WebSocket disconnect when idleTimeout is less than 6 seconds

[DarkMatterMatt]

Hey, I've found that websockets will be dropped when idleTimeout is less than 6 seconds.

Method of testing:
Run a websocket with a short timeout
Go to http://crysislinux.github.io/smart_websocket_client/
Connect to the websocket and spam a message (connection should remain until the server has not received a message for 5 seconds)
Watch as it drops the connection.

Sample code, using uWS v17.3.0

require('uWebSockets.js').App().ws('/*', {
    idleTimeout: 5.9999, // disconnects
    // idleTimeout: 6, // doesn't disconnect

    message: (ws, message, isBinary) => {
        let ok = ws.send(message, isBinary);
    }
}).listen(9001, (listenSocket) => {
    if (listenSocket) {
        console.log('Listening to port 9001');
    }
});

[ghost]

What if you specify 6.9999

[DarkMatterMatt]

Timeout	Disconnects
4	✓
5	✓
5.5	✓
5.9999	✓
6	✗
6.5	✗
6.9999	✗
7	✗

Edit to add screenshot (idleTimeout = 5):

x = new WebSocket("ws://localhost:9001/");
x.addEventListener("open", () => console.log("open ", (new Date()).getTime()));
x.addEventListener("close", ev => console.log("close", (new Date()).getTime(), ev.code, ev.reason));

[ghost]

I cannot reproduce this issue. Your screenshot seems to show how it is supposed to act. Timeout is very granular and works in steps of 4 seconds. This means 5 seconds will round to 4 seconds which is anything between 0 to 4 seconds if I remember correctly. This while 6 will round to 8 seconds, which is anything between 4 to 8 seconds.

This is controlled by LIBUS_TIMEOUT_GRANULARITY which is 4 seconds by default.

[DarkMatterMatt]

Interesting, I didn't know about LIBUS_TIMEOUT_GRANULARITY, thanks :)