: DOMHighResTimeStamp;
+  // We don't use private fields because they're significantly slower to
+  // initialize on construction and to access.
+  // We also need these to be protected so they can be initialized in subclasses
+  // where we avoid calling `super()` for performance reasons.
+  __name: string;
+  __entryType: PerformanceEntryType;
+  __startTime: DOMHighResTimeStamp;
+  __duration: DOMHighResTimeStamp;

  constructor(init: {
    name: string,
@@ -40,34 +44,34 @@ export class PerformanceEntry {
    startTime: DOMHighResTimeStamp,
    duration: DOMHighResTimeStamp,
  }) {
-    this.#name = init.name;
-    this.#entryType = init.entryType;
-    this.#startTime = init.startTime;
-    this.#duration = init.duration;
+    this.__name = init.name;
+    this.__entryType = init.entryType;
+    this.__startTime = init.startTime;
+    this.__duration = init.duration;
  }

  get name(): string {
-    return this.#name;
+    return this.__name;
  }

  get entryType(): PerformanceEntryType {
-    return this.#entryType;
+    return this.__entryType;
  }

  get startTime(): DOMHighResTimeStamp {
-    return this.#startTime;
+    return this.__startTime;
  }

  get duration(): DOMHighResTimeStamp {
-    return this.#duration;
+    return this.__duration;
  }

  toJSON(): PerformanceEntryJSON {
    return {
-      name: this.#name,
-      entryType: this.#entryType,
-      startTime: this.#startTime,
-      duration: this.#duration,
+      name: this.__name,
+      entryType: this.__entryType,
+      startTime: this.__startTime,
+      duration: this.__duration,
    };
  }
 }
@@ -29,9 +29,12 @@ export type PerformanceMeasureInit = {
  duration: DOMHighResTimeStamp,
 };

-export class PerformanceMark extends PerformanceEntry {
-  #detail: DetailType;
+class PerformanceMarkTemplate extends PerformanceEntry {
+  // We don't use private fields because they're significantly slower to
+  // initialize on construction and to access.
+  _detail: DetailType;

+  // This constructor isn't really used. See `PerformanceMark` below.
  constructor(markName: string, markOptions?: PerformanceMarkOptions) {
    super({
      name: markName,
@@ -41,18 +44,46 @@ export class PerformanceMark extends PerformanceEntry {
    });

    if (markOptions) {
-      this.#detail = markOptions.detail;
+      this._detail = markOptions.detail;
    }
  }

  get detail(): DetailType {
-    return this.#detail;
+    return this._detail;
  }
 }

-export class PerformanceMeasure extends PerformanceEntry {
-  #detail: DetailType;
+// This is the real value we're exporting where we define the class a function
+// so we don't need to call `super()` and we can avoid the performance penalty
+// of the current code transpiled with Babel.
+// We should remove this when we have built-in support for classes in the
+// runtime.
+export const PerformanceMark: typeof PerformanceMarkTemplate =
+  // $FlowExpectedError[incompatible-type]
+  function PerformanceMark(
+    this: PerformanceMarkTemplate,
+    markName: string,
+    markOptions?: PerformanceMarkOptions,
+  ) {
+    this.__name = markName;
+    this.__entryType = 'mark';
+    this.__startTime = markOptions?.startTime ?? performance.now();
+    this.__duration = 0;

+    if (markOptions) {
+      this._detail = markOptions.detail;
+    }
+  };
+
+// $FlowExpectedError[prop-missing]
+PerformanceMark.prototype = PerformanceMarkTemplate.prototype;
+
+class PerformanceMeasureTemplate extends PerformanceEntry {
+  // We don't use private fields because they're significantly slower to
+  // initialize on construction and to access.
+  _detail: DetailType;
+
+  // This constructor isn't really used. See `PerformanceMeasure` below.
  constructor(measureName: string, measureOptions: PerformanceMeasureInit) {
    super({
      name: measureName,
@@ -62,11 +93,32 @@ export class PerformanceMeasure extends PerformanceEntry {
    });

    if (measureOptions) {
-      this.#detail = measureOptions.detail;
+      this._detail = measureOptions.detail;
    }
  }

  get detail(): DetailType {
-    return this.#detail;
+    return this._detail;
  }
 }
+
+// We do the same here as we do for `PerformanceMark` for performance reasons.
+export const PerformanceMeasure: typeof PerformanceMeasureTemplate =
+  // $FlowExpectedError[incompatible-type]
+  function PerformanceMeasure(
+    this: PerformanceMeasureTemplate,
+    measureName: string,
+    measureOptions: PerformanceMeasureInit,
+  ) {
+    this.__name = measureName;
+    this.__entryType = 'measure';
+    this.__startTime = measureOptions.startTime;
+    this.__duration = measureOptions.duration;
+
+    if (measureOptions) {
+      this._detail = measureOptions.detail;
+    }
+  };
+
+// $FlowExpectedError[prop-missing]
+PerformanceMeasure.prototype = PerformanceMeasureTemplate.prototype;