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// Copyright 2020 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 intern
import (
"fmt"
"runtime"
"testing"
)
func TestBasics(t *testing.T) {
clearMap()
foo := Get("foo")
bar := Get("bar")
empty := Get("")
nilEface := Get(nil)
i := Get(0x7777777)
foo2 := Get("foo")
bar2 := Get("bar")
empty2 := Get("")
nilEface2 := Get(nil)
i2 := Get(0x7777777)
foo3 := GetByString("foo")
empty3 := GetByString("")
if foo.Get() != foo2.Get() {
t.Error("foo/foo2 values differ")
}
if foo.Get() != foo3.Get() {
t.Error("foo/foo3 values differ")
}
if foo.Get() != "foo" {
t.Error("foo.Get not foo")
}
if foo != foo2 {
t.Error("foo/foo2 pointers differ")
}
if foo != foo3 {
t.Error("foo/foo3 pointers differ")
}
if bar.Get() != bar2.Get() {
t.Error("bar values differ")
}
if bar.Get() != "bar" {
t.Error("bar.Get not bar")
}
if bar != bar2 {
t.Error("bar pointers differ")
}
if i.Get() != i.Get() {
t.Error("i values differ")
}
if i.Get() != 0x7777777 {
t.Error("i.Get not 0x7777777")
}
if i != i2 {
t.Error("i pointers differ")
}
if empty.Get() != empty2.Get() {
t.Error("empty/empty2 values differ")
}
if empty.Get() != empty.Get() {
t.Error("empty/empty3 values differ")
}
if empty.Get() != "" {
t.Error("empty.Get not empty string")
}
if empty != empty2 {
t.Error("empty/empty2 pointers differ")
}
if empty != empty3 {
t.Error("empty/empty3 pointers differ")
}
if nilEface.Get() != nilEface2.Get() {
t.Error("nilEface values differ")
}
if nilEface.Get() != nil {
t.Error("nilEface.Get not nil")
}
if nilEface != nilEface2 {
t.Error("nilEface pointers differ")
}
if n := mapLen(); n != 5 {
if runtime.Compiler != "gccgo" {
t.Errorf("map len = %d; want 4", n)
}
}
wantEmpty(t)
}
func wantEmpty(t testing.TB) {
if runtime.Compiler == "gccgo" {
// Fails with conservative GC.
return
}
t.Helper()
const gcTries = 5000
for try := 0; try < gcTries; try++ {
runtime.GC()
n := mapLen()
if n == 0 {
break
}
if try == gcTries-1 {
t.Errorf("map len = %d after (%d GC tries); want 0, contents: %v", n, gcTries, mapKeys())
}
}
}
func TestStress(t *testing.T) {
iters := 10000
if testing.Short() {
iters = 1000
}
var sink []byte
for i := 0; i < iters; i++ {
_ = Get("foo")
sink = make([]byte, 1<<20)
}
_ = sink
}
func BenchmarkStress(b *testing.B) {
done := make(chan struct{})
defer close(done)
go func() {
for {
select {
case <-done:
return
default:
}
runtime.GC()
}
}()
clearMap()
v1 := Get("foo")
b.ReportAllocs()
b.RunParallel(func(pb *testing.PB) {
for pb.Next() {
v2 := Get("foo")
if v1 != v2 {
b.Fatal("wrong value")
}
// And also a key we don't retain:
_ = Get("bar")
}
})
runtime.GC()
wantEmpty(b)
}
func mapLen() int {
mu.Lock()
defer mu.Unlock()
return len(valMap)
}
func mapKeys() (keys []string) {
mu.Lock()
defer mu.Unlock()
for k := range valMap {
keys = append(keys, fmt.Sprint(k))
}
return keys
}
func clearMap() {
mu.Lock()
defer mu.Unlock()
for k := range valMap {
delete(valMap, k)
}
}
var (
globalString = "not a constant"
sink string
)
func TestGetByStringAllocs(t *testing.T) {
allocs := int(testing.AllocsPerRun(100, func() {
GetByString(globalString)
}))
if allocs != 0 {
t.Errorf("GetString allocated %d objects, want 0", allocs)
}
}
func BenchmarkGetByString(b *testing.B) {
b.ReportAllocs()
for i := 0; i < b.N; i++ {
v := GetByString(globalString)
sink = v.Get().(string)
}
}
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