/**
|
* The `worker_threads` module enables the use of threads that execute JavaScript
|
* in parallel. To access it:
|
*
|
* ```js
|
* const worker = require('worker_threads');
|
* ```
|
*
|
* Workers (threads) are useful for performing CPU-intensive JavaScript operations.
|
* They do not help much with I/O-intensive work. The Node.js built-in
|
* asynchronous I/O operations are more efficient than Workers can be.
|
*
|
* Unlike `child_process` or `cluster`, `worker_threads` can share memory. They do
|
* so by transferring `ArrayBuffer` instances or sharing `SharedArrayBuffer`instances.
|
*
|
* ```js
|
* const {
|
* Worker, isMainThread, parentPort, workerData
|
* } = require('worker_threads');
|
*
|
* if (isMainThread) {
|
* module.exports = function parseJSAsync(script) {
|
* return new Promise((resolve, reject) => {
|
* const worker = new Worker(__filename, {
|
* workerData: script
|
* });
|
* worker.on('message', resolve);
|
* worker.on('error', reject);
|
* worker.on('exit', (code) => {
|
* if (code !== 0)
|
* reject(new Error(`Worker stopped with exit code ${code}`));
|
* });
|
* });
|
* };
|
* } else {
|
* const { parse } = require('some-js-parsing-library');
|
* const script = workerData;
|
* parentPort.postMessage(parse(script));
|
* }
|
* ```
|
*
|
* The above example spawns a Worker thread for each `parse()` call. In actual
|
* practice, use a pool of Workers for these kinds of tasks. Otherwise, the
|
* overhead of creating Workers would likely exceed their benefit.
|
*
|
* When implementing a worker pool, use the `AsyncResource` API to inform
|
* diagnostic tools (e.g. to provide asynchronous stack traces) about the
|
* correlation between tasks and their outcomes. See `"Using AsyncResource for a Worker thread pool"` in the `async_hooks` documentation for an example implementation.
|
*
|
* Worker threads inherit non-process-specific options by default. Refer to `Worker constructor options` to know how to customize worker thread options,
|
* specifically `argv` and `execArgv` options.
|
* @see [source](https://github.com/nodejs/node/blob/v17.0.0/lib/worker_threads.js)
|
*/
|
declare module 'worker_threads' {
|
import { Blob } from 'node:buffer';
|
import { Context } from 'node:vm';
|
import { EventEmitter } from 'node:events';
|
import { EventLoopUtilityFunction } from 'node:perf_hooks';
|
import { FileHandle } from 'node:fs/promises';
|
import { Readable, Writable } from 'node:stream';
|
import { URL } from 'node:url';
|
import { X509Certificate } from 'node:crypto';
|
const isMainThread: boolean;
|
const parentPort: null | MessagePort;
|
const resourceLimits: ResourceLimits;
|
const SHARE_ENV: unique symbol;
|
const threadId: number;
|
const workerData: any;
|
/**
|
* Instances of the `worker.MessageChannel` class represent an asynchronous,
|
* two-way communications channel.
|
* The `MessageChannel` has no methods of its own. `new MessageChannel()`yields an object with `port1` and `port2` properties, which refer to linked `MessagePort` instances.
|
*
|
* ```js
|
* const { MessageChannel } = require('worker_threads');
|
*
|
* const { port1, port2 } = new MessageChannel();
|
* port1.on('message', (message) => console.log('received', message));
|
* port2.postMessage({ foo: 'bar' });
|
* // Prints: received { foo: 'bar' } from the `port1.on('message')` listener
|
* ```
|
* @since v10.5.0
|
*/
|
class MessageChannel {
|
readonly port1: MessagePort;
|
readonly port2: MessagePort;
|
}
|
interface WorkerPerformance {
|
eventLoopUtilization: EventLoopUtilityFunction;
|
}
|
type TransferListItem = ArrayBuffer | MessagePort | FileHandle | X509Certificate | Blob;
|
/**
|
* Instances of the `worker.MessagePort` class represent one end of an
|
* asynchronous, two-way communications channel. It can be used to transfer
|
* structured data, memory regions and other `MessagePort`s between different `Worker` s.
|
*
|
* This implementation matches [browser `MessagePort`](https://developer.mozilla.org/en-US/docs/Web/API/MessagePort) s.
