From b70c15adaa0983b3d07312f425b8c6d4df71457f Mon Sep 17 00:00:00 2001
From: Eli Bendersky <eliben@gmail.com>
Date: Thu, 5 Sep 2019 13:26:08 -0700
Subject: [PATCH] Clarify reading op non-atomically

---
 examples/atomic-counters/atomic-counters.go   |  6 +++++
 examples/atomic-counters/atomic-counters.hash |  4 ++--
 public/atomic-counters                        | 24 +++++++++++++++----
 3 files changed, 28 insertions(+), 6 deletions(-)

diff --git a/examples/atomic-counters/atomic-counters.go b/examples/atomic-counters/atomic-counters.go
index 2a0901b..046a347 100644
--- a/examples/atomic-counters/atomic-counters.go
+++ b/examples/atomic-counters/atomic-counters.go
@@ -42,5 +42,11 @@ func main() {
 
 	// Wait until all the goroutines are done.
 	wg.Wait()
+
+	// It's safe to access `ops` now because we know
+	// no other goroutine is writing to it. Reading
+	// atomics safely while they are being updated is
+	// also possible, using functions like
+	// `atomic.LoadUint64`.
 	fmt.Println("ops:", ops)
 }
diff --git a/examples/atomic-counters/atomic-counters.hash b/examples/atomic-counters/atomic-counters.hash
index e35f8f2..989ed19 100644
--- a/examples/atomic-counters/atomic-counters.hash
+++ b/examples/atomic-counters/atomic-counters.hash
@@ -1,2 +1,2 @@
-103c9b7d036e3a5c14dc481755b78b10dc9f894e
-GRkVf6J1--B
+8ebec0be3b167021c96b8b497d0e8c0a2ea99385
+F2pJfduyQiA
diff --git a/public/atomic-counters b/public/atomic-counters
index 6c9d94c..9627c97 100644
--- a/public/atomic-counters
+++ b/public/atomic-counters
@@ -46,7 +46,7 @@ counters</em> accessed by multiple goroutines.</p>
             
           </td>
           <td class="code leading">
-            <a href="http://play.golang.org/p/GRkVf6J1--B"><img title="Run code" src="play.png" class="run" /></a><img title="Copy code" src="clipboard.png" class="copy" />
+            <a href="http://play.golang.org/p/F2pJfduyQiA"><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>
 
@@ -162,10 +162,26 @@ address of our <code>ops</code> counter with the
             <p>Wait until all the goroutines are done.</p>
 
           </td>
-          <td class="code">
+          <td class="code leading">
             
           <div class="highlight"><pre>    <span class="nx">wg</span><span class="p">.</span><span class="nx">Wait</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">&quot;ops:&quot;</span><span class="p">,</span> <span class="nx">ops</span><span class="p">)</span>
+</pre></div>
+
+          </td>
+        </tr>
+        
+        <tr>
+          <td class="docs">
+            <p>It&rsquo;s safe to access <code>ops</code> now because we know
+no other goroutine is writing to it. Reading
+atomics safely while they are being updated is
+also possible, using functions like
+<code>atomic.LoadUint64</code>.</p>
+
+          </td>
+          <td class="code">
+            
+          <div class="highlight"><pre>    <span class="nx">fmt</span><span class="p">.</span><span class="nx">Println</span><span class="p">(</span><span class="s">&quot;ops:&quot;</span><span class="p">,</span> <span class="nx">ops</span><span class="p">)</span>
 <span class="p">}</span>
 </pre></div>
 
@@ -220,7 +236,7 @@ state.</p>
     </div>
     <script>
       var codeLines = [];
-      codeLines.push('');codeLines.push('package main\u000A');codeLines.push('import (\u000A    \"fmt\"\u000A    \"sync\"\u000A    \"sync/atomic\"\u000A)\u000A');codeLines.push('func main() {\u000A');codeLines.push('    var ops uint64\u000A');codeLines.push('    var wg sync.WaitGroup\u000A');codeLines.push('    for i := 0; i \x3C 50; i++ {\u000A        wg.Add(1)\u000A');codeLines.push('        go func() {\u000A            for c := 0; c \x3C 1000; c++ {\u000A');codeLines.push('                atomic.AddUint64(&ops, 1)\u000A            }\u000A            wg.Done()\u000A        }()\u000A    }\u000A');codeLines.push('    wg.Wait()\u000A    fmt.Println(\"ops:\", ops)\u000A}\u000A');codeLines.push('');codeLines.push('');
+      codeLines.push('');codeLines.push('package main\u000A');codeLines.push('import (\u000A    \"fmt\"\u000A    \"sync\"\u000A    \"sync/atomic\"\u000A)\u000A');codeLines.push('func main() {\u000A');codeLines.push('    var ops uint64\u000A');codeLines.push('    var wg sync.WaitGroup\u000A');codeLines.push('    for i := 0; i \x3C 50; i++ {\u000A        wg.Add(1)\u000A');codeLines.push('        go func() {\u000A            for c := 0; c \x3C 1000; c++ {\u000A');codeLines.push('                atomic.AddUint64(&ops, 1)\u000A            }\u000A            wg.Done()\u000A        }()\u000A    }\u000A');codeLines.push('    wg.Wait()\u000A');codeLines.push('    fmt.Println(\"ops:\", ops)\u000A}\u000A');codeLines.push('');codeLines.push('');
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