testing: add AllocsPerRun
This CL also replaces similar loops in other stdlib
package tests with calls to AllocsPerRun.
Fixes #4461.
R=minux.ma, rsc
CC=golang-dev
https://golang.org/cl/7002055
diff --git a/src/pkg/encoding/gob/timing_test.go b/src/pkg/encoding/gob/timing_test.go
index 9a0e51d..13eb119 100644
--- a/src/pkg/encoding/gob/timing_test.go
+++ b/src/pkg/encoding/gob/timing_test.go
@@ -9,7 +9,6 @@
"fmt"
"io"
"os"
- "runtime"
"testing"
)
@@ -50,49 +49,43 @@
}
func TestCountEncodeMallocs(t *testing.T) {
- defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(1))
+ const N = 1000
+
var buf bytes.Buffer
enc := NewEncoder(&buf)
bench := &Bench{7, 3.2, "now is the time", []byte("for all good men")}
- memstats := new(runtime.MemStats)
- runtime.ReadMemStats(memstats)
- mallocs := 0 - memstats.Mallocs
- const count = 1000
- for i := 0; i < count; i++ {
+
+ allocs := testing.AllocsPerRun(N, func() {
err := enc.Encode(bench)
if err != nil {
t.Fatal("encode:", err)
}
- }
- runtime.ReadMemStats(memstats)
- mallocs += memstats.Mallocs
- fmt.Printf("mallocs per encode of type Bench: %d\n", mallocs/count)
+ })
+ fmt.Printf("mallocs per encode of type Bench: %v\n", allocs)
}
func TestCountDecodeMallocs(t *testing.T) {
- defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(1))
+ const N = 1000
+
var buf bytes.Buffer
enc := NewEncoder(&buf)
bench := &Bench{7, 3.2, "now is the time", []byte("for all good men")}
- const count = 1000
- for i := 0; i < count; i++ {
+
+ // Fill the buffer with enough to decode
+ testing.AllocsPerRun(N, func() {
err := enc.Encode(bench)
if err != nil {
t.Fatal("encode:", err)
}
- }
+ })
+
dec := NewDecoder(&buf)
- memstats := new(runtime.MemStats)
- runtime.ReadMemStats(memstats)
- mallocs := 0 - memstats.Mallocs
- for i := 0; i < count; i++ {
+ allocs := testing.AllocsPerRun(N, func() {
*bench = Bench{}
err := dec.Decode(&bench)
if err != nil {
t.Fatal("decode:", err)
}
- }
- runtime.ReadMemStats(memstats)
- mallocs += memstats.Mallocs
- fmt.Printf("mallocs per decode of type Bench: %d\n", mallocs/count)
+ })
+ fmt.Printf("mallocs per decode of type Bench: %v\n", allocs)
}
