net: TestDialerLocalAddr and TestNetpollDeadlock are flaky on macOS 10.12

[dr2chase]

What version of Go are you using (go version)?

development (1.9+)
go version devel +4fa3d69e00 Fri Sep 22 14:03:36 2017 -0400 darwin/amd64

Does this issue reproduce with the latest release?

intermittently. That's the bug.

What operating system and processor architecture are you using (go env)?

go env
GOARCH="amd64"
GOBIN=""
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOOS="darwin"
GOPATH="/Users/drchase/GoogleDrive/work/gocode"
GORACE=""
GOROOT="/Users/drchase/GoogleDrive/work/go"
GOTOOLDIR="/Users/drchase/GoogleDrive/work/go/pkg/tool/darwin_amd64"
GCCGO="gccgo"
CC="clang"
GOGCCFLAGS="-fPIC -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/y4/90mx9nxx54bfvgh9jh0_410h0095tn/T/go-build459430235=/tmp/go-build -gno-record-gcc-switches -fno-common"
CXX="clang++"
CGO_ENABLED="1"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"

If you run run.bash repeatedly on a Mac, for instance running a binary search to isolate a single failing function, the test sometimes fails. This then causes the binary search to go down a false path and not work.

[ianlancetaylor]

CC @mikioh

[ianlancetaylor]

Here are some failures from the builders:

2017-12-01T00:23:05-301b127/darwin-amd64-10_12:
--- FAIL: TestDialerLocalAddr (75.11s)
	dial_test.go:642: tcp6 [::]:0->::1: got dial tcp6 [::]:0->[::1]:59465: getsockopt: operation timed out; want <nil>
FAIL
FAIL	net

2017-12-01T15:43:52-08176b2/darwin-amd64-10_12:
--- FAIL: TestDialerLocalAddr (75.03s)
	dial_test.go:642: tcp [::1]:0->::1: got dial tcp [::1]:0->[::1]:49317: getsockopt: operation timed out; want <nil>
FAIL
FAIL	net

2017-12-01T20:54:31-7b57e21/darwin-amd64-10_12:
--- FAIL: TestDialerLocalAddr (75.05s)
	dial_test.go:642: tcp6 :0->::1: got dial tcp6 :0->[::1]:59475: getsockopt: operation timed out; want <nil>
FAIL
FAIL	net

2017-12-01T21:05:40-8bb51a7/darwin-amd64-10_12:
--- FAIL: TestDialerLocalAddr (75.03s)
	dial_test.go:642: tcp [::]:0->::1: got dial tcp [::]:0->[::1]:49294: getsockopt: operation timed out; want <nil>
FAIL
FAIL	net

2017-12-01T23:50:23-bfa7a55/darwin-amd64-10_12:
--- FAIL: TestDialerLocalAddr (75.03s)
	dial_test.go:642: tcp 0.0.0.0:0->::1: got dial tcp 0.0.0.0:0->[::1]:59413: getsockopt: operation timed out; want <nil>
FAIL
FAIL	net

2017-12-04T21:45:40-9d70b3a/darwin-amd64-10_12:
--- FAIL: TestDialerLocalAddr (75.02s)
	dial_test.go:642: tcp6 0.0.0.0:0->::1: got dial tcp6 0.0.0.0:0->[::1]:49309: getsockopt: operation timed out; want <nil>
FAIL
FAIL	net

2017-12-05T18:42:38-49fec9b/darwin-amd64-10_12:
--- FAIL: TestDialerLocalAddr (75.03s)
	dial_test.go:642: tcp6 [::1]:0->::1: got dial tcp6 [::1]:0->[::1]:49296: getsockopt: operation timed out; want <nil>
FAIL
FAIL	net

2017-12-06T18:33:50-3e52f22/darwin-amd64-10_12:
--- FAIL: TestDialerLocalAddr (75.03s)
	dial_test.go:642: tcp6 [::]:0->::1: got dial tcp6 [::]:0->[::1]:53707: getsockopt: operation timed out; want <nil>
FAIL
FAIL	net

2017-12-14T17:12:09-1fc71e3/darwin-amd64-10_12:
--- FAIL: TestDialerLocalAddr (75.03s)
	dial_test.go:637: tcp 0.0.0.0:0->::1: got dial tcp 0.0.0.0:0->[::1]:49306: getsockopt: operation timed out; want <nil>
FAIL
FAIL	net

2017-12-18T20:24:12-3aeb395/freebsd-arm-paulzhol:
--- FAIL: TestDialerLocalAddr (0.03s)
	dial_test.go:637: tcp [::]:0->127.0.0.1: got dial tcp [::]:0->127.0.0.1:46629: connect: address already in use; want <nil>
FAIL
FAIL	net

2018-01-02T20:02:06-2ba3fd4/darwin-amd64-10_12:
--- FAIL: TestDialerLocalAddr (75.02s)
	dial_test.go:637: tcp [::]:0->::1: got dial tcp [::]:0->[::1]:59610: getsockopt: operation timed out; want <nil>
FAIL
FAIL	net

[gopherbot]