|
* @since v10.5.0
|
*/
|
class MessagePort extends EventEmitter {
|
/**
|
* Disables further sending of messages on either side of the connection.
|
* This method can be called when no further communication will happen over this`MessagePort`.
|
*
|
* The `'close' event` is emitted on both `MessagePort` instances that
|
* are part of the channel.
|
* @since v10.5.0
|
*/
|
close(): void;
|
/**
|
* Sends a JavaScript value to the receiving side of this channel.`value` is transferred in a way which is compatible with
|
* the [HTML structured clone algorithm](https://developer.mozilla.org/en-US/docs/Web/API/Web_Workers_API/Structured_clone_algorithm).
|
*
|
* In particular, the significant differences to `JSON` are:
|
*
|
* * `value` may contain circular references.
|
* * `value` may contain instances of builtin JS types such as `RegExp`s,`BigInt`s, `Map`s, `Set`s, etc.
|
* * `value` may contain typed arrays, both using `ArrayBuffer`s
|
* and `SharedArrayBuffer`s.
|
* * `value` may contain [`WebAssembly.Module`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/WebAssembly/Module) instances.
|
* * `value` may not contain native (C++-backed) objects other than:
|
*
|
* ```js
|
* const { MessageChannel } = require('worker_threads');
|
* const { port1, port2 } = new MessageChannel();
|
*
|
* port1.on('message', (message) => console.log(message));
|
*
|
* const circularData = {};
|
* circularData.foo = circularData;
|
* // Prints: { foo: [Circular] }
|
* port2.postMessage(circularData);
|
* ```
|
*
|
* `transferList` may be a list of [`ArrayBuffer`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer), `MessagePort` and `FileHandle` objects.
|
* After transferring, they are not usable on the sending side of the channel
|
* anymore (even if they are not contained in `value`). Unlike with `child processes`, transferring handles such as network sockets is currently
|
* not supported.
|
*
|
* If `value` contains [`SharedArrayBuffer`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/SharedArrayBuffer) instances, those are accessible
|
* from either thread. They cannot be listed in `transferList`.
|
*
|
* `value` may still contain `ArrayBuffer` instances that are not in`transferList`; in that case, the underlying memory is copied rather than moved.
|
*
|
* ```js
|
* const { MessageChannel } = require('worker_threads');
|
* const { port1, port2 } = new MessageChannel();
|
*
|
* port1.on('message', (message) => console.log(message));
|
*
|
* const uint8Array = new Uint8Array([ 1, 2, 3, 4 ]);
|
* // This posts a copy of `uint8Array`:
|
* port2.postMessage(uint8Array);
|
* // This does not copy data, but renders `uint8Array` unusable:
|
* port2.postMessage(uint8Array, [ uint8Array.buffer ]);
|
*
|
* // The memory for the `sharedUint8Array` is accessible from both the
|
* // original and the copy received by `.on('message')`:
|
* const sharedUint8Array = new Uint8Array(new SharedArrayBuffer(4));
|
* port2.postMessage(sharedUint8Array);
|
*
|
* // This transfers a freshly created message port to the receiver.
|
* // This can be used, for example, to create communication channels between
|
* // multiple `Worker` threads that are children of the same parent thread.
|
* const otherChannel = new MessageChannel();
|
* port2.postMessage({ port: otherChannel.port1 }, [ otherChannel.port1 ]);
|
* ```
|
*
|
* The message object is cloned immediately, and can be modified after
|
* posting without having side effects.
|
*
|
* For more information on the serialization and deserialization mechanisms
|
* behind this API, see the `serialization API of the v8 module`.
|
* @since v10.5.0
|
*/
|
postMessage(value: any, transferList?: ReadonlyArray<TransferListItem>): void;
|
/**
|
* Opposite of `unref()`. Calling `ref()` on a previously `unref()`ed port does_not_ let the program exit if it's the only active handle left (the default
|
* behavior). If the port is `ref()`ed, calling `ref()` again has no effect.
|
*
|
* If listeners are attached or removed using `.on('message')`, the port
|
* is `ref()`ed and `unref()`ed automatically depending on whether
|
* listeners for the event exist.
|
* @since v10.5.0
|
*/
|
ref(): void;
|
/**
|
* Calling `unref()` on a port allows the thread to exit if this is the only
|
* active handle in the event system. If the port is already `unref()`ed calling`unref()` again has no effect.
