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<!DOCTYPE html>
<html>
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<title>
  Class: Concurrent::Channel::Buffer::Unbuffered
  
    &mdash; Concurrent Ruby
  
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     &raquo; 
    <span class="title">Unbuffered</span>
  
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      <div id="content"><h1>Class: Concurrent::Channel::Buffer::Unbuffered
  
  
  
</h1>
<div class="box_info">
  
  <dl>
    <dt>Inherits:</dt>
    <dd>
      <span class="inheritName"><span class='object_link'><a href="Base.html" title="Concurrent::Channel::Buffer::Base (class)">Base</a></span></span>
      
        <ul class="fullTree">
          <li>Object</li>
          
            <li class="next"><span class='object_link'>Synchronization::LockableObject</span></li>
          
            <li class="next"><span class='object_link'><a href="Base.html" title="Concurrent::Channel::Buffer::Base (class)">Base</a></span></li>
          
            <li class="next">Concurrent::Channel::Buffer::Unbuffered</li>
          
        </ul>
        <a href="#" class="inheritanceTree">show all</a>
      
    </dd>
  </dl>
  

  
  
  
  
  

  

  
  <dl>
    <dt>Defined in:</dt>
    <dd>lib-edge/concurrent/channel/buffer/unbuffered.rb</dd>
  </dl>
  
</div>

<h2>Overview</h2><div class="docstring">
  <div class="discussion">
    <p>A blocking buffer with a size of zero. An item can only be put onto
the buffer when a thread is waiting to take. Similarly, an item can
only be put onto the buffer when a thread is waiting to put. When
either <span class='object_link'><a href="#put-instance_method" title="Concurrent::Channel::Buffer::Unbuffered#put (method)">#put</a></span> or <span class='object_link'><a href="#take-instance_method" title="Concurrent::Channel::Buffer::Unbuffered#take (method)">#take</a></span> is called and there is no corresponding call
in progress, the call will block indefinitely. Any other calls to the
same method will queue behind the first call and block as well. As
soon as a corresponding put/take call is made an exchange will occur
and the first blocked call will return.</p>


  </div>
</div>
<div class="tags">
  

</div>






  
    <h2>
      Instance Method Summary
      <small><a href="#" class="summary_toggle">collapse</a></small>
    </h2>

    <ul class="summary">
      
        <li class="public ">
  <span class="summary_signature">
    
      <a href="#empty%3F-instance_method" title="#empty? (instance method)">#<strong>empty?</strong>  &#x21d2; Boolean </a>
    

    
  </span>
  
  
  
  
  
  
  

  
    <span class="summary_desc"><div class='inline'><p>Predicate indicating if the buffer is empty.</p>
</div></span>
  
</li>

      
        <li class="public ">
  <span class="summary_signature">
    
      <a href="#full%3F-instance_method" title="#full? (instance method)">#<strong>full?</strong>  &#x21d2; Boolean </a>
    

    
  </span>
  
  
  
  
  
  
  

  
    <span class="summary_desc"><div class='inline'><p>Predicate indicating if the buffer is full.</p>
</div></span>
  
</li>

      
        <li class="public ">
  <span class="summary_signature">
    
      <a href="#next-instance_method" title="#next (instance method)">#<strong>next</strong>  &#x21d2; Object, Boolean </a>
    

    
  </span>
  
  
  
  
  
  
  

  
    <span class="summary_desc"><div class='inline'><p>Take the next &quot;item&quot; from the buffer and also return a boolean indicating if &quot;more&quot; items can be taken.</p>
</div></span>
  
</li>

      
        <li class="public ">
  <span class="summary_signature">
    
      <a href="#offer-instance_method" title="#offer (instance method)">#<strong>offer</strong>(item)  &#x21d2; Boolean </a>
    

    
  </span>
  
  
  
  
  
  
  

  
    <span class="summary_desc"><div class='inline'><p>Put an item onto the buffer if possible.</p>
</div></span>
  
</li>

      
        <li class="public ">
  <span class="summary_signature">
    
      <a href="#poll-instance_method" title="#poll (instance method)">#<strong>poll</strong>  &#x21d2; Object </a>
    

