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mirror of https://github.com/golang/go synced 2024-09-30 17:38:33 -06:00

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
This commit is contained in:
Kyle Lemons 2013-02-02 22:52:29 -05:00 committed by Russ Cox
parent f418c505d0
commit 9bfd3c3937
10 changed files with 105 additions and 144 deletions

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@ -9,7 +9,6 @@ import (
"fmt"
"io"
"os"
"runtime"
"testing"
)
@ -50,49 +49,43 @@ func BenchmarkEndToEndByteBuffer(b *testing.B) {
}
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)
}

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@ -9,7 +9,6 @@ import (
. "fmt"
"io"
"math"
"runtime" // for the malloc count test only
"strings"
"testing"
"time"
@ -598,19 +597,10 @@ var mallocTest = []struct {
var _ bytes.Buffer
func TestCountMallocs(t *testing.T) {
defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(1))
for _, mt := range mallocTest {
const N = 100
memstats := new(runtime.MemStats)
runtime.ReadMemStats(memstats)
mallocs := 0 - memstats.Mallocs
for i := 0; i < N; i++ {
mt.fn()
}
runtime.ReadMemStats(memstats)
mallocs += memstats.Mallocs
if mallocs/N > uint64(mt.count) {
t.Errorf("%s: expected %d mallocs, got %d", mt.desc, mt.count, mallocs/N)
mallocs := testing.AllocsPerRun(100, mt.fn)
if got, max := mallocs, float64(mt.count); got > max {
t.Errorf("%s: got %v allocs, want <=%v", mt.desc, got, max)
}
}
}

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@ -6,7 +6,6 @@ package http
import (
"bytes"
"runtime"
"testing"
"time"
)
@ -175,38 +174,31 @@ func TestHasToken(t *testing.T) {
}
}
var testHeader = Header{
"Content-Length": {"123"},
"Content-Type": {"text/plain"},
"Date": {"some date at some time Z"},
"Server": {"Go http package"},
}
var buf bytes.Buffer
func BenchmarkHeaderWriteSubset(b *testing.B) {
doHeaderWriteSubset(b.N, b)
b.ReportAllocs()
for i := 0; i < b.N; i++ {
buf.Reset()
testHeader.WriteSubset(&buf, nil)
}
}
func TestHeaderWriteSubsetMallocs(t *testing.T) {
doHeaderWriteSubset(100, t)
}
type errorfer interface {
Errorf(string, ...interface{})
}
func doHeaderWriteSubset(n int, t errorfer) {
defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(1))
h := Header(map[string][]string{
"Content-Length": {"123"},
"Content-Type": {"text/plain"},
"Date": {"some date at some time Z"},
"Server": {"Go http package"},
})
var buf bytes.Buffer
var m0 runtime.MemStats
runtime.ReadMemStats(&m0)
for i := 0; i < n; i++ {
n := testing.AllocsPerRun(100, func() {
buf.Reset()
h.WriteSubset(&buf, nil)
}
var m1 runtime.MemStats
runtime.ReadMemStats(&m1)
if mallocs := m1.Mallocs - m0.Mallocs; n >= 100 && mallocs >= uint64(n) {
testHeader.WriteSubset(&buf, nil)
})
if n > 1 {
// TODO(bradfitz,rsc): once we can sort without allocating,
// make this an error. See http://golang.org/issue/3761
// t.Errorf("did %d mallocs (>= %d iterations); should have avoided mallocs", mallocs, n)
// t.Errorf("got %v allocs, want <= %v", n, 1)
}
}

View File

@ -445,8 +445,7 @@ func dialHTTP() (*Client, error) {
return DialHTTP("tcp", httpServerAddr)
}
func countMallocs(dial func() (*Client, error), t *testing.T) uint64 {
defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(1))
func countMallocs(dial func() (*Client, error), t *testing.T) float64 {
once.Do(startServer)
client, err := dial()
if err != nil {
@ -454,11 +453,7 @@ func countMallocs(dial func() (*Client, error), t *testing.T) uint64 {
}
args := &Args{7, 8}
reply := new(Reply)
memstats := new(runtime.MemStats)
runtime.ReadMemStats(memstats)
mallocs := 0 - memstats.Mallocs
const count = 100
for i := 0; i < count; i++ {
return testing.AllocsPerRun(100, func() {
err := client.Call("Arith.Add", args, reply)
if err != nil {
t.Errorf("Add: expected no error but got string %q", err.Error())
@ -466,18 +461,15 @@ func countMallocs(dial func() (*Client, error), t *testing.T) uint64 {
if reply.C != args.A+args.B {
t.Errorf("Add: expected %d got %d", reply.C, args.A+args.B)
}
}
runtime.ReadMemStats(memstats)
mallocs += memstats.Mallocs
return mallocs / count
})
}
func TestCountMallocs(t *testing.T) {
fmt.Printf("mallocs per rpc round trip: %d\n", countMallocs(dialDirect, t))
fmt.Printf("mallocs per rpc round trip: %v\n", countMallocs(dialDirect, t))
}
func TestCountMallocsOverHTTP(t *testing.T) {
fmt.Printf("mallocs per HTTP rpc round trip: %d\n", countMallocs(dialHTTP, t))
fmt.Printf("mallocs per HTTP rpc round trip: %v\n", countMallocs(dialHTTP, t))
}
type writeCrasher struct {

