Subversion Repositories openrisc

// Copyright 2011 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"
)

func testWaitGroup(t *testing.T, wg1 *WaitGroup, wg2 *WaitGroup) {
        n := 16
        wg1.Add(n)
        wg2.Add(n)
        exited := make(chan bool, n)
        for i := 0; i != n; i++ {
                go func(i int) {
                        wg1.Done()
                        wg2.Wait()
                        exited <- true
                }(i)
        }
        wg1.Wait()
        for i := 0; i != n; i++ {
                select {
                case <-exited:
                        t.Fatal("WaitGroup released group too soon")
                default:
                }
                wg2.Done()
        }
        for i := 0; i != n; i++ {
                <-exited // Will block if barrier fails to unlock someone.
        }
}

func TestWaitGroup(t *testing.T) {
        wg1 := &WaitGroup{}
        wg2 := &WaitGroup{}

        // Run the same test a few times to ensure barrier is in a proper state.
        for i := 0; i != 8; i++ {
                testWaitGroup(t, wg1, wg2)
        }
}

func TestWaitGroupMisuse(t *testing.T) {
        defer func() {
                err := recover()
                if err != "sync: negative WaitGroup count" {
                        t.Fatalf("Unexpected panic: %#v", err)
                }
        }()
        wg := &WaitGroup{}
        wg.Add(1)
        wg.Done()
        wg.Done()
        t.Fatal("Should panic")
}

func BenchmarkWaitGroupUncontended(b *testing.B) {
        type PaddedWaitGroup struct {
                WaitGroup
                pad [128]uint8
        }
        const CallsPerSched = 1000
        procs := runtime.GOMAXPROCS(-1)
        N := int32(b.N / CallsPerSched)
        c := make(chan bool, procs)
        for p := 0; p < procs; p++ {
                go func() {
                        var wg PaddedWaitGroup
                        for atomic.AddInt32(&N, -1) >= 0 {
                                runtime.Gosched()
                                for g := 0; g < CallsPerSched; g++ {
                                        wg.Add(1)
                                        wg.Done()
                                        wg.Wait()
                                }
                        }
                        c <- true
                }()
        }
        for p := 0; p < procs; p++ {
                <-c
        }
}

func benchmarkWaitGroupAddDone(b *testing.B, localWork int) {
        const CallsPerSched = 1000
        procs := runtime.GOMAXPROCS(-1)
        N := int32(b.N / CallsPerSched)
        c := make(chan bool, procs)
        var wg WaitGroup
        for p := 0; p < procs; p++ {
                go func() {
                        foo := 0
                        for atomic.AddInt32(&N, -1) >= 0 {
                                runtime.Gosched()
                                for g := 0; g < CallsPerSched; g++ {
                                        wg.Add(1)
                                        for i := 0; i < localWork; i++ {
                                                foo *= 2
                                                foo /= 2
                                        }
                                        wg.Done()
                                }
                        }
                        c <- foo == 42
                }()
        }
        for p := 0; p < procs; p++ {
                <-c
        }
}

func BenchmarkWaitGroupAddDone(b *testing.B) {
        benchmarkWaitGroupAddDone(b, 0)
}

func BenchmarkWaitGroupAddDoneWork(b *testing.B) {
        benchmarkWaitGroupAddDone(b, 100)
}

func benchmarkWaitGroupWait(b *testing.B, localWork int) {
        const CallsPerSched = 1000
        procs := runtime.GOMAXPROCS(-1)
        N := int32(b.N / CallsPerSched)
        c := make(chan bool, procs)
        var wg WaitGroup
        wg.Add(procs)
        for p := 0; p < procs; p++ {
                go wg.Done()
        }
        for p := 0; p < procs; p++ {
                go func() {
                        foo := 0
                        for atomic.AddInt32(&N, -1) >= 0 {
                                runtime.Gosched()
                                for g := 0; g < CallsPerSched; g++ {
                                        wg.Wait()
                                        for i := 0; i < localWork; i++ {
                                                foo *= 2
                                                foo /= 2
                                        }
                                }
                        }
                        c <- foo == 42
                }()
        }
        for p := 0; p < procs; p++ {
                <-c
        }
}

func BenchmarkWaitGroupWait(b *testing.B) {
        benchmarkWaitGroupWait(b, 0)
}

func BenchmarkWaitGroupWaitWork(b *testing.B) {
        benchmarkWaitGroupWait(b, 100)
}