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454 lines
9.7 KiB
HTML
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
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"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
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<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
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<head>
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<title>Go, Networked (January 21, 2010)</title>
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<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
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<meta name="font-size-adjustment" content="-1" />
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<link rel="stylesheet" href="slidy.css"
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type="text/css" media="screen, projection, print" />
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<script src="slidy.js" type="text/javascript">
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</script>
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</head>
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<body>
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<!-- this defines the slide background -->
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<div class="background">
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<div class="header">
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<!-- sized and colored via CSS -->
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</div>
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<div class="footer"></div>
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</div>
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<div class="slide titlepage">
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<div style="height: 135px; width: 480px; overflow: hidden; position: fixed; top: auto; bottom: 10px; left: auto; right: 0; ">
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<img src="../gordon/bumper480x270.png" style="margin: -135px 0 0 0;"/>
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</div>
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<!-- <img src="../google.png" style="position: fixed; top: auto; bottom: 30px; left: 20px; right: auto;"/> -->
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<br/>
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<img src="../go-logo-white.png">
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<br/>
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<br/>
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<h1 style="padding-right: 0pt; margin-right: 0pt; color: #0066cc; font-size: 250%; border-bottom: 0px;">The Go Programming Language</h1>
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<div style="color: #ffcc00;">
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<h2>Russ Cox</h2>
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<!-- <h3><i>rsc@google.com</i></h3> -->
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<br/>
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<h3>CNS Winter Research Review<br/><br/>January 21, 2010</h3>
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<br/>
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<br/>
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<!--
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<h4><i>click to start; then left/right arrow to change slides</i></h4> -->
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</div>
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</div>
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<div class="slide">
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<h1>Go</h1>
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<h2>New</h2>
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<h2>Experimental</h2>
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<h2>Concurrent</h2>
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<h2>Garbage-collected</h2>
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<h2>Systems</h2>
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<h2>Language</h2>
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</div>
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<div class="slide">
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<h1>Hello, world</h1>
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<pre>
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package main
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import "fmt"
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func main() {
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fmt.Printf("Hello, 世界\n")
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}
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</pre>
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</div>
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<div class="slide">
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<h1>History</h1>
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<h2>Design started in late 2007.</h2>
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<h2>Implementation starting to work mid-2008.</h2>
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<h2>Released as an open source project in November 2009.</h2>
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<h2>Work continues.<h2>
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<h2>Robert Griesemer, Ken Thompson, Rob Pike, Ian Lance Taylor, Russ Cox, many others</h2>
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</div>
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<div class="slide">
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<h1>Goals and Motivation</h1>
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<h2>Go fast!</h2>
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<h2>Make programming fun again.</h2>
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<h2>Targeted at systems software, broadly.</h2>
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</div>
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<div class="slide">
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<h1>Why isn't programming fun?</h1>
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<div class="incremental">
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<h2>Compiled, statically-typed languages (C, C++, Java) require too much typing and too much typing:</h2>
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<ul>
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<li>verbose, lots of repetition</li>
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<li>too much focus on type hierarchy</li>
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<li>types get in the way as much as they help</li>
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<li>compiles take far too long</li>
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</ul>
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</div>
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<div class="incremental">
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<h2>Dynamic languages (Python, JavaScript) fix these problems (no more types, no more compiler) but introduce others:</h2>
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<ul>
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<li>errors at run time that should be caught statically</li>
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<li>no compilation means slow code</li>
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</ul>
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</div>
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<h2 class="incremental">Can we combine the best of both?</h2>
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</div>
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<div class="slide">
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<h1>Why a new language?</h1>
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<div class="incremental">
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<h2>No new systems language in 10+ years.</h2>
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<h2>Current languages designed before ...</h2>
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<h3>... rise of large-scale, networked and multicore computing</h3>
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<h3>... rise of Internet-scale distributed development (many libraries)</h3>
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</div>
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</div>
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<div class="slide">
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<h1>Go</h1>
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<h2>Make the language fast.</h2>
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<h2>Make the tools fast.</h2>
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</div>
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<div class="slide">
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<h1>Compilation Demo</h1>
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<h2>Build all standard Go packages: ~120,000 lines of code.</h2>
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</div>
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<div class="slide">
