add chapter 15.9 (#686)

eBook/examples/chapter_15/rpc/rpc_client.go

@@ -0,0 +1,39 @@
+// rpc_client.go
+// if the server is not started:
+// can't get the server to start, so client stops immediately with error:
+// 2011/08/01 16:08:05 Error dialing:dial tcp :1234: 
+//		The requested address is not valid in its context.
+// with serverAddress = localhost:
+// 2011/08/01 16:09:23 Error dialing:dial tcp 127.0.0.1:1234: 
+//		No connection could be made because the target machine actively refused it.
+package main
+
+import (
+	"fmt"
+	"log"
+	"net/rpc"
+	"./rpc_objects"
+)
+
+const serverAddress = "localhost"
+
+func main() {
+	client, err := rpc.DialHTTP("tcp", serverAddress + ":1234")
+	if err != nil {
+		log.Fatal("Error dialing:", err)
+	}
+	// Synchronous call
+	args := &rpc_objects.Args{7, 8}
+	var reply int
+	err = client.Call("Args.Multiply", args, &reply)
+	if err != nil {
+		log.Fatal("Args error:", err)
+	}
+	fmt.Printf("Args: %d * %d = %d", args.N, args.M, reply)
+}
+/* Output:
+Starting Process E:/Go/GoBoek/code_examples/chapter_14/rpc_client.exe ...
+
+Args: 7 * 8 = 56
+End Process exit status 0
+*/

eBook/examples/chapter_15/rpc/rpc_objects.go

@@ -0,0 +1,13 @@
+// rpc_objects.go
+package rpc_objects
+
+import "net"
+
+type Args struct {
+	N, M int
+}
+
+func (t *Args) Multiply(args *Args, reply *int) net.Error {
+	*reply = args.N * args.M
+	return nil
+}

eBook/examples/chapter_15/rpc/rpc_server.go

@@ -0,0 +1,32 @@
+// rpc_server.go
+// after client-exits the server shows the message:
+//       1:1234: The specified network name is no longer available.
+//       2011/08/01 16:19:04 rpc: rpc: server cannot decode request: WSARecv tcp 127.0.0.
+package main
+
+import (
+	"net/http"
+	"log"
+	"net"
+	"net/rpc"
+	"time"
+	"./rpc_objects"
+)
+
+func main() {
+	calc := new(rpc_objects.Args)
+	rpc.Register(calc)
+	rpc.HandleHTTP()
+	listener, e := net.Listen("tcp", "localhost:1234")
+	if e != nil {
+		log.Fatal("Starting RPC-server -listen error:", e)
+	}
+	go http.Serve(listener, nil)
+	time.Sleep(1000e9)
+}
+/* Output:
+Starting Process E:/Go/GoBoek/code_examples/chapter_14/rpc_server.exe ...
+
+** after 5 s: **
+End Process exit status 0
+*/

eBook/examples/chapter_15/rpc_updated/rpc_client.go

@@ -0,0 +1,39 @@
+// rpc_client.go
+// if the server is not started:
+// can't get the server to start, so client stops immediately with error:
+// 2011/08/01 16:08:05 Error dialing:dial tcp :1234: 
+//		The requested address is not valid in its context.
+// with serverAddress = localhost:
+// 2011/08/01 16:09:23 Error dialing:dial tcp 127.0.0.1:1234: 
+//		No connection could be made because the target machine actively refused it.
+package main
+
+import (
+	"fmt"
+	"log"
+	"net/rpc"
+	"./rpc_objects"
+)
+
+const serverAddress = "localhost"
+
+func main() {
+	client, err := rpc.DialHTTP("tcp", serverAddress + ":1234")
+	if err != nil {
+		log.Fatal("Error dialing:", err)
+	}
+	// Synchronous call
+	args := &rpc_objects.Args{7, 8}
+	var reply int
+	err = client.Call("Args.Multiply", args, &reply)
+	if err != nil {
+		log.Fatal("Args error:", err)
+	}
+	fmt.Printf("Args: %d * %d = %d", args.N, args.M, reply)
+}
+/* Output:
+Starting Process E:/Go/GoBoek/code_examples/chapter_14/rpc_client.exe ...
+
+Args: 7 * 8 = 56
+End Process exit status 0
+*/

eBook/examples/chapter_15/rpc_updated/rpc_objects/rpc_objects.go

@@ -0,0 +1,11 @@
+// rpc_objects.go
+package rpc_objects
+
+type Args struct {
+	N, M int
+}
+
+func (t *Args) Multiply(args *Args, reply *int) error {
+	*reply = args.N * args.M
+	return nil
+}

eBook/examples/chapter_15/rpc_updated/rpc_server.go

@@ -0,0 +1,32 @@
+// rpc_server.go
+// after client-exits the server shows the message:
+//       1:1234: The specified network name is no longer available.
+//       2011/08/01 16:19:04 rpc: rpc: server cannot decode request: WSARecv tcp 127.0.0.
+package main
+
+import (
+	"net/http"
+	"log"
+	"net"
+	"net/rpc"
+	"time"
+	"./rpc_objects"
+)
+
+func main() {
+	calc := new(rpc_objects.Args)
+	rpc.Register(calc)
+	rpc.HandleHTTP()
+	listener, e := net.Listen("tcp", "localhost:1234")
+	if e != nil {
+		log.Fatal("Starting RPC-server -listen error:", e)
+	}
+	go http.Serve(listener, nil)
+	time.Sleep(1000e9)
+}
+/* Output:
+Starting Process E:/Go/GoBoek/code_examples/chapter_14/rpc_server.exe ...
+
+** after 5 s: **
+End Process exit status 0
+*/