1668706 - "[GPU ..., Renderer] WARNING: Failed to duplicate file handle for current process!" flooding windows terminal running local debug build

Status: RESOLVED FIXED

(Core :: Graphics: WebRender, defect)

Description

[Gerald Squelart (he/him) (not at Mozilla since 2022-09-15)]

For a little while now, when I'm running a local m-c build on Windows 10, I'm getting the following warning tens to hundreds of times per second:

[GPU 2271172, Renderer] WARNING: Failed to duplicate file handle for current process!: file c:/mozilla-source/mozilla-central/ipc/glue/FileDescriptor.cpp, line 124

This floods my terminal, it's quite distracting (to me) when I'm trying to do something in Firefox, and I may miss more important log messages. Is this warning really useful?

In any case, moz-regression gave me this range:
https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=a7975fa65a251e8e4e6631666c09d3fc4737f43d&tochange=0de10c26da552953484a56f0fbdb3ab70196988e
The most likely culprit would be bug 1658684. Though it's for Android, it adds some platform-independent code.

I was able to capture a stack at the first warning:

Assertion failure: false (Failed to duplicate file handle for current process!), at c:/mozilla-source/mozilla-central/ipc/glue/FileDescriptor.cpp:124
#01: mozilla::wr::RenderThread::UpdateAndRender (c:\mozilla-source\mozilla-central\gfx\webrender_bindings\RenderThread.cpp:521)
#02: mozilla::wr::RenderThread::HandleFrameOneDoc (c:\mozilla-source\mozilla-central\gfx\webrender_bindings\RenderThread.cpp:331)
#03: mozilla::detail::RunnableMethodImpl<mozilla::wr::RenderThread ,void (mozilla::wr::RenderThread::)(mozilla::wr::WrWindowId, bool),1,mozilla::RunnableKind::Standard,mozilla::wr::WrWindowId,bool>::Run (c:\mozilla-source\obj-mc-dbg\dist\include\nsThreadUtils.h:1243)
#04: MessageLoop::RunTask (c:\mozilla-source\mozilla-central\ipc\chromium\src\base\message_loop.cc:466)

This confirms that the source of the warning is code that was modified in bug 1658684.
Sotaro, could you please have a look, see if there's a way to silence this warning on Windows (and maybe other non-Android platforms, I haven't tried)?
It's probably not high priority because it wouldn't affect end users, but it would be nice to lessen the visual burden for us devs, thanks! 😉

Comment 1

[Sotaro Ikeda [:sotaro]]

Thanks for the report! I take a bug.

Comment 2

[Sotaro Ikeda [:sotaro]]

It seems that FileDescriptor::Clone() was called for std::move() and FileDescriptor::Clone() expects that file descriptor is valid.

Comment 3

[Sotaro Ikeda [:sotaro]]

It seems that INVALID_HANDLE_VALUE is not used for invalid file descriptor

• https://searchfox.org/mozilla-central/rev/222e4f64b769413ac1a1991d2397b13a0acb5d9d/ipc/glue/FileDescriptor.cpp#108
• https://searchfox.org/mozilla-central/rev/222e4f64b769413ac1a1991d2397b13a0acb5d9d/ipc/glue/FileDescriptor.cpp#87

Comment 4

[Sotaro Ikeda [:sotaro]]

(In reply to Sotaro Ikeda [:sotaro] from comment #3)

It seems that INVALID_HANDLE_VALUE is not used for invalid file descriptor on Windows.

nullptr is used on current gecko.

• https://searchfox.org/mozilla-central/rev/222e4f64b769413ac1a1991d2397b13a0acb5d9d/mfbt/UniquePtrExtensions.h#145

It seemed to be changed by Bug 1534780.

Comment 5

[Sotaro Ikeda [:sotaro]]

Attachment: Bug 1668706 - Fix invalid handle handling of FileDescriptor::Clone() on Windows

Comment 6

[BugBot [:suhaib / :marco/ :calixte]]

Set release status flags based on info from the regressing bug 1658684

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/90c91aaebe61
Fix invalid handle handling of FileDescriptor::Clone() on Windows r=jld

Comment 8

[Bogdan Tara[:bogdan_tara | bogdant]]

https://hg.mozilla.org/mozilla-central/rev/90c91aaebe61