1899863 - Extremely frequent PNecko::Msg_CancelHTMLDNSPrefetch log spam

Status: RESOLVED FIXED

(Core :: Networking: DNS, task, P2)

Description

[Andrew McCreight [:mccr8]]

Across a single mozilla-central OSX try push, I see over 600,000 instances of this warning:

638469 WARNING: IPC message 'PNecko::Msg_CancelHTMLDNSPrefetch' discarded: actor cannot send: file ipc/glue/ProtocolUtils.cpp:551

The next on the list is only 120k, and the one after that is only about 78k.

There are about 63k instances of this warning in individual logs for bc12, 40k in bc4, 52k in bc 3. Approximately 50% of the lines of bc12 are just this warning.

It looks like that message is going to come from this call to SendCancelHTMLDNSPrefetch. This warning can be avoided by checking gNeckoChild->CanSend() first. This send is not new, so I'm not sure why this warning is so frequent.

Comment 1

[Andrew McCreight [:mccr8]]

Attachment: Bug 1899863 - Don't try to SendCancelHTMLDNSPrefetch or SendRemoveRequestContext if it will fail.

This causes extremely frequent warning spam in debug builds.

Comment 2

[Andrew McCreight [:mccr8]]

I tested this patch locally. While running a single XPConnect mochitest plain directory, this reduced the number of instances of this warning from almost 970 to 0.

Comment 3

[Andrew McCreight [:mccr8]]

I added another similar check to some networking-related code to the patch. This is the number 3 source of warning spam, with 77921 instances:
WARNING: IPC message 'PNecko::Msg_RemoveRequestContext' discarded: actor cannot send: file ipc/glue/ProtocolUtils.cpp:551

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/51c9689da203
Don't try to SendCancelHTMLDNSPrefetch or SendRemoveRequestContext if it will fail. r=necko-reviewers,jesup

Comment 5

[Andrew McCreight [:mccr8]]

Doesn't seem to be a problem on ESR115 FWIW.

Comment 6

[pstanciu]

https://hg.mozilla.org/mozilla-central/rev/51c9689da203