|
*
|
* If listeners are attached or removed using `.on('message')`, the port is`ref()`ed and `unref()`ed automatically depending on whether
|
* listeners for the event exist.
|
* @since v10.5.0
|
*/
|
unref(): void;
|
/**
|
* Starts receiving messages on this `MessagePort`. When using this port
|
* as an event emitter, this is called automatically once `'message'`listeners are attached.
|
*
|
* This method exists for parity with the Web `MessagePort` API. In Node.js,
|
* it is only useful for ignoring messages when no event listener is present.
|
* Node.js also diverges in its handling of `.onmessage`. Setting it
|
* automatically calls `.start()`, but unsetting it lets messages queue up
|
* until a new handler is set or the port is discarded.
|
* @since v10.5.0
|
*/
|
start(): void;
|
addListener(event: 'close', listener: () => void): this;
|
addListener(event: 'message', listener: (value: any) => void): this;
|
addListener(event: 'messageerror', listener: (error: Error) => void): this;
|
addListener(event: string | symbol, listener: (...args: any[]) => void): this;
|
emit(event: 'close'): boolean;
|
emit(event: 'message', value: any): boolean;
|
emit(event: 'messageerror', error: Error): boolean;
|
emit(event: string | symbol, ...args: any[]): boolean;
|
on(event: 'close', listener: () => void): this;
|
on(event: 'message', listener: (value: any) => void): this;
|
on(event: 'messageerror', listener: (error: Error) => void): this;
|
on(event: string | symbol, listener: (...args: any[]) => void): this;
|
once(event: 'close', listener: () => void): this;
|
once(event: 'message', listener: (value: any) => void): this;
|
once(event: 'messageerror', listener: (error: Error) => void): this;
|
once(event: string | symbol, listener: (...args: any[]) => void): this;
|
prependListener(event: 'close', listener: () => void): this;
|
prependListener(event: 'message', listener: (value: any) => void): this;
|
prependListener(event: 'messageerror', listener: (error: Error) => void): this;
|
prependListener(event: string | symbol, listener: (...args: any[]) => void): this;
|
prependOnceListener(event: 'close', listener: () => void): this;
|
prependOnceListener(event: 'message', listener: (value: any) => void): this;
|
prependOnceListener(event: 'messageerror', listener: (error: Error) => void): this;
|
prependOnceListener(event: string | symbol, listener: (...args: any[]) => void): this;
|
removeListener(event: 'close', listener: () => void): this;
|
removeListener(event: 'message', listener: (value: any) => void): this;
|
removeListener(event: 'messageerror', listener: (error: Error) => void): this;
|
removeListener(event: string | symbol, listener: (...args: any[]) => void): this;
|
off(event: 'close', listener: () => void): this;
|
off(event: 'message', listener: (value: any) => void): this;
|
off(event: 'messageerror', listener: (error: Error) => void): this;
|
off(event: string | symbol, listener: (...args: any[]) => void): this;
|
}
|
interface WorkerOptions {
|
/**
|
* List of arguments which would be stringified and appended to
|
* `process.argv` in the worker. This is mostly similar to the `workerData`
|
* but the values will be available on the global `process.argv` as if they
|
* were passed as CLI options to the script.
|
*/
|
argv?: any[] | undefined;
|
env?: NodeJS.Dict<string> | typeof SHARE_ENV | undefined;
|
eval?: boolean | undefined;
|
workerData?: any;
|
stdin?: boolean | undefined;
|
stdout?: boolean | undefined;
|
stderr?: boolean | undefined;
|
execArgv?: string[] | undefined;
|
resourceLimits?: ResourceLimits | undefined;
|
/**
|
* Additional data to send in the first worker message.
|
*/
|
transferList?: TransferListItem[] | undefined;
|
/**
|
* @default true
|
*/
|
trackUnmanagedFds?: boolean | undefined;
|
}
|
interface ResourceLimits {
|
/**
|
* The maximum size of a heap space for recently created objects.
|
*/
|
maxYoungGenerationSizeMb?: number | undefined;
|
/**
|
* The maximum size of the main heap in MB.
|
*/
|
maxOldGenerationSizeMb?: number | undefined;
|
/**
|
* The size of a pre-allocated memory range used for generated code.
