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@ymotongpoo
Last active January 14, 2019 16:22
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sample trace in Go 1.11
// Copyright 2018 Yoshi Yamaguchi
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package main
import (
"context"
"log"
"math/big"
"math/rand"
"os"
"runtime/trace"
"sync"
)
const Limit = 100
func main() {
file, err := os.Create("trace.out")
if err != nil {
log.Fatal(err)
}
defer func() {
if file.Close(); err != nil {
log.Fatal(err)
}
}()
if err := trace.Start(file); err != nil {
log.Fatal(err)
}
defer trace.Stop()
ctx := context.Background()
ctx, task := trace.NewTask(ctx, "printFibonacci")
defer task.End()
ch := genFibonacci(ctx, 10)
for n := range ch {
log.Println(n.String())
}
}
func genFibonacci(ctx context.Context, length int) <-chan big.Int {
ctx, task := trace.NewTask(ctx, "task-genFibonacci")
defer task.End()
ch := make(chan big.Int)
var wg sync.WaitGroup
go func(ch chan<- big.Int) {
for i := 0; i < length; i++ {
wg.Add(1)
defer trace.StartRegion(ctx, "region-genFibonacci").End()
defer wg.Done()
n := rand.Intn(Limit)
fibonacci(ctx, n, ch)
}
close(ch)
}(ch)
return ch
}
func fibonacci(ctx context.Context, n int, ch chan<- big.Int) {
a, b := big.NewInt(0), big.NewInt(1)
for i := 0; i < n; i++ {
a.Add(a, b)
a, b = b, a
}
ch <- *a
}
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