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< ol class = "chapter" > < li class = "chapter-item expanded affix " > < a href = "../index.html" > Go语言圣经< / a > < / li > < li class = "chapter-item expanded affix " > < a href = "../preface.html" > 前言< / a > < / li > < li class = "chapter-item expanded " > < a href = "../ch1/ch1.html" > < strong aria-hidden = "true" > 1.< / strong > 入门< / a > < / li > < li > < ol class = "section" > < li class = "chapter-item expanded " > < a href = "../ch1/ch1-01.html" > < strong aria-hidden = "true" > 1.1.< / strong > Hello, World< / a > < / li > < li class = "chapter-item expanded " > < a href = "../ch1/ch1-02.html" > < strong aria-hidden = "true" > 1.2.< / strong > 命令行参数< / a > < / li > < li class = "chapter-item expanded " > < a href = "../ch1/ch1-03.html" > < strong aria-hidden = "true" > 1.3.< / strong > 查找重复的行< / a > < / li > < li class = "chapter-item expanded " > < a href = "../ch1/ch1-04.html" > < strong aria-hidden = "true" > 1.4.< / strong > GIF动画< / a > < / li > < li class = "chapter-item expanded " > < a href = "../ch1/ch1-05.html" > < strong aria-hidden = "true" > 1.5.< / strong > 获取URL< / a > < / li > < li class = "chapter-item expanded " > < a href = "../ch1/ch1-06.html" > < strong aria-hidden = "true" > 1.6.< / strong > 并发获取多个URL< / a > < / li > < li class = "chapter-item expanded " > < a href = "../ch1/ch1-07.html" > < strong aria-hidden = "true" > 1.7.< / strong > Web服务< / a > < / li > < li class = "chapter-item expanded " > < a href = "../ch1/ch1-08.html" > < strong aria-hidden = "true" > 1.8.< / strong > 本章要点< / a > < / li > < / ol > < / li > < li class = "chapter-item expanded " > < a href = "../ch2/ch2.html" > < strong aria-hidden = "true" > 2.< / strong > 程序结构< / a > < / li > < li > < ol class = "section" > < li class = "chapter-item expanded " > < a href = "../ch2/ch2-01.html" > < strong aria-hidden = "true" > 2.1.< / strong > 命名< / a > < / li > < li class = "chapter-item expanded " > < a href = "../ch2/ch2-02.html" > < strong aria-hidden = "true" > 2.2.< / strong > 声明< / a > < / li > < li class = "chapter-item expanded " > < a href = "../ch2/ch2-03.html" > < strong aria-hidden = "true" > 2.3.< / strong > 变量< / a > < / li > < li class = "chapter-item expanded " > < a href = "../ch2/ch2-04.html" > < strong aria-hidden = "true" > 2.4.< / strong > 赋值< / a > < / li > < li class = "chapter-item expanded " > < a href = "../ch2/ch2-05.html" > < strong aria-hidden = "true" > 2.5.< / strong > 类型< / a > < / li > < li class = "chapter-item expanded " > < a href = "../ch2/ch2-06.html" > < strong aria-hidden = "true" > 2.6.< / strong > 包和文件< / a > < / li > < li class = "chapter-item expanded " > < a href = "../ch2/ch2-07.html" > < strong aria-hidden = "true" > 2.7.< / strong > 作用域< / a > < / li > < / ol > < / li > < li class = "chapter-item expanded " > < a href = "../ch3/ch3.html" > < strong aria-hidden = "true" > 3.< / strong > 基础数据类型< / a > < / li > < li > < ol class = "section" > < li class = "chapter-item expanded " > < a href = "../ch3/ch3-01.html" > < strong aria-hidden = "true" > 3.1.< / strong > 整型< / a > < / li > < li class = "chapter-item expanded " > < a href = "../ch3/ch3-02.html" > < strong aria-hidden = "true" > 3.2.< / strong > 浮点数< / a > < / li > < li class = "chapter-item expanded " > < a href = "../ch3/ch3-03.html" > < strong aria-hidden = "true" > 3.3.< / strong > 复数< / a > < / li > < li class = "chapter-item expanded " > < a href = "../ch3/ch3-04.html" > < strong aria-hidden = "true" > 3.4.< / strong > 布尔型< / a > < / li > < li class = "chapter-item expanded " > < a href = "../ch3/ch3-05.html" > < strong aria-hidden = "true" > 3.5.< / strong > 字符串< / a > < / li > < li class = "chapter-item expanded " > < a href = "../ch3/ch3-06.html" > < strong aria-hidden = "true" > 3.6.< / strong > 常量< / a > < / li > < / ol > < / li > < li class = "chapter-item expanded " > < a href = "../ch4/ch4.html" > < strong aria-hidden = "true" > 4.