mingw/html/lib/attrs.html

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  13 <big><strong><span class="block">&nbsp;attrs - set/get attributes of a subroutine</span></strong></big>
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  19
  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 </ul>
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  29 <p>
  30 </p>
  31 <h1><a name="name">NAME</a></h1>
  32 <p>attrs - set/get attributes of a subroutine (deprecated)</p>
  33 <p>
  34 </p>
  35 <hr />
  36 <h1><a name="synopsis">SYNOPSIS</a></h1>
  37 <pre>
  38     sub foo {
  39         use attrs qw(locked method);
  40         ...
  41     }</pre>
  42 <pre>
  43     @a = attrs::get(\&amp;foo);</pre>
  44 <p>
  45 </p>
  46 <hr />
  47 <h1><a name="description">DESCRIPTION</a></h1>
  48 <p>NOTE: Use of this pragma is deprecated.  Use the syntax</p>
  49 <pre>
  50     sub foo : locked method { }</pre>
  51 <p>to declare attributes instead.  See also <a href="file://C|\msysgit\mingw\html/lib/attributes.html">the attributes manpage</a>.</p>
  52 <p>This pragma lets you set and get attributes for subroutines.
  53 Setting attributes takes place at compile time; trying to set
  54 invalid attribute names causes a compile-time error. Calling
  55 <code>attrs::get</code> on a subroutine reference or name returns its list
  56 of attribute names. Notice that <code>attrs::get</code> is not exported.
  57 Valid attributes are as follows.</p>
  58 <dl>
  59 <dt><strong><a name="item_method">method</a></strong>
  60
  61 <dd>
  62 <p>Indicates that the invoking subroutine is a method.</p>
  63 </dd>
  64 </li>
  65 <dt><strong><a name="item_locked">locked</a></strong>
  66
  67 <dd>
  68 <p>Setting this attribute is only meaningful when the subroutine or
  69 method is to be called by multiple threads. When set on a method
  70 subroutine (i.e. one marked with the <strong>method</strong> attribute above),
  71 perl ensures that any invocation of it implicitly locks its first
  72 argument before execution. When set on a non-method subroutine,
  73 perl ensures that a lock is taken on the subroutine itself before
  74 execution. The semantics of the lock are exactly those of one
  75 explicitly taken with the <code>lock</code> operator immediately after the
  76 subroutine is entered.</p>
  77 </dd>
  78 </li>
  79 </dl>
  80 <table border="0" width="100%" cellspacing="0" cellpadding="3">
  81 <tr><td class="block" style="background-color: #cccccc" valign="middle">
  82 <big><strong><span class="block">&nbsp;attrs - set/get attributes of a subroutine</span></strong></big>
  83 </td></tr>
  84 </table>
  85
  86 </body>
  87
  88 </html>