Retro68/gcc/libgo/go/sync/runtime_sema_test.go
2018-12-28 16:30:48 +01:00

76 lines
1.3 KiB
Go

// 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"
"testing"
)
func BenchmarkSemaUncontended(b *testing.B) {
type PaddedSem struct {
sem uint32
pad [32]uint32
}
b.RunParallel(func(pb *testing.PB) {
sem := new(PaddedSem)
for pb.Next() {
Runtime_Semrelease(&sem.sem, false)
Runtime_Semacquire(&sem.sem)
}
})
}
func benchmarkSema(b *testing.B, block, work bool) {
if b.N == 0 {
return
}
sem := uint32(0)
if block {
done := make(chan bool)
go func() {
for p := 0; p < runtime.GOMAXPROCS(0)/2; p++ {
Runtime_Semacquire(&sem)
}
done <- true
}()
defer func() {
<-done
}()
}
b.RunParallel(func(pb *testing.PB) {
foo := 0
for pb.Next() {
Runtime_Semrelease(&sem, false)
if work {
for i := 0; i < 100; i++ {
foo *= 2
foo /= 2
}
}
Runtime_Semacquire(&sem)
}
_ = foo
Runtime_Semrelease(&sem, false)
})
}
func BenchmarkSemaSyntNonblock(b *testing.B) {
benchmarkSema(b, false, false)
}
func BenchmarkSemaSyntBlock(b *testing.B) {
benchmarkSema(b, true, false)
}
func BenchmarkSemaWorkNonblock(b *testing.B) {
benchmarkSema(b, false, true)
}
func BenchmarkSemaWorkBlock(b *testing.B) {
benchmarkSema(b, true, true)
}