|
*/
|
codeRangeSizeMb?: number | undefined;
|
/**
|
* The default maximum stack size for the thread. Small values may lead to unusable Worker instances.
|
* @default 4
|
*/
|
stackSizeMb?: number | undefined;
|
}
|
/**
|
* The `Worker` class represents an independent JavaScript execution thread.
|
* Most Node.js APIs are available inside of it.
|
*
|
* Notable differences inside a Worker environment are:
|
*
|
* * The `process.stdin`, `process.stdout` and `process.stderr` may be redirected by the parent thread.
|
* * The `require('worker_threads').isMainThread` property is set to `false`.
|
* * The `require('worker_threads').parentPort` message port is available.
|
* * `process.exit()` does not stop the whole program, just the single thread,
|
* and `process.abort()` is not available.
|
* * `process.chdir()` and `process` methods that set group or user ids
|
* are not available.
|
* * `process.env` is a copy of the parent thread's environment variables,
|
* unless otherwise specified. Changes to one copy are not visible in other
|
* threads, and are not visible to native add-ons (unless `worker.SHARE_ENV` is passed as the `env` option to the `Worker` constructor).
|
* * `process.title` cannot be modified.
|
* * Signals are not delivered through `process.on('...')`.
|
* * Execution may stop at any point as a result of `worker.terminate()` being invoked.
|
* * IPC channels from parent processes are not accessible.
|
* * The `trace_events` module is not supported.
|
* * Native add-ons can only be loaded from multiple threads if they fulfill `certain conditions`.
|
*
|
* Creating `Worker` instances inside of other `Worker`s is possible.
|
*
|
* Like [Web Workers](https://developer.mozilla.org/en-US/docs/Web/API/Web_Workers_API) and the `cluster module`, two-way communication can be
|
* achieved through inter-thread message passing. Internally, a `Worker` has a
|
* built-in pair of `MessagePort` s that are already associated with each other
|
* when the `Worker` is created. While the `MessagePort` object on the parent side
|
* is not directly exposed, its functionalities are exposed through `worker.postMessage()` and the `worker.on('message')` event
|
* on the `Worker` object for the parent thread.
|
*
|
* To create custom messaging channels (which is encouraged over using the default
|
* global channel because it facilitates separation of concerns), users can create
|
* a `MessageChannel` object on either thread and pass one of the`MessagePort`s on that `MessageChannel` to the other thread through a
|
* pre-existing channel, such as the global one.
|
*
|
* See `port.postMessage()` for more information on how messages are passed,
|
* and what kind of JavaScript values can be successfully transported through
|
* the thread barrier.
|
*
|
* ```js
|
* const assert = require('assert');
|
* const {
|
* Worker, MessageChannel, MessagePort, isMainThread, parentPort
|
* } = require('worker_threads');
|
* if (isMainThread) {
|
* const worker = new Worker(__filename);
|
* const subChannel = new MessageChannel();
|
* worker.postMessage({ hereIsYourPort: subChannel.port1 }, [subChannel.port1]);
|
* subChannel.port2.on('message', (value) => {
|
* console.log('received:', value);
|
* });
|
* } else {
|
* parentPort.once('message', (value) => {
|
* assert(value.hereIsYourPort instanceof MessagePort);
|
* value.hereIsYourPort.postMessage('the worker is sending this');
|
* value.hereIsYourPort.close();
|
* });
|
* }
|
* ```
|
* @since v10.5.0
|
*/
|
class Worker extends EventEmitter {
|
/**
|
* If `stdin: true` was passed to the `Worker` constructor, this is a
|
* writable stream. The data written to this stream will be made available in
|
* the worker thread as `process.stdin`.
|
* @since v10.5.0
|
*/
|
readonly stdin: Writable | null;
|
/**
|
* This is a readable stream which contains data written to `process.stdout` inside the worker thread. If `stdout: true` was not passed to the `Worker` constructor, then data is piped to the
|
* parent thread's `process.stdout` stream.
|
* @since v10.5.0
|
*/
|
readonly stdout: Readable;
|
/**
|
* This is a readable stream which contains data written to `process.stderr` inside the worker thread. If `stderr: true` was not passed to the `Worker` constructor, then data is piped to the
|
* parent thread's `process.stderr` stream.
|
* @since v10.5.0
|
*/
|
readonly stderr: Readable;
|
/**
|
* An integer identifier for the referenced thread. Inside the worker thread,
|
* it is available as `require('worker_threads').threadId`.
