1 files changed, 54 insertions, 0 deletions
diff --git a/libgo/go/testing/benchmark_test.go b/libgo/go/testing/benchmark_test.go
index 94e994dfae0..9997b992042 100644
--- a/libgo/go/testing/benchmark_test.go
+++ b/libgo/go/testing/benchmark_test.go
@@ -5,7 +5,11 @@
 package testing_test
 
 import (
+	"bytes"
+	"runtime"
+	"sync/atomic"
 	"testing"
+	"text/template"
 )
 
 var roundDownTests = []struct {
@@ -56,3 +60,53 @@ func TestRoundUp(t *testing.T) {
 		}
 	}
 }
+
+func TestRunParallel(t *testing.T) {
+	testing.Benchmark(func(b *testing.B) {
+		procs := uint32(0)
+		iters := uint64(0)
+		b.SetParallelism(3)
+		b.RunParallel(func(pb *testing.PB) {
+			atomic.AddUint32(&procs, 1)
+			for pb.Next() {
+				atomic.AddUint64(&iters, 1)
+			}
+		})
+		if want := uint32(3 * runtime.GOMAXPROCS(0)); procs != want {
+			t.Errorf("got %v procs, want %v", procs, want)
+		}
+		if iters != uint64(b.N) {
+			t.Errorf("got %v iters, want %v", iters, b.N)
+		}
+	})
+}
+
+func TestRunParallelFail(t *testing.T) {
+	testing.Benchmark(func(b *testing.B) {
+		b.RunParallel(func(pb *testing.PB) {
+			// The function must be able to log/abort
+			// w/o crashing/deadlocking the whole benchmark.
+			b.Log("log")
+			b.Error("error")
+			b.Fatal("fatal")
+		})
+	})
+}
+
+func ExampleB_RunParallel() {
+	// Parallel benchmark for text/template.Template.Execute on a single object.
+	testing.Benchmark(func(b *testing.B) {
+		templ := template.Must(template.New("test").Parse("Hello, {{.}}!"))
+		// RunParallel will create GOMAXPROCS goroutines
+		// and distribute work among them.
+		b.RunParallel(func(pb *testing.PB) {
+			// Each goroutine has its own bytes.Buffer.
+			var buf bytes.Buffer
+			for pb.Next() {
+				// The loop body is executed b.N times total across all goroutines.
+				buf.Reset()
+				templ.Execute(&buf, "World")
+			}
+		})
+	})
+}