    
  </span>
  
  
  
  
  
  
  

  
    <span class="summary_desc"><div class='inline'><p>Take the next item from the buffer if one is available else return immediately.</p>
</div></span>
  
</li>

      
        <li class="public ">
  <span class="summary_signature">
    
      <a href="#put-instance_method" title="#put (instance method)">#<strong>put</strong>(item)  &#x21d2; Boolean </a>
    

    
  </span>
  
  
  
  
  
  
  

  
    <span class="summary_desc"><div class='inline'><p>Put an item onto the buffer if possible.</p>
</div></span>
  
</li>

      
        <li class="public ">
  <span class="summary_signature">
    
      <a href="#size-instance_method" title="#size (instance method)">#<strong>size</strong>  &#x21d2; undocumented </a>
    

    
  </span>
  
  
  
  
  
  
  

  
    <span class="summary_desc"><div class='inline'><p>The number of items currently in the buffer.</p>
</div></span>
  
</li>

      
        <li class="public ">
  <span class="summary_signature">
    
      <a href="#take-instance_method" title="#take (instance method)">#<strong>take</strong>  &#x21d2; Object </a>
    

    
  </span>
  
  
  
  
  
  
  

  
    <span class="summary_desc"><div class='inline'><p>Take an item from the buffer if one is available.</p>
</div></span>
  
</li>

      
    </ul>
  


  
  
  
  <div id="constructor_details" class="method_details_list">
  <h2>Constructor Details</h2>
  
    <p class="notice">This class inherits a constructor from <span class='object_link'><a href="Base.html#initialize-instance_method" title="Concurrent::Channel::Buffer::Base#initialize (method)">Concurrent::Channel::Buffer::Base</a></span></p>
  
</div>


  <div id="instance_method_details" class="method_details_list">
    <h2>Instance Method Details</h2>

    
      <div class="method_details first">
  <h3 class="signature first" id="empty?-instance_method">
  
    #<strong>empty?</strong>  &#x21d2; <tt>Boolean</tt> 
  

  

  
</h3><div class="docstring">
  <div class="discussion">
    <p>Predicate indicating if the buffer is empty.</p>


  </div>
</div>
<div class="tags">
  
<p class="tag_title">Returns:</p>
<ul class="return">
  
    <li>
      
      
        <span class='type'>(<tt>Boolean</tt>)</span>
      
      
      
        &mdash;
        <div class='inline'><p>true if this buffer is empty else false</p>
</div>
      
    </li>
  
</ul>

</div><table class="source_code">
  <tr>
    <td>
      <pre class="lines">


27
28
29</pre>
    </td>
    <td>
      <pre class="code"><span class="info file"># File 'lib-edge/concurrent/channel/buffer/unbuffered.rb', line 27</span>

<span class='kw'>def</span> <span class='id identifier rubyid_empty?'>empty?</span>
  <span class='id identifier rubyid_size'>size</span> <span class='op'>==</span> <span class='int'>0</span>
<span class='kw'>end</span></pre>
    </td>
  </tr>
</table>
</div>
    
      <div class="method_details ">
  <h3 class="signature " id="full?-instance_method">
  
    #<strong>full?</strong>  &#x21d2; <tt>Boolean</tt> 
  

  

  
</h3><div class="docstring">
  <div class="discussion">
    <p>Predicate indicating if the buffer is full.</p>


  </div>
</div>
<div class="tags">
  
<p class="tag_title">Returns:</p>
<ul class="return">
  
    <li>
      
      
        <span class='type'>(<tt>Boolean</tt>)</span>
      
      
      
        &mdash;
        <div class='inline'><p>true if this buffer is full else false</p>
</div>
      
    </li>
  
</ul>

</div><table class="source_code">
  <tr>
    <td>
      <pre class="lines">


32
33
34</pre>
    </td>
    <td>
      <pre class="code"><span class="info file"># File 'lib-edge/concurrent/channel/buffer/unbuffered.rb', line 32</span>