|
* This value is unique for each `Worker` instance inside a single process.
|
* @since v10.5.0
|
*/
|
readonly threadId: number;
|
/**
|
* Provides the set of JS engine resource constraints for this Worker thread.
|
* If the `resourceLimits` option was passed to the `Worker` constructor,
|
* this matches its values.
|
*
|
* If the worker has stopped, the return value is an empty object.
|
* @since v13.2.0, v12.16.0
|
*/
|
readonly resourceLimits?: ResourceLimits | undefined;
|
/**
|
* An object that can be used to query performance information from a worker
|
* instance. Similar to `perf_hooks.performance`.
|
* @since v15.1.0, v14.17.0, v12.22.0
|
*/
|
readonly performance: WorkerPerformance;
|
/**
|
* @param filename The path to the Worker’s main script or module.
|
* Must be either an absolute path or a relative path (i.e. relative to the current working directory) starting with ./ or ../,
|
* or a WHATWG URL object using file: protocol. If options.eval is true, this is a string containing JavaScript code rather than a path.
|
*/
|
constructor(filename: string | URL, options?: WorkerOptions);
|
/**
|
* Send a message to the worker that is received via `require('worker_threads').parentPort.on('message')`.
|
* See `port.postMessage()` for more details.
|
* @since v10.5.0
|
*/
|
postMessage(value: any, transferList?: ReadonlyArray<TransferListItem>): void;
|
/**
|
* Opposite of `unref()`, calling `ref()` on a previously `unref()`ed worker does_not_ let the program exit if it's the only active handle left (the default
|
* behavior). If the worker is `ref()`ed, calling `ref()` again has
|
* no effect.
|
* @since v10.5.0
|
*/
|
ref(): void;
|
/**
|
* Calling `unref()` on a worker allows the thread to exit if this is the only
|
* active handle in the event system. If the worker is already `unref()`ed calling`unref()` again has no effect.
|
* @since v10.5.0
|
*/
|
unref(): void;
|
/**
|
* Stop all JavaScript execution in the worker thread as soon as possible.
|
* Returns a Promise for the exit code that is fulfilled when the `'exit' event` is emitted.
|
* @since v10.5.0
|
*/
|
terminate(): Promise<number>;
|
/**
|
* Returns a readable stream for a V8 snapshot of the current state of the Worker.
|
* See `v8.getHeapSnapshot()` for more details.
|
*
|
* If the Worker thread is no longer running, which may occur before the `'exit' event` is emitted, the returned `Promise` is rejected
|
* immediately with an `ERR_WORKER_NOT_RUNNING` error.
|
* @since v13.9.0, v12.17.0
|
* @return A promise for a Readable Stream containing a V8 heap snapshot
|
*/
|
getHeapSnapshot(): Promise<Readable>;
|
addListener(event: 'error', listener: (err: Error) => void): this;
|
addListener(event: 'exit', listener: (exitCode: number) => void): this;
|
addListener(event: 'message', listener: (value: any) => void): this;
|
addListener(event: 'messageerror', listener: (error: Error) => void): this;
|
addListener(event: 'online', listener: () => void): this;
|
addListener(event: string | symbol, listener: (...args: any[]) => void): this;
|
emit(event: 'error', err: Error): boolean;
|
emit(event: 'exit', exitCode: number): boolean;
|
emit(event: 'message', value: any): boolean;
|
emit(event: 'messageerror', error: Error): boolean;
|
emit(event: 'online'): boolean;
|
emit(event: string | symbol, ...args: any[]): boolean;
|
on(event: 'error', listener: (err: Error) => void): this;
|
on(event: 'exit', listener: (exitCode: number) => void): this;
|
on(event: 'message', listener: (value: any) => void): this;
|
on(event: 'messageerror', listener: (error: Error) => void): this;
|
on(event: 'online', listener: () => void): this;
|
on(event: string | symbol, listener: (...args: any[]) => void): this;
|
once(event: 'error', listener: (err: Error) => void): this;
|
once(event: 'exit', listener: (exitCode: number) => void): this;
|
once(event: 'message', listener: (value: any) => void): this;
|
once(event: 'messageerror', listener: (error: Error) => void): this;
|
once(event: 'online', listener: () => void): this;
|
once(event: string | symbol, listener: (...args: any[]) => void): this;
|
