From 3075ffc93e962792ddf43b2a528ef19b1577ffb7 Mon Sep 17 00:00:00 2001 From: Ian Lance Taylor Date: Wed, 26 May 2021 15:17:27 -0700 Subject: [PATCH] os: deflake TestFdReadRace The test would hang if the call to Fd set the pipe to be non-blocking before the Read entered the first read system call. Avoid that problem by writing data to the pipe to wake up the read. For #24481 Fixes #44818 Change-Id: I0b798874c7b81e7308a38ebbf657efc4392ffacd Reviewed-on: https://go-review.googlesource.com/c/go/+/322893 Trust: Ian Lance Taylor Run-TryBot: Ian Lance Taylor TryBot-Result: Go Bot Reviewed-by: Damien Neil --- src/os/pipe_test.go | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/src/os/pipe_test.go b/src/os/pipe_test.go index b663618502..41a1e9c78a 100644 --- a/src/os/pipe_test.go +++ b/src/os/pipe_test.go @@ -442,12 +442,14 @@ func TestFdReadRace(t *testing.T) { defer r.Close() defer w.Close() - c := make(chan bool) + const count = 10 + + c := make(chan bool, 1) var wg sync.WaitGroup wg.Add(1) go func() { defer wg.Done() - var buf [10]byte + var buf [count]byte r.SetReadDeadline(time.Now().Add(time.Minute)) c <- true if _, err := r.Read(buf[:]); os.IsTimeout(err) { @@ -466,8 +468,9 @@ func TestFdReadRace(t *testing.T) { r.Fd() // The bug was that Fd would hang until Read timed out. - // If the bug is fixed, then closing r here will cause - // the Read to exit before the timeout expires. + // If the bug is fixed, then writing to w and closing r here + // will cause the Read to exit before the timeout expires. + w.Write(make([]byte, count)) r.Close() }()