refactor(core): allow multiple profilers (#60548)

This commit changes the profiler infrastructure to
allow multiple profilers running at the same time.

PR Close #60548

packages/core/src/render3/profiler.ts

@@ -8,21 +8,40 @@
 
 import {type Profiler} from './profiler_types';
 
-let profilerCallback: Profiler | null = null;
+const profilerCallbacks: Profiler[] = [];
+
+const NOOP_PROFILER_REMOVAL = () => {};
+
+function removeProfiler(profiler: Profiler) {
+  const profilerIdx = profilerCallbacks.indexOf(profiler);
+  if (profilerIdx !== -1) {
+    profilerCallbacks.splice(profilerIdx, 1);
+  }
+}
 
 /**
- * Sets the callback function which will be invoked before and after performing certain actions at
- * runtime (for example, before and after running change detection).
+ * Adds a callback function which will be invoked before and after performing certain actions at
+ * runtime (for example, before and after running change detection). Multiple profiler callbacks can be set:
+ * in this case profiling events are reported to every registered callback.
  *
  * Warning: this function is *INTERNAL* and should not be relied upon in application's code.
  * The contract of the function might be changed in any release and/or the function can be removed
  * completely.
  *
- * @param profiler function provided by the caller or null value to disable profiling.
+ * @param profiler function provided by the caller or null value to disable all profilers.
+ * @returns a cleanup function that, when invoked, removes a given profiler callback.
  */
-export const setProfiler = (profiler: Profiler | null) => {
-  profilerCallback = profiler;
-};
+export function setProfiler(profiler: Profiler | null): () => void {
+  if (profiler !== null) {
+    if (!profilerCallbacks.includes(profiler)) {
+      profilerCallbacks.push(profiler);
+    }
+    return () => removeProfiler(profiler);
+  } else {
+    profilerCallbacks.length = 0;
+    return NOOP_PROFILER_REMOVAL;
+  }
+}
 
 /**
  * Profiler function which wraps user code executed by the runtime.
@@ -32,10 +51,10 @@ export const setProfiler = (profiler: Profiler | null) => {
  * @param eventFn function associated with event.
  *    For example a template function, lifecycle hook, or output listener.
  *    The value depends on the execution context
- * @returns
  */
-export const profiler: Profiler = function (event, instance = null, eventFn) {
-  if (profilerCallback != null /* both `null` and `undefined` */) {
+export const profiler: Profiler = function (event, instance = null, eventFn): void {
+  for (let i = 0; i < profilerCallbacks.length; i++) {
+    const profilerCallback = profilerCallbacks[i];
     profilerCallback(event, instance, eventFn);
   }
 };

packages/core/test/acceptance/profiler_spec.ts

@@ -6,7 +6,7 @@
  * found in the LICENSE file at https://angular.dev/license
  */
 
-import {setProfiler} from '../../src/render3/profiler';
+import {setProfiler, profiler} from '../../src/render3/profiler';
 import {ProfilerEvent} from '../../src/render3/profiler_types';
 import {TestBed} from '../../testing';
 
@@ -540,3 +540,54 @@ describe('profiler', () => {
     });
   });
 });
+
+describe('profiler activation and removal', () => {
+  it('should allow adding and removing multiple profilers', () => {
+    const events: string[] = [];
+    const r1 = setProfiler((e) => events.push('P1: ' + e));
+    const r2 = setProfiler((e) => events.push('P2: ' + e));
+
+    profiler(ProfilerEvent.TemplateCreateStart);
+    expect(events).toEqual(['P1: 0', 'P2: 0']);
+
+    r1();
+    profiler(ProfilerEvent.TemplateCreateEnd);
+    expect(events).toEqual(['P1: 0', 'P2: 0', 'P2: 1']);
+
+    r2();
+    profiler(ProfilerEvent.TemplateCreateStart);
+    expect(events).toEqual(['P1: 0', 'P2: 0', 'P2: 1']);
+  });
+
+  it('should not add / remove the same profiler twice', () => {
+    const events: string[] = [];
+    const p1 = (e: ProfilerEvent) => events.push('P1: ' + e);
+    const r1 = setProfiler(p1);
+    const r2 = setProfiler(p1);
+
+    profiler(ProfilerEvent.TemplateCreateStart);
+    expect(events).toEqual(['P1: 0']);
+
+    r1();
+    profiler(ProfilerEvent.TemplateCreateStart);
+    expect(events).toEqual(['P1: 0']);
+
+    // subsequent removals should be noop
+    r1();
+    r2();
+  });
+
+  it('should clear all profilers when passing null', () => {
+    const events: string[] = [];
+    setProfiler((e) => events.push('P1: ' + e));
+    setProfiler((e) => events.push('P2: ' + e));
+
+    profiler(ProfilerEvent.TemplateCreateStart);
+    expect(events).toEqual(['P1: 0', 'P2: 0']);
+
+    // clear all profilers
+    setProfiler(null);
+    profiler(ProfilerEvent.TemplateCreateEnd);
+    expect(events).toEqual(['P1: 0', 'P2: 0']);
+  });
+});

