atomic, spinlock and mutex性能比较 .

最新推荐文章于 2022-11-05 17:27:34 发布
最新推荐文章于 2022-11-05 17:27:34 发布
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atomic, spinlock and mutex性能比较
转载请说明出处：http://blog.youkuaiyun.com/cywosp/article/details/8987593
我非常好奇于不同同步原理的性能，于是对atomic, spinlock和mutex做了如下实验来比较：
1. 无同步的情况 
<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(0,130,0); PADDING-TOP: 0px" class="hl ppc">#include <future></span>
<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(0,130,0); PADDING-TOP: 0px" class="hl ppc">#include <iostream></span>

<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; FONT-WEIGHT: bold; PADDING-TOP: 0px" class="hl kwc">volatile</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(0,87,174); PADDING-TOP: 0px" class="hl kwb">int</span> value <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">=</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(176,126,0); PADDING-TOP: 0px" class="hl num">0</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">;</span>

<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(0,87,174); PADDING-TOP: 0px" class="hl kwb">int</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(1,1,129); PADDING-TOP: 0px" class="hl kwd">loop </span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">(</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(0,87,174); PADDING-TOP: 0px" class="hl kwb">bool</span> inc<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">,</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(0,87,174); PADDING-TOP: 0px" class="hl kwb">int</span> limit<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">) {</span>
  std<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span>cout <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt"><<</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(191,3,3); PADDING-TOP: 0px" class="hl str">"Started "</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt"><<</span> inc <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt"><<</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(191,3,3); PADDING-TOP: 0px" class="hl str">" "</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt"><<</span> limit <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt"><<</span> std<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span>endl<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">;</span>
  <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; FONT-WEIGHT: bold; PADDING-TOP: 0px" class="hl kwa">for</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">(</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(0,87,174); PADDING-TOP: 0px" class="hl kwb">int</span> i <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">=</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(176,126,0); PADDING-TOP: 0px" class="hl num">0</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">;</span> i <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt"><</span> limit<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">; ++</span>i<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">) {</span>
    <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; FONT-WEIGHT: bold; PADDING-TOP: 0px" class="hl kwa">if</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">(</span>inc<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">) {</span> 
      <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">++</span>value<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">;</span>
    <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">}</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; FONT-WEIGHT: bold; PADDING-TOP: 0px" class="hl kwa">else</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">{</span>
      <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">--</span>value<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">;</span>
    <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">}</span>
  <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">}</span>
  <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; FONT-WEIGHT: bold; PADDING-TOP: 0px" class="hl kwa">return</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(176,126,0); PADDING-TOP: 0px" class="hl num">0</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">;</span>
<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">}</span>

<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(0,87,174); PADDING-TOP: 0px" class="hl kwb">int</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(1,1,129); PADDING-TOP: 0px" class="hl kwd">main </span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">() {</span>
  <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; FONT-WEIGHT: bold; PADDING-TOP: 0px" class="hl kwc">auto</span> f <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">=</span> std<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(1,1,129); PADDING-TOP: 0px" class="hl kwd">async </span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">(</span>std<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span>launch<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span>async<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">,</span> std<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(1,1,129); PADDING-TOP: 0px" class="hl kwd">bind</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">(</span>loop<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">,</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; FONT-WEIGHT: bold; PADDING-TOP: 0px" class="hl kwa">true</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">,</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(176,126,0); PADDING-TOP: 0px" class="hl num">20000000</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">));//开启一个线程来执行loop函数，c++11的高级特性</span>
  <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(1,1,129); PADDING-TOP: 0px" class="hl kwd">loop </span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">(</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; FONT-WEIGHT: bold; PADDING-TOP: 0px" class="hl kwa">false</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">,</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(176,126,0); PADDING-TOP: 0px" class="hl num">10000000</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">);</span>
  f<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">.</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(1,1,129); PADDING-TOP: 0px" class="hl kwd">wait </span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">();</span>
  std<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span>cout <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt"><<</span> value <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt"><<</span> std<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span>endl<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">;</span>
<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">}</span>
通过clang编译器： 
clang++ -std=c++11 -stdlib=libc++ -O3 -o test test.cpp && time ./test
运行 
SSttaarrtteedd  10  2100000000000000

