From a6aec5bed0302e2477a9bfada26b4fefea1d89ca Mon Sep 17 00:00:00 2001
From: glight2000 <173959153@qq.com>
Date: Wed, 30 Dec 2015 17:31:42 +0800
Subject: [PATCH] =?UTF-8?q?=E5=AE=8C=E6=88=9014.4?=
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---
 eBook/14.4.md | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/eBook/14.4.md b/eBook/14.4.md
index 17b309a..392b290 100644
--- a/eBook/14.4.md
+++ b/eBook/14.4.md
@@ -137,7 +137,38 @@ Received on channel 1: 94348
 
 习惯用法：后台服务模式
 
+服务通常是是用后台协程中的无限循环实现的，在循环中使用`select`获取并处理通道中的数据：
+```go
+// Backend goroutine.
+func backend() {
+	for {
+		select {
+		case cmd := <-ch1:
+			// Handle ...
+		case cmd := <-ch2:
+			...
+		case cmd := <-chStop:
+			// stop server
+		}
+	}
+}
+```
+在程序的其他地方给通道`ch1`，`ch2`发送数据，比如：通道`stop`用来清理结束服务程序。
 
+另一种方式（但是不太灵活）就是（客户端）在`chRequest`上提交请求，后台协程循环这个通道，使用`switch`根据请求的行为来分别处理：
+```go
+func backent() {
+	for req := range chRequest {
+		switch req.Subjext() {
+			case A1:  // Handle case ...
+			case A2:  // Handle case ...
+			default:
+			  // Handle illegal request ..
+			  // ...
+		}
+	}
+}
+```
 
 ## 链接