update book code

eBook/examples/chapter_14/channel_block2.go

@@ -0,0 +1,25 @@
+package main
+
+import (
+	"fmt"
+	"time"
+)
+
+func main() {
+	ch1 := make(chan int)
+	go pump(ch1)
+	go suck(ch1) // tons of numbers appear 
+	time.Sleep(1e9)
+}
+
+func pump(ch chan int) {
+	for i := 0; ; i++ {
+		ch <- i
+	}
+}
+
+func suck(ch chan int) {
+	for {
+		fmt.Println(<-ch)
+	}
+}