11177087

real    0m0.070s
user    0m0.089s
sys 0m0.002s
从运行结果很显然的我们可以看出增减不是原子性操作的，变量value最后所包含的值是不确定的（垃圾）。

2. 汇编LOCK 
<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(0,130,0); PADDING-TOP: 0px" class="hl ppc">#include <future></span>
<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(0,130,0); PADDING-TOP: 0px" class="hl ppc">#include <iostream></span>

<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; FONT-WEIGHT: bold; PADDING-TOP: 0px" class="hl kwc">volatile</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(0,87,174); PADDING-TOP: 0px" class="hl kwb">int</span> value <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">=</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(176,126,0); PADDING-TOP: 0px" class="hl num">0</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">;</span>

<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(0,87,174); PADDING-TOP: 0px" class="hl kwb">int</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(1,1,129); PADDING-TOP: 0px" class="hl kwd">loop </span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">(</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(0,87,174); PADDING-TOP: 0px" class="hl kwb">bool</span> inc<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">,</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(0,87,174); PADDING-TOP: 0px" class="hl kwb">int</span> limit<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">) {</span>
  std<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span>cout <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt"><<</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(191,3,3); PADDING-TOP: 0px" class="hl str">"Started "</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt"><<</span> inc <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt"><<</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(191,3,3); PADDING-TOP: 0px" class="hl str">" "</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt"><<</span> limit <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt"><<</span> std<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span>endl<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">;</span>
  <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; FONT-WEIGHT: bold; PADDING-TOP: 0px" class="hl kwa">for</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">(</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(0,87,174); PADDING-TOP: 0px" class="hl kwb">int</span> i <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">=</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(176,126,0); PADDING-TOP: 0px" class="hl num">0</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">;</span> i <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt"><</span> limit<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">; ++</span>i<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">) {</span>
    <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; FONT-WEIGHT: bold; PADDING-TOP: 0px" class="hl kwa">if</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">(</span>inc<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">) {</span> 
      <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; FONT-WEIGHT: bold; PADDING-TOP: 0px" class="hl kwa">asm</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">(</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(191,3,3); PADDING-TOP: 0px" class="hl str">"LOCK"</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">);</span>
      <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">++</span>value<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">;</span>
    <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">}</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; FONT-WEIGHT: bold; PADDING-TOP: 0px" class="hl kwa">else</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">{</span>
      <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; FONT-WEIGHT: bold; PADDING-TOP: 0px" class="hl kwa">asm</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">(</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(191,3,3); PADDING-TOP: 0px" class="hl str">"LOCK"</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">);</span>
      <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">--</span>value<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">;</span>
    <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">}</span>
  <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">}</span>
  <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; FONT-WEIGHT: bold; PADDING-TOP: 0px" class="hl kwa">return</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(176,126,0); PADDING-TOP: 0px" class="hl num">0</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">;</span>
<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">}</span>

<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(0,87,174); PADDING-TOP: 0px" class="hl kwb">int</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(1,1,129); PADDING-TOP: 0px" class="hl kwd">main </span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">() {</span>
  <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; FONT-WEIGHT: bold; PADDING-TOP: 0px" class="hl kwc">auto</span> f <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">=</span> std<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(1,1,129); PADDING-TOP: 0px" class="hl kwd">async </span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">(</span>std<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span>launch<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span>async<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">,</span> std<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(1,1,129); PADDING-TOP: 0px" class="hl kwd">bind</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">(</span>loop<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">,</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; FONT-WEIGHT: bold; PADDING-TOP: 0px" class="hl kwa">true</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">,</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(176,126,0); PADDING-TOP: 0px" class="hl num">20000000</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">)); <span style="LINE-HEIGHT: 1.4em; FONT-SIZE: 0.8em">//开启一个线程来执行loop函数，c++11的高级特性</span>
</span>  <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(1,1,129); PADDING-TOP: 0px" class="hl kwd">loop </span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">(</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; FONT-WEIGHT: bold; PADDING-TOP: 0px" class="hl kwa">false</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">,</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(176,126,0); PADDING-TOP: 0px" class="hl num">10000000</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">);</span>
  f<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">.</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(1,1,129); PADDING-TOP: 0px" class="hl kwd">wait </span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">();</span>
  std<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span>cout <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt"><<</span> value <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt"><<</span> std<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span>endl<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">;</span>
<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">}</span>
运行： 
SSttaarrtteedd  10  2000000100000000

