@dandre3000/thread

thread

Thread is a class that features a consistent API for using Workers on a web browser, node, bun or deno. All Threads are interconnected and can import modules to and call functions from each other.

Installation

npm install @dandre3000/thread

Usage

import { Thread } from '@dandre3000/thread'

// When a Thread is created
Thread.eventTarget.addEventListener('online', event => console.log('online event', event.thread.id, Thread.id))

// When a Thread has closed
Thread.eventTarget.addEventListener('exit', event => console.log('exit event', event.threadId, Thread.id))

// This function is exposed to other Threads
Thread.expose('test', (...args) => {
    return `Thread ${Thread.id} says: YO`
})

if (Thread.isMainThread) {
    console.log(Thread.id) // 0
    console.log(Thread.workerData) // null
    console.log(Thread.mainThread) // null

    Thread.create(999).then(async thread => {
        await thread.import(new URL(import.meta.url))

        console.log(await thread.invoke('test')) // Thread 1 says: YO
    })
} else {
    console.log(Thread.id) // 1
    console.log(Thread.workerData) // 999
    console.log(Thread.mainThread) // Thread instance for main thread
}

Exports

Class: Thread

Static properties

isMainThread

True if the current thread is the main thread.

id

Identifier for the current thread.

workerdata

Data sent to a thread upon creation.

transfer

Array of objects that will be transfered and emptied whenever another thread uses Thread.prototype.invoke to call a function on this thread made available using Thread.expose.

// transfer a MessagePort from a worker to the main thread
import { Thread } from '@dandre3000/thread'

if (Thread.isMainThread) {
    const thread = await Thread.create()
    await thread.import(new URL(import.meta.url))

    ;(await thread.invoke('getPort')).postMessage('Transfer successful')
} else {
    Thread.expose('getPort', () => {
        const { port1, port2 } = new MessageChannel
        port1.addEventListener('message', ({ data }) => console.log(data))
        port1.start()
        Thread.transfer.push(port2)
        return port2
    })
}

eventTarget

The target for events broadcasted from other threads.

import { Thread } from '@dandre3000/thread'

Thread.eventTarget.addEventListener('online', event => console.log(event))
Thread.eventTarget.addEventListener('exit', event => console.log(event))

mainThread

The Thread instance connected to the main thread if the current thread is a worker otherwise null.

create()

Return a Promise that resolves to a new Thread. This method is the only way to create a new Thread.

getThread()

Return the Thread corresponding to the given threadId or return null if no online Thread exists where Thread.id === threadId.

getAllThreads()

Return an array of all online Threads.

expose()

Make a function available to other threads when using Thread.prototype.invoke.

unexpose()

Remove a function from those available to other threads when using Thread.prototype.invoke.

close()

Alias for globalThis.close or process.exit.

Instance properties

id

Identifier for this Thread instance.

isOnline()

Returns true until the thread is closed.

import()

Dynamically import an ES module to the thread and return a Promise that resolves when the module is loaded.

invoke()

Call a function on the thread added using Thread.expose and return a Promise that resolves to the value returned by that function.

terminate()

Close this Thread instance.

License

MIT