panic: send on closed channel in github.com/pion/ice.(*Agent).updateConnectionState

[anacrolix]

panic: send on closed channel

goroutine 2270100 [running]:
github.com/pion/ice.(*Agent).updateConnectionState(...)
        /root/go/pkg/mod/github.com/pion/ice@v0.7.13/agent.go:642
github.com/pion/ice.(*controlledSelector).ContactCandidates(0xc001e74ba0)
        /root/go/pkg/mod/github.com/pion/ice@v0.7.13/selection.go:214 +0x21c
github.com/pion/ice.(*Agent).startConnectivityChecks.func1.1.1.1(0xc000f2e000)
        /root/go/pkg/mod/github.com/pion/ice@v0.7.13/agent.go:615 +0x3a
github.com/pion/ice.(*Agent).run(0xc000f2e000, 0xe4d648, 0x0, 0x0)
        /root/go/pkg/mod/github.com/pion/ice@v0.7.13/agent.go:194 +0xfd
github.com/pion/ice.(*Agent).startConnectivityChecks.func1.1.1()
        /root/go/pkg/mod/github.com/pion/ice@v0.7.13/agent.go:614 +0x3f
github.com/pion/ice.(*Agent).startConnectivityChecks.func1.1(0xc000f2e000)
        /root/go/pkg/mod/github.com/pion/ice@v0.7.13/agent.go:626 +0x110
created by github.com/pion/ice.(*Agent).startConnectivityChecks.func1
        /root/go/pkg/mod/github.com/pion/ice@v0.7.13/agent.go:612 +0x186

I'm running a very active instance of https://github.com/anacrolix/confluence, which makes frequent and implicit use of several webtorrent trackers. There's probably 100s or 1000s of webrtc PeerConnections being opened and closed, so unless I'm using the API incorrectly, this is probably a very elusive race condition in pion code somewhere.

[at-wat]

seems caused by ContactCandidates() called after Agent.Close()

[at-wat]

@anacrolix I think #183 will fix this.

[anacrolix]

Thanks!