prependListener(event: 'error', listener: (err: Error) => void): this;
|
prependListener(event: 'exit', listener: (exitCode: number) => void): this;
|
prependListener(event: 'message', listener: (value: any) => void): this;
|
prependListener(event: 'messageerror', listener: (error: Error) => void): this;
|
prependListener(event: 'online', listener: () => void): this;
|
prependListener(event: string | symbol, listener: (...args: any[]) => void): this;
|
prependOnceListener(event: 'error', listener: (err: Error) => void): this;
|
prependOnceListener(event: 'exit', listener: (exitCode: number) => void): this;
|
prependOnceListener(event: 'message', listener: (value: any) => void): this;
|
prependOnceListener(event: 'messageerror', listener: (error: Error) => void): this;
|
prependOnceListener(event: 'online', listener: () => void): this;
|
prependOnceListener(event: string | symbol, listener: (...args: any[]) => void): this;
|
removeListener(event: 'error', listener: (err: Error) => void): this;
|
removeListener(event: 'exit', listener: (exitCode: number) => void): this;
|
removeListener(event: 'message', listener: (value: any) => void): this;
|
removeListener(event: 'messageerror', listener: (error: Error) => void): this;
|
removeListener(event: 'online', listener: () => void): this;
|
removeListener(event: string | symbol, listener: (...args: any[]) => void): this;
|
off(event: 'error', listener: (err: Error) => void): this;
|
off(event: 'exit', listener: (exitCode: number) => void): this;
|
off(event: 'message', listener: (value: any) => void): this;
|
off(event: 'messageerror', listener: (error: Error) => void): this;
|
off(event: 'online', listener: () => void): this;
|
off(event: string | symbol, listener: (...args: any[]) => void): this;
|
}
|
interface BroadcastChannel extends NodeJS.RefCounted {}
|
/**
|
* Instances of `BroadcastChannel` allow asynchronous one-to-many communication
|
* with all other `BroadcastChannel` instances bound to the same channel name.
|
*
|
* ```js
|
* 'use strict';
|
*
|
* const {
|
* isMainThread,
|
* BroadcastChannel,
|
* Worker
|
* } = require('worker_threads');
|
*
|
* const bc = new BroadcastChannel('hello');
|
*
|
* if (isMainThread) {
|
* let c = 0;
|
* bc.onmessage = (event) => {
|
* console.log(event.data);
|
* if (++c === 10) bc.close();
|
* };
|
* for (let n = 0; n < 10; n++)
|
* new Worker(__filename);
|
* } else {
|
* bc.postMessage('hello from every worker');
|
* bc.close();
|
* }
|
* ```
|
* @since v15.4.0
|
* @experimental
|
*/
|
class BroadcastChannel {
|
readonly name: string;
|
/**
|
* Invoked with a single \`MessageEvent\` argument when a message is received.
|
* @since v15.4.0
|
*/
|
onmessage: (message: unknown) => void;
|
/**
|
* Invoked with a received message cannot be deserialized.
|
* @since v15.4.0
|
*/
|
onmessageerror: (message: unknown) => void;
|
constructor(name: string);
|
/**
|
* Closes the `BroadcastChannel` connection.
|
* @since v15.4.0
|
*/
|
close(): void;
|
/**
|
* @since v15.4.0
|
* @param message Any cloneable JavaScript value.
|
*/
|
postMessage(message: unknown): void;
|
}
|
/**
|
* Mark an object as not transferable. If `object` occurs in the transfer list of
|
* a `port.postMessage()` call, it is ignored.
|
*
|
* In particular, this makes sense for objects that can be cloned, rather than
|
* transferred, and which are used by other objects on the sending side.
|
* For example, Node.js marks the `ArrayBuffer`s it uses for its `Buffer pool` with this.
|
*
|
* This operation cannot be undone.
|
*
|
* ```js
|
* const { MessageChannel, markAsUntransferable } = require('worker_threads');
|
*
|
* const pooledBuffer = new ArrayBuffer(8);
|
* const typedArray1 = new Uint8Array(pooledBuffer);
|
* const typedArray2 = new Float64Array(pooledBuffer);
|
*
|
* markAsUntransferable(pooledBuffer);
|
*
|
* const { port1 } = new MessageChannel();
|
* port1.postMessage(typedArray1, [ typedArray1.buffer ]);
|
*
|
* // The following line prints the contents of typedArray1 -- it still owns
|
* // its memory and has been cloned, not transferred. Without
|
* // `markAsUntransferable()`, this would print an empty Uint8Array.
