update book code

eBook/examples/chapter_14/goroutine1.go

@@ -0,0 +1,29 @@
+package main
+
+import (
+	"fmt"
+	"time"
+)
+
+func main() {
+	fmt.Println("In main()")
+	// longWait()
+	go longWait()
+	// shortWait()
+	go shortWait()
+	fmt.Println("About to sleep in main()")
+	time.Sleep(10 * 1e9) // sleep works with a Duration in nanoseconds (ns) !
+	fmt.Println("At the end of main()")
+}
+
+func longWait() {
+	fmt.Println("Beginning longWait()")
+	time.Sleep(5 * 1e9) // sleep for 5 seconds
+	fmt.Println("End of longWait()")
+}
+
+func shortWait() {
+	fmt.Println("Beginning shortWait()")
+	time.Sleep(2 * 1e9) // sleep for 2 seconds
+	fmt.Println("End of shortWait()")
+}