• Add method to set the number of goroutines to wait for.

• Done method which is called by each of the goroutines when finished.

• Wait method which is used to block till all goroutines have finished and have called the Done method

Let’s see a working code

package main

import (
    "fmt"
    "sync"
    "time"
)

func main() {
    var wg sync.WaitGroup
    wg.Add(2)
 
    go sleep(&wg, time.Second*1)
    go sleep(&wg, time.Second*2)
 
    wg.Wait()
    fmt.Println("All goroutines finished")
}

func sleep(wg *sync.WaitGroup, t time.Duration) {
    defer wg.Done()
    time.Sleep(t)
    fmt.Println("Finished Execution")
}

Output:

Finished Execution
Finished Execution
All goroutines finished

The post Wait for all Go routines to finish execution in Golang appeared first on Welcome To Golang By Example.

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

The post Get number of currently running/active goroutines appeared first on Welcome To Golang By Example.