sync: don't assume b.N > 0

Change-Id: I6eb91ea73ef887b025e5a8de1dd55f30618e1aa6
Reviewed-on: https://go-review.googlesource.com/20857
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

diff --git a/src/sync/runtime_sema_test.go b/src/sync/runtime_sema_test.go
index 5b7dd3df3f0ff58001c3fd17338f157c214043d9..a2382f465546c25efdbfefbc4cc66e6e0ab92c55 100644 (file)
--- a/src/sync/runtime_sema_test.go
+++ b/src/sync/runtime_sema_test.go
@@ -25,6 +25,9 @@ func BenchmarkSemaUncontended(b *testing.B) {
 }
 
 func benchmarkSema(b *testing.B, block, work bool) {
+       if b.N == 0 {
+               return
+       }
        sem := uint32(0)
        if block {
                done := make(chan bool)