要点:
1 boost提供了如下lock模板类,以mutex类型作为模板参数
- Class template
lock_guard
Class template
unique_lock
Class template
shared_lock
Class template
upgrade_lock
Class template
upgrade_to_unique_lock
Mutex-specific class
scoped_try_lock
2 boost提供了如下mutex类型,分别用于上面的lock模板类的参数
- Class
mutex
Typedef
try_mutex
Class
timed_mutex
Class
recursive_mutex
Typedef
recursive_try_mutex
Class
recursive_timed_mutex
Class
shared_mutex
- Class
condition_variable
Class
condition_variable_any
Typedef
condition
4 仅初始化一次问题
<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">thread</span><span class="special">/</span><span class="identifier">once</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">> </span>
<span class="identifier">boost</span><span class="special">::</span><span class="identifier">once_flag</span> <span class="identifier">f</span><span class="special">=</span><span class="identifier">BOOST_ONCE_INIT</span><span class="special">;</span>
<span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> <span class="identifier">Callable</span><span class="special">></span> <span class="keyword">void</span> <span class="identifier">call_once</span><span class="special">(</span><span class="identifier">once_flag</span><span class="special">&</span> <span class="identifier">flag</span><span class="special">,</span><span class="identifier">Callable</span> <span class="identifier">func</span><span class="special">);</span>
<span class="keyword">void</span> <span class="identifier">call_once</span><span class="special">(</span><span class="keyword">void</span> <span class="special">(*</span><span class="identifier">func</span><span class="special">)(),</span><span class="identifier">once_flag</span><span class="special">&</span> <span class="identifier">flag</span><span class="special">);</span>两个函数,一个flag,用于程序中仅调用一次func
5 Barriers
<span class="keyword">class</span> <span class="identifier">barrier</span> <span class="special">{</span> <span class="keyword">public</span><span class="special">:</span> <span class="identifier">barrier</span><span class="special">(</span><span class="keyword">unsigned</span> <span class="keyword">int</span> <span class="identifier">count</span><span class="special">);</span> <span class="special">~</span><span class="identifier">barrier</span><span class="special">();</span> <span class="keyword">bool</span> <span class="identifier">wait</span><span class="special">();</span> <span class="special">};</span>
障碍是一个同步点,在wait的地方,必须count个线程都执行到该位置,才开始wait后面的内容;
6 futures
应用场合是:一个线程发出命令,另外一个线程执行命令,发出命令线程通过future获得命令的执行结果;详细内容参考分布式网络编程内容《面向模式的软件体系结构卷2》
相关的类有boost::promise
or a boost::packaged_task
;
总结,同步内容很多,详细参考boost文档;该内容很实用;