gistfile1.go

  wg := &sync.WaitGroup{}
  ch := make(chan struct{})
  for i := 0; i < 100; i++ {
    wg.Add(1)
    go func(ch chan struct{}) {
      defer wg.Done()
      for _ = range ch {
        r, err := c.SayHello(context.Background(), &pb.HelloRequest{Name: name})
        if err != nil {
          log.Fatalf("could not greet: %v", err)
        }
        log.Printf("Greeting: %s", r.Message)
      }
    }(ch)
  }

  numJobs := 10000
  start := time.Now()
  for i := 0; i < numJobs; i++ {
    ch <- struct{}{}
  }

  close(ch)

  fmt.Printf("Waiting for workers...\n")
  wg.Wait()
  elapsed := time.Since(start)

  fmt.Printf("%d jobs in %0.2f seconds (%0.2f jobs/sec)\n", numJobs, float64(elapsed)/float64(time.Second), float64(numJobs)/(float64(elapsed)/float64(time.Second)))