207 lines
6.9 KiB
Plaintext
Generated
207 lines
6.9 KiB
Plaintext
Generated
<!DOCTYPE html>
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<html>
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<meta charset="utf-8">
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<title>Go by Example: Channel Buffering</title>
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<script>
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onkeydown = (e) => {
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window.location.href = 'channels';
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window.location.href = 'channel-synchronization';
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<body>
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<div class="example" id="channel-buffering">
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<h2><a href="./">Go by Example</a>: Channel Buffering</h2>
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<table>
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<tr>
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<td class="docs">
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<p>By default channels are <em>unbuffered</em>, meaning that they
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will only accept sends (<code>chan <-</code>) if there is a
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corresponding receive (<code><- chan</code>) ready to receive the
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sent value. <em>Buffered channels</em> accept a limited
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number of values without a corresponding receiver for
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those values.</p>
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</td>
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<td class="code empty leading">
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</td>
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</tr>
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<tr>
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<td class="docs">
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</td>
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<td class="code leading">
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<a href="https://go.dev/play/p/3BRCdRnRszb"><img title="Run code" src="play.png" class="run" /></a><img title="Copy code" src="clipboard.png" class="copy" />
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<pre class="chroma"><span class="kn">package</span> <span class="nx">main</span>
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</pre>
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</td>
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</tr>
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<tr>
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<td class="docs">
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</td>
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<td class="code leading">
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<pre class="chroma"><span class="kn">import</span> <span class="s">"fmt"</span>
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</pre>
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</td>
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</tr>
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<tr>
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<td class="docs">
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</td>
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<td class="code leading">
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<pre class="chroma"><span class="kd">func</span> <span class="nf">main</span><span class="p">()</span> <span class="p">{</span>
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</pre>
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</td>
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</tr>
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<tr>
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<td class="docs">
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<p>Here we <code>make</code> a channel of strings buffering up to
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2 values.</p>
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</td>
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<td class="code leading">
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<pre class="chroma">
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<span class="nx">messages</span> <span class="o">:=</span> <span class="nb">make</span><span class="p">(</span><span class="kd">chan</span> <span class="kt">string</span><span class="p">,</span> <span class="mi">2</span><span class="p">)</span>
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</pre>
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</td>
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</tr>
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<tr>
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<td class="docs">
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<p>Because this channel is buffered, we can send these
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values into the channel without a corresponding
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concurrent receive.</p>
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</td>
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<td class="code leading">
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<pre class="chroma">
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<span class="nx">messages</span> <span class="o"><-</span> <span class="s">"buffered"</span>
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<span class="nx">messages</span> <span class="o"><-</span> <span class="s">"channel"</span>
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</pre>
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</td>
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</tr>
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<tr>
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<td class="docs">
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<p>Later we can receive these two values as usual.</p>
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</td>
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<td class="code">
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<pre class="chroma">
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<span class="nx">fmt</span><span class="p">.</span><span class="nf">Println</span><span class="p">(</span><span class="o"><-</span><span class="nx">messages</span><span class="p">)</span>
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<span class="nx">fmt</span><span class="p">.</span><span class="nf">Println</span><span class="p">(</span><span class="o"><-</span><span class="nx">messages</span><span class="p">)</span>
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<span class="p">}</span>
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</pre>
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</td>
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</tr>
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</table>
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<table>
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<tr>
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<td class="docs">
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</td>
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<td class="code">
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<pre class="chroma"><span class="gp">$</span> go run channel-buffering.go
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<span class="go">buffered
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</span><span class="go">channel</span></pre>
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</td>
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</tr>
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</table>
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<p class="next">
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Next example: <a href="channel-synchronization">Channel Synchronization</a>.
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</p>
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by <a href="https://markmcgranaghan.com">Mark McGranaghan</a> and <a href="https://eli.thegreenplace.net">Eli Bendersky</a> | <a href="https://github.com/mmcgrana/gobyexample">source</a> | <a href="https://github.com/mmcgrana/gobyexample#license">license</a> | <button id="theme-button">Toggle theme</button>
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</p>
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</div>
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<script>
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var codeLines = [];
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codeLines.push('');codeLines.push('package main\u000A');codeLines.push('import \"fmt\"\u000A');codeLines.push('func main() {\u000A');codeLines.push(' messages :\u003D make(chan string, 2)\u000A');codeLines.push(' messages \u003C- \"buffered\"\u000A messages \u003C- \"channel\"\u000A');codeLines.push(' fmt.Println(\u003C-messages)\u000A fmt.Println(\u003C-messages)\u000A}\u000A');codeLines.push('');
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