< / strong > 复合数据类型< / a > < / li > < li > < ol class = "section" > < li class = "chapter-item expanded " > < a href = "../ch4/ch4-01.html" > < strong aria-hidden = "true" > 4.1.< / strong > 数组< / a > < / li > < li class = "chapter-item expanded " > < a href = "../ch4/ch4-02.html" > < strong aria-hidden = "true" > 4.2.< / strong > Slice< / a > < / li > < li class = "chapter-item expanded " > < a href = "../ch4/ch4-03.html" > < strong aria-hidden = "true" > 4.3.< / strong > Map< / a > < / li > < li class = "chapter-item expanded " > < a href = "../ch4/ch4-04.html" > < strong aria-hidden = "true" > 4.4.< / strong > 结构体< / a > < / li > < li class = "chapter-item expanded " > < a href = "../ch4/ch4-05.html" > < strong aria-hidden = "true" > 4.5.< / strong > JSON< / a > < / li > < li class = "chapter-item expanded " > < a href = "../ch4/ch4-06.html" > < strong aria-hidd
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2022-08-24 10:48:15 +00:00
< li > < em > KusonStack一站式可编程配置技术栈(Go): < a href = "https://github.com/KusionStack/kusion" > https://github.com/KusionStack/kusion< / a > < / em > < / li >
< li > < em > KCL 配置编程语言(Rust): < a href = "https://github.com/KusionStack/KCLVM" > https://github.com/KusionStack/KCLVM< / a > < / em > < / li >
< li > < em > 凹语言™: < a href = "https://github.com/wa-lang/wa" > https://github.com/wa-lang/wa< / a > < / em > < / li >
2022-08-04 06:59:33 +00:00
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< hr >
< h2 id = "83-示例-并发的echo服务" > < a class = "header" href = "#83-示例-并发的echo服务" > 8.3. 示例: 并发的Echo服务< / a > < / h2 >
< p > clock服务器每一个连接都会起一个goroutine。在本节中我们会创建一个echo服务器， ， ： < / p >
< pre > < code class = "language-go" > func handleConn(c net.Conn) {
io.Copy(c, c) // NOTE: ignoring errors
c.Close()
}
< / code > < / pre >
< p > 一个更有意思的echo服务应该模拟一个实际的echo的“回响”， ， ， ， ： < / p >
< p > < u > < i > gopl.io/ch8/reverb1< / i > < / u > < / p >
< pre > < code class = "language-go" > func echo(c net.Conn, shout string, delay time.Duration) {
fmt.Fprintln(c, " \t" , strings.ToUpper(shout))
time.Sleep(delay)
fmt.Fprintln(c, " \t" , shout)
time.Sleep(delay)
fmt.Fprintln(c, " \t" , strings.ToLower(shout))
}
func handleConn(c net.Conn) {
input := bufio.NewScanner(c)
for input.Scan() {
echo(c, input.Text(), 1*time.Second)
}
// NOTE: ignoring potential errors from input.Err()
c.Close()
}
< / code > < / pre >
< p > 我们需要升级我们的客户端程序，这样它就可以发送终端的输入到服务器，并把服务端的返回输出到终端上，这使我们有了使用并发的另一个好机会：< / p >
< p > < u > < i > gopl.io/ch8/netcat2< / i > < / u > < / p >
< pre > < code class = "language-go" > func main() {
conn, err := net.Dial(" tcp" , " localhost:8000" )
if err != nil {
log.Fatal(err)
}
defer conn.Close()
go mustCopy(os.Stdout, conn)
mustCopy(conn, os.Stdin)
}
< / code > < / pre >
< p > 当main goroutine从标准输入流中读取内容并将其发送给服务器时， ， ， ， ， ， （ ） < / p >
< p > 下面这个会话中，客户端的输入是左对齐的，服务端的响应会用缩进来区别显示。
客户端会向服务器“喊三次话”：< / p >
< pre > < code > $ go build gopl.io/ch8/reverb1
$ ./reverb1 &
$ go build gopl.io/ch8/netcat2
$ ./netcat2
Hello?
HELLO?
Hello?
hello?
Is there anybody there?
IS THERE ANYBODY THERE?
Yooo-hooo!
Is there anybody there?
is there anybody there?
YOOO-HOOO!
Yooo-hooo!
yooo-hooo!
^D
$ killall reverb1
< / code > < / pre >
< p > 注意客户端的第三次shout在前一个shout处理完成之前一直没有被处理， ， ， ： < / p >
< p > < u > < i > gopl.io/ch8/reverb2< / i > < / u > < / p >
< pre > < code class = "language-go" > func handleConn(c net.Conn) {
input := bufio.NewScanner(c)
for input.Scan() {
go echo(c, input.Text(), 1*time.Second)
}
// NOTE: ignoring potential errors from input.Err()
c.Close()
}
< / code > < / pre >
< p > go后跟的函数的参数会在go语句自身执行时被求值；
现在回响是并发并且会按时间来覆盖掉其它响应了：< / p >
< pre > < code > $ go build gopl.io/ch8/reverb2
$ ./reverb2 &
$ ./netcat2
Is there anybody there?
IS THERE ANYBODY THERE?
Yooo-hooo!
Is there anybody there?
YOOO-HOOO!
is there anybody there?
Yooo-hooo!
yooo-hooo!
^D
$ killall reverb2
< / code > < / pre >
< p > 让服务使用并发不只是处理多个客户端的请求， ， ， ， < / p >
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