<span class='kw'>def</span> <span class='id identifier rubyid_full?'>full?</span>
  <span class='op'>!</span><span class='id identifier rubyid_empty?'>empty?</span>
<span class='kw'>end</span></pre>
    </td>
  </tr>
</table>
</div>
    
      <div class="method_details ">
  <h3 class="signature " id="next-instance_method">
  
    #<strong>next</strong>  &#x21d2; <tt>Object</tt>, <tt>Boolean</tt> 
  

  

  
</h3><div class="docstring">
  <div class="discussion">
    <p>Take the next &quot;item&quot; from the buffer and also return a boolean
indicating if &quot;more&quot; items can be taken. Used for iterating
over a buffer until it is closed and empty.</p>

<p>If the buffer is open but no items remain the calling thread will
block until an item is available. The second of the two return
values, &quot;more&quot; (a boolean), will always be <code>true</code> when the buffer is
open. The &quot;more&quot; value will be <code>false</code> when the channel has been
closed and all values have already been received. When &quot;more&quot; is
false the returned item will be <code>Concurrent::NULL</code>.</p>

<p>Note that when multiple threads access the same channel a race
condition can occur when using this method. A call to <code>next</code> from
one thread may return <code>true</code> for the second return value, but
another thread may <code>take</code> the last value before the original
thread makes another call. Code which iterates over a channel
must be programmed to properly handle these race conditions.</p>

<p>Items can only be taken from the buffer when one or more threads are
waiting to <span class='object_link'><a href="#put-instance_method" title="Concurrent::Channel::Buffer::Unbuffered#put (method)">#put</a></span> items onto the buffer. This method exhibits the
same blocking behavior as <span class='object_link'><a href="#take-instance_method" title="Concurrent::Channel::Buffer::Unbuffered#take (method)">#take</a></span>.</p>


  </div>
</div>
<div class="tags">
  
<p class="tag_title">Returns:</p>
<ul class="return">
  
    <li>
      
      
        <span class='type'>(<tt>Object</tt>, <tt>Boolean</tt>)</span>
      
      
      
        &mdash;
        <div class='inline'><p>the first return value will be the item
taken from the buffer and the second return value will be a
boolean indicating whether or not more items remain.</p>
</div>
      
    </li>
  
</ul>

  <p class="tag_title">See Also:</p>
  <ul class="see">
    
      <li><span class='object_link'><a href="#take-instance_method" title="Concurrent::Channel::Buffer::Unbuffered#take (method)">#take</a></span></li>
    
  </ul>

</div><table class="source_code">
  <tr>
    <td>
      <pre class="lines">


135
136
137
138
139</pre>
    </td>
    <td>
      <pre class="code"><span class="info file"># File 'lib-edge/concurrent/channel/buffer/unbuffered.rb', line 135</span>

<span class='kw'>def</span> <span class='kw'>next</span>
  <span class='id identifier rubyid_item'>item</span> <span class='op'>=</span> <span class='id identifier rubyid_take'>take</span>
  <span class='id identifier rubyid_more'>more</span> <span class='op'>=</span> <span class='lparen'>(</span><span class='id identifier rubyid_item'>item</span> <span class='op'>!=</span> <span class='const'><span class='object_link'><a href="../../../Concurrent.html" title="Concurrent (module)">Concurrent</a></span></span><span class='op'>::</span><span class='const'>NULL</span><span class='rparen'>)</span>
  <span class='kw'>return</span> <span class='id identifier rubyid_item'>item</span><span class='comma'>,</span> <span class='id identifier rubyid_more'>more</span>
<span class='kw'>end</span></pre>
    </td>
  </tr>
</table>
</div>
    
      <div class="method_details ">
  <h3 class="signature " id="offer-instance_method">
  
    #<strong>offer</strong>(item)  &#x21d2; <tt>Boolean</tt> 
  

  

  
</h3><div class="docstring">
  <div class="discussion">
    <p>Put an item onto the buffer if possible. If the buffer is open but
unable to add an item, probably due to being full, the method will
return immediately. Similarly, the method will return immediately
when the buffer is closed. A return value of <code>false</code> does not
necessarily indicate that the buffer is closed, just that the item
could not be added.</p>

