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esm: move hook execution to separate thread · nodejs/node@2613a9c · GitHub

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esm: move hook execution to separate thread
 PR-URL: #44710 Reviewed-By: Yagiz Nizipli <yagiz@nizipli.com> Reviewed-By: Geoffrey Booth <webadmin@geoffreybooth.com> Co-authored-by: Antoine du Hamel <duhamelantoine1995@gmail.com> Co-authored-by: Geoffrey Booth <webadmin@geoffreybooth.com> Co-authored-by: Michaël Zasso <targos@protonmail.com>
1 parent 7359b92 commit 2613a9c

37 files changed

Lines changed: 997 additions & 457 deletions

‎doc/api/esm.md‎

Lines changed: 25 additions & 14 deletions
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@@ -7,6 +7,9 @@
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<!-- YAML
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added: v8.5.0
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changes:
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- version: REPLACEME
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pr-url: https://github.com/nodejs/node/pull/44710
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description: Loader hooks are executed off the main thread.
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- version:
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- v18.6.0
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- v16.17.0
@@ -325,6 +328,9 @@ added:
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- v13.9.0
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- v12.16.2
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changes:
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- version: REPLACEME
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pr-url: https://github.com/nodejs/node/pull/44710
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description: This API now returns a string synchronously instead of a Promise.
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- version:
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- v16.2.0
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- v14.18.0
@@ -340,29 +346,26 @@ command flag enabled.
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* `specifier` {string} The module specifier to resolve relative to `parent`.
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* `parent` {string|URL} The absolute parent module URL to resolve from. If none
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is specified, the value of `import.meta.url` is used as the default.
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* Returns: {Promise}
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* Returns: {string}
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Provides a module-relative resolution function scoped to each module, returning
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the URL string.
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the URL string. In alignment with browser behavior, this now returns
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synchronously.
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<!-- eslint-skip -->
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> **Caveat** This can result in synchronous file-system operations, which
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> can impact performance similarly to `require.resolve`.
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```js
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const dependencyAsset = await import.meta.resolve('component-lib/asset.css');
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const dependencyAsset = import.meta.resolve('component-lib/asset.css');
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```
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`import.meta.resolve` also accepts a second argument which is the parent module
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from which to resolve from:
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<!-- eslint-skip -->
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from which to resolve:
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```js
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await import.meta.resolve('./dep', import.meta.url);
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import.meta.resolve('./dep', import.meta.url);
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```
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This function is asynchronous because the ES module resolver in Node.js is
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allowed to be asynchronous.
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## Interoperability with CommonJS
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### `import` statements
@@ -730,6 +733,11 @@ A hook that returns without calling `next<hookName>()` _and_ without returning
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`shortCircuit: true` also triggers an exception. These errors are to help
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prevent unintentional breaks in the chain.
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Hooks are run in a separate thread, isolated from the main. That means it is a
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different [realm](https://tc39.es/ecma262/#realm). The hooks thread may be
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terminated by the main thread at any time, so do not depend on asynchronous
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operations to (like `console.log`) complete.
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#### `resolve(specifier, context, nextResolve)`
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<!-- YAML
@@ -762,7 +770,7 @@ changes:
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Node.js default `resolve` hook after the last user-supplied `resolve` hook
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* `specifier` {string}
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* `context` {Object}
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* Returns: {Object}
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* Returns: {Object|Promise}
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* `format` {string|null|undefined} A hint to the load hook (it might be
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ignored)
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`'builtin' | 'commonjs' | 'json' | 'module' | 'wasm'`
@@ -772,6 +780,9 @@ changes:
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terminate the chain of `resolve` hooks. **Default:** `false`
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* `url` {string} The absolute URL to which this input resolves
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> **Caveat** Despite support for returning promises and async functions, calls
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> to `resolve` may block the main thread which can impact performance.
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The `resolve` hook chain is responsible for telling Node.js where to find and
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how to cache a given `import` statement or expression. It can optionally return
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its format (such as `'module'`) as a hint to the `load` hook. If a format is
@@ -797,7 +808,7 @@ Node.js module specifier resolution behavior_ when calling `defaultResolve`, the
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`context.conditions` array originally passed into the `resolve` hook.
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```js
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export async function resolve(specifier, context, nextResolve) {
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export function resolve(specifier, context, nextResolve) {
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const { parentURL = null } = context;
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if (Math.random() > 0.5) { // Some condition.
@@ -1100,7 +1111,7 @@ const baseURL = pathToFileURL(`${cwd()}/`).href;
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// CoffeeScript files end in .coffee, .litcoffee, or .coffee.md.
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const extensionsRegex = /\.coffee$|\.litcoffee$|\.coffee\.md$/;
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export async function resolve(specifier, context, nextResolve) {
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export function resolve(specifier, context, nextResolve) {
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if (extensionsRegex.test(specifier)) {
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const { parentURL = baseURL } = context;
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‎lib/internal/main/worker_thread.js‎

