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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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