|
* // typedArray2 is intact as well.
|
* console.log(typedArray1);
|
* console.log(typedArray2);
|
* ```
|
*
|
* There is no equivalent to this API in browsers.
|
* @since v14.5.0, v12.19.0
|
*/
|
function markAsUntransferable(object: object): void;
|
/**
|
* Transfer a `MessagePort` to a different `vm` Context. The original `port`object is rendered unusable, and the returned `MessagePort` instance
|
* takes its place.
|
*
|
* The returned `MessagePort` is an object in the target context and
|
* inherits from its global `Object` class. Objects passed to the [`port.onmessage()`](https://developer.mozilla.org/en-US/docs/Web/API/MessagePort/onmessage) listener are also created in the
|
* target context
|
* and inherit from its global `Object` class.
|
*
|
* However, the created `MessagePort` no longer inherits from [`EventTarget`](https://developer.mozilla.org/en-US/docs/Web/API/EventTarget), and only
|
* [`port.onmessage()`](https://developer.mozilla.org/en-US/docs/Web/API/MessagePort/onmessage) can be used to receive
|
* events using it.
|
* @since v11.13.0
|
* @param port The message port to transfer.
|
* @param contextifiedSandbox A `contextified` object as returned by the `vm.createContext()` method.
|
*/
|
function moveMessagePortToContext(port: MessagePort, contextifiedSandbox: Context): MessagePort;
|
/**
|
* Receive a single message from a given `MessagePort`. If no message is available,`undefined` is returned, otherwise an object with a single `message` property
|
* that contains the message payload, corresponding to the oldest message in the`MessagePort`’s queue.
|
*
|
* ```js
|
* const { MessageChannel, receiveMessageOnPort } = require('worker_threads');
|
* const { port1, port2 } = new MessageChannel();
|
* port1.postMessage({ hello: 'world' });
|
*
|
* console.log(receiveMessageOnPort(port2));
|
* // Prints: { message: { hello: 'world' } }
|
* console.log(receiveMessageOnPort(port2));
|
* // Prints: undefined
|
* ```
|
*
|
* When this function is used, no `'message'` event is emitted and the`onmessage` listener is not invoked.
|
* @since v12.3.0
|
*/
|
function receiveMessageOnPort(port: MessagePort):
|
| {
|
message: any;
|
}
|
| undefined;
|
type Serializable = string | object | number | boolean | bigint;
|
/**
|
* Within a worker thread, `worker.getEnvironmentData()` returns a clone
|
* of data passed to the spawning thread's `worker.setEnvironmentData()`.
|
* Every new `Worker` receives its own copy of the environment data
|
* automatically.
|
*
|
* ```js
|
* const {
|
* Worker,
|
* isMainThread,
|
* setEnvironmentData,
|
* getEnvironmentData,
|
* } = require('worker_threads');
|
*
|
* if (isMainThread) {
|
* setEnvironmentData('Hello', 'World!');
|
* const worker = new Worker(__filename);
|
* } else {
|
* console.log(getEnvironmentData('Hello')); // Prints 'World!'.
|
* }
|
* ```
|
* @since v15.12.0, v14.18.0
|
* @experimental
|
* @param key Any arbitrary, cloneable JavaScript value that can be used as a {Map} key.
|
*/
|
function getEnvironmentData(key: Serializable): Serializable;
|
/**
|
* The `worker.setEnvironmentData()` API sets the content of`worker.getEnvironmentData()` in the current thread and all new `Worker`instances spawned from the current context.
|
* @since v15.12.0, v14.18.0
|
* @experimental
|
* @param key Any arbitrary, cloneable JavaScript value that can be used as a {Map} key.
|
* @param value Any arbitrary, cloneable JavaScript value that will be cloned and passed automatically to all new `Worker` instances. If `value` is passed as `undefined`, any previously set value
|
* for the `key` will be deleted.
|
*/
|
function setEnvironmentData(key: Serializable, value: Serializable): void;
|
}
|
declare module 'node:worker_threads' {
|
export * from 'worker_threads';
|
}
|
