<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <!-- saved from url=(0014)about:internet --> <html xmlns:MSHelp="http://www.microsoft.com/MSHelp/" lang="en-us" xml:lang="en-us"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <meta name="DC.Type" content="reference"> <meta name="DC.Title" content="Threads"> <meta name="DC.subject" content="Threads"> <meta name="keywords" content="Threads"> <meta name="DC.Relation" scheme="URI" content="../reference/reference.htm"> <meta name="DC.Relation" scheme="URI" content="../reference/threads/thread_cls.htm"> <meta name="DC.Relation" scheme="URI" content="../reference/threads/thread_id.htm"> <meta name="DC.Relation" scheme="URI" content="../reference/threads/this_thread_namespace.htm"> <meta name="DC.Relation" scheme="URI" content="general_conventions/namespaces.htm"> <meta name="DC.Format" content="XHTML"> <meta name="DC.Identifier" content="threads"> <meta name="DC.Language" content="en-US"> <link rel="stylesheet" type="text/css" href="../intel_css_styles.css"> <title>Threads</title> </head> <body id="threads"> <!-- ==============(Start:NavScript)================= --> <script src="..\NavScript.js" language="JavaScript1.2" type="text/javascript"></script> <script language="JavaScript1.2" type="text/javascript">WriteNavLink(1);</script> <!-- ==============(End:NavScript)================= --> <a name="threads"><!-- --></a> <h1 class="topictitle1">Threads</h1> <div> <div class="section"> <p>Intel® Threading Building Blocks (Intel® TBB) provides a wrapper around the platform's native threads, based upon the N3000 working draft for C++11. Using this wrapper has two benefits: </p> <ul type="disc"> <li> <p>It makes threaded code portable across platforms. </p> </li> <li> <p>It eases later migration to ISO C++11 threads. </p> </li> </ul> <p>The library defines the wrapper in namespace <samp class="codeph">std</samp>, not namespace <samp class="codeph">tbb</samp>, as explained in Section Namespace. </p> <p>The significant departures from N3000 are shown in the table below. </p> <div class="tablenoborder"><a name="tbl36"><!-- --></a><table cellpadding="4" summary="" id="tbl36" width="100%" frame="hsides" border="1" rules="all"><caption><span class="tablecap">Differences Between N3000 and Intel® TBB Thread Class</span></caption> <thead align="left"> <tr> <th class="cellrowborder" valign="top" width="