1605862 - Decrease UDP socket read timeout in mDNS service

Status: RESOLVED FIXED

(Core :: WebRTC: Networking, defect, P2)

Description

[Dan Minor [:dminor]]

In Bug 1601992 we're seeing occasional shutdown hangs with a stack trace like:
0 ntdll.dll NtWaitForSingleObject
1 mswsock.dll SockWaitForSingleObject
2 mswsock.dll guard_check_icall_nop
3 ws2_32.dll WSARecvFrom
4 wsock32.dll recvfrom
5 xul.dll static void mdns_service::{{impl}}::start::{{closure}}(struct mdns_service::{{impl}}::start::closure-0) media/mtransport/mdns_service/src/lib.rs:382

The current read timeout of 10ms was chosen arbitrarily. I'd like to try a smaller timeout to see if it helps with the shutdown hangs we're seeing.

Comment 1

[Dan Minor [:dminor]]

Attachment: Bug 1605862 - Decrease UDP socket timeouts in mDNS service; r=mjf!

The original values of 10ms were chosen arbitrarily. Decreasing the values may
help prevent shutdown hanges like those seen in Bug 1601992.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/ec9b07bbdf77
Decrease UDP socket timeouts in mDNS service; r=mjf

Comment 3

[Cristian Brindusan [:cbrindusan]]

https://hg.mozilla.org/mozilla-central/rev/ec9b07bbdf77

Comment 4

[Ryan VanderMeulen [:RyanVM]]

I'm having a difficult time ascertaining what affect this patch had. Have you seen a noticeable change in any shutdown hang bugs you're looking at, Dan?

Comment 5

[Dan Minor [:dminor]]

(In reply to Ryan VanderMeulen [:RyanVM] from comment #4)

I'm having a difficult time ascertaining what affect this patch had. Have you seen a noticeable change in any shutdown hang bugs you're looking at, Dan?

The shutdown hangs were pretty uncommon and only showed up in beta, but the mDNS stuff is currently disabled there, so we won't see the effect (if any) of this patch until Firefox 74 hits beta.