646c8b39da
This bugfix implements correct way to calculate source sha1 hash, before it will changed, by propagation of unchanged sources. This commit will also include regenerated static files and *.hash files.
192 lines
6.4 KiB
Plaintext
Generated
192 lines
6.4 KiB
Plaintext
Generated
<!DOCTYPE html>
|
|
<html>
|
|
<head>
|
|
<meta charset="utf-8">
|
|
<title>Go by Example: Channel Synchronization</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</a>: Channel Synchronization</h2>
|
|
|
|
<table>
|
|
|
|
<tr>
|
|
<td class="docs">
|
|
<p>We can use channels to synchronize execution
|
|
across goroutines. Here’s an example of using a
|
|
blocking receive to wait for a goroutine to finish.
|
|
When waiting for multiple goroutines to finish,
|
|
you may prefer to use a <a href="waitgroups">WaitGroup</a>.</p>
|
|
|
|
</td>
|
|
<td class="code empty leading">
|
|
|
|
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td class="docs">
|
|
|
|
</td>
|
|
<td class="code leading">
|
|
<a href="http://play.golang.org/p/Nw-1DzIGk5f"><img title="Run code" src="play.png" class="run" /></a><img title="Copy code" src="clipboard.png" class="copy" />
|
|
<div class="highlight"><pre><span class="kn">package</span> <span class="nx">main</span>
|
|
</pre></div>
|
|
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td class="docs">
|
|
|
|
</td>
|
|
<td class="code leading">
|
|
|
|
<div class="highlight"><pre><span class="kn">import</span> <span class="p">(</span>
|
|
<span class="s">"fmt"</span>
|
|
<span class="s">"time"</span>
|
|
<span class="p">)</span>
|
|
</pre></div>
|
|
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td class="docs">
|
|
<p>This is the function we’ll run in a goroutine. The
|
|
<code>done</code> channel will be used to notify another
|
|
goroutine that this function’s work is done.</p>
|
|
|
|
</td>
|
|
<td class="code leading">
|
|
|
|
<div class="highlight"><pre><span class="kd">func</span> <span class="nx">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="nx">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="nx">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="nx">Println</span><span class="p">(</span><span class="s">"done"</span><span class="p">)</span>
|
|
</pre></div>
|
|
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td class="docs">
|
|
<p>Send a value to notify that we’re done.</p>
|
|
|
|
</td>
|
|
<td class="code leading">
|
|
|
|
<div class="highlight"><pre> <span class="nx">done</span> <span class="o"><-</span> <span class="kc">true</span>
|
|
<span class="p">}</span>
|
|
</pre></div>
|
|
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td class="docs">
|
|
|
|
</td>
|
|
<td class="code leading">
|
|
|
|
<div class="highlight"><pre><span class="kd">func</span> <span class="nx">main</span><span class="p">()</span> <span class="p">{</span>
|
|
</pre></div>
|
|
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td class="docs">
|
|
<p>Start a worker goroutine, giving it the channel to
|
|
notify on.</p>
|
|
|
|
</td>
|
|
<td class="code leading">
|
|
|
|
<div class="highlight"><pre> <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="nx">worker</span><span class="p">(</span><span class="nx">done</span><span class="p">)</span>
|
|
</pre></div>
|
|
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td class="docs">
|
|
<p>Block until we receive a notification from the
|
|
worker on the channel.</p>
|
|
|
|
</td>
|
|
<td class="code">
|
|
|
|
<div class="highlight"><pre> <span class="o"><-</span><span class="nx">done</span>
|
|
<span class="p">}</span>
|
|
</pre></div>
|
|
|
|
</td>
|
|
</tr>
|
|
|
|
</table>
|
|
|
|
<table>
|
|
|
|
<tr>
|
|
<td class="docs">
|
|
|
|
</td>
|
|
<td class="code leading">
|
|
|
|
<div class="highlight"><pre><span class="gp">$</span> go run channel-synchronization.go
|
|
<span class="go">working...done </span>
|
|
</pre></div>
|
|
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td class="docs">
|
|
<p>If you removed the <code><- done</code> line from this program, the
|
|
program would exit before the <code>worker</code> even
|
|
started.</p>
|
|
|
|
</td>
|
|
<td class="code empty">
|
|
|
|
|
|
</td>
|
|
</tr>
|
|
|
|
</table>
|
|
|
|
|
|
<p class="next">
|
|
Next example: <a href="channel-directions">Channel Directions</a>.
|
|
</p>
|
|
|
|
<p class="footer">
|
|
by <a href="https://markmcgranaghan.com">Mark McGranaghan</a> | <a href="https://github.com/mmcgrana/gobyexample/blob/master/examples/channel-synchronization">source</a> | <a href="https://github.com/mmcgrana/gobyexample#license">license</a>
|
|
</p>
|
|
</div>
|
|
<script>
|
|
var codeLines = [];
|
|
codeLines.push('');codeLines.push('package main\u000A');codeLines.push('import (\u000A \"fmt\"\u000A \"time\"\u000A)\u000A');codeLines.push('func worker(done chan bool) {\u000A fmt.Print(\"working...\")\u000A time.Sleep(time.Second)\u000A fmt.Println(\"done\")\u000A');codeLines.push(' done \x3C- true\u000A}\u000A');codeLines.push('func main() {\u000A');codeLines.push(' done := make(chan bool, 1)\u000A go worker(done)\u000A');codeLines.push(' \x3C-done\u000A}\u000A');codeLines.push('');codeLines.push('');
|
|
</script>
|
|
<script src="site.js" async></script>
|
|
</body>
|
|
</html>
|