crypto/tls: TestConnCloseWrite flake

[bradfitz]

Trybot failure flake:

https://storage.googleapis.com/go-build-log/ae11a8d3/nacl-386_4211e444.log

panic: Fail in goroutine after  has completed

goroutine 318 [running]:
panic(0x274c00, 0x1223bcc0)
    /tmp/workdir/go/src/runtime/panic.go:527 +0x1a0
testing.(*common).Fail(0x10b40580)
    /tmp/workdir/go/src/testing/testing.go:422 +0x160
testing.(*common).Fail(0x1254cf80)
    /tmp/workdir/go/src/testing/testing.go:416 +0x1c0
testing.(*common).FailNow(0x1254cf80)
    /tmp/workdir/go/src/testing/testing.go:441 +0x40
testing.(*common).Fatal(0x1254cf80, 0x12a37fc4, 0x1, 0x1)
    /tmp/workdir/go/src/testing/testing.go:501 +0x80
crypto/tls.TestConnCloseWrite.func2(0x7c2040, 0x1223bbd0, 0x1254cf80)
    /tmp/workdir/go/src/crypto/tls/tls_test.go:526 +0xc0
created by crypto/tls.TestConnCloseWrite
    /tmp/workdir/go/src/crypto/tls/tls_test.go:534 +0x780
FAIL    crypto/tls  2.810s

/cc @benburkert
/cc @randall77 from https://go-review.googlesource.com/c/31260

[aclements]

Been happening a lot:

$ greplogs -dashboard -E "TestConnCloseWrite has completed" -l -md
2016-10-17T14:26:55-c6185aa/solaris-amd64-smartosbuildlet
2016-10-17T15:21:33-f444b48/solaris-amd64-smartosbuildlet
2016-10-17T15:22:11-15040c1/linux-ppc64-buildlet
2016-10-17T15:22:17-237d7e3/solaris-amd64-smartosbuildlet
2016-10-17T15:26:25-0ce1d79/linux-amd64-noopt
2016-10-17T15:26:25-0ce1d79/solaris-amd64-smartosbuildlet
2016-10-17T16:06:04-d26b066/solaris-amd64-smartosbuildlet
2016-10-17T17:05:39-9a97c3b/linux-amd64-noopt
2016-10-17T18:11:24-77b6a08/solaris-amd64-smartosbuildlet
2016-10-17T18:23:32-cbf28ff/solaris-amd64-smartos
2016-10-17T18:26:20-6f4a6fa/solaris-amd64-smartosbuildlet
2016-10-17T18:34:02-7c46f03/solaris-amd64-smartos
2016-10-17T18:34:02-7c46f03/solaris-amd64-smartosbuildlet
2016-10-17T18:46:20-1e28dce/solaris-amd64-smartosbuildlet
2016-10-17T18:53:22-0ba3c60/solaris-amd64-smartosbuildlet
2016-10-17T18:56:09-687d9d5/solaris-amd64-smartosbuildlet
2016-10-17T18:57:01-d5bd797/solaris-amd64-smartos
2016-10-17T18:57:01-d5bd797/solaris-amd64-smartosbuildlet
2016-10-17T19:09:07-395d36a/solaris-amd64-smartos
2016-10-17T19:09:07-395d36a/solaris-amd64-smartosbuildlet
2016-10-17T19:09:30-81c431a/solaris-amd64-smartos
2016-10-17T19:09:30-81c431a/solaris-amd64-smartosbuildlet
2016-10-17T19:09:30-81c431a/windows-amd64-race
2016-10-17T19:09:37-984753b/solaris-amd64-smartosbuildlet
2016-10-17T19:09:37-984753b/windows-amd64-race

$ greplogs -dashboard -E "TestConnCloseWrite has completed" -l | findflakes -dir ~/.cache/fetchlogs/rev -paths
First observed c6185aa 17 Oct 14:26 2016 (18 commits ago)
Last observed  984753b 17 Oct 19:09 2016 (1 commits ago)
0.00% chance failure is still happening
100% failure probability (18 of 18 commits)
Likely culprits:
  100% c6185aa crypto/tls: add CloseWrite method to Conn
No known past failures

Commit c6185aa was by @benburkert.

[bradfitz]

@benburkert, can you look into making that test non-flaky?

[mdempsky]

FYI, https://go-review.googlesource.com/#/c/31310/ is up to revert CL 31260 since it seems to be causing other failures too. The TestConnCloseWrite flakes predate it, but somehow CL 31260 seems to make them more frequent.

[gopherbot]

CL https://golang.org/cl/31318 mentions this issue.

[rsc]

Fixed by CL 31318.