10000000

real    0m0.481s
user    0m0.779s
sys 0m0.005s
在最后变量value得到了正确的值，但是这些代码是不可移植的（平台不兼容的），只能在X86体系结构的硬件上运行，而且要想程序能正确运行编译的时候必须使用-O3编译选项。另外，由于编译器会在LOCK指令和增加或者减少指令之间注入其他指令，因此程序很容易出现“illegal instruction”异常从而导致程序被崩溃。

3. 原子操作atomic 
<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(0,130,0); PADDING-TOP: 0px" class="hl ppc">#include <future></span>
<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(0,130,0); PADDING-TOP: 0px" class="hl ppc">#include <iostream></span>
<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(0,130,0); PADDING-TOP: 0px" class="hl ppc">#include</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(129,129,0); PADDING-TOP: 0px" class="hl pps">"boost/interprocess/detail/atomic.hpp"</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(0,130,0); PADDING-TOP: 0px" class="hl ppc"></span>

<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; FONT-WEIGHT: bold; PADDING-TOP: 0px" class="hl kwa">using namespace</span> boost<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span>interprocess<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span>ipcdetail<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">;</span>

<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; FONT-WEIGHT: bold; PADDING-TOP: 0px" class="hl kwc">volatile</span> boost<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(0,87,174); PADDING-TOP: 0px" class="hl kwb">uint32_t</span> value <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">=</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(176,126,0); PADDING-TOP: 0px" class="hl num">0</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">;</span>

<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(0,87,174); PADDING-TOP: 0px" class="hl kwb">int</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(1,1,129); PADDING-TOP: 0px" class="hl kwd">loop </span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">(</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(0,87,174); PADDING-TOP: 0px" class="hl kwb">bool</span> inc<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">,</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(0,87,174); PADDING-TOP: 0px" class="hl kwb">int</span> limit<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">) {</span>
  std<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span>cout <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt"><<</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(191,3,3); PADDING-TOP: 0px" class="hl str">"Started "</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt"><<</span> inc <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt"><<</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(191,3,3); PADDING-TOP: 0px" class="hl str">" "</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt"><<</span> limit <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt"><<</span> std<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span>endl<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">;</span>
  <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; FONT-WEIGHT: bold; PADDING-TOP: 0px" class="hl kwa">for</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">(</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(0,87,174); PADDING-TOP: 0px" class="hl kwb">int</span> i <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">=</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(176,126,0); PADDING-TOP: 0px" class="hl num">0</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">;</span> i <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt"><</span> limit<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">; ++</span>i<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">) {</span>
    <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; FONT-WEIGHT: bold; PADDING-TOP: 0px" class="hl kwa">if</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">(</span>inc<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">) {</span> 
      <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(1,1,129); PADDING-TOP: 0px" class="hl kwd">atomic_inc32 </span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">(&</span>value<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">);</span>
    <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">}</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; FONT-WEIGHT: bold; PADDING-TOP: 0px" class="hl kwa">else</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">{</span>
      <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(1,1,129); PADDING-TOP: 0px" class="hl kwd">atomic_dec32 </span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">(&</span>value<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">);</span>
    <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">}</span>
  <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">}</span>
  <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; FONT-WEIGHT: bold; PADDING-TOP: 0px" class="hl kwa">return</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(176,126,0); PADDING-TOP: 0px" class="hl num">0</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">;</span>
<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">}</span>