<p>Items can only be put onto the buffer when one or more threads are
waiting to <span class='object_link'><a href="#take-instance_method" title="Concurrent::Channel::Buffer::Unbuffered#take (method)">#take</a></span> items off the buffer. When there is a thread
waiting to take an item this method will give its item and return
<code>true</code> immediately. When there are no threads waiting to take or the
buffer is closed, this method will return <code>false</code> immediately.</p>


  </div>
</div>
<div class="tags">
  <p class="tag_title">Parameters:</p>
<ul class="param">
  
    <li>
      
        <span class='name'>item</span>
      
      
        <span class='type'>(<tt>Object</tt>)</span>
      
      
      
        &mdash;
        <div class='inline'><p>the item/value to put onto the buffer.</p>
</div>
      
    </li>
  
</ul>

<p class="tag_title">Returns:</p>
<ul class="return">
  
    <li>
      
      
        <span class='type'>(<tt>Boolean</tt>)</span>
      
      
      
        &mdash;
        <div class='inline'><p>true if the item was added to the buffer else
false (always false when closed).</p>
</div>
      
    </li>
  
</ul>

</div><table class="source_code">
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    </td>
    <td>
      <pre class="code"><span class="info file"># File 'lib-edge/concurrent/channel/buffer/unbuffered.rb', line 71</span>

<span class='kw'>def</span> <span class='id identifier rubyid_offer'>offer</span><span class='lparen'>(</span><span class='id identifier rubyid_item'>item</span><span class='rparen'>)</span>
  <span class='id identifier rubyid_synchronize'>synchronize</span> <span class='kw'>do</span>
    <span class='kw'>return</span> <span class='kw'>false</span> <span class='kw'>if</span> <span class='id identifier rubyid_ns_closed?'>ns_closed?</span> <span class='op'>||</span> <span class='id identifier rubyid_taking'>taking</span><span class='period'>.</span><span class='id identifier rubyid_empty?'>empty?</span>

    <span class='id identifier rubyid_taken'>taken</span> <span class='op'>=</span> <span class='id identifier rubyid_taking'>taking</span><span class='period'>.</span><span class='id identifier rubyid_shift'>shift</span>
    <span class='id identifier rubyid_taken'>taken</span><span class='period'>.</span><span class='id identifier rubyid_value'>value</span> <span class='op'>=</span> <span class='id identifier rubyid_item'>item</span>
    <span class='kw'>true</span>
  <span class='kw'>end</span>
<span class='kw'>end</span></pre>
    </td>
  </tr>
</table>
</div>
    
      <div class="method_details ">
  <h3 class="signature " id="poll-instance_method">
  
    #<strong>poll</strong>  &#x21d2; <tt>Object</tt> 
  

  

  
</h3><div class="docstring">
  <div class="discussion">
    <p>Take the next item from the buffer if one is available else return
immediately. Failing to return a value does not necessarily
indicate that the buffer is closed, just that it is empty.</p>

<p>Items can only be taken off the buffer when one or more threads are
waiting to <span class='object_link'><a href="#put-instance_method" title="Concurrent::Channel::Buffer::Unbuffered#put (method)">#put</a></span> items onto the buffer. When there is a thread
waiting to put an item this method will take the item and return
it immediately. When there are no threads waiting to put or the
buffer is closed, this method will return <code>Concurrent::NULL</code> immediately.</p>


  </div>
</div>
<div class="tags">
  
<p class="tag_title">Returns:</p>
<ul class="return">
  
    <li>
      
      
        <span class='type'>(<tt>Object</tt>)</span>
      
      
      
        &mdash;
        <div class='inline'><p>the next item from the buffer or <code>Concurrent::NULL</code> if
the buffer is empty.</p>
</div>
      
    </li>
  
</ul>

</div><table class="source_code">
  <tr>
    <td>
      <pre class="lines">


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    </td>
    <td>
      <pre class="code"><span class="info file"># File 'lib-edge/concurrent/channel/buffer/unbuffered.rb', line 117</span>