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<h1>Go in one slide</h1>
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<h2 class="incremental">Lightweight syntax.</h2>
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<h2 class="incremental">Static types: enough to compile well, but inferred much of the time.</h2>
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<h2 class="incremental">Methods: on any type, orthogonal to type system.</h2>
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<h2 class="incremental">Abstract types: interface values, relations inferred statically.</h2>
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<h2 class="incremental">Visibility: inferred from case of name.</h2>
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<h2 class="incremental">First-class functions.</h2>
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<h2 class="incremental">Garbage collection.</h2>
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<br/>
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<h2 class="incremental">Lightweight feel of a scripting language but compiled.</h2>
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</div>
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<div class="slide">
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<h1>Go, concurrently</h1>
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<h2>Cheap to create a new flow of control (goroutine):</h2>
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<pre>
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func main() {
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go expensiveComputation(x, y, z)
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anotherExpensiveComputation(a, b, c)
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}
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</pre>
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<h2>Two expensive computations in parallel.</h2>
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</div>
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<div class="slide">
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<h1>Go, concurrently</h1>
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<h2>Cheap to create a new flow of control (goroutine):</h2>
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<pre>
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for {
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rw := l.Accept()
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conn := newConn(rw, handler)
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go conn.serve()
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}
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</pre>
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<h2>Concurrent web server.</h2>
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<h2>Network connections multiplexed onto epoll.</h2>
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<ul>
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<li>many blocked Read calls != many blocked OS threads</li>
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</ul>
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</div>
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<div class="slide">
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<h1>Go, synchronized</h1>
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<h2>Use explicit messages to communicate and synchronize.</h2>
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<pre>
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func computeAndSend(ch chan int, x, y, z int) {
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ch <- expensiveComputation(x, y, z)
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}
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func main() {
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ch := make(chan int)
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go computeAndSend(ch, x, y, z)
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v2 := anotherExpensiveComputation(a, b, c)
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v1 := <-ch
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fmt.Println(v1, v2)
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}
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</pre>
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<h2>Notice communication of result in addition to synchronization.</h2>
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</div>
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<div class="slide">
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<h1>Go, synchronized</h1>
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<h2>RPC client</h2>
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<pre>
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func (client *Client) Call(method string, args, reply interface{}) os.Error {
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// Send RPC message.
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call := client.Go(method, args, reply, nil)
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// Read reply from Done channel.
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<-call.Done
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return call.Error
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}
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</pre>
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</div>
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<div class="slide">
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<h1>Go, synchronized</h1>
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<h2>RPC client demux</h2>
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<pre>
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func (client *Client) input() {
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for {
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resp := client.readResponse()
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client.mutex.Lock()
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c := client.pending[resp.Seq]
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client.pending[resp.Seq] = c, false
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client.mutex.Unlock()
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if resp.Error != "" {
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c.Error = os.ErrorString(resp.error)
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}
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resp.Decode(c.Reply)
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c.Done <- c
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}
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}
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</pre>
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</div>
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<div class="slide">
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<h1>Go, synchronized</h1>
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<h2>RPC client demux</h2>
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<pre>
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func (client *Client) input() {
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for {
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<font style="color: black;">resp := client.readResponse()</font>
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client.mutex.Lock()
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c := client.pending[resp.Seq]
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client.pending[resp.Seq] = c, false
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client.mutex.Unlock()
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if resp.Error != "" {
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c.Error = os.ErrorString(resp.error)
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}
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resp.Decode(c.Reply)
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c.Done <- c
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}
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}
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</pre>
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<h2>Read response from network.</h2
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</div>
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<div class="slide">
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<h1>Go, synchronized</h1>
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<h2>RPC client demux</h2>
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<pre>
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func (client *Client) input() {
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for {
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resp := client.readResponse()
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<font style="color: black;">client.mutex.Lock()
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c := client.pending[resp.Seq]
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client.pending[resp.Seq] = c, false
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client.mutex.Unlock()</font>
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if resp.Error != "" {
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c.Error = os.ErrorString(resp.error)
