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<center><h1>Module <a href="type_Condition.html">Condition</a></h1></center>
<br>
<pre><span class="keyword">module</span> Condition: <code class="code"><span class="keyword">sig</span></code> <a href="Condition.html">..</a> <code class="code"><span class="keyword">end</span></code></pre>Condition variables to synchronize between threads.
<p>
Condition variables are used when one thread wants to wait until another
thread has finished doing something: the former thread ``waits'' on the
condition variable, the latter thread ``signals'' the condition when it
is done. Condition variables should always be protected by a mutex.
The typical use is (if <code class="code"><span class="constructor">D</span></code> is a shared data structure, <code class="code">m</code> its mutex,
and <code class="code">c</code> is a condition variable):
<pre></pre><code class="code"> <span class="constructor">Mutex</span>.lock m;<br>
<span class="keyword">while</span> <span class="comment">(* some predicate P over D is not satisfied *)</span> <span class="keyword">do</span><br>
<span class="constructor">Condition</span>.wait c m<br>
<span class="keyword">done</span>;<br>
<span class="comment">(* Modify D *)</span><br>
<span class="keyword">if</span> <span class="comment">(* the predicate P over D is now satified *)</span> <span class="keyword">then</span> <span class="constructor">Condition</span>.signal c;<br>
<span class="constructor">Mutex</span>.unlock m<br>
</code><pre></pre><br>
<hr width="100%">
<pre><span class="keyword">type</span> <a name="TYPEt"></a><code class="type"></code>t </pre>
<div class="info">
The type of condition variables.<br>
</div>
<pre><span class="keyword">val</span> <a name="VALcreate"></a>create : <code class="type">unit -> <a href="Condition.html#TYPEt">t</a></code></pre><div class="info">
Return a new condition variable.<br>
</div>
<pre><span class="keyword">val</span> <a name="VALwait"></a>wait : <code class="type"><a href="Condition.html#TYPEt">t</a> -> <a href="Mutex.html#TYPEt">Mutex.t</a> -> unit</code></pre><div class="info">
<code class="code">wait c m</code> atomically unlocks the mutex <code class="code">m</code> and suspends the
calling process on the condition variable <code class="code">c</code>. The process will
restart after the condition variable <code class="code">c</code> has been signalled.
The mutex <code class="code">m</code> is locked again before <code class="code">wait</code> returns.<br>
</div>
<pre><span class="keyword">val</span> <a name="VALsignal"></a>signal : <code class="type"><a href="Condition.html#TYPEt">t</a> -> unit</code></pre><div class="info">
<code class="code">signal c</code> restarts one of the processes waiting on the
condition variable <code class="code">c</code>.<br>
</div>
<pre><span class="keyword">val</span> <a name="VALbroadcast"></a>broadcast : <code class="type"><a href="Condition.html#TYPEt">t</a> -> unit</code></pre><div class="info">
<code class="code">broadcast c</code> restarts all processes waiting on the
condition variable <code class="code">c</code>.<br>
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