Get number of currently running/active goroutines

NumGoroutine function of runtime package can be used to know the currently running/active goroutines.

https://golang.org/pkg/runtime/#NumGoroutine

Below is the signature of the function

func NumGoroutine() int

Working Code:

package main
import (
"fmt"
"runtime"
"time"
)
func main() {
for i := 0; i < 20; i++ {
go execute()
}
fmt.Println(runtime.NumGoroutine())
}
func execute() {
time.Sleep(time.Second * 10)
}

Output:

21