126 lines
2.3 KiB
Go
126 lines
2.3 KiB
Go
// Copyright 2011 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 runtime_test
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import (
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"runtime"
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"sync/atomic"
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"testing"
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)
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var stop = make(chan bool, 1)
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func perpetuumMobile() {
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select {
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case <-stop:
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default:
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go perpetuumMobile()
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}
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}
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func TestStopTheWorldDeadlock(t *testing.T) {
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if testing.Short() {
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t.Logf("skipping during short test")
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return
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}
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maxprocs := runtime.GOMAXPROCS(3)
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compl := make(chan bool, 2)
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go func() {
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for i := 0; i != 1000; i += 1 {
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runtime.GC()
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}
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compl <- true
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}()
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go func() {
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for i := 0; i != 1000; i += 1 {
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runtime.GOMAXPROCS(3)
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}
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compl <- true
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}()
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go perpetuumMobile()
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<-compl
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<-compl
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stop <- true
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runtime.GOMAXPROCS(maxprocs)
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}
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func stackGrowthRecursive(i int) {
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var pad [128]uint64
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if i != 0 && pad[0] == 0 {
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stackGrowthRecursive(i - 1)
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}
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}
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func BenchmarkStackGrowth(b *testing.B) {
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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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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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stackGrowthRecursive(10)
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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 BenchmarkSyscall(b *testing.B) {
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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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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.Entersyscall()
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runtime.Exitsyscall()
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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 BenchmarkSyscallWork(b *testing.B) {
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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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for p := 0; p < procs; p++ {
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go func() {
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foo := 42
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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.Entersyscall()
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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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runtime.Exitsyscall()
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}
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}
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c <- foo == 42
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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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