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channel-synchronization.html
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<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Go by Example 中文版: 通道同步</title>
<link rel=stylesheet href="site.css">
</head>
<script>
onkeydown = (e) => {
if (e.key == "ArrowLeft") {
window.location.href = 'channel-buffering';
}
if (e.key == "ArrowRight") {
window.location.href = 'channel-directions';
}
}
</script>
<body>
<div class="example" id="channel-synchronization">
<h2><a href="./">Go by Example 中文版</a>: 通道同步</h2>
<table>
<tr>
<td class="docs">
<p>我们可以使用通道来同步协程之间的执行状态。
这儿有一个例子，使用阻塞接收的方式，实现了等待另一个协程完成。
如果需要等待多个协程，<a href="waitgroups">WaitGroup</a> 是一个更好的选择。</p>
</td>
<td class="code empty leading">
</td>
</tr>
<tr>
<td class="docs">
</td>
<td class="code leading">
<a href="https://play.studygolang.com/p/LxyiU-YgJlz"><img title="Run code" src="play.png" class="run" /></a><img title="Copy code" src="clipboard.png" class="copy" />
<pre class="chroma"><span class="kn">package</span> <span class="nx">main</span>
</pre>
</td>
</tr>
<tr>
<td class="docs">
</td>
<td class="code leading">
<pre class="chroma"><span class="kn">import</span> <span class="p">(</span>
<span class="s">"fmt"</span>
<span class="s">"time"</span>
<span class="p">)</span>
</pre>
</td>
</tr>
<tr>
<td class="docs">
<p>我们将要在协程中运行这个函数。
<code>done</code> 通道将被用于通知其他协程这个函数已经完成工作。</p>
</td>
<td class="code leading">
<pre class="chroma">
<span class="kd">func</span> <span class="nf">worker</span><span class="p">(</span><span class="nx">done</span> <span class="kd">chan</span> <span class="kt">bool</span><span class="p">)</span> <span class="p">{</span>
<span class="nx">fmt</span><span class="p">.</span><span class="nf">Print</span><span class="p">(</span><span class="s">"working..."</span><span class="p">)</span>
<span class="nx">time</span><span class="p">.</span><span class="nf">Sleep</span><span class="p">(</span><span class="nx">time</span><span class="p">.</span><span class="nx">Second</span><span class="p">)</span>
<span class="nx">fmt</span><span class="p">.</span><span class="nf">Println</span><span class="p">(</span><span class="s">"done"</span><span class="p">)</span>
</pre>
</td>
</tr>
<tr>
<td class="docs">
<p>发送一个值来通知我们已经完工啦。</p>
</td>
<td class="code leading">
<pre class="chroma">
<span class="nx">done</span> <span class="o"><-</span> <span class="kc">true</span>
<span class="p">}</span>
</pre>
</td>
</tr>
<tr>
<td class="docs">
</td>
<td class="code leading">
<pre class="chroma"><span class="kd">func</span> <span class="nf">main</span><span class="p">()</span> <span class="p">{</span>
</pre>
</td>
</tr>
<tr>
<td class="docs">
<p>运行一个 worker 协程，并给予用于通知的通道。</p>
</td>
<td class="code leading">
<pre class="chroma">
<span class="nx">done</span> <span class="o">:=</span> <span class="nb">make</span><span class="p">(</span><span class="kd">chan</span> <span class="kt">bool</span><span class="p">,</span> <span class="mi">1</span><span class="p">)</span>
<span class="k">go</span> <span class="nf">worker</span><span class="p">(</span><span class="nx">done</span><span class="p">)</span>
</pre>
</td>
</tr>
<tr>
<td class="docs">
<p>程序将一直阻塞，直至收到 worker 使用通道发送的通知。</p>
</td>
<td class="code">
<pre class="chroma">
<span class="o"><-</span><span class="nx">done</span>
<span class="p">}</span>
</pre>
</td>
</tr>
</table>
<table>
<tr>
<td class="docs">
</td>
<td class="code leading">
<pre class="chroma"><span class="gp">$</span> go run channel-synchronization.go
<span class="go">working...done</span></pre>
</td>
</tr>
<tr>
<td class="docs">
<p>如果你把 <code><- done</code> 这行代码从程序中移除，
程序甚至可能在 <code>worker</code> 开始运行前就结束了。</p>
</td>
<td class="code empty">
</td>
</tr>
</table>
<p class="next">
下一个例子: <a href="channel-directions.html">通道方向</a>
</p>
<p class="footer">
<a href="https://twitter.com/mmcgrana">@mmcgrana</a> 和<a href="https://eli.thegreenplace.net">Eli Bendersky</a>编写 | <a href="https://github.com/gobyexample-cn">gobyexample-cn</a> 翻译 | <a href="https://github.com/gobyexample-cn/gobyexample/issues">反馈</a> | <a href="https://github.com/gobyexample-cn/gobyexample">源码</a> | <a href="https://github.com/mmcgrana/gobyexample#license">license</a> </p>
</p>
</div>
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