packages/core/test/bundling/animations-standalone/bundle.golden_symbols.json

@@ -429,6 +429,8 @@
   "producerMarkClean",
   "producerRemoveLiveConsumerAtIndex",
   "producerUpdateValueVersion",
+  "profiler",
+  "profilerCallbacks",
   "refreshContentQueries",
   "refreshView",
   "rememberChangeHistoryAndInvokeOnChangesHook",

packages/core/test/bundling/animations/bundle.golden_symbols.json

@@ -455,6 +455,8 @@
   "producerMarkClean",
   "producerRemoveLiveConsumerAtIndex",
   "producerUpdateValueVersion",
+  "profiler",
+  "profilerCallbacks",
   "refreshContentQueries",
   "refreshView",
   "rememberChangeHistoryAndInvokeOnChangesHook",

packages/core/test/bundling/cyclic_import/bundle.golden_symbols.json

@@ -369,6 +369,8 @@
   "producerMarkClean",
   "producerRemoveLiveConsumerAtIndex",
   "producerUpdateValueVersion",
+  "profiler",
+  "profilerCallbacks",
   "refreshContentQueries",
   "refreshView",
   "rememberChangeHistoryAndInvokeOnChangesHook",

packages/core/test/bundling/defer/bundle.golden_symbols.json

@@ -433,6 +433,7 @@
   "producerRemoveLiveConsumerAtIndex",
   "producerUpdateValueVersion",
   "profiler",
+  "profilerCallbacks",
   "refreshContentQueries",
   "refreshView",
   "registerPostOrderHooks",

packages/core/test/bundling/forms_reactive/bundle.golden_symbols.json

@@ -552,6 +552,8 @@
   "producerRemoveLiveConsumerAtIndex",
   "producerUpdateValueVersion",
   "producerUpdatesAllowed",
+  "profiler",
+  "profilerCallbacks",
   "providerToFactory",
   "readableStreamLikeToAsyncGenerator",
   "refreshContentQueries",

packages/core/test/bundling/forms_template_driven/bundle.golden_symbols.json

@@ -541,6 +541,8 @@
   "producerRemoveLiveConsumerAtIndex",
   "producerUpdateValueVersion",
   "producerUpdatesAllowed",
+  "profiler",
+  "profilerCallbacks",
   "providerToFactory",
   "readableStreamLikeToAsyncGenerator",
   "refreshContentQueries",

packages/core/test/bundling/hello_world/bundle.golden_symbols.json

@@ -297,6 +297,8 @@
   "producerMarkClean",
   "producerRemoveLiveConsumerAtIndex",
   "producerUpdateValueVersion",
+  "profiler",
+  "profilerCallbacks",
   "refreshContentQueries",
   "refreshView",
   "rememberChangeHistoryAndInvokeOnChangesHook",

packages/core/test/bundling/hydration/bundle.golden_symbols.json

@@ -396,6 +396,8 @@
   "producerMarkClean",
   "producerRemoveLiveConsumerAtIndex",
   "producerUpdateValueVersion",
+  "profiler",
+  "profilerCallbacks",
   "readableStreamLikeToAsyncGenerator",
   "refreshContentQueries",
   "refreshView",

packages/core/test/bundling/router/bundle.golden_symbols.json

@@ -633,6 +633,8 @@
   "producerNotifyConsumers",
   "producerRemoveLiveConsumerAtIndex",
   "producerUpdateValueVersion",
+  "profiler",
+  "profilerCallbacks",
   "readableStreamLikeToAsyncGenerator",
   "redirectIfUrlTree",
   "redirectingNavigationError",

packages/core/test/bundling/standalone_bootstrap/bundle.golden_symbols.json

@@ -329,6 +329,8 @@
   "producerMarkClean",
   "producerRemoveLiveConsumerAtIndex",
   "producerUpdateValueVersion",
+  "profiler",
+  "profilerCallbacks",
   "refreshContentQueries",
   "refreshView",
   "rememberChangeHistoryAndInvokeOnChangesHook",

packages/core/test/bundling/todo/bundle.golden_symbols.json

@@ -442,6 +442,8 @@
   "producerMarkClean",
   "producerRemoveLiveConsumerAtIndex",
   "producerUpdateValueVersion",
+  "profiler",
+  "profilerCallbacks",
   "refreshContentQueries",
   "refreshView",
   "registerPostOrderHooks",