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// Copyright 2012 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 race_test
import (
"sync"
"testing"
"time"
)
func TestNoRaceMutex(t *testing.T) {
var mu sync.Mutex
var x int16 = 0
_ = x
ch := make(chan bool, 2)
go func() {
mu.Lock()
defer mu.Unlock()
x = 1
ch <- true
}()
go func() {
mu.Lock()
x = 2
mu.Unlock()
ch <- true
}()
<-ch
<-ch
}
func TestRaceMutex(t *testing.T) {
var mu sync.Mutex
var x int16 = 0
_ = x
ch := make(chan bool, 2)
go func() {
x = 1
mu.Lock()
defer mu.Unlock()
ch <- true
}()
go func() {
x = 2
mu.Lock()
mu.Unlock()
ch <- true
}()
<-ch
<-ch
}
func TestRaceMutex2(t *testing.T) {
var mu1 sync.Mutex
var mu2 sync.Mutex
var x int8 = 0
_ = x
ch := make(chan bool, 2)
go func() {
mu1.Lock()
defer mu1.Unlock()
x = 1
ch <- true
}()
go func() {
mu2.Lock()
x = 2
mu2.Unlock()
ch <- true
}()
<-ch
<-ch
}
func TestNoRaceMutexPureHappensBefore(t *testing.T) {
var mu sync.Mutex
var x int16 = 0
_ = x
written := false
ch := make(chan bool, 2)
go func() {
x = 1
mu.Lock()
written = true
mu.Unlock()
ch <- true
}()
go func() {
time.Sleep(100 * time.Microsecond)
mu.Lock()
for !written {
mu.Unlock()
time.Sleep(100 * time.Microsecond)
mu.Lock()
}
mu.Unlock()
x = 1
ch <- true
}()
<-ch
<-ch
}
func TestNoRaceMutexSemaphore(t *testing.T) {
var mu sync.Mutex
ch := make(chan bool, 2)
x := 0
_ = x
mu.Lock()
go func() {
x = 1
mu.Unlock()
ch <- true
}()
go func() {
mu.Lock()
x = 2
mu.Unlock()
ch <- true
}()
<-ch
<-ch
}
// from doc/go_mem.html
func TestNoRaceMutexExampleFromHtml(t *testing.T) {
var l sync.Mutex
a := ""
l.Lock()
go func() {
a = "hello, world"
l.Unlock()
}()
l.Lock()
_ = a
}
func TestRaceMutexOverwrite(t *testing.T) {
c := make(chan bool, 1)
var mu sync.Mutex
go func() {
mu = sync.Mutex{}
c <- true
}()
mu.Lock()
<-c
}
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