initial import

concurrency/best-practices-sync/main.go

@@ -0,0 +1,54 @@
+package main
+
+import (
+	"fmt"
+	"math/rand"
+	"time"
+)
+
+type Message struct {
+	text string
+	wait chan interface{}
+}
+
+func printOut() <-chan Message {
+	finish := make(chan interface{})
+	c := make(chan Message)
+	go func() {
+		for i := 1; ; i++ {
+			c <- Message{fmt.Sprintf("Print %v", i), finish}
+			time.Sleep(time.Duration(rand.Intn(9000)) * time.Millisecond)
+			<-finish
+		}
+	}()
+	return c
+}
+
+func join(in1, in2 <-chan Message) <-chan Message {
+	out := make(chan Message)
+	go func() {
+		for {
+			out <- <-in1
+		}
+	}()
+	go func() {
+		for {
+			out <- <-in2
+		}
+	}()
+	return out
+}
+
+func main() {
+	c1 := printOut()
+	c2 := printOut()
+	c3 := join(c1, c2)
+	for i := 1; i < 20; i++ {
+		message1 := <-c3
+		message2 := <-c3
+		fmt.Println(message1.text)
+		fmt.Println(message2.text)
+		message1.wait <- ""
+		message2.wait <- ""
+	}
+}