tree b8d57aa3881802e77fe46c004ca555a73d4437b0
parent b3e1573b75205f2905c4b27986413d2e2be9803c
author Cuong Manh Le <cuong.manhle.vn@gmail.com> 1603201982 +0700
committer Cuong Manh Le <cuong.manhle.vn@gmail.com> 1603209812 +0000

singleflight: fix flaky TestForget

There can be a race condition in current TestForget, that said when
"close(secondCh)" is executed, the second goroutine will be finished
immediately, causing the third "g.Do" is evaluated.

To fix this, we change to use "g.DoChan" for both second and third. In
second, we block to make sure it's still running at the time we call
third. after then we unblock second and verify the result.

Fixes golang/go#42092

Change-Id: I980fdf109a531e2b7a74c8149b4fcaa338775e08
Reviewed-on: https://go-review.googlesource.com/c/sync/+/263877
Trust: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>