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// Copyright 2014 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 context_test
import (
. "context"
"fmt"
"runtime"
"sync"
"testing"
"time"
)
func BenchmarkCommonParentCancel(b *testing.B) {
root := WithValue(Background(), "key", "value")
shared, sharedcancel := WithCancel(root)
defer sharedcancel()
b.ResetTimer()
b.RunParallel(func(pb *testing.PB) {
x := 0
for pb.Next() {
ctx, cancel := WithCancel(shared)
if ctx.Value("key").(string) != "value" {
b.Fatal("should not be reached")
}
for i := 0; i < 100; i++ {
x /= x + 1
}
cancel()
for i := 0; i < 100; i++ {
x /= x + 1
}
}
})
}
func BenchmarkWithTimeout(b *testing.B) {
for concurrency := 40; concurrency <= 4e5; concurrency *= 100 {
name := fmt.Sprintf("concurrency=%d", concurrency)
b.Run(name, func(b *testing.B) {
benchmarkWithTimeout(b, concurrency)
})
}
}
func benchmarkWithTimeout(b *testing.B, concurrentContexts int) {
gomaxprocs := runtime.GOMAXPROCS(0)
perPContexts := concurrentContexts / gomaxprocs
root := Background()
// Generate concurrent contexts.
var wg sync.WaitGroup
ccf := make([][]CancelFunc, gomaxprocs)
for i := range ccf {
wg.Add(1)
go func(i int) {
defer wg.Done()
cf := make([]CancelFunc, perPContexts)
for j := range cf {
_, cf[j] = WithTimeout(root, time.Hour)
}
ccf[i] = cf
}(i)
}
wg.Wait()
b.ResetTimer()
b.RunParallel(func(pb *testing.PB) {
wcf := make([]CancelFunc, 10)
for pb.Next() {
for i := range wcf {
_, wcf[i] = WithTimeout(root, time.Hour)
}
for _, f := range wcf {
f()
}
}
})
b.StopTimer()
for _, cf := range ccf {
for _, f := range cf {
f()
}
}
}
func BenchmarkCancelTree(b *testing.B) {
depths := []int{1, 10, 100, 1000}
for _, d := range depths {
b.Run(fmt.Sprintf("depth=%d", d), func(b *testing.B) {
b.Run("Root=Background", func(b *testing.B) {
for i := 0; i < b.N; i++ {
buildContextTree(Background(), d)
}
})
b.Run("Root=OpenCanceler", func(b *testing.B) {
for i := 0; i < b.N; i++ {
ctx, cancel := WithCancel(Background())
buildContextTree(ctx, d)
cancel()
}
})
b.Run("Root=ClosedCanceler", func(b *testing.B) {
for i := 0; i < b.N; i++ {
ctx, cancel := WithCancel(Background())
cancel()
buildContextTree(ctx, d)
}
})
})
}
}
func buildContextTree(root Context, depth int) {
for d := 0; d < depth; d++ {
root, _ = WithCancel(root)
}
}
func BenchmarkCheckCanceled(b *testing.B) {
ctx, cancel := WithCancel(Background())
cancel()
b.Run("Err", func(b *testing.B) {
for i := 0; i < b.N; i++ {
ctx.Err()
}
})
b.Run("Done", func(b *testing.B) {
for i := 0; i < b.N; i++ {
select {
case <-ctx.Done():
default:
}
}
})
}
|
