add channel for week3

week3-channeel/channel_select.go

@@ -0,0 +1,31 @@
+package main
+
+import (
+	"log"
+	"time"
+)
+
+func main() {
+	ch1 := make(chan int)
+	ch2 := make(chan int)
+	go func() {
+		time.Sleep(3 * time.Second)
+		ch1 <- 1
+	}()
+
+	go func() {
+		time.Sleep(3 * time.Second)
+		ch2 <- 2
+	}()
+
+	select {
+	case <-ch1:
+		log.Println("can read from ch1")
+	case <-ch2:
+		log.Println("can read from ch2")
+	default:
+		log.Println("defaults......")
+
+	}
+
+}

week3-channeel/channel_timeout.go

@@ -0,0 +1,35 @@
+package main
+
+import (
+	"fmt"
+	"time"
+)
+
+func main() {
+	ch1 := make(chan  string)
+	go func() {
+		time.Sleep(4 * time.Second)
+		ch1 <- "ch1 is ready!"
+	}()
+
+	select {
+	case mess := <-ch1:
+		fmt.Println(mess)
+	case t := <- time.After(2 * time.Second):
+		fmt.Println("ch1 timeout ", t)
+
+	}
+
+	ch2 := make(chan string)
+	go func() {
+		time.Sleep(4 * time.Second)
+		ch2 <- "ch2 is ready !"
+	}()
+	select {
+	case mess := <- ch2:
+		fmt.Println(mess)
+	case t := <-time.After(5 * time.Second):
+		fmt.Println("ch2 is timeout", t)
+	}
+
+}

week3-channeel/channel_w_data.go

@@ -0,0 +1,20 @@
+package main
+
+import (
+	"log"
+	"time"
+)
+
+func main() {
+	c := make(chan int)
+	go writeChan(c, 666)
+	time.Sleep(2 * time.Second)
+
+}
+
+func writeChan(c chan int, x int) {
+	log.Println(x)
+	c <- x
+	close(c)
+	log.Println(x)
+}