<span class='kw'>def</span> <span class='id identifier rubyid_poll'>poll</span>
  <span class='id identifier rubyid_synchronize'>synchronize</span> <span class='kw'>do</span>
    <span class='kw'>return</span> <span class='const'><span class='object_link'><a href="../../../Concurrent.html" title="Concurrent (module)">Concurrent</a></span></span><span class='op'>::</span><span class='const'>NULL</span> <span class='kw'>if</span> <span class='id identifier rubyid_putting'>putting</span><span class='period'>.</span><span class='id identifier rubyid_empty?'>empty?</span>

    <span class='id identifier rubyid_put'>put</span> <span class='op'>=</span> <span class='id identifier rubyid_putting'>putting</span><span class='period'>.</span><span class='id identifier rubyid_shift'>shift</span>
    <span class='id identifier rubyid_value'>value</span> <span class='op'>=</span> <span class='id identifier rubyid_put'>put</span><span class='period'>.</span><span class='id identifier rubyid_value'>value</span>
    <span class='id identifier rubyid_put'>put</span><span class='period'>.</span><span class='id identifier rubyid_value'>value</span> <span class='op'>=</span> <span class='kw'>nil</span>
    <span class='id identifier rubyid_value'>value</span>
  <span class='kw'>end</span>
<span class='kw'>end</span></pre>
    </td>
  </tr>
</table>
</div>
    
      <div class="method_details ">
  <h3 class="signature " id="put-instance_method">
  
    #<strong>put</strong>(item)  &#x21d2; <tt>Boolean</tt> 
  

  

  
</h3><div class="docstring">
  <div class="discussion">
    <p>Put an item onto the buffer if possible. If the buffer is open
but not able to accept the item the calling thread will block
until the item can be put onto the buffer.</p>

<p>Items can only be put onto the buffer when one or more threads are
waiting to <span class='object_link'><a href="#take-instance_method" title="Concurrent::Channel::Buffer::Unbuffered#take (method)">#take</a></span> items off the buffer. When there is a thread
waiting to take an item this method will give its item and return
immediately. When there are no threads waiting to take, this method
will block. As soon as a thread calls <code>take</code> the exchange will
occur and this method will return.</p>


  </div>
</div>
<div class="tags">
  <p class="tag_title">Parameters:</p>
<ul class="param">
  
    <li>
      
        <span class='name'>item</span>
      
      
        <span class='type'>(<tt>Object</tt>)</span>
      
      
      
        &mdash;
        <div class='inline'><p>the item/value to put onto the buffer.</p>
</div>
      
    </li>
  
</ul>

<p class="tag_title">Returns:</p>
<ul class="return">
  
    <li>
      
      
        <span class='type'>(<tt>Boolean</tt>)</span>
      
      
      
        &mdash;
        <div class='inline'><p>true if the item was added to the buffer else
false (always false when closed).</p>
</div>
      
    </li>
  
</ul>

</div><table class="source_code">
  <tr>
    <td>
      <pre class="lines">


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    </td>
    <td>
      <pre class="code"><span class="info file"># File 'lib-edge/concurrent/channel/buffer/unbuffered.rb', line 44</span>

<span class='kw'>def</span> <span class='id identifier rubyid_put'>put</span><span class='lparen'>(</span><span class='id identifier rubyid_item'>item</span><span class='rparen'>)</span>
  <span class='id identifier rubyid_mine'>mine</span> <span class='op'>=</span> <span class='id identifier rubyid_synchronize'>synchronize</span> <span class='kw'>do</span>
    <span class='kw'>return</span> <span class='kw'>false</span> <span class='kw'>if</span> <span class='id identifier rubyid_ns_closed?'>ns_closed?</span>