<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(0,87,174); PADDING-TOP: 0px" class="hl kwb">int</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(1,1,129); PADDING-TOP: 0px" class="hl kwd">main </span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">() {</span>
  <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; FONT-WEIGHT: bold; PADDING-TOP: 0px" class="hl kwc">auto</span> f <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">=</span> std<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(1,1,129); PADDING-TOP: 0px" class="hl kwd">async </span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">(</span>std<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span>launch<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span>async<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">,</span> std<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(1,1,129); PADDING-TOP: 0px" class="hl kwd">bind </span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">(</span>loop<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">,</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; FONT-WEIGHT: bold; PADDING-TOP: 0px" class="hl kwa">true</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">,</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(176,126,0); PADDING-TOP: 0px" class="hl num">20000000</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">));</span>
  <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(1,1,129); PADDING-TOP: 0px" class="hl kwd">loop </span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">(</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; FONT-WEIGHT: bold; PADDING-TOP: 0px" class="hl kwa">false</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">,</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(176,126,0); PADDING-TOP: 0px" class="hl num">10000000</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">);</span>
  f<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">.</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(1,1,129); PADDING-TOP: 0px" class="hl kwd">wait </span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">();</span>
  std<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span>cout <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt"><<</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(1,1,129); PADDING-TOP: 0px" class="hl kwd">atomic_read32 </span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">(&</span>value<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">) <<</span> std<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span>endl<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">;</span>
<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">}</span>
运行： 
SSttaarrtteedd  10  2100000000000000

10000000

real    0m0.457s
user    0m0.734s
sys 0m0.004s
最后结果是正确的，从所用时间来看跟汇编LOCK的差不多。当然原子操作的底层也是使用了LOCK汇编来实现的，只不过是使用了可移植的方法而已。

4. 自旋锁spinlock 
<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(0,130,0); PADDING-TOP: 0px" class="hl ppc">#include <future></span>
<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(0,130,0); PADDING-TOP: 0px" class="hl ppc">#include <iostream></span>
<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(0,130,0); PADDING-TOP: 0px" class="hl ppc">#include</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(129,129,0); PADDING-TOP: 0px" class="hl pps">"boost/smart_ptr/detail/spinlock.hpp"</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(0,130,0); PADDING-TOP: 0px" class="hl ppc"></span>

boost<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span>detail<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span>spinlock lock<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">;</span>
<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; FONT-WEIGHT: bold; PADDING-TOP: 0px" class="hl kwc">volatile</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(0,87,174); PADDING-TOP: 0px" class="hl kwb">int</span> value <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">=</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(176,126,0); PADDING-TOP: 0px" class="hl num">0</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">;</span>

<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(0,87,174); PADDING-TOP: 0px" class="hl kwb">int</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(1,1,129); PADDING-TOP: 0px" class="hl kwd">loop </span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">(</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(0,87,174); PADDING-TOP: 0px" class="hl kwb">bool</span> inc<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">,</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(0,87,174); PADDING-TOP: 0px" class="hl kwb">int</span> limit<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">) {</span>
  std<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span>cout <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt"><<</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(191,3,3); PADDING-TOP: 0px" class="hl str">"Started "</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt"><<</span> inc <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt"><<</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(191,3,3); PADDING-TOP: 0px" class="hl str">" "</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt"><<</span> limit <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt"><<</span> std<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span>endl<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">;</span>
  <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; FONT-WEIGHT: bold; PADDING-TOP: 0px" class="hl kwa">for</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">(</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(0,87,174); PADDING-TOP: 0px" class="hl kwb">int</span> i <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">=</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(176,126,0); PADDING-TOP: 0px" class="hl num">0</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">;</span> i <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt"><</span> limit<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">; ++</span>i<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">) {</span>
    std<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span>lock_guard<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt"><</span>boost<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span>detail<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span>spinlock<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">></span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(1,1,129); PADDING-TOP: 0px" class="hl kwd">guard</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">(</span>lock<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">);</span>
    <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; FONT-WEIGHT: bold; PADDING-TOP: 0px" class="hl kwa">if</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">(</span>inc<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">) {</span> 
      <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">++</span>value<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">;</span>
    <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">}</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; FONT-WEIGHT: bold; PADDING-TOP: 0px" class="hl kwa">else</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">{</span>
      <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">--</span>value<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">;</span>
    <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">}</span>
  <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">}</span>
  <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; FONT-WEIGHT: bold; PADDING-TOP: 0px" class="hl kwa">return</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(176,126,0); PADDING-TOP: 0px" class="hl num">0</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">;</span>
<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">}</span>

