Cloudflare Developers•4mo ago

Durable object websocket close not working

Hey, I recently got into Durable objects but I think i'm not getting some parts of it. In my code I was just trying to close the connection immediately after establishing it, but it is not working for some reason and ws.close does nothing while ws.send()works great. This is my code:

export class Manager extends DurableObject {

    async fetch(request: Request) {
        // Creates two ends of a WebSocket connection.
        const webSocketPair = new WebSocketPair();
        const [client, server] = Object.values(webSocketPair);

        // Calling `acceptWebSocket()` informs the runtime that this WebSocket is to begin terminating
        // request within the Durable Object. It has the effect of "accepting" the connection,
        // and allowing the WebSocket to send and receive messages.
        // Unlike `ws.accept()`, `state.acceptWebSocket(ws)` informs the Workers Runtime that the WebSocket
        // is "hibernatable", so the runtime does not need to pin this Durable Object to memory while
        // the connection is open. During periods of inactivity, the Durable Object can be evicted
        // from memory, but the WebSocket connection will remain open. If at some later point the
        // WebSocket receives a message, the runtime will recreate the Durable Object
        // (run the `constructor`) and deliver the message to the appropriate handler.
        this.ctx.acceptWebSocket(server);

        this.ctx.waitUntil((async () => {
            const websockets = this.ctx.getWebSockets();
            for (const ws of websockets) {
                if (ws === server) {
                    ws.send('Hello from the Durable Object!');
                    ws.close(1008, 'Connection closed');
                }
            }
        })());

        console.log('Handler finished');

        return new Response(null, {
            status: 101,
            webSocket: client,
        });
    }

    async processRequest(request: Request) {

    }

}

export class Manager extends DurableObject {

    async fetch(request: Request) {
        // Creates two ends of a WebSocket connection.
        const webSocketPair = new WebSocketPair();
        const [client, server] = Object.values(webSocketPair);

        // Calling `acceptWebSocket()` informs the runtime that this WebSocket is to begin terminating
        // request within the Durable Object. It has the effect of "accepting" the connection,
        // and allowing the WebSocket to send and receive messages.
        // Unlike `ws.accept()`, `state.acceptWebSocket(ws)` informs the Workers Runtime that the WebSocket
        // is "hibernatable", so the runtime does not need to pin this Durable Object to memory while
        // the connection is open. During periods of inactivity, the Durable Object can be evicted
        // from memory, but the WebSocket connection will remain open. If at some later point the
        // WebSocket receives a message, the runtime will recreate the Durable Object
        // (run the `constructor`) and deliver the message to the appropriate handler.
        this.ctx.acceptWebSocket(server);

        this.ctx.waitUntil((async () => {
            const websockets = this.ctx.getWebSockets();
            for (const ws of websockets) {
                if (ws === server) {
                    ws.send('Hello from the Durable Object!');
                    ws.close(1008, 'Connection closed');
                }
            }
        })());

        console.log('Handler finished');

        return new Response(null, {
            status: 101,
            webSocket: client,
        });
    }

    async processRequest(request: Request) {

    }

}

3 Replies

ZetaxOP•4mo ago

Also, for some reason my waitUntil code runs before the handler, which it isn't supposed to do, right?

kev-ac•4mo ago

I'm unsure if waitUntil() is really neccessary here. All methods are called synchronously, there is nothing to await for. Why are you checking if ws === server? getWebSockets() should return all accepted websockets, so all client connections. Thats where you want to send your messages to.

ZetaxOP•4mo ago

I am using waitUntil to actually test if I can actually close the websocket connecton, because if I do ws.close before returning the response, then it will just give me an http error because it did not return the upgrade response. And I am checking if ws === server to only send the message to the client connecting (At least that's what I think "server" represents, because when I do client.send, it doesnt do anything)

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Durable object websocket close not working