    <span class='id identifier rubyid_ref'>ref</span> <span class='op'>=</span> <span class='const'><span class='object_link'><a href="../../../Concurrent.html" title="Concurrent (module)">Concurrent</a></span></span><span class='op'>::</span><span class='const'><span class='object_link'><a href="../../AtomicReference.html" title="Concurrent::AtomicReference (class)">AtomicReference</a></span></span><span class='period'>.</span><span class='id identifier rubyid_new'><span class='object_link'><a href="../../AtomicReference.html#initialize-instance_method" title="Concurrent::AtomicReference#initialize (method)">new</a></span></span><span class='lparen'>(</span><span class='id identifier rubyid_item'>item</span><span class='rparen'>)</span>
    <span class='kw'>if</span> <span class='id identifier rubyid_taking'>taking</span><span class='period'>.</span><span class='id identifier rubyid_empty?'>empty?</span>
      <span class='id identifier rubyid_putting'>putting</span><span class='period'>.</span><span class='id identifier rubyid_push'>push</span><span class='lparen'>(</span><span class='id identifier rubyid_ref'>ref</span><span class='rparen'>)</span>
    <span class='kw'>else</span>
      <span class='id identifier rubyid_taken'>taken</span> <span class='op'>=</span> <span class='id identifier rubyid_taking'>taking</span><span class='period'>.</span><span class='id identifier rubyid_shift'>shift</span>
      <span class='id identifier rubyid_taken'>taken</span><span class='period'>.</span><span class='id identifier rubyid_value'>value</span> <span class='op'>=</span> <span class='id identifier rubyid_item'>item</span>
      <span class='id identifier rubyid_ref'>ref</span><span class='period'>.</span><span class='id identifier rubyid_value'>value</span> <span class='op'>=</span> <span class='kw'>nil</span>
    <span class='kw'>end</span>
    <span class='id identifier rubyid_ref'>ref</span>
  <span class='kw'>end</span>
  <span class='id identifier rubyid_loop'>loop</span> <span class='kw'>do</span>
    <span class='kw'>return</span> <span class='kw'>true</span> <span class='kw'>if</span> <span class='id identifier rubyid_mine'>mine</span><span class='period'>.</span><span class='id identifier rubyid_value'>value</span><span class='period'>.</span><span class='id identifier rubyid_nil?'>nil?</span>
    <span class='const'>Thread</span><span class='period'>.</span><span class='id identifier rubyid_pass'>pass</span>
  <span class='kw'>end</span>
<span class='kw'>end</span></pre>
    </td>
  </tr>
</table>
</div>
    
      <div class="method_details ">
  <h3 class="signature " id="size-instance_method">
  
    #<strong>size</strong>  &#x21d2; <tt>undocumented</tt> 
  

  

  
</h3><div class="docstring">
  <div class="discussion">
    <p>The number of items currently in the buffer.</p>


  </div>
</div>
<div class="tags">
  

</div><table class="source_code">
  <tr>
    <td>
      <pre class="lines">


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21
22
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    </td>
    <td>
      <pre class="code"><span class="info file"># File 'lib-edge/concurrent/channel/buffer/unbuffered.rb', line 20</span>

<span class='kw'>def</span> <span class='id identifier rubyid_size'>size</span>
  <span class='id identifier rubyid_synchronize'>synchronize</span> <span class='kw'>do</span>
    <span class='id identifier rubyid_putting'>putting</span><span class='period'>.</span><span class='id identifier rubyid_empty?'>empty?</span> <span class='op'>?</span> <span class='int'>0</span> <span class='op'>:</span> <span class='int'>1</span>
  <span class='kw'>end</span>
<span class='kw'>end</span></pre>
    </td>
  </tr>
</table>
</div>
    
      <div class="method_details ">
  <h3 class="signature " id="take-instance_method">
  
    #<strong>take</strong>  &#x21d2; <tt>Object</tt> 
  

  

  
</h3><div class="docstring">
  <div class="discussion">
    <p>Take an item from the buffer if one is available. If the buffer
is open and no item is available the calling thread will block
until an item is available. If the buffer is closed but items
are available the remaining items can still be taken. Once the
buffer closes, no remaining items can be taken.</p>

<p>Items can only be taken from the buffer when one or more threads are
waiting to <span class='object_link'><a href="#put-instance_method" title="Concurrent::Channel::Buffer::Unbuffered#put (method)">#put</a></span> items onto the buffer. When there is a thread
waiting to put an item this method will take that item and return it
immediately. When there are no threads waiting to put, this method
will block. As soon as a thread calls <code>pur</code> the exchange will occur
and this method will return.</p>