<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(0,87,174); PADDING-TOP: 0px" class="hl kwb">int</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(1,1,129); PADDING-TOP: 0px" class="hl kwd">main </span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">() {</span>
  <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; FONT-WEIGHT: bold; PADDING-TOP: 0px" class="hl kwc">auto</span> f <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">=</span> std<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(1,1,129); PADDING-TOP: 0px" class="hl kwd">async </span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">(</span>std<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span>launch<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span>async<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">,</span> std<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(1,1,129); PADDING-TOP: 0px" class="hl kwd">bind </span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">(</span>loop<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">,</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; FONT-WEIGHT: bold; PADDING-TOP: 0px" class="hl kwa">true</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">,</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(176,126,0); PADDING-TOP: 0px" class="hl num">20000000</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">));</span>
  <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(1,1,129); PADDING-TOP: 0px" class="hl kwd">loop </span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">(</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; FONT-WEIGHT: bold; PADDING-TOP: 0px" class="hl kwa">false</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">,</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(176,126,0); PADDING-TOP: 0px" class="hl num">10000000</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">);</span>
  f<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">.</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(1,1,129); PADDING-TOP: 0px" class="hl kwd">wait </span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">();</span>
  std<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span>cout <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt"><<</span> value <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt"><<</span> std<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span>endl<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">;</span>
<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">}</span>
运行： 
SSttaarrtteedd  10  2100000000000000

10000000

real    0m0.541s
user    0m0.675s
sys 0m0.089s
最后结果是正确的，从用时来看比上述的慢点，但是并没有慢太多

5. 互斥锁mutex 
<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(0,130,0); PADDING-TOP: 0px" class="hl ppc">#include <future></span>
<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(0,130,0); PADDING-TOP: 0px" class="hl ppc">#include <iostream></span>

std<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span>mutex mutex<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">;</span>
<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; FONT-WEIGHT: bold; PADDING-TOP: 0px" class="hl kwc">volatile</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(0,87,174); PADDING-TOP: 0px" class="hl kwb">int</span> value <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">=</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(176,126,0); PADDING-TOP: 0px" class="hl num">0</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">;</span>

<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(0,87,174); PADDING-TOP: 0px" class="hl kwb">int</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(1,1,129); PADDING-TOP: 0px" class="hl kwd">loop </span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">(</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(0,87,174); PADDING-TOP: 0px" class="hl kwb">bool</span> inc<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">,</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(0,87,174); PADDING-TOP: 0px" class="hl kwb">int</span> limit<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">) {</span>
  std<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span>cout <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt"><<</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(191,3,3); PADDING-TOP: 0px" class="hl str">"Started "</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt"><<</span> inc <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt"><<</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(191,3,3); PADDING-TOP: 0px" class="hl str">" "</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt"><<</span> limit <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt"><<</span> std<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span>endl<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">;</span>
  <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; FONT-WEIGHT: bold; PADDING-TOP: 0px" class="hl kwa">for</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">(</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(0,87,174); PADDING-TOP: 0px" class="hl kwb">int</span> i <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">=</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(176,126,0); PADDING-TOP: 0px" class="hl num">0</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">;</span> i <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt"><</span> limit<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">; ++</span>i<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">) {</span>
    std<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span>lock_guard<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt"><</span>std<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span>mutex<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">></span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(1,1,129); PADDING-TOP: 0px" class="hl kwd">guard </span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">(</span>mutex<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">);</span>
    <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; FONT-WEIGHT: bold; PADDING-TOP: 0px" class="hl kwa">if</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">(</span>inc<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">) {</span> 
      <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">++</span>value<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">;</span>
    <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">}</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; FONT-WEIGHT: bold; PADDING-TOP: 0px" class="hl kwa">else</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">{</span>
      <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">--</span>value<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">;</span>
    <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">}</span>
  <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">}</span>
  <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; FONT-WEIGHT: bold; PADDING-TOP: 0px" class="hl kwa">return</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(176,126,0); PADDING-TOP: 0px" class="hl num">0</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">;</span>
<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">}</span>

