59 lines
1.2 KiB
Go
59 lines
1.2 KiB
Go
// Copyright 2013 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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// The file contains tests that can not run under race detector for some reason.
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// +build !race
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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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// Syscall tests split stack between Entersyscall and Exitsyscall under race detector.
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func BenchmarkSyscall(b *testing.B) {
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benchmarkSyscall(b, 0, 1)
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}
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func BenchmarkSyscallWork(b *testing.B) {
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benchmarkSyscall(b, 100, 1)
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}
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func BenchmarkSyscallExcess(b *testing.B) {
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benchmarkSyscall(b, 0, 4)
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}
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func BenchmarkSyscallExcessWork(b *testing.B) {
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benchmarkSyscall(b, 100, 4)
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}
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func benchmarkSyscall(b *testing.B, work, excess int) {
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const CallsPerSched = 1000
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procs := runtime.GOMAXPROCS(-1) * excess
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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 < work; 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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