Change https://golang.org/cl/86000 mentions this issue: net: ignore TestDialerLocalAddr timeout failures on Darwin

[bcmills]

#22403 was marked as a duplicate of this, and recurred in https://build.golang.org/log/b8eabc31874c5ab9c691a4a3e4dceb2c8656b16c:

--- FAIL: TestNetpollDeadlock (60.07s)
    crash_test.go:95: testprognet NetpollDeadlock exit status: exit status 2
    crash_test.go:409: output does not start with "done\n":
        dialing
        SIGQUIT: quit
        PC=0x7fffa2d6dc86 m=0 sigcode=0
        
        goroutine 0 [idle]:
        runtime.pthread_cond_wait(0x123c288, 0x123c248, 0x7fff00000000)
        	/var/folders/dx/k53rs1s93538b4x20g46cj_w0000gn/T/workdir/go/src/runtime/sys_darwin.go:368 +0x39
        runtime.semasleep(0xffffffffffffffff, 0x7fff5fbff4f8)
        	/var/folders/dx/k53rs1s93538b4x20g46cj_w0000gn/T/workdir/go/src/runtime/os_darwin.go:63 +0x85
        runtime.notesleep(0x123c048)
        	/var/folders/dx/k53rs1s93538b4x20g46cj_w0000gn/T/workdir/go/src/runtime/lock_sema.go:173 +0xe0
        runtime.stoplockedm()
        	/var/folders/dx/k53rs1s93538b4x20g46cj_w0000gn/T/workdir/go/src/runtime/proc.go:2068 +0x88
        runtime.schedule()
        	/var/folders/dx/k53rs1s93538b4x20g46cj_w0000gn/T/workdir/go/src/runtime/proc.go:2469 +0x485
        runtime.park_m(0xc000000180)
        	/var/folders/dx/k53rs1s93538b4x20g46cj_w0000gn/T/workdir/go/src/runtime/proc.go:2610 +0x9d
        runtime.mcall(0x1057ce6)
        	/var/folders/dx/k53rs1s93538b4x20g46cj_w0000gn/T/workdir/go/src/runtime/asm_amd64.s:318 +0x5b
        
        goroutine 1 [select, locked to thread]:
        net.(*sysDialer).dialParallel(0xc0000ee080, 0x1168940, 0xc0000ae008, 0xc0000dc060, 0x1, 0x1, 0xc0000dc070, 0x1, 0x1, 0x0, ...)
        	/var/folders/dx/k53rs1s93538b4x20g46cj_w0000gn/T/workdir/go/src/net/dial.go:489 +0x322
        net.(*Dialer).DialContext(0xc000044e30, 0x1168940, 0xc0000ae008, 0x1140620, 0x3, 0x11421f0, 0xf, 0x0, 0x0, 0x0, ...)
        	/var/folders/dx/k53rs1s93538b4x20g46cj_w0000gn/T/workdir/go/src/net/dial.go:422 +0x4f0
        net.(*Dialer).Dial(...)
        	/var/folders/dx/k53rs1s93538b4x20g46cj_w0000gn/T/workdir/go/src/net/dial.go:347
        net.Dial(0x1140620, 0x3, 0x11421f0, 0xf, 0x1, 0x8, 0x0, 0x0)
        	/var/folders/dx/k53rs1s93538b4x20g46cj_w0000gn/T/workdir/go/src/net/dial.go:318 +0xa8
        main.NetpollDeadlockInit()
        	/private/var/folders/dx/k53rs1s93538b4x20g46cj_w0000gn/T/workdir/go/src/runtime/testdata/testprognet/net.go:19 +0xa7
        main.registerInit(...)
        	/private/var/folders/dx/k53rs1s93538b4x20g46cj_w0000gn/T/workdir/go/src/runtime/testdata/testprognet/main.go:20
        main.init.0()
        	/private/var/folders/dx/k53rs1s93538b4x20g46cj_w0000gn/T/workdir/go/src/runtime/testdata/testprognet/net.go:13 +0x106
        
        goroutine 34 [syscall]:
        os/signal.signal_recv(0x0)
        	/var/folders/dx/k53rs1s93538b4x20g46cj_w0000gn/T/workdir/go/src/runtime/sigqueue.go:139 +0x9f
        os/signal.loop()
        	/var/folders/dx/k53rs1s93538b4x20g46cj_w0000gn/T/workdir/go/src/os/signal/signal_unix.go:23 +0x22
        created by os/signal.init.0
        	/var/folders/dx/k53rs1s93538b4x20g46cj_w0000gn/T/workdir/go/src/os/signal/signal_unix.go:29 +0x41
        
