Subversion Repositories openrisc

// 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.

package sync_test

import (

        "runtime"

        . "sync"

        "sync/atomic"

        "testing"

)

type one int

func (o *one) Increment() {

        *o++

}

func run(once *Once, o *one, c chan bool) {

        once.Do(func() { o.Increment() })

        c <- true

}

func TestOnce(t *testing.T) {

        o := new(one)

        once := new(Once)

        c := make(chan bool)

        const N = 10

        for i := 0; i < N; i++ {

                go run(once, o, c)

        }

        for i := 0; i < N; i++ {

                <-c

        }

        if *o != 1 {

                t.Errorf("once failed: %d is not 1", *o)

        }

}

func BenchmarkOnce(b *testing.B) {

        const CallsPerSched = 1000

        procs := runtime.GOMAXPROCS(-1)

        N := int32(b.N / CallsPerSched)

        var once Once

        f := func() {}

        c := make(chan bool, procs)

        for p := 0; p < procs; p++ {

                go func() {

                        for atomic.AddInt32(&N, -1) >= 0 {

                                runtime.Gosched()

                                for g := 0; g < CallsPerSched; g++ {

                                        once.Do(f)

                                }

                        }

                        c <- true

                }()

        }

        for p := 0; p < procs; p++ {

                <-c

        }

}