fmt: make benchmarks parallel
This seems to be the best target to benchmark sync.Pool changes.
This is resend of cl/49910043 which was LGTMed by
TBR=bradfitz
R=golang-codereviews
CC=golang-codereviews
https://golang.org/cl/50140045
diff --git a/src/pkg/fmt/fmt_test.go b/src/pkg/fmt/fmt_test.go
index 444297d..971e8a3 100644
--- a/src/pkg/fmt/fmt_test.go
+++ b/src/pkg/fmt/fmt_test.go
@@ -11,6 +11,7 @@
"math"
"runtime"
"strings"
+ "sync/atomic"
"testing"
"time"
"unicode"
@@ -606,46 +607,66 @@
}
func BenchmarkSprintfEmpty(b *testing.B) {
- for i := 0; i < b.N; i++ {
+ benchmarkSprintf(b, func(buf *bytes.Buffer) {
Sprintf("")
- }
+ })
}
func BenchmarkSprintfString(b *testing.B) {
- for i := 0; i < b.N; i++ {
+ benchmarkSprintf(b, func(buf *bytes.Buffer) {
Sprintf("%s", "hello")
- }
+ })
}
func BenchmarkSprintfInt(b *testing.B) {
- for i := 0; i < b.N; i++ {
+ benchmarkSprintf(b, func(buf *bytes.Buffer) {
Sprintf("%d", 5)
- }
+ })
}
func BenchmarkSprintfIntInt(b *testing.B) {
- for i := 0; i < b.N; i++ {
+ benchmarkSprintf(b, func(buf *bytes.Buffer) {
Sprintf("%d %d", 5, 6)
- }
+ })
}
func BenchmarkSprintfPrefixedInt(b *testing.B) {
- for i := 0; i < b.N; i++ {
+ benchmarkSprintf(b, func(buf *bytes.Buffer) {
Sprintf("This is some meaningless prefix text that needs to be scanned %d", 6)
- }
+ })
}
func BenchmarkSprintfFloat(b *testing.B) {
- for i := 0; i < b.N; i++ {
+ benchmarkSprintf(b, func(buf *bytes.Buffer) {
Sprintf("%g", 5.23184)
- }
+ })
}
func BenchmarkManyArgs(b *testing.B) {
- var buf bytes.Buffer
- for i := 0; i < b.N; i++ {
+ benchmarkSprintf(b, func(buf *bytes.Buffer) {
buf.Reset()
- Fprintf(&buf, "%2d/%2d/%2d %d:%d:%d %s %s\n", 3, 4, 5, 11, 12, 13, "hello", "world")
+ Fprintf(buf, "%2d/%2d/%2d %d:%d:%d %s %s\n", 3, 4, 5, 11, 12, 13, "hello", "world")
+ })
+}
+
+func benchmarkSprintf(b *testing.B, f func(buf *bytes.Buffer)) {
+ const CallsPerSched = 1000
+ procs := runtime.GOMAXPROCS(-1)
+ N := int32(b.N / CallsPerSched)
+ c := make(chan bool, procs)
+ for p := 0; p < procs; p++ {
+ go func() {
+ var buf bytes.Buffer
+ for atomic.AddInt32(&N, -1) >= 0 {
+ for g := 0; g < CallsPerSched; g++ {
+ f(&buf)
+ }
+ }
+ c <- true
+ }()
+ }
+ for p := 0; p < procs; p++ {
+ <-c
}
}