        goroutine 23 [IO wait]:
        internal/poll.runtime_pollWait(0x1671f08, 0x77, 0xc000045950)
        	/var/folders/dx/k53rs1s93538b4x20g46cj_w0000gn/T/workdir/go/src/runtime/netpoll.go:184 +0x55
        internal/poll.(*pollDesc).wait(0xc0000f4018, 0x77, 0x1168900, 0xc000086200, 0xc0000f4000)
        	/var/folders/dx/k53rs1s93538b4x20g46cj_w0000gn/T/workdir/go/src/internal/poll/fd_poll_runtime.go:87 +0x10b
        internal/poll.(*pollDesc).waitWrite(...)
        	/var/folders/dx/k53rs1s93538b4x20g46cj_w0000gn/T/workdir/go/src/internal/poll/fd_poll_runtime.go:96
        internal/poll.(*FD).WaitWrite(...)
        	/var/folders/dx/k53rs1s93538b4x20g46cj_w0000gn/T/workdir/go/src/internal/poll/fd_unix.go:498
        net.(*netFD).connect(0xc0000f4000, 0x1168900, 0xc000086200, 0x0, 0x0, 0x11674c0, 0xc0000f2080, 0x0, 0x0, 0x0, ...)
        	/var/folders/dx/k53rs1s93538b4x20g46cj_w0000gn/T/workdir/go/src/net/fd_unix.go:152 +0x27e
        net.(*netFD).dial(0xc0000f4000, 0x1168900, 0xc000086200, 0x1168f20, 0x0, 0x1168f20, 0xc0000b0150, 0x0, 0x1, 0xc000045b78)
        	/var/folders/dx/k53rs1s93538b4x20g46cj_w0000gn/T/workdir/go/src/net/sock_posix.go:149 +0xff
        net.socket(0x1168900, 0xc000086200, 0x1140620, 0x3, 0x1e, 0x1, 0x0, 0x0, 0x1168f20, 0x0, ...)
        	/var/folders/dx/k53rs1s93538b4x20g46cj_w0000gn/T/workdir/go/src/net/sock_posix.go:70 +0x1c0
        net.internetSocket(0x1168900, 0xc000086200, 0x1140620, 0x3, 0x1168f20, 0x0, 0x1168f20, 0xc0000b0150, 0x1, 0x0, ...)
        	/var/folders/dx/k53rs1s93538b4x20g46cj_w0000gn/T/workdir/go/src/net/ipsock_posix.go:141 +0x141
        net.(*sysDialer).doDialTCP(0xc0000ee080, 0x1168900, 0xc000086200, 0x0, 0xc0000b0150, 0x1116f00, 0x1256a30, 0x0)
        	/var/folders/dx/k53rs1s93538b4x20g46cj_w0000gn/T/workdir/go/src/net/tcpsock_posix.go:65 +0xc2
        net.(*sysDialer).dialTCP(0xc0000ee080, 0x1168900, 0xc000086200, 0x0, 0xc0000b0150, 0xa3036326a7, 0x2b9c0830, 0x2b9c0830000345b8)
        	/var/folders/dx/k53rs1s93538b4x20g46cj_w0000gn/T/workdir/go/src/net/tcpsock_posix.go:61 +0xd7
        net.(*sysDialer).dialSingle(0xc0000ee080, 0x1168900, 0xc000086200, 0x1167900, 0xc0000b0150, 0x0, 0x0, 0x0, 0x0)
        	/var/folders/dx/k53rs1s93538b4x20g46cj_w0000gn/T/workdir/go/src/net/dial.go:578 +0x34b
        net.(*sysDialer).dialSerial(0xc0000ee080, 0x1168900, 0xc000086200, 0xc0000dc060, 0x1, 0x1, 0x0, 0x0, 0x0, 0x0)
        	/var/folders/dx/k53rs1s93538b4x20g46cj_w0000gn/T/workdir/go/src/net/dial.go:546 +0x221
        net.(*sysDialer).dialParallel.func1(0x1168900, 0xc000086200, 0xc0000dc001)
        	/var/folders/dx/k53rs1s93538b4x20g46cj_w0000gn/T/workdir/go/src/net/dial.go:467 +0x95
        created by net.(*sysDialer).dialParallel
        	/var/folders/dx/k53rs1s93538b4x20g46cj_w0000gn/T/workdir/go/src/net/dial.go:482 +0x226
        
        goroutine 35 [select]:
        net.(*netFD).connect.func2(0x1168900, 0xc000086200, 0xc0000f4000, 0xc00008a1e0, 0xc00008a180)
        	/var/folders/dx/k53rs1s93538b4x20g46cj_w0000gn/T/workdir/go/src/net/fd_unix.go:129 +0xba
        created by net.(*netFD).connect
        	/var/folders/dx/k53rs1s93538b4x20g46cj_w0000gn/T/workdir/go/src/net/fd_unix.go:128 +0x256
        
        rax    0x104
        rbx    0x500
        rcx    0x7fff5fbff318
        rdx    0x500
        rdi    0x123c288
        rsi    0x50100000600
        rbp    0x7fff5fbff3b0
        rsp    0x7fff5fbff318
        r8     0x0
        r9     0x60
        r10    0x0
        r11    0x202
        r12    0x123c288
        r13    0x16
        r14    0x1
        r15    0x7fffaba873c0
        rip    0x7fffa2d6dc86
        rflags 0x203
        cs     0x7
        fs     0x0
        gs     0x0
FAIL
FAIL	runtime	90.150s

[bcmills]

darwin-amd64-race: https://build.golang.org/log/30be737aea80d64fe1c31e7d335e61ab6490402d