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- // Copyright 2016 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 syncmap_test
-
- import (
- "fmt"
- "reflect"
- "sync/atomic"
- "testing"
-
- "golang.org/x/sync/syncmap"
- )
-
- type bench struct {
- setup func(*testing.B, mapInterface)
- perG func(b *testing.B, pb *testing.PB, i int, m mapInterface)
- }
-
- func benchMap(b *testing.B, bench bench) {
- for _, m := range [...]mapInterface{&DeepCopyMap{}, &RWMutexMap{}, &syncmap.Map{}} {
- b.Run(fmt.Sprintf("%T", m), func(b *testing.B) {
- m = reflect.New(reflect.TypeOf(m).Elem()).Interface().(mapInterface)
- if bench.setup != nil {
- bench.setup(b, m)
- }
-
- b.ResetTimer()
-
- var i int64
- b.RunParallel(func(pb *testing.PB) {
- id := int(atomic.AddInt64(&i, 1) - 1)
- bench.perG(b, pb, id*b.N, m)
- })
- })
- }
- }
-
- func BenchmarkLoadMostlyHits(b *testing.B) {
- const hits, misses = 1023, 1
-
- benchMap(b, bench{
- setup: func(_ *testing.B, m mapInterface) {
- for i := 0; i < hits; i++ {
- m.LoadOrStore(i, i)
- }
- // Prime the map to get it into a steady state.
- for i := 0; i < hits*2; i++ {
- m.Load(i % hits)
- }
- },
-
- perG: func(b *testing.B, pb *testing.PB, i int, m mapInterface) {
- for ; pb.Next(); i++ {
- m.Load(i % (hits + misses))
- }
- },
- })
- }
-
- func BenchmarkLoadMostlyMisses(b *testing.B) {
- const hits, misses = 1, 1023
-
- benchMap(b, bench{
- setup: func(_ *testing.B, m mapInterface) {
- for i := 0; i < hits; i++ {
- m.LoadOrStore(i, i)
- }
- // Prime the map to get it into a steady state.
- for i := 0; i < hits*2; i++ {
- m.Load(i % hits)
- }
- },
-
- perG: func(b *testing.B, pb *testing.PB, i int, m mapInterface) {
- for ; pb.Next(); i++ {
- m.Load(i % (hits + misses))
- }
- },
- })
- }
-
- func BenchmarkLoadOrStoreBalanced(b *testing.B) {
- const hits, misses = 128, 128
-
- benchMap(b, bench{
- setup: func(b *testing.B, m mapInterface) {
- if _, ok := m.(*DeepCopyMap); ok {
- b.Skip("DeepCopyMap has quadratic running time.")
- }
- for i := 0; i < hits; i++ {
- m.LoadOrStore(i, i)
- }
- // Prime the map to get it into a steady state.
- for i := 0; i < hits*2; i++ {
- m.Load(i % hits)
- }
- },
-
- perG: func(b *testing.B, pb *testing.PB, i int, m mapInterface) {
- for ; pb.Next(); i++ {
- j := i % (hits + misses)
- if j < hits {
- if _, ok := m.LoadOrStore(j, i); !ok {
- b.Fatalf("unexpected miss for %v", j)
- }
- } else {
- if v, loaded := m.LoadOrStore(i, i); loaded {
- b.Fatalf("failed to store %v: existing value %v", i, v)
- }
- }
- }
- },
- })
- }
-
- func BenchmarkLoadOrStoreUnique(b *testing.B) {
- benchMap(b, bench{
- setup: func(b *testing.B, m mapInterface) {
- if _, ok := m.(*DeepCopyMap); ok {
- b.Skip("DeepCopyMap has quadratic running time.")
- }
- },
-
- perG: func(b *testing.B, pb *testing.PB, i int, m mapInterface) {
- for ; pb.Next(); i++ {
- m.LoadOrStore(i, i)
- }
- },
- })
- }
-
- func BenchmarkLoadOrStoreCollision(b *testing.B) {
- benchMap(b, bench{
- setup: func(_ *testing.B, m mapInterface) {
- m.LoadOrStore(0, 0)
- },
-
- perG: func(b *testing.B, pb *testing.PB, i int, m mapInterface) {
- for ; pb.Next(); i++ {
- m.LoadOrStore(0, 0)
- }
- },
- })
- }
-
- func BenchmarkRange(b *testing.B) {
- const mapSize = 1 << 10
-
- benchMap(b, bench{
- setup: func(_ *testing.B, m mapInterface) {
- for i := 0; i < mapSize; i++ {
- m.Store(i, i)
- }
- },
-
- perG: func(b *testing.B, pb *testing.PB, i int, m mapInterface) {
- for ; pb.Next(); i++ {
- m.Range(func(_, _ interface{}) bool { return true })
- }
- },
- })
- }
-
- // BenchmarkAdversarialAlloc tests performance when we store a new value
- // immediately whenever the map is promoted to clean and otherwise load a
- // unique, missing key.
- //
- // This forces the Load calls to always acquire the map's mutex.
- func BenchmarkAdversarialAlloc(b *testing.B) {
- benchMap(b, bench{
- perG: func(b *testing.B, pb *testing.PB, i int, m mapInterface) {
- var stores, loadsSinceStore int64
- for ; pb.Next(); i++ {
- m.Load(i)
- if loadsSinceStore++; loadsSinceStore > stores {
- m.LoadOrStore(i, stores)
- loadsSinceStore = 0
- stores++
- }
- }
- },
- })
- }
-
- // BenchmarkAdversarialDelete tests performance when we periodically delete
- // one key and add a different one in a large map.
- //
- // This forces the Load calls to always acquire the map's mutex and periodically
- // makes a full copy of the map despite changing only one entry.
- func BenchmarkAdversarialDelete(b *testing.B) {
- const mapSize = 1 << 10
-
- benchMap(b, bench{
- setup: func(_ *testing.B, m mapInterface) {
- for i := 0; i < mapSize; i++ {
- m.Store(i, i)
- }
- },
-
- perG: func(b *testing.B, pb *testing.PB, i int, m mapInterface) {
- for ; pb.Next(); i++ {
- m.Load(i)
-
- if i%mapSize == 0 {
- m.Range(func(k, _ interface{}) bool {
- m.Delete(k)
- return false
- })
- m.Store(i, i)
- }
- }
- },
- })
- }
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