golang cpu leak time.Tick()

Go time.Tick CPU Leak issue

package main

import (
	"log"
	"net/http"
	"time"

	_ "net/http/pprof"
)

func main() {
	http.HandleFunc("/test", handler)
	log.Fatal(http.ListenAndServe(":9876", nil))
}

func handler(w http.ResponseWriter, r *http.Request) {
	doSomething(10000)
}

func doSomething(times int) {
	for i := 0; i < times; i++ {
		for j := 0; j < times; j++ {
			timeTick_loop()
		}
	}
}

func timeTick_loop() {
	throttle := time.Tick(300 * time.Millisecond)
	for i := 0; i < 100; i++ {
		// fmt.Println("do some db save")
		<-throttle
	}
}

func timeTick_lifetime() {
	for range time.Tick(300 * time.Millisecond) {
		// fmt.Println("test")
		return
	}
}

func timeNewTicker() {
	ticker := time.NewTicker(300 * time.Millisecond)
	defer ticker.Stop()
	for {
		select {
		case <-ticker.C:
			// fmt.Println("do some db save")
			return
		}
	}
}

Local Case by Pprof: create a simple web app:

brew install wrk
wrk -t8 -c400 -d3m http://localhost:9876/test
http://localhost:9876/debug/pprof/profile

golang cpu leak time.Tick()

Pprof CPU leak

Activity_Monitor CPU leak