github.com/graybobo/golang.org-package-offline-cache@v0.0.0-20200626051047-6608995c132f/x/talks/2012/concurrency/support/timeout.go (about)

     1  // +build OMIT
     2  
     3  package main
     4  
     5  import (
     6  	"fmt"
     7  	"math/rand"
     8  	"time"
     9  )
    10  
    11  // START1 OMIT
    12  func main() {
    13  	c := boring("Joe")
    14  	for {
    15  		select {
    16  		case s := <-c:
    17  			fmt.Println(s)
    18  		case <-time.After(1 * time.Second): // HL
    19  			fmt.Println("You're too slow.")
    20  			return
    21  		}
    22  	}
    23  }
    24  // STOP1 OMIT
    25  
    26  // START2 OMIT
    27  func boring(msg string) <-chan string { // Returns receive-only channel of strings. // HL
    28  	c := make(chan string)
    29  	go func() { // We launch the goroutine from inside the function. // HL
    30  		for i := 0; ; i++ {
    31  			c <- fmt.Sprintf("%s: %d", msg, i)
    32  			time.Sleep(time.Duration(rand.Intn(1500)) * time.Millisecond)
    33  		}
    34  	}()
    35  	return c // Return the channel to the caller. // HL
    36  }
    37  // STOP2 OMIT
    38  
    39  
    40  // START3 OMIT
    41  func fanIn(input1, input2 <-chan string) <-chan string { // HL
    42  	c := make(chan string)
    43  	go func() {
    44  		for {
    45  			select {
    46  			case s := <-input1:
    47  				c <- s
    48  			case s := <-input2:
    49  				c <- s
    50  			}
    51  		}
    52  	}()
    53  	return c
    54  }
    55  // STOP3 OMIT