Networked A-Frame new connections force exokit to close

[kfarr]

Describe the bug
What happened, and what did you expect to happen?

When using an a-frame project with networked aframe component, and when a new user joins the scene, exokit closes, usually without an error message.

Instead I would expect exokit to stay running and that both users can interact in the scene together.

To Reproduce
Steps or commands ran to reproduce the behavior:

Install and build exokit 1462531
git clone from https://github.com/MozillaReality/networked-aframe (NAF 27d9765bef5f0e10617a4f7dd8dc33572219db05)
npm install
npm run dev

in exokit dir:
node . -x webvr localhost:8080/tracked-controllers.html

then open in another browser
localhost:8080/tracked-controllers.html

exokit will crash within a few seconds but usually with no error. sometimes a console error is displayed:

uncaught exception: TypeError: Cannot read property 'owner' of undefined
    at i.networkUpdate (/build.js:1895:19)
    at NetworkEntities.updateEntity (/build.js:663:53)
    at NetworkConnection.receivedData (/build.js:570:37)
    at Easyrtc.receivePeerDistribute (/easyrtc/easyrtc.js:5103:25)
    at Socket.onChannelMsg (/easyrtc/easyrtc.js:7389:18)
    at Socket.Emitter.emit (https://cdnjs.cloudflare.com/ajax/libs/socket.io/1.4.5/socket.io.min.js:3:10860)
    at Socket.onevent (https://cdnjs.cloudflare.com/ajax/libs/socket.io/1.4.5/socket.io.min.js:3:5790)
    at Socket.onpacket (https://cdnjs.cloudflare.com/ajax/libs/socket.io/1.4.5/socket.io.min.js:3:5306)
    at Manager.<anonymous> (https://cdnjs.cloudflare.com/ajax/libs/socket.io/1.4.5/socket.io.min.js:3:9520)
    at Manager.Emitter.emit (https://cdnjs.cloudflare.com/ajax/libs/socket.io/1.4.5/socket.io.min.js:3:10860)

Additional context
Add any other context about the problem here.

workaround - load exokit last after other naf users have joined

System information:

• OS: [e.g. Windows 10]

• Exokit Version [e.g. v0.0.512]
  1462531

• Node version

• Npm version/build log if applicable

• Is your Exokit downloaded or built?

Screenshots
If applicable, add screenshots to help explain your problem.

[kfarr]

unfortunately the "workaround" of running other client first before opening exokit doesn't actually seem to work, exokit user isn't providing pose updates to the scene

[avaer]

Managed to repro the "no pose update".

[avaer]

I think there are several issues here. The first is a timers bug: #1218

[avaer]

The current bug is:

• Connect with browser
• Connect with Exokit
• Disconnect+reconnect with browser
• Jiggle browser input

The browser input will not be reflected in Exokit's view.

[avaer]

☝️ The above only happened when using websockets, so it could be a rarely-tested corner case for NAF.

I was unable to reproduce any crashes or hangs with the current code in master.

@kfarr Can you confirm?

[kfarr]

☝️ The above only happened when using websockets, so it could be a rarely-tested corner case for NAF.

Unfortunately this test case is intending to use websockets but I will experiment with the alternate protocols such as firebase as a workaround

I am still able to reliably reproduce this issue with 6fc129d

[kfarr]

There is application error on other WebVR browser (Firefox) when following the same instructions, so not just an exokit issue. (When add'l client connects after Firefox WebVR mode was first client, then WebVR client resets its tracked poses to 0 0 0 and stops sending updates.

Digging in more.

[avaer]

Thanks, does that mean the repro requires setting websockets as the protocol (as opposed to RTC)?

[kfarr]

For me I see issue with both and it's my understanding that websockets is default https://github.com/MozillaReality/networked-aframe#adapters

I do not see issue tab on that repo so I have not filed w/NAF.