runtime: remove race out of BenchmarkChanToSyscallPing1ms

Fixes #15119

Change-Id: I31445bf282a5e2a160ff4e66c5a592b989a5798f
Reviewed-on: https://go-review.googlesource.com/21448
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

diff --git a/src/runtime/syscall_windows_test.go b/src/runtime/syscall_windows_test.go
index 730b6d6d9cf8fbb4385fcd30e47aed21b3f891ee..0b3ebe504dd135d9bd11a2bd38b183e6eafa8eee 100644 (file)
--- a/src/runtime/syscall_windows_test.go
+++ b/src/runtime/syscall_windows_test.go
@@ -901,18 +901,19 @@ func setEvent(h syscall.Handle) error {
 }
 
 func benchChanToSyscallPing(b *testing.B) {
+       n := b.N
        ch := make(chan int)
        event, err := createEvent()
        if err != nil {
                b.Fatal(err)
        }
        go func() {
-               for i := 0; i < b.N; i++ {
+               for i := 0; i < n; i++ {
                        syscall.WaitForSingleObject(event, syscall.INFINITE)
                        ch <- 1
                }
        }()
-       for i := 0; i < b.N; i++ {
+       for i := 0; i < n; i++ {
                err := setEvent(event)
                if err != nil {
                        b.Fatal(err)
@@ -932,6 +933,7 @@ func BenchmarkChanToSyscallPing15ms(b *testing.B) {
 }
 
 func benchSyscallToSyscallPing(b *testing.B) {
+       n := b.N
        event1, err := createEvent()
        if err != nil {
                b.Fatal(err)
@@ -941,7 +943,7 @@ func benchSyscallToSyscallPing(b *testing.B) {
                b.Fatal(err)
        }
        go func() {
-               for i := 0; i < b.N; i++ {
+               for i := 0; i < n; i++ {
                        syscall.WaitForSingleObject(event1, syscall.INFINITE)
                        err := setEvent(event2)
                        if err != nil {
@@ -949,7 +951,7 @@ func benchSyscallToSyscallPing(b *testing.B) {
                        }
                }
        }()
-       for i := 0; i < b.N; i++ {
+       for i := 0; i < n; i++ {
                err := setEvent(event1)
                if err != nil {
                        b.Fatal(err)
@@ -969,15 +971,16 @@ func BenchmarkSyscallToSyscallPing15ms(b *testing.B) {
 }
 
 func benchChanToChanPing(b *testing.B) {
+       n := b.N
        ch1 := make(chan int)
        ch2 := make(chan int)
        go func() {
-               for i := 0; i < b.N; i++ {
+               for i := 0; i < n; i++ {
                        <-ch1
                        ch2 <- 1
                }
        }()
-       for i := 0; i < b.N; i++ {
+       for i := 0; i < n; i++ {
                ch1 <- 1
                <-ch2
        }