mirror of
https://github.com/protocolbuffers/protobuf-go.git
synced 2025-02-21 18:40:03 +00:00
a6af044c3f
The problem is that atomicNilMessage.m.mi is accessed both by atomic and
non-atomic operations. (Init uses an atomic read to verify that m.mi is
non-nil, but then returns a non-atomic m.)
Race condition is demonstrated by this test with
"go test -race -count=1000":
func TestPointer(t *testing.T) {
var m atomicNilMessage
var mi MessageInfo
ch := make(chan *MessageInfo)
for i := 0; i < 20; i++ {
go func() {
r := m.Init(&mi)
if &mi != r.mi {
// This conditional exists just
// ensure r.mi is touched.
t.Error("mismatch")
}
ch <- r.mi
}()
}
for i := 0; i < 20; i++ {
<-ch
}
}
I chose not to add the test since it seems a bit overfit to the specific
situation.
Change-Id: Id4664ef3cd5b29515ed310851b9aeb7561be30d0
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/188337
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>