<ppdoc>
<copyright>
Copyright (c) 2001 by Addison Wesley Longman, Inc. This material may
be distributed only subject to the terms and conditions set forth in
the Open Publication License, v1.0 or later (the latest version is
presently available at http://www.opencontent.org/openpub/).
<p/>
Distribution of substantively modified versions of this document is
prohibited without the explicit permission of the copyright holder.
<p/>
Distribution of the work or derivative of the work in any standard
(paper) book form is prohibited unless prior permission is obtained
from the copyright holder.
</copyright>
<class name="ThreadGroup" super="Object" type="class" ref="xref-000001">
<p/>
  <classname>ThreadGroup</classname> provides a means of keeping track of a number of
  threads as a group.  A <classname>Thread</classname> can belong to only one
  <classname>ThreadGroup</classname> at a time; adding a thread to a new group will
  remove it from any previous group.  
<p/>
  Newly created threads belong to the same group as the thread from
  which they were created.
  <constants>
<tr>
  <td><constant>
       <constname>Default</constname>
       <constval></constval>
       <constdesc>Default thread group.</constdesc>
     </constant>
</td>
</tr>
</constants>
<p/>
  <methods type="class">
<p/>
        <method name="new" ref="new">
      <callseq>
        ThreadGroup.new
        <returns><obj>thgrp</obj></returns>
      </callseq>
      <desc>
<p/>
      Returns a newly created <classname>ThreadGroup</classname>.  The group is initially 
      empty.
<p/>
      </desc>
    </method>
<p/>
  </methods>
<p/>
  <methods type="instance">
<p/>
        <method name="add" ref="add">
      <callseq>
        <obj>thgrp</obj>.add( <obj>aThread</obj> )
        <returns><obj>thgrp</obj></returns>
      </callseq>
      <desc>
<p/>
            Adds the given thread to this group, removing it from any other
      group to which it may have previously belonged.
<p/>
<codefragment>
<alltt><fullcode><![CDATA[        puts "Initial group is #{ThreadGroup::Default.list}"
        tg = ThreadGroup.new
        t1 = Thread.new { sleep 10 }
        t2 = Thread.new { sleep 10 }
        puts "t1 is #{t1}"
        puts "t2 is #{t2}"
        tg.add( t1 )
        puts "Initial group now #{ThreadGroup::Default.list}"
        puts "tg group now #{tg.list}"
]]></fullcode>
puts<nbsp/>"Initial<nbsp/>group<nbsp/>is<nbsp/>#{ThreadGroup::Default.list}"
tg<nbsp/>=<nbsp/>ThreadGroup.new
t1<nbsp/>=<nbsp/>Thread.new<nbsp/>{<nbsp/>sleep<nbsp/>10<nbsp/>}
t2<nbsp/>=<nbsp/>Thread.new<nbsp/>{<nbsp/>sleep<nbsp/>10<nbsp/>}
puts<nbsp/>"t1<nbsp/>is<nbsp/>#{t1}"
puts<nbsp/>"t2<nbsp/>is<nbsp/>#{t2}"
tg.add(<nbsp/>t1<nbsp/>)
puts<nbsp/>"Initial<nbsp/>group<nbsp/>now<nbsp/>#{ThreadGroup::Default.list}"
puts<nbsp/>"tg<nbsp/>group<nbsp/>now<nbsp/>#{tg.list}"
</alltt>
</codefragment>
<em>produces:</em>
<codefragment><alltt>
Initial<nbsp/>group<nbsp/>is<nbsp/>#&lt;Thread:0x401be5c8&gt;
t1<nbsp/>is<nbsp/>#&lt;Thread:0x401b5428&gt;
t2<nbsp/>is<nbsp/>#&lt;Thread:0x401b53d8&gt;
Initial<nbsp/>group<nbsp/>now<nbsp/>#&lt;Thread:0x401b53d8&gt;#&lt;Thread:0x401be5c8&gt;
tg<nbsp/>group<nbsp/>now<nbsp/>#&lt;Thread:0x401b5428&gt;
</alltt>
</codefragment>
<p/>
      </desc>
    </method>
<p/>
        <method name="list" ref="list">
      <callseq>
        <obj>thgrp</obj>.list
        <returns><obj>anArray</obj></returns>
      </callseq>
      <desc>
<p/>
      Returns an array of all existing <classname>Thread</classname> objects that belong 
      to this group.
<p/>
<codefragment>
<fullcode><![CDATA[        ThreadGroup::Default.list
]]></fullcode><rubycode>
<tr>
  <td><tt>ThreadGroup::Default.list</tt></td>
  <td>&#187;</td>
  <td><tt>[#&lt;Thread:0x401be5c8<nbsp/>run&gt;]</tt></td>
</tr>
</rubycode>
<p/>
</codefragment>
<p/>
      </desc>
    </method>
<p/>
  </methods>
<p/>
</class>
</ppdoc>