<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(0,87,174); PADDING-TOP: 0px" class="hl kwb">int</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(1,1,129); PADDING-TOP: 0px" class="hl kwd">main </span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">() {</span>
  <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; FONT-WEIGHT: bold; PADDING-TOP: 0px" class="hl kwc">auto</span> f <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">=</span> std<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(1,1,129); PADDING-TOP: 0px" class="hl kwd">async </span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">(</span>std<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span>launch<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span>async<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">,</span> std<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(1,1,129); PADDING-TOP: 0px" class="hl kwd">bind</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">(</span>loop<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">,</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; FONT-WEIGHT: bold; PADDING-TOP: 0px" class="hl kwa">true</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">,</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(176,126,0); PADDING-TOP: 0px" class="hl num">20000000</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">));</span>
  <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(1,1,129); PADDING-TOP: 0px" class="hl kwd">loop </span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">(</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; FONT-WEIGHT: bold; PADDING-TOP: 0px" class="hl kwa">false</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">,</span> <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(176,126,0); PADDING-TOP: 0px" class="hl num">10000000</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">);</span>
  f<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">.</span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; COLOR: rgb(1,1,129); PADDING-TOP: 0px" class="hl kwd">wait </span><span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">();</span>
  std<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span>cout <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt"><<</span> value <span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt"><<</span> std<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">::</span>endl<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">;</span>
<span style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" class="hl opt">}</span>
运行： 
SSttaarrtteedd  10  2010000000000000

10000000

real    0m25.229s
user    0m7.011s
sys 0m22.667s
互斥锁要比前面几种的慢很多

Benchmark

Method Time (sec.)
No synchronization 0.070
LOCK 0.481
Atomic 0.457
Spinlock 0.541
Mutex 22.667

