async_hooks: remove experimental onPropagate option

jasnell · danielleadams · commit b1bde695749a · 2023-04-02T21:37:37.000-04:00
The `onPropagate` option for `AsyncLocalStorage` is problematic for a couple of reasons: 1. It is not expected to be forwards compatible in any way with the upcoming TC-39 `AsyncContext` proposal. 2. It introduces a non-trivial O(n) cost invoking a JavaScript callback for *every* AsyncResource that is created, including every Promise. While it is still experimental, I recommend removing it while we can revisit the fundamental use cases in light of the coming `AsyncContext` proposal. Refs: #46374 PR-URL: #46386 Reviewed-By: Stephen Belanger <admin@stephenbelanger.com> Reviewed-By: Vladimir de Turckheim <vlad2t@hotmail.com> Reviewed-By: Geoffrey Booth <webadmin@geoffreybooth.com> Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com> Reviewed-By: Gerhard Stöbich <deb2001-github@yahoo.de> Reviewed-By: Chengzhong Wu <legendecas@gmail.com>
diff --git a/doc/api/async_context.md b/doc/api/async_context.md
@@ -116,35 +116,24 @@ Each instance of `AsyncLocalStorage` maintains an independent storage context.
 Multiple instances can safely exist simultaneously without risk of interfering
 with each other's data.
 
-### `new AsyncLocalStorage([options])`
+### `new AsyncLocalStorage()`
 
 <!-- YAML
 added:
  - v13.10.0
  - v12.17.0
 changes:
+ - version: REPLACEME
+   pr-url: https://github.com/nodejs/node/pull/46386
+   description: Removed experimental onPropagate option.
  - version: v18.13.0
    pr-url: https://github.com/nodejs/node/pull/45386
    description: Add option onPropagate.
 -->
 
-> Stability: 1 - `options.onPropagate` is experimental.
-
-* `options` {Object}
-  * `onPropagate` {Function} Optional callback invoked before a store is
-    propagated to a new async resource. Returning `true` allows propagation,
-    returning `false` avoids it. Default is to propagate always.
-
 Creates a new instance of `AsyncLocalStorage`. Store is only provided within a
 `run()` call or after an `enterWith()` call.
 
-The `onPropagate` is called during creation of an async resource. Throwing at
-this time will print the stack trace and exit. See
-[`async_hooks` Error handling][] for details.
-
-Creating an async resource within the `onPropagate` callback will result in
-a recursive call to `onPropagate`.
-
 ### `asyncLocalStorage.disable()`
 
 <!-- YAML
@@ -830,5 +819,4 @@ const server = createServer((req, res) => {
 [`EventEmitter`]: events.md#class-eventemitter
 [`Stream`]: stream.md#stream
 [`Worker`]: worker_threads.md#class-worker
-[`async_hooks` Error handling]: async_hooks.md#error-handling
 [`util.promisify()`]: util.md#utilpromisifyoriginal
diff --git a/lib/async_hooks.js b/lib/async_hooks.js
@@ -23,7 +23,6 @@ const {
 const { kEmptyObject } = require('internal/util');
 const {
   validateFunction,
-  validateObject,
   validateString,
 } = require('internal/validators');
 const internal_async_hooks = require('internal/async_hooks');
@@ -275,17 +274,9 @@ const storageHook = createHook({
 });
 
 class AsyncLocalStorage {
-  constructor(options = kEmptyObject) {
-    validateObject(options, 'options');
-
-    const { onPropagate = null } = options;
-    if (onPropagate !== null) {
-      validateFunction(onPropagate, 'options.onPropagate');
-    }
-
+  constructor() {
     this.kResourceStore = Symbol('kResourceStore');
     this.enabled = false;
-    this._onPropagate = onPropagate;
   }
 
   disable() {
@@ -312,9 +303,7 @@ class AsyncLocalStorage {
   _propagate(resource, triggerResource, type) {
     const store = triggerResource[this.kResourceStore];
     if (this.enabled) {
-      if (this._onPropagate === null || this._onPropagate(type, store)) {
-        resource[this.kResourceStore] = store;
-      }
+      resource[this.kResourceStore] = store;
     }
   }
 
diff --git a/test/async-hooks/test-async-local-storage-stop-propagation.js b/test/async-hooks/test-async-local-storage-stop-propagation.js
