1// Copyright 2013 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5package main
6
7import (
8	"math/rand"
9	"runtime"
10	"sync"
11)
12
13func mapTypes() []MapType {
14	// TODO(bradfitz): bunch more map types of all different key and value types.
15	// Use reflect.MapOf and a program to generate lots of types & struct types.
16	// For now, just one:
17	return []MapType{intMapType{}}
18}
19
20type MapType interface {
21	NewMap() Map
22}
23
24type Map interface {
25	AddItem()
26	DelItem()
27	Len() int
28	GetItem()
29	RangeAll()
30}
31
32func stressMapType(mt MapType, done func()) {
33	defer done()
34	m := mt.NewMap()
35	for m.Len() < 10000 {
36		Println("map at ", m.Len())
37		if m.Len()%100 == 0 {
38			runtime.Gosched()
39		}
40		m.AddItem()
41		m.AddItem()
42		m.DelItem()
43		var wg sync.WaitGroup
44		const numGets = 10
45		wg.Add(numGets)
46		for i := 0; i < numGets; i++ {
47			go func(i int) {
48				if i&1 == 0 {
49					m.GetItem()
50				} else {
51					m.RangeAll()
52				}
53				wg.Done()
54			}(i)
55		}
56		wg.Wait()
57	}
58	for m.Len() > 0 {
59		m.DelItem()
60	}
61}
62
63type intMapType struct{}
64
65func (intMapType) NewMap() Map {
66	return make(intMap)
67}
68
69var deadcafe = []byte("\xDE\xAD\xCA\xFE")
70
71type intMap map[int][]byte
72
73func (m intMap) AddItem() {
74	s0 := len(m)
75	for len(m) == s0 {
76		key := rand.Intn(s0 + 1)
77		m[key] = make([]byte, rand.Intn(64<<10))
78	}
79}
80
81func (m intMap) DelItem() {
82	for k := range m {
83		delete(m, k)
84		return
85	}
86}
87
88func (m intMap) GetItem() {
89	key := rand.Intn(len(m))
90	if s, ok := m[key]; ok {
91		copy(s, deadcafe)
92	}
93}
94
95func (m intMap) Len() int { return len(m) }
96
97func (m intMap) RangeAll() {
98	for _ = range m {
99	}
100	for range m {
101	}
102}
103
104func stressMaps() {
105	for {
106		var wg sync.WaitGroup
107		for _, mt := range mapTypes() {
108			wg.Add(1)
109			go stressMapType(mt, wg.Done)
110		}
111		wg.Wait()
112	}
113}
114