当然，测试结果会依赖于不同的平台和编译器（我是在Mac Air和clang上做的测试）。 But for me it was quite interesting to see that spinlock, in spite of its more sophisticated implementation comparing to atomics, works not much slower.
Sadly, my clang 3.1 still doesn’t support atomic, and I had to use boost.
haoopp
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相比于 Go 语言宣扬的“用通讯的方式共享数据”，通过共享数据的方式来传递信息和协调线程运行的做法其实更加主流，毕竟大多数的现代编程语言，都是用后一种方式作为并发编程的解决方案的（这种方案的历史非常悠久，恐怕可以追溯到上个世纪多进程编程时代伊始了）。比如，在解锁未锁定的写锁或读锁时的表现，又比如，对写操作之间互斥的实现方式。这其中还包括了我的一些理解。因为在一个 goroutine 执行的流程中，可能会出现诸如“锁定、解锁、再锁定、再解锁”的操作，所以如果我们忘记了中间的解锁操作，那就一定会造成重复锁定。
多线程性能测试：ConcurrentQueue（无锁队列）、std::atomic_flag 和 std::mutex
Where there is life, there is hope.
07-01 1820
本测试比较了无锁队列和std::mutex在多线程环境下的表现。结论对于使用 std::mutex 的 std::list 或 std::deque，如果 Item 结构体较小，推荐使用 std::atomic_flag 代替 std::mutex。如果 Item 结构体较大，继续使用 std::mutex。新的业务代码可以酌情使用无锁队列 ConcurrentQueue。
Linux并发与同步（一）原子操作/spinlock/mutex
小二的博客
09-23 1224
背景在linux内核和驱动代码中，需要对共享数据进行保护，防止共度资源被并发访问而发生数据覆盖，被访问数据不一致的情况．这些情况可能会造成系统不稳定，且很难跟踪调试． 临界区：　访问和操作共享数据的代码段． 临界资源：　共享的数据(静态局部变量，全局变量，buffer,　链表等)． 并发源：访问临界区的线程或执行路径． 内核４种并发源： 中断和异常　 软中断和taskelt 内核抢占 多处理器并发执
atomic_ops.pdf
07-10
在本文档中，我们将深入探讨Linux系统中实现原子操作（atomic operations）的原理以及在使用原子操作时应该注意的问题。原子操作是一类特殊的操作，它保证了即使在多线程环境下，也能够被当作一个不可分割的整体来...
环境流体力学：河流流动模拟.zip
04-10
光电材料仿真，电子仿真等；从入门到精通教程；含代码案例解析。
C#实现Stewart六自由度平台反解算法及其应用
04-10
内容概要：本文详细介绍了如何使用C#实现Stewart六自由度平台的逆解算法。首先定义了平台的基本结构，包括上下平台的半径、安装角度以及舵机零位偏移等参数。接着，通过欧拉角转换为旋转矩阵的方式实现了姿态转换，并在此基础上计算各个支腿的长度。文中还特别强调了一些常见的陷阱，如角度单位一致性、安装方向匹配、零位校准和数值稳定性等问题。此外，提供了具体的测试用例用于验证算法的正确性和性能。 适合人群：具有一定C#编程基础并对机械臂控制、飞行模拟器或手术机器人等领域感兴趣的开发者和技术人员。 使用场景及目标：适用于需要精确控制六自由度平台的应用场合，如飞行模拟器、手术机器人等。主要目的是通过数学模型将平台的姿态转换为具体的操作指令，从而实现精准定位与操控。 其他说明：文中不仅给出了完整的代码实现，还分享了许多实践经验，帮助读者更好地理解和应用该算法。同时提醒开发者在实际项目中需要注意的一些关键点，如行程限制检查、运动学奇异性检测等。
夸克网盘批量处理助手，同步更新保存分享链接文件，增量更新文件，批量重命名文件夹，文件名称关键词替换
最新发布
04-10
夸克网盘批量处理助手，同步更新保存分享链接文件，增量更新文件，批量重命名文件夹，文件名称关键词替换
XML.md
04-10
XML.md
MATLAB实现光纤光栅均匀与非均匀应变仿真及其在光学传感的应用
04-10
内容概要：本文详细介绍了利用MATLAB进行光纤光栅的均匀应变和非均匀应变仿真的方法。文中提供了具体的代码实例，解释了如何通过调整光栅的基本参数如中心波长、光栅长度、有效折射率等，以及引入应变系数和应变分布函数，分别计算均匀应变和非均匀应变下光纤光栅的反射率，并展示了相应的反射率曲线图。此外，还讨论了这两种应变模式对光栅反射谱的不同影响，强调了非均匀应变可能导致的光谱畸变现象。 适用人群：对光纤光栅仿真感兴趣的研究人员和技术爱好者，尤其是那些希望通过MATLAB进行光器件设计和测试的人群。 使用场景及目标：①用于科研项目中光纤光栅特性的研究；②辅助工程师在实际工程项目中评估光纤光栅传感器的表现；③帮助学生理解光纤光栅的工作机制和应变对其性能的影响。 其他说明：文章不仅提供了详细的代码实现步骤，还分享了一些调试技巧和注意事项，有助于读者更好地理解和应用所介绍的技术。
计算机网络基于b站的学习笔记
04-10
计算机网络概念，计算机网络，互联网，互连网的区别；计算机网络的组成、功能；三种交换技术；计算机网络的性能指标；以及计算机网络的分类
C++11实现无锁多线程队列：queue_atomic详解
综上所述，"queue_atomic"代表了一个具体而深入的C++ 11多线程编程实践案例，它通过运用原子操作和特定算法来确保队列操作的线程安全和高效性，尤其在处理多生产者和多消费者场景时的性能问题。
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