1 // Copyright 2012 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 5 package race_test 6 7 import ( 8 "sync" 9 "testing" 10 "time" 11 ) 12 13 func TestNoRaceMutex(t *testing.T) { 14 var mu sync.Mutex 15 var x int16 = 0 16 ch := make(chan bool, 2) 17 go func() { 18 mu.Lock() 19 defer mu.Unlock() 20 x = 1 21 ch <- true 22 }() 23 go func() { 24 mu.Lock() 25 x = 2 26 mu.Unlock() 27 ch <- true 28 }() 29 <-ch 30 <-ch 31 } 32 33 func TestRaceMutex(t *testing.T) { 34 var mu sync.Mutex 35 var x int16 = 0 36 ch := make(chan bool, 2) 37 go func() { 38 x = 1 39 mu.Lock() 40 defer mu.Unlock() 41 ch <- true 42 }() 43 go func() { 44 x = 2 45 mu.Lock() 46 mu.Unlock() 47 ch <- true 48 }() 49 <-ch 50 <-ch 51 } 52 53 func TestRaceMutex2(t *testing.T) { 54 var mu1 sync.Mutex 55 var mu2 sync.Mutex 56 var x int8 = 0 57 ch := make(chan bool, 2) 58 go func() { 59 mu1.Lock() 60 defer mu1.Unlock() 61 x = 1 62 ch <- true 63 }() 64 go func() { 65 mu2.Lock() 66 x = 2 67 mu2.Unlock() 68 ch <- true 69 }() 70 <-ch 71 <-ch 72 } 73 74 func TestNoRaceMutexPureHappensBefore(t *testing.T) { 75 var mu sync.Mutex 76 var x int16 = 0 77 ch := make(chan bool, 2) 78 go func() { 79 x = 1 80 mu.Lock() 81 mu.Unlock() 82 ch <- true 83 }() 84 go func() { 85 <-time.After(1e5) 86 mu.Lock() 87 mu.Unlock() 88 x = 1 89 ch <- true 90 }() 91 <-ch 92 <-ch 93 } 94 95 func TestNoRaceMutexSemaphore(t *testing.T) { 96 var mu sync.Mutex 97 ch := make(chan bool, 2) 98 x := 0 99 mu.Lock() 100 go func() { 101 x = 1 102 mu.Unlock() 103 ch <- true 104 }() 105 go func() { 106 mu.Lock() 107 x = 2 108 mu.Unlock() 109 ch <- true 110 }() 111 <-ch 112 <-ch 113 } 114 115 // from doc/go_mem.html 116 func TestNoRaceMutexExampleFromHtml(t *testing.T) { 117 var l sync.Mutex 118 a := "" 119 120 l.Lock() 121 go func() { 122 a = "hello, world" 123 l.Unlock() 124 }() 125 l.Lock() 126 _ = a 127 } 128 129 func TestRaceMutexOverwrite(t *testing.T) { 130 c := make(chan bool, 1) 131 var mu sync.Mutex 132 go func() { 133 mu = sync.Mutex{} 134 c <- true 135 }() 136 mu.Lock() 137 <-c 138 } 139
