102 lines
1.9 KiB
Go
102 lines
1.9 KiB
Go
// Copyright 2009 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package sync_test
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import (
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"runtime"
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. "sync"
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"sync/atomic"
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"testing"
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)
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func BenchmarkSemaUncontended(b *testing.B) {
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type PaddedSem struct {
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sem uint32
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pad [32]uint32
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}
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const CallsPerSched = 1000
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procs := runtime.GOMAXPROCS(-1)
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N := int32(b.N / CallsPerSched)
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c := make(chan bool, procs)
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for p := 0; p < procs; p++ {
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go func() {
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sem := new(PaddedSem)
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for atomic.AddInt32(&N, -1) >= 0 {
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runtime.Gosched()
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for g := 0; g < CallsPerSched; g++ {
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Runtime_Semrelease(&sem.sem)
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Runtime_Semacquire(&sem.sem)
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}
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}
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c <- true
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}()
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}
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for p := 0; p < procs; p++ {
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<-c
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}
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}
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func benchmarkSema(b *testing.B, block, work bool) {
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const CallsPerSched = 1000
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const LocalWork = 100
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procs := runtime.GOMAXPROCS(-1)
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N := int32(b.N / CallsPerSched)
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c := make(chan bool, procs)
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c2 := make(chan bool, procs/2)
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sem := uint32(0)
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if block {
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for p := 0; p < procs/2; p++ {
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go func() {
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Runtime_Semacquire(&sem)
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c2 <- true
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}()
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}
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}
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for p := 0; p < procs; p++ {
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go func() {
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foo := 0
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for atomic.AddInt32(&N, -1) >= 0 {
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runtime.Gosched()
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for g := 0; g < CallsPerSched; g++ {
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Runtime_Semrelease(&sem)
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if work {
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for i := 0; i < LocalWork; i++ {
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foo *= 2
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foo /= 2
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}
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}
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Runtime_Semacquire(&sem)
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}
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}
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c <- foo == 42
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Runtime_Semrelease(&sem)
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}()
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}
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if block {
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for p := 0; p < procs/2; p++ {
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<-c2
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}
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}
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for p := 0; p < procs; p++ {
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<-c
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}
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}
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func BenchmarkSemaSyntNonblock(b *testing.B) {
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benchmarkSema(b, false, false)
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}
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func BenchmarkSemaSyntBlock(b *testing.B) {
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benchmarkSema(b, true, false)
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}
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func BenchmarkSemaWorkNonblock(b *testing.B) {
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benchmarkSema(b, false, true)
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}
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func BenchmarkSemaWorkBlock(b *testing.B) {
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benchmarkSema(b, true, true)
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}
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