mingw/html/lib/Thread/Queue.html

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  13 <big><strong><span class="block">&nbsp;Thread::Queue - thread-safe queues</span></strong></big>
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  20 <ul>
  21
  22         <li><a href="#name">NAME</a></li>
  23         <li><a href="#synopsis">SYNOPSIS</a></li>
  24         <li><a href="#description">DESCRIPTION</a></li>
  25         <li><a href="#functions_and_methods">FUNCTIONS AND METHODS</a></li>
  26         <li><a href="#see_also">SEE ALSO</a></li>
  27 </ul>
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  29
  30 <hr />
  31 <p>
  32 </p>
  33 <h1><a name="name">NAME</a></h1>
  34 <p>Thread::Queue - thread-safe queues</p>
  35 <p>
  36 </p>
  37 <hr />
  38 <h1><a name="synopsis">SYNOPSIS</a></h1>
  39 <pre>
  40     use Thread::Queue;
  41     my $q = new Thread::Queue;
  42     $q-&gt;enqueue(&quot;foo&quot;, &quot;bar&quot;);
  43     my $foo = $q-&gt;dequeue;    # The &quot;bar&quot; is still in the queue.
  44     my $foo = $q-&gt;dequeue_nb; # returns &quot;bar&quot;, or undef if the queue was empty
  45     my $left = $q-&gt;pending;   # returns the number of items still in the queue</pre>
  46 <p>
  47 </p>
  48 <hr />
  49 <h1><a name="description">DESCRIPTION</a></h1>
  50 <p>A queue, as implemented by <code>Thread::Queue</code> is a thread-safe
  51 data structure much like a list.  Any number of threads can safely
  52 add elements to the end of the list, or remove elements from the head
  53 of the list. (Queues don't permit adding or removing elements from
  54 the middle of the list).</p>
  55 <p>
  56 </p>
  57 <hr />
  58 <h1><a name="functions_and_methods">FUNCTIONS AND METHODS</a></h1>
  59 <dl>
  60 <dt><strong><a name="item_new">new</a></strong>
  61
  62 <dd>
  63 <p>The <a href="#item_new"><code>new</code></a> function creates a new empty queue.</p>
  64 </dd>
  65 </li>
  66 <dt><strong><a name="item_enqueue">enqueue LIST</a></strong>
  67
  68 <dd>
  69 <p>The <a href="#item_enqueue"><code>enqueue</code></a> method adds a list of scalars on to the end of the queue.
  70 The queue will grow as needed to accommodate the list.</p>
  71 </dd>
  72 </li>
  73 <dt><strong><a name="item_dequeue">dequeue</a></strong>
  74
  75 <dd>
  76 <p>The <a href="#item_dequeue"><code>dequeue</code></a> method removes a scalar from the head of the queue and
  77 returns it. If the queue is currently empty, <a href="#item_dequeue"><code>dequeue</code></a> will block the
  78 thread until another thread <a href="#item_enqueue"><code>enqueue</code></a>s a scalar.</p>
  79 </dd>
  80 </li>
  81 <dt><strong><a name="item_dequeue_nb">dequeue_nb</a></strong>
  82
  83 <dd>
  84 <p>The <a href="#item_dequeue_nb"><code>dequeue_nb</code></a> method, like the <a href="#item_dequeue"><code>dequeue</code></a> method, removes a scalar from
  85 the head of the queue and returns it. Unlike <a href="#item_dequeue"><code>dequeue</code></a>, though,
  86 <a href="#item_dequeue_nb"><code>dequeue_nb</code></a> won't block if the queue is empty, instead returning
  87 <a href="file://C|\msysgit\mingw\html/pod/perlfunc.html#item_undef"><code>undef</code></a>.</p>
  88 </dd>
  89 </li>
  90 <dt><strong><a name="item_pending">pending</a></strong>
  91
  92 <dd>
  93 <p>The <a href="#item_pending"><code>pending</code></a> method returns the number of items still in the queue.</p>
  94 </dd>
  95 </li>
  96 </dl>
  97 <p>
  98 </p>
  99 <hr />
 100 <h1><a name="see_also">SEE ALSO</a></h1>
 101 <p><a href="file://C|\msysgit\mingw\html/lib/threads.html">the threads manpage</a>, <a href="file://C|\msysgit\mingw\html/lib/threads/shared.html">the threads::shared manpage</a></p>
 102 <table border="0" width="100%" cellspacing="0" cellpadding="3">
 103 <tr><td class="block" style="background-color: #cccccc" valign="middle">
 104 <big><strong><span class="block">&nbsp;Thread::Queue - thread-safe queues</span></strong></big>
 105 </td></tr>
 106 </table>
 107
 108 </body>
 109
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