1 files changed, 55 insertions, 1 deletions
diff --git a/libgo/go/context/benchmark_test.go b/libgo/go/context/benchmark_test.go
index b792327..3c526dd 100644
--- a/libgo/go/context/benchmark_test.go
+++ b/libgo/go/context/benchmark_test.go
@@ -7,10 +7,64 @@ package context_test
 import (
 	. "context"
 	"fmt"
+	"runtime"
+	"sync"
 	"testing"
+	"time"
 )
 
-func BenchmarkContextCancelTree(b *testing.B) {
+func BenchmarkWithTimeout(b *testing.B) {
+	for concurrency := 40; concurrency <= 4e5; concurrency *= 100 {
+		name := fmt.Sprintf("concurrency=%d", concurrency)
+		b.Run(name, func(b *testing.B) {
+			benchmarkWithTimeout(b, concurrency)
+		})
+	}
+}
+
+func benchmarkWithTimeout(b *testing.B, concurrentContexts int) {
+	gomaxprocs := runtime.GOMAXPROCS(0)
+	perPContexts := concurrentContexts / gomaxprocs
+	root := Background()
+
+	// Generate concurrent contexts.
+	var wg sync.WaitGroup
+	ccf := make([][]CancelFunc, gomaxprocs)
+	for i := range ccf {
+		wg.Add(1)
+		go func(i int) {
+			defer wg.Done()
+			cf := make([]CancelFunc, perPContexts)
+			for j := range cf {
+				_, cf[j] = WithTimeout(root, time.Hour)
+			}
+			ccf[i] = cf
+		}(i)
+	}
+	wg.Wait()
+
+	b.ResetTimer()
+	b.RunParallel(func(pb *testing.PB) {
+		wcf := make([]CancelFunc, 10)
+		for pb.Next() {
+			for i := range wcf {
+				_, wcf[i] = WithTimeout(root, time.Hour)
+			}
+			for _, f := range wcf {
+				f()
+			}
+		}
+	})
+	b.StopTimer()
+
+	for _, cf := range ccf {
+		for _, f := range cf {
+			f()
+		}
+	}
+}
+
+func BenchmarkCancelTree(b *testing.B) {
 	depths := []int{1, 10, 100, 1000}
 	for _, d := range depths {
 		b.Run(fmt.Sprintf("depth=%d", d), func(b *testing.B) {