onnegotiationneeded event fired twice in Chrome about samples-server HOT 5 OPEN

ONN twice issue can be fixed with a re-entrancy guard:

pc.onnegotiationneeded = async e => {
  if (pc._negotiating == true) return;
  pc._negotiating = true;
  try {
    return cb(e);
  } finally {
    pc._negotiating = false;
  }
}

So the updated code from tutorial will look like (ah, and it is async/await instead of promises too :) )

async function handleNegotiationNeededEvent() {
    if (myPeerConnection._negotiating == true) return;
    log("*** Negotiation needed");
    myPeerConnection._negotiating = true;
    try {
        log("---> Creating offer");
        const offer = await myPeerConnection.createOffer();

        log("---> Creating new description object to send to remote peer");
        await myPeerConnection.setLocalDescription(offer);

        log("---> Sending offer to remote peer");
        sendToServer({
            name: myUsername,
            target: targetUsername,
            type: "video-offer",
            sdp: myPeerConnection.localDescription
        });
    } catch (e) {
        reportError(e)
    } finally {
        myPeerConnection._negotiating = false;
    }
}

from samples-server.

Here is bug https://bugs.chromium.org/p/chromium/issues/detail?id=740501

from samples-server.

Solved that error but now this one.
Failed to execute 'addTrack' on 'RTCPeerConnection': A sender already exists for the track.

from samples-server.

yes, when two addTrack() are used , two onnegotiationneeded events will be fired. Still dont know what to do now

from samples-server.

I am having similar issue. Anyone able to figure this out. My scenarios:

1. One user (say User A) connects with only audio track. Other user (say User B) connects with both audio and video tracks.
2. If User B is offerer, connection is established perfectly and User A can display User B video and both are able to talk to each other.
3. If User B is answerer and User it has to send 2 tracks, in which case it is triggering onnegotiationneeded event. Which in-turn starting another session of offer-answer session. Which is not desired.
4. If I discard this extra onnegotiationneeded event, User A cannot see User B video. But only able to talk to each other.

Let me know if there is any solution for such solution. I am trying for last more than 1 week.

Thanks

from samples-server.