net/http: test race on linux/amd64 trybot

[cespare]

I see a race on the linux-amd64-race trybot running over some unrelated code (CL 32923):

https://storage.googleapis.com/go-build-log/17537d3e/linux-amd64-race_d3fd3644.log

I see that there are some recent test-flake-related commits in net/http but I cannot reproduce the race locally within a few test -race runs so I don't know whether it's fixed or not.

==================
WARNING: DATA RACE
Write at 0x00c420c44080 by goroutine 426:
  net/http.(*http2serverConn).newWriterAndRequestNoBody()
      /tmp/workdir/go/src/net/http/h2_bundle.go:4479 +0xaa4
  net/http.(*http2serverConn).newWriterAndRequest()
      /tmp/workdir/go/src/net/http/h2_bundle.go:4382 +0x4cc
  net/http.(*http2serverConn).processHeaders()
      /tmp/workdir/go/src/net/http/h2_bundle.go:4240 +0x4ac
  net/http.(*http2serverConn).processFrame()
      /tmp/workdir/go/src/net/http/h2_bundle.go:3930 +0x4d9
  net/http.(*http2serverConn).processFrameFromReader()
      /tmp/workdir/go/src/net/http/h2_bundle.go:3889 +0x8af
  net/http.(*http2serverConn).serve()
      /tmp/workdir/go/src/net/http/h2_bundle.go:3527 +0xacf
  net/http.(*http2Server).ServeConn()
      /tmp/workdir/go/src/net/http/h2_bundle.go:3166 +0xc82
  net/http.http2ConfigureServer.func1()
      /tmp/workdir/go/src/net/http/h2_bundle.go:3048 +0xe7
  net/http.(*conn).serve()
      /tmp/workdir/go/src/net/http/server.go:1709 +0x1952

Previous read at 0x00c420c44080 by goroutine 355:
  [failed to restore the stack]

Goroutine 426 (running) created at:
  net/http.(*Server).Serve()
      /tmp/workdir/go/src/net/http/server.go:2608 +0x35f
  net/http/httptest.(*Server).goServe.func1()
      /tmp/workdir/go/src/net/http/httptest/server.go:236 +0xa2

Goroutine 355 (finished) created at:
  net/http.(*http2responseWriter).CloseNotify()
      /tmp/workdir/go/src/net/http/h2_bundle.go:4932 +0x129
  net/http_test.testTransportAndServerSharedBodyRace.func2()
      /tmp/workdir/go/src/net/http/serve_test.go:3362 +0x93
  net/http.HandlerFunc.ServeHTTP()
      /tmp/workdir/go/src/net/http/server.go:1895 +0x51
  net/http.serverHandler.ServeHTTP()
      /tmp/workdir/go/src/net/http/server.go:2508 +0xbc
  net/http.initNPNRequest.ServeHTTP()
      /tmp/workdir/go/src/net/http/server.go:3028 +0x109
  net/http.(*initNPNRequest).ServeHTTP()
      <autogenerated>:318 +0x98
  net/http.(Handler).ServeHTTP-fm()
      /tmp/workdir/go/src/net/http/h2_bundle.go:4251 +0x64
  net/http.(*http2serverConn).runHandler()
      /tmp/workdir/go/src/net/http/h2_bundle.go:4529 +0x96
==================

[cespare]

/cc @bradfitz

[bradfitz]

Previous read at 0x00c420c44080 by goroutine 355:
  [failed to restore the stack]

Well, that's frickin' useless.

/cc @dvyukov @ianlancetaylor

[dvyukov]

$ GORACE="atexit_sleep_ms=0 history_size=7" stress -failure="DATA RACE" -p 16 ./http.test -test.short

gives full report in a minute:

1 second passes in backend, proxygone= false
1 second passes in backend, proxygone= false
==================
WARNING: DATA RACE
Write at 0x00c4206a9100 by goroutine 304:
  net/http.(*http2serverConn).newWriterAndRequestNoBody()
      /home/dvyukov/src/go/src/net/http/h2_bundle.go:4479 +0xaa4
  net/http.(*http2serverConn).newWriterAndRequest()
      /home/dvyukov/src/go/src/net/http/h2_bundle.go:4382 +0x4cc
  net/http.(*http2serverConn).processHeaders()
      /home/dvyukov/src/go/src/net/http/h2_bundle.go:4240 +0x4ac
  net/http.(*http2serverConn).processFrame()
      /home/dvyukov/src/go/src/net/http/h2_bundle.go:3930 +0x4d9
  net/http.(*http2serverConn).processFrameFromReader()
      /home/dvyukov/src/go/src/net/http/h2_bundle.go:3889 +0x8af
  net/http.(*http2serverConn).serve()
      /home/dvyukov/src/go/src/net/http/h2_bundle.go:3527 +0xacf
  net/http.(*http2Server).ServeConn()
      /home/dvyukov/src/go/src/net/http/h2_bundle.go:3166 +0xc82
  net/http.http2ConfigureServer.func1()
      /home/dvyukov/src/go/src/net/http/h2_bundle.go:3048 +0xe7
  net/http.(*conn).serve()
      /home/dvyukov/src/go/src/net/http/server.go:1709 +0x1952

Previous read at 0x00c4206a9100 by goroutine 218:
  net/http.(*http2responseWriter).CloseNotify.func1()
      /home/dvyukov/src/go/src/net/http/h2_bundle.go:4930 +0x3f

Goroutine 304 (running) created at:
  net/http.(*Server).Serve()
      /home/dvyukov/src/go/src/net/http/server.go:2608 +0x35f
  net/http/httptest.(*Server).goServe.func1()
      /home/dvyukov/src/go/src/net/http/httptest/server.go:236 +0xa2

Goroutine 218 (finished) created at:
  net/http.(*http2responseWriter).CloseNotify()
      /home/dvyukov/src/go/src/net/http/h2_bundle.go:4932 +0x129
  net/http_test.testTransportAndServerSharedBodyRace.func2()
      /home/dvyukov/src/go/src/net/http/serve_test.go:3362 +0x93
  net/http.HandlerFunc.ServeHTTP()
      /home/dvyukov/src/go/src/net/http/server.go:1895 +0x51
  net/http.serverHandler.ServeHTTP()
      /home/dvyukov/src/go/src/net/http/server.go:2508 +0xbc
  net/http.initNPNRequest.ServeHTTP()
      /home/dvyukov/src/go/src/net/http/server.go:3028 +0x109
  net/http.(*initNPNRequest).ServeHTTP()
      <autogenerated>:318 +0x98
  net/http.(Handler).ServeHTTP-fm()
      /home/dvyukov/src/go/src/net/http/h2_bundle.go:4251 +0x64
  net/http.(*http2serverConn).runHandler()
      /home/dvyukov/src/go/src/net/http/h2_bundle.go:4529 +0x96

[bradfitz]

https://go-review.googlesource.com/33013

[gopherbot]

CL https://golang.org/cl/33013 mentions this issue.

[FZambia]

@bradfitz hello, just came across panic that most probably caused by this issue. I am a bit lost - why data race fix like this have not been included into go1.7.5? Should we use golang.org/x/net/http2 to avoid waiting for next Go stable release to get fixes inside HTTP/2?

[bradfitz]

You can wait two days for Go 1.8 final.