Possible bug in Windows runtime?

[tobyk...@googlemail.com]

Hi All

I'm seeing intermittent crashes in my unit test and wanted to check here first to see if anyone has suggestions before I filed an official issue.

Go version: go1.10.3 windows/amd64

GOPATH: C:\go

GOROOT: C:\toolss\go

OS: Windows 10 (10.0.17134) Pro

Computer: Dell XPS 15 9560 with intel core i7

I have written a client/server application. Both client and server are on the same machine and communicate via gRPC over a named pipe. In the unit tests for the client side I spin up a stubbed server implementation and connect to it. The tests pass around 75% of the time, but the remaining 25% of the time they fail with runtime errors like this (I can't give the full stacktrace as the code is private):

runtime: waitforsingleobject wait_failed; errno=6

fatal error: runtime.semasleep wait_failed

runtime stack:

runtime.throw(0x94ba8a, 0x1d)

        C:/tools/go/src/runtime/panic.go:616 +0x88

runtime.semasleep.func2()

        C:/tools/go/src/runtime/os_windows.go:579 +0x80

runtime.semasleep(0xffffffffffffffff, 0x0)

        C:/tools/go/src/runtime/os_windows.go:577 +0xe7

runtime.notesleep(0xc04225ed18)

        C:/tools/go/src/runtime/lock_sema.go:167 +0xf7

runtime.stopm()

        C:/tools/go/src/runtime/proc.go:1952 +0xf3

runtime.findrunnable(0xc04202c500, 0x0)

        C:/tools/go/src/runtime/proc.go:2415 +0x521

runtime.schedule()

        C:/tools/go/src/runtime/proc.go:2541 +0x149

runtime.goexit0(0xc042214f00)

        C:/tools/go/src/runtime/proc.go:2713 +0x244

runtime.mcall(0x0)

        C:/tools/go/src/runtime/asm_amd64.s:351 +0x5e

goroutine 1 [chan receive]:

testing.(*T).Run(0xc0423b62d0, 0x93fd1d, 0xb, 0x961438, 0x4932ad)

        C:/tools/go/src/testing/testing.go:825 +0x308

testing.runTests.func1(0xc0423b61e0)

        C:/tools/go/src/testing/testing.go:1063 +0x6b

testing.tRunner(0xc0423b61e0, 0xc042091dd8)

        C:/tools/go/src/testing/testing.go:777 +0xd7

testing.runTests(0xc042178ee0, 0xc13f20, 0x9, 0x9, 0x0)

        C:/tools/go/src/testing/testing.go:1061 +0x2cb

testing.(*M).Run(0xc04218c280, 0x0)

        C:/tools/go/src/testing/testing.go:978 +0x178

path/to/my/client.TestMain(0xc04218c280)

        C:/go/src/path/to/my/client/my_client_test.go:390 +0x4e

main.main()

        _testmain.go:56 +0x158

.... <rest of stack trace> .....

And like this:

runtime: setevent failed; errno=6

fatal error: runtime.semawakeup

runtime stack:

runtime.throw(0x944972, 0x12)

        C:/tools/go/src/runtime/panic.go:616 +0x88

runtime.semawakeup.func1()

        C:/tools/go/src/runtime/os_windows.go:597 +0x80

runtime.semawakeup(0xc042204800)

        C:/tools/go/src/runtime/os_windows.go:595 +0x53

runtime.notewakeup(0xc042204918)

        C:/tools/go/src/runtime/lock_sema.go:147 +0x60

runtime.startm(0x0, 0xc042028001)

        C:/tools/go/src/runtime/proc.go:2017 +0xe1

runtime.wakep()

        C:/tools/go/src/runtime/proc.go:2083 +0x4f

runtime.resetspinning()

        C:/tools/go/src/runtime/proc.go:2454 +0x7f

runtime.schedule()

        C:/tools/go/src/runtime/proc.go:2548 +0x133

runtime.goexit0(0xc042348000)

        C:/tools/go/src/runtime/proc.go:2713 +0x244

runtime.mcall(0x0)

        C:/tools/go/src/runtime/asm_amd64.s:351 +0x5e

goroutine 1 [chan receive]:

testing.(*T).Run(0xc04249a1e0, 0x93fd1d, 0xb, 0x961438, 0x4932ad)

        C:/tools/go/src/testing/testing.go:825 +0x308

testing.runTests.func1(0xc04249a0f0)

        C:/tools/go/src/testing/testing.go:1063 +0x6b

testing.tRunner(0xc04249a0f0, 0xc042091dd8)

        C:/tools/go/src/testing/testing.go:777 +0xd7

testing.runTests(0xc042178ec0, 0xc13f20, 0x9, 0x9, 0x0)

        C:/tools/go/src/testing/testing.go:1061 +0x2cb

testing.(*M).Run(0xc04218e280, 0x0)

        C:/tools/go/src/testing/testing.go:978 +0x178

path/to/my/client.TestMain(0xc04218e280)

        C:/go/src/path/to/my/client/my_client_test.go:390 +0x4e

main.main()

        _testmain.go:56 +0x158

.... <rest of stack trace> .....

Errno 6 is Windows jargon for an invalid handle which is an expected error from WaitForSingleObject (https://docs.microsoft.com/en-us/windows/desktop/api/synchapi/nf-synchapi-waitforsingleobject). Has anyone seen this before?

Any help greatly appreciate, and let me know if I can provide more information.

Cheers

Toby