Question

Yes I’m aware that asking for a formal memory model in Javascript is a hopeless undertaking, so I’m settling for “All browsers follow these rules” or something.

My problem is the following: I have to send events in a defined interval to a server, but events may be added to my array while doing so, i.e.:

function storeEvent(event) {
    // may be called at any time
    storedEvents.push(event);
}

function broadcastEvents() {
    if (storedEvents.length !== 0) {
        var eventString = JSON.stringify(storedEvents);
        storedEvents = [];
        // send eventString to server
    }
    window.setTimeout(broadcastEvents, BROADCAST_TIMER);
}

There’s an obvious race condition in there and not even think of the missing memory barriers.

What to do? Really missing the Java memory model here..

Answer 1

There isn’t any race condition.

All JavaScript code in the browser is single-threaded.

The setTimeout callback will run on the UI thread while it isn’t doing anything else.