Lines changed: 54 additions & 35 deletions
Original file line numberDiff line numberDiff line change
@@ -10,6 +10,7 @@ const {
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ObjectDefineProperty,
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PromisePrototypeThen,
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RegExpPrototypeExec,
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SafeWeakMap,
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globalThis: {
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Atomics,
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SharedArrayBuffer,
@@ -89,23 +90,25 @@ port.on('message', (message) => {
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const {
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argv,
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cwdCounter,
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filename,
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doEval,
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workerData,
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environmentData,
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publicPort,
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filename,
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hasStdin,
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manifestSrc,
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manifestURL,
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hasStdin,
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publicPort,
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workerData,
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} = message;
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102-
if (argv !== undefined) {
103-
ArrayPrototypePushApply(process.argv, argv);
104-
}
103+
if (doEval !== 'internal') {
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if (argv !== undefined) {
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ArrayPrototypePushApply(process.argv, argv);
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}
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106-
const publicWorker = require('worker_threads');
107-
publicWorker.parentPort = publicPort;
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publicWorker.workerData = workerData;
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const publicWorker = require('worker_threads');
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publicWorker.parentPort = publicPort;
110+
publicWorker.workerData = workerData;
111+
}
109112

110113
require('internal/worker').assignEnvironmentData(environmentData);
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@@ -138,31 +141,47 @@ port.on('message', (message) => {
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debug(`[${threadId}] starts worker script ${filename} ` +
139142
`(eval = ${doEval}) at cwd = ${process.cwd()}`);
140143
port.postMessage({ type: UP_AND_RUNNING });
141-
if (doEval === 'classic') {
142-
const { evalScript } = require('internal/process/execution');
143-
const name = '[worker eval]';
144-
// This is necessary for CJS module compilation.
145-
// TODO: pass this with something really internal.
146-
ObjectDefineProperty(process, '_eval', {
147-
__proto__: null,
148-
configurable: true,
149-
enumerable: true,
150-
value: filename,
151-
});
152-
ArrayPrototypeSplice(process.argv, 1, 0, name);
153-
evalScript(name, filename);
154-
} else if (doEval === 'module') {
155-
const { evalModule } = require('internal/process/execution');
156-
PromisePrototypeThen(evalModule(filename), undefined, (e) => {
157-
workerOnGlobalUncaughtException(e, true);
158-
});
159-
} else {
160-
// script filename
161-
// runMain here might be monkey-patched by users in --require.
162-
// XXX: the monkey-patchability here should probably be deprecated.
163-
ArrayPrototypeSplice(process.argv, 1, 0, filename);
164-
const CJSLoader = require('internal/modules/cjs/loader');
165-
CJSLoader.Module.runMain(filename);
144+
switch (doEval) {
145+
case 'internal': {
146+
// Create this WeakMap in js-land because V8 has no C++ API for WeakMap.
147+
internalBinding('module_wrap').callbackMap = new SafeWeakMap();
148+
require(filename)(workerData, publicPort);
149+
break;
150+
}
151+
152+
case 'classic': {
153+
const { evalScript } = require('internal/process/execution');
154+
const name = '[worker eval]';
155+
// This is necessary for CJS module compilation.
156+
// TODO: pass this with something really internal.
157+
ObjectDefineProperty(process, '_eval', {
158+
__proto__: null,
159+
configurable: true,
160+
enumerable: true,
161+
value: filename,
162+
});
163+
ArrayPrototypeSplice(process.argv, 1, 0, name);
164+
evalScript(name, filename);
165+
break;
166+
}
167+
168+
case 'module': {
169+
const { evalModule } = require('internal/process/execution');
170+
PromisePrototypeThen(evalModule(filename), undefined, (e) => {
171+
workerOnGlobalUncaughtException(e, true);
172+
});
173+
break;
174+
}
175+
176+
default: {
177+
// script filename
178+
// runMain here might be monkey-patched by users in --require.
179+
// XXX: the monkey-patchability here should probably be deprecated.
180+
ArrayPrototypeSplice(process.argv, 1, 0, filename);
181+
const CJSLoader = require('internal/modules/cjs/loader');
182+
CJSLoader.Module.runMain(filename);
183+
break;
184+
}
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}
167186
} else if (message.type === STDIO_PAYLOAD) {
168187
const { stream, chunks } = message;

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