  </div>
</div>
<div class="tags">
  
<p class="tag_title">Returns:</p>
<ul class="return">
  
    <li>
      
      
        <span class='type'>(<tt>Object</tt>)</span>
      
      
      
        &mdash;
        <div class='inline'><p>the item removed from the buffer; <code>Concurrent::NULL</code> once
the buffer has closed.</p>
</div>
      
    </li>
  
</ul>

</div><table class="source_code">
  <tr>
    <td>
      <pre class="lines">


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108</pre>
    </td>
    <td>
      <pre class="code"><span class="info file"># File 'lib-edge/concurrent/channel/buffer/unbuffered.rb', line 89</span>

<span class='kw'>def</span> <span class='id identifier rubyid_take'>take</span>
  <span class='id identifier rubyid_mine'>mine</span> <span class='op'>=</span> <span class='id identifier rubyid_synchronize'>synchronize</span> <span class='kw'>do</span>
    <span class='kw'>return</span> <span class='const'><span class='object_link'><a href="../../../Concurrent.html" title="Concurrent (module)">Concurrent</a></span></span><span class='op'>::</span><span class='const'>NULL</span> <span class='kw'>if</span> <span class='id identifier rubyid_ns_closed?'>ns_closed?</span> <span class='op'>&amp;&amp;</span> <span class='id identifier rubyid_putting'>putting</span><span class='period'>.</span><span class='id identifier rubyid_empty?'>empty?</span>

    <span class='id identifier rubyid_ref'>ref</span> <span class='op'>=</span> <span class='const'><span class='object_link'><a href="../../../Concurrent.html" title="Concurrent (module)">Concurrent</a></span></span><span class='op'>::</span><span class='const'><span class='object_link'><a href="../../AtomicReference.html" title="Concurrent::AtomicReference (class)">AtomicReference</a></span></span><span class='period'>.</span><span class='id identifier rubyid_new'><span class='object_link'><a href="../../AtomicReference.html#initialize-instance_method" title="Concurrent::AtomicReference#initialize (method)">new</a></span></span><span class='lparen'>(</span><span class='kw'>nil</span><span class='rparen'>)</span>
    <span class='kw'>if</span> <span class='id identifier rubyid_putting'>putting</span><span class='period'>.</span><span class='id identifier rubyid_empty?'>empty?</span>
      <span class='id identifier rubyid_taking'>taking</span><span class='period'>.</span><span class='id identifier rubyid_push'>push</span><span class='lparen'>(</span><span class='id identifier rubyid_ref'>ref</span><span class='rparen'>)</span>
    <span class='kw'>else</span>
      <span class='id identifier rubyid_put'>put</span> <span class='op'>=</span> <span class='id identifier rubyid_putting'>putting</span><span class='period'>.</span><span class='id identifier rubyid_shift'>shift</span>
      <span class='id identifier rubyid_ref'>ref</span><span class='period'>.</span><span class='id identifier rubyid_value'>value</span> <span class='op'>=</span> <span class='id identifier rubyid_put'>put</span><span class='period'>.</span><span class='id identifier rubyid_value'>value</span>
      <span class='id identifier rubyid_put'>put</span><span class='period'>.</span><span class='id identifier rubyid_value'>value</span> <span class='op'>=</span> <span class='kw'>nil</span>
    <span class='kw'>end</span>
    <span class='id identifier rubyid_ref'>ref</span>
  <span class='kw'>end</span>
  <span class='id identifier rubyid_loop'>loop</span> <span class='kw'>do</span>
    <span class='id identifier rubyid_item'>item</span> <span class='op'>=</span> <span class='id identifier rubyid_mine'>mine</span><span class='period'>.</span><span class='id identifier rubyid_value'>value</span>
    <span class='kw'>return</span> <span class='id identifier rubyid_item'>item</span> <span class='kw'>if</span> <span class='id identifier rubyid_item'>item</span>
    <span class='const'>Thread</span><span class='period'>.</span><span class='id identifier rubyid_pass'>pass</span>
  <span class='kw'>end</span>
<span class='kw'>end</span></pre>
    </td>
  </tr>
</table>
</div>
    
  </div>

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