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// Copyright 2009 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.
// GOMAXPROCS=10 gotest
package sync_test
import (
"runtime"
. "sync"
"testing"
)
func HammerSemaphore(s *uint32, loops int, cdone chan bool) {
for i := 0; i < loops; i++ {
runtime.Semacquire(s)
runtime.Semrelease(s)
}
cdone <- true
}
func TestSemaphore(t *testing.T) {
s := new(uint32)
*s = 1
c := make(chan bool)
for i := 0; i < 10; i++ {
go HammerSemaphore(s, 1000, c)
}
for i := 0; i < 10; i++ {
<-c
}
}
func BenchmarkUncontendedSemaphore(b *testing.B) {
s := new(uint32)
*s = 1
HammerSemaphore(s, b.N, make(chan bool, 2))
}
func BenchmarkContendedSemaphore(b *testing.B) {
b.StopTimer()
s := new(uint32)
*s = 1
c := make(chan bool)
runtime.GOMAXPROCS(2)
b.StartTimer()
go HammerSemaphore(s, b.N/2, c)
go HammerSemaphore(s, b.N/2, c)
<-c
<-c
}
func HammerMutex(m *Mutex, loops int, cdone chan bool) {
for i := 0; i < loops; i++ {
m.Lock()
m.Unlock()
}
cdone <- true
}
func TestMutex(t *testing.T) {
m := new(Mutex)
c := make(chan bool)
for i := 0; i < 10; i++ {
go HammerMutex(m, 1000, c)
}
for i := 0; i < 10; i++ {
<-c
}
}
func BenchmarkUncontendedMutex(b *testing.B) {
m := new(Mutex)
HammerMutex(m, b.N, make(chan bool, 2))
}
func BenchmarkContendedMutex(b *testing.B) {
b.StopTimer()
m := new(Mutex)
c := make(chan bool)
runtime.GOMAXPROCS(2)
b.StartTimer()
go HammerMutex(m, b.N/2, c)
go HammerMutex(m, b.N/2, c)
<-c
<-c
}
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