131 lines
2.8 KiB
Go
131 lines
2.8 KiB
Go
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// Copyright 2017 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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// +build go1.7
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package semaphore
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import (
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"fmt"
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"testing"
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"golang.org/x/net/context"
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)
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// weighted is an interface matching a subset of *Weighted. It allows
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// alternate implementations for testing and benchmarking.
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type weighted interface {
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Acquire(context.Context, int64) error
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TryAcquire(int64) bool
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Release(int64)
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}
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// semChan implements Weighted using a channel for
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// comparing against the condition variable-based implementation.
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type semChan chan struct{}
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func newSemChan(n int64) semChan {
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return semChan(make(chan struct{}, n))
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}
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func (s semChan) Acquire(_ context.Context, n int64) error {
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for i := int64(0); i < n; i++ {
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s <- struct{}{}
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}
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return nil
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}
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func (s semChan) TryAcquire(n int64) bool {
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if int64(len(s))+n > int64(cap(s)) {
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return false
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}
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for i := int64(0); i < n; i++ {
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s <- struct{}{}
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}
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return true
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}
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func (s semChan) Release(n int64) {
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for i := int64(0); i < n; i++ {
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<-s
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}
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}
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// acquireN calls Acquire(size) on sem N times and then calls Release(size) N times.
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func acquireN(b *testing.B, sem weighted, size int64, N int) {
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b.ResetTimer()
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for i := 0; i < b.N; i++ {
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for j := 0; j < N; j++ {
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sem.Acquire(context.Background(), size)
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}
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for j := 0; j < N; j++ {
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sem.Release(size)
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}
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}
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}
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// tryAcquireN calls TryAcquire(size) on sem N times and then calls Release(size) N times.
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func tryAcquireN(b *testing.B, sem weighted, size int64, N int) {
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b.ResetTimer()
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for i := 0; i < b.N; i++ {
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for j := 0; j < N; j++ {
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if !sem.TryAcquire(size) {
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b.Fatalf("TryAcquire(%v) = false, want true", size)
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}
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}
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for j := 0; j < N; j++ {
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sem.Release(size)
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}
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}
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}
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func BenchmarkNewSeq(b *testing.B) {
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for _, cap := range []int64{1, 128} {
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b.Run(fmt.Sprintf("Weighted-%d", cap), func(b *testing.B) {
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for i := 0; i < b.N; i++ {
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_ = NewWeighted(cap)
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}
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})
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b.Run(fmt.Sprintf("semChan-%d", cap), func(b *testing.B) {
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for i := 0; i < b.N; i++ {
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_ = newSemChan(cap)
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}
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})
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}
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}
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func BenchmarkAcquireSeq(b *testing.B) {
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for _, c := range []struct {
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cap, size int64
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N int
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}{
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{1, 1, 1},
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{2, 1, 1},
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{16, 1, 1},
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{128, 1, 1},
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{2, 2, 1},
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{16, 2, 8},
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{128, 2, 64},
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{2, 1, 2},
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{16, 8, 2},
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{128, 64, 2},
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} {
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for _, w := range []struct {
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name string
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w weighted
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}{
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{"Weighted", NewWeighted(c.cap)},
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{"semChan", newSemChan(c.cap)},
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} {
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b.Run(fmt.Sprintf("%s-acquire-%d-%d-%d", w.name, c.cap, c.size, c.N), func(b *testing.B) {
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acquireN(b, w.w, c.size, c.N)
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})
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b.Run(fmt.Sprintf("%s-tryAcquire-%d-%d-%d", w.name, c.cap, c.size, c.N), func(b *testing.B) {
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tryAcquireN(b, w.w, c.size, c.N)
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})
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}
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}
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}
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