Ttykuu

I'm beginning to learn about Golang and I would like to have some advice about the following program.

package main

import (
 "fmt"
 "net/http"
 "time"
)

const BenchmarkTry = 1000

type PageBenchmark struct 
 url string
 time int64 // microseconds


func execBenchmark(url string, channel chan PageBenchmark) 
 totalExecTimeChan := make(chan int64, BenchmarkTry) // set size to prevent blocked goroutine
 totalExecTime := int64(0)

 // start all the goroutines
 for i := 0; i < BenchmarkTry; i++ 
 go execHttpRequest(url, totalExecTimeChan)
 

 // catch new values from totalExecTimeChan values come from execHttpRequest()) and add it to the total
 for i := 0; i < BenchmarkTry; i++ 
 totalExecTime += <-totalExecTimeChan // waiting to get a value from one of the goroutines started in the previous for loop
 

 channel <- PageBenchmarkurl, totalExecTime / BenchmarkTry


// exec http request and attach exec time to channel
func execHttpRequest(url string, channel chan int64) 
 begin := time.Now()
 _, _ = http.Get(url)
 channel <- time.Since(begin).Nanoseconds() / 1000000 // convert to milliseconds


func main() 
 sites := [...]string

 

 pages := [...]string

 

 benchmarkChan := make(chan PageBenchmark, len(sites)*len(pages)) // set size to prevent blocked goroutine

 begin := time.Now()
 fmt.Println("Beginning !")

 // start all the goroutines
 for site := range sites 
 for page := range pages 
 go execBenchmark(sites[site]+pages[page], benchmarkChan)
 
 

 // catch new values from benchmarkChan and "print" the PageBenchmark
 for i := 0; i < len(sites)*len(pages); i++ 
 benchmark := <-benchmarkChan
 fmt.Printf("Url : %vnResponse Time : %d msnn", benchmark.url, benchmark.time)
 

 // print execution time
 fmt.Println("End.")
 fmt.Println(fmt.Sprintf("%d ms", time.Since(begin).Nanoseconds()/1000000))

So basically here, I'm making HTTP requests (GET method) to multiple urls on multiple web sites. 1000 requests by url in this example.

For now, I just want to start some goroutines in this order :

• (First goroutine) mainroutine : start a benchmark (goroutine) foreach web site pages, get the average execution time and print it




• (Second goroutine) page routine : start 1000 goroutines (benchmark tries), get the execution times from a channel and store the average execution time in an other channel




• (Third goroutine) Execute an HTTP request on the page and store the execution time in a channel

Actually, this piece of code works but I'm not sure that it works as intended.

• Is that the case ?




• Is the execution scheduling valid ?




• Is it appropriate to use defined size channels here ?




• Is there a better/more effective way to achieve this task ?

I would be very grateful if you would please take some time to read this topic. Thank you and have a nice day.