View File

@ -91,7 +91,6 @@ var wincleantests = []PathTest{
}
func TestClean(t *testing.T) {
defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(1))
tests := cleantests
if runtime.GOOS == "windows" {
for i := range tests {
@ -108,20 +107,12 @@ func TestClean(t *testing.T) {
}
}
var ms runtime.MemStats
runtime.ReadMemStats(&ms)
allocs := -ms.Mallocs
const rounds = 100
for i := 0; i < rounds; i++ {
for _, test := range tests {
filepath.Clean(test.result)
for _, test := range tests {
allocs := testing.AllocsPerRun(100, func() { filepath.Clean(test.result) })
if allocs > 0 {
t.Errorf("Clean(%q): %v allocs, want zero", test.result, allocs)
}
}
runtime.ReadMemStats(&ms)
allocs += ms.Mallocs
if allocs >= rounds {
t.Errorf("Clean cleaned paths: %d allocations per test round, want zero", allocs/rounds)
}
}
const sep = filepath.Separator

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@ -5,7 +5,6 @@
package path
import (
"runtime"
"testing"
)
@ -64,7 +63,6 @@ var cleantests = []PathTest{
}
func TestClean(t *testing.T) {
defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(1))
for _, test := range cleantests {
if s := Clean(test.path); s != test.result {
t.Errorf("Clean(%q) = %q, want %q", test.path, s, test.result)
@ -74,20 +72,12 @@ func TestClean(t *testing.T) {
}
}
var ms runtime.MemStats
runtime.ReadMemStats(&ms)
allocs := -ms.Mallocs
const rounds = 100
for i := 0; i < rounds; i++ {
for _, test := range cleantests {
Clean(test.result)
for _, test := range cleantests {
allocs := testing.AllocsPerRun(100, func() { Clean(test.result) })
if allocs > 0 {
t.Errorf("Clean(%q): %v allocs, want zero", test.result, allocs)
}
}
runtime.ReadMemStats(&ms)
allocs += ms.Mallocs
if allocs >= rounds {
t.Errorf("Clean cleaned paths: %d allocations per test round, want zero", allocs/rounds)
}
}
type SplitTest struct {

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@ -13,7 +13,6 @@ import (
"math/rand"
"os"
. "reflect"
"runtime"
"sync"
"testing"
"time"
@ -2012,20 +2011,13 @@ func TestAddr(t *testing.T) {
}
func noAlloc(t *testing.T, n int, f func(int)) {
defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(1))
// once to prime everything
f(-1)
memstats := new(runtime.MemStats)
runtime.ReadMemStats(memstats)
oldmallocs := memstats.Mallocs
for j := 0; j < n; j++ {
f(j)
}
runtime.ReadMemStats(memstats)
mallocs := memstats.Mallocs - oldmallocs
if mallocs > 0 {
t.Fatalf("%d mallocs after %d iterations", mallocs, n)
i := -1
allocs := testing.AllocsPerRun(n, func() {
f(i)
i++
})
if allocs > 0 {
t.Errorf("%d iterations: got %v mallocs, want 0", n, allocs)
}
}

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@ -5,7 +5,6 @@
package strconv_test
import (
"runtime"
. "strconv"
"strings"
"testing"
@ -44,19 +43,10 @@ var (
)
func TestCountMallocs(t *testing.T) {
defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(1))
for _, mt := range mallocTest {
const N = 100
memstats := new(runtime.MemStats)
runtime.ReadMemStats(memstats)
mallocs := 0 - memstats.Mallocs
for i := 0; i < N; i++ {
mt.fn()
}
runtime.ReadMemStats(memstats)
mallocs += memstats.Mallocs
if mallocs/N > uint64(mt.count) {
t.Errorf("%s: expected %d mallocs, got %d", mt.desc, mt.count, mallocs/N)
allocs := testing.AllocsPerRun(100, mt.fn)
if max := float64(mt.count); allocs > max {
t.Errorf("%s: %v allocs, want <=%v", mt.desc, allocs, max)
}
}
}

41
src/pkg/testing/allocs.go Normal file
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@ -0,0 +1,41 @@
// Copyright 2013 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package testing
import (
"runtime"
)
// AllocsPerRun returns the average number of allocations during calls to f.
//
// To compute the number of allocations, the function will first be run once as
// a warm-up. The average number of allocations over the specified number of
// runs will then be measured and returned.
//
// AllocsPerRun sets GOMAXPROCS to 1 during its measurement and will restore
// it before returning.
func AllocsPerRun(runs int, f func()) (avg float64) {
defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(1))
// Warm up the function
f()
// Measure the starting statistics
var memstats runtime.MemStats
runtime.ReadMemStats(&memstats)
mallocs := 0 - memstats.Mallocs
// Run the function the specified number of times
for i := 0; i < runs; i++ {
f()
}
// Read the final statistics
runtime.ReadMemStats(&memstats)
mallocs += memstats.Mallocs
// Average the mallocs over the runs (not counting the warm-up)
return float64(mallocs) / float64(runs)
}

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@ -11,7 +11,6 @@ import (
"fmt"
"math/big"
"math/rand"
"runtime"
"strconv"
"strings"
"testing"
@ -1258,19 +1257,10 @@ var mallocTest = []struct {
}
func TestCountMallocs(t *testing.T) {
defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(1))
for _, mt := range mallocTest {
const N = 100
memstats := new(runtime.MemStats)
runtime.ReadMemStats(memstats)
mallocs := 0 - memstats.Mallocs
for i := 0; i < N; i++ {
mt.fn()
}
runtime.ReadMemStats(memstats)
mallocs += memstats.Mallocs
if mallocs/N > uint64(mt.count) {
t.Errorf("%s: expected %d mallocs, got %d", mt.desc, mt.count, mallocs/N)
allocs := int(testing.AllocsPerRun(100, mt.fn))
if allocs > mt.count {
t.Errorf("%s: %d allocs, want %d", mt.desc, allocs, mt.count)
}
}
}