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}
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resp.Decode(c.Reply)
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c.Done <- c
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}
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}
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</pre>
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<h2>Look up request by sequence number.</h2
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</div>
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<div class="slide">
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<h1>Go, synchronized</h1>
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<h2>RPC client demux</h2>
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<pre>
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func (client *Client) input() {
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for {
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resp := client.readResponse()
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client.mutex.Lock()
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c := client.pending[resp.Seq]
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client.pending[resp.Seq] = c, false
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client.mutex.Unlock()
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<font style="color: black;">if resp.Error != "" {
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c.Error = os.ErrorString(resp.error)
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}
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resp.Decode(c.Reply)</font>
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c.Done <- c
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}
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}
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</pre>
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<h2>Decode response fields from payload.</h2
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</div>
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<div class="slide">
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<h1>Go, synchronized</h1>
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<h2>RPC client demux</h2>
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<pre>
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func (client *Client) input() {
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for {
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resp := client.readResponse()
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client.mutex.Lock()
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c := client.pending[resp.Seq]
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client.pending[resp.Seq] = c, false
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client.mutex.Unlock()
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if resp.Error != "" {
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c.Error = os.ErrorString(resp.error)
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}
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resp.Decode(c.Reply)
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<font style="color: black;">c.Done <- c</font>
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}
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}
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</pre>
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<h2>Tell client that it finished.</h2
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</div>
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<div class="slide">
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<h1>Go, synchronized</h1>
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<h2>RPC client demux</h2>
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<pre>
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func (client *Client) input() {
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for {
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resp := client.readResponse()
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client.mutex.Lock()
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c := client.pending[resp.Seq]
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client.pending[resp.Seq] = c, false
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client.mutex.Unlock()
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if resp.Error != "" {
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c.Error = os.ErrorString(resp.error)
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}
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resp.Decode(c.Reply)
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c.Done <- c
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}
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}
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</pre>
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<h2>Can create multiple Calls with same Done channel
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and distinguish which finished by inspecting value sent on channel.
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</h2>
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</div>
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<div class="slide">
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<h1>Goroutine demo</h1>
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<h2>Chain together 100,000 goroutines connected by 100,001 channels.</h2>
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<h2>Send a value to one end of the chain.</h2>
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<h2>Each passes it along, increments.</h2>
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<h2>Receive value out the other end of the chain.</h2>
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</div>
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<div class="slide">
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<h1>Go Status</h1>
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</div>
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<div class="slide">
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<h1>Go Status</h1>
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<h2>Open source:</h2>
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<ul>
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<li>released on November 10, 2009
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<li>regular releases (~ weekly)
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<li>all development done in public Mercurial repository
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<li>outside contributions welcome
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<li>two independent compiler implementations
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<li>XML, JSON, HTTP, TLS/SSL, native RPC, (network channels,) ...
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</ul>
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</div>
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<div class="slide">
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<h1>Go Status</h1>
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<h2>Open source</h2>
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<h2>Portable:</h2>
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<ul>
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<li>FreeBSD, Linux, OS X (x86, x86-64)
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<li>(in progress) Linux arm, Native Client x86, Windows x86.
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</ul>
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</div>
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<div class="slide">
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<h1>Go Status</h1>
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<h2>Open source</h2>
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<h2>Portable</h2>
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<h2>Still in progress, experimental. Yet to come:</h2>
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<ul>
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<li>production garbage collector
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<li>generics?
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<li>exceptions?
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<li>unions or sum types?
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</ul>
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</div>
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<div class="slide titlepage">
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<h1>Questions?</h1>
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<br><br>
|
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<center>
|
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<img src="../gordon/bumper640x360.png">
|
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</center>
|
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<br><br>
|
|
<div style="color: #ffcc00;">
|
|
<!-- <h3><i>rsc@google.com</i></h3> -->
|
|
</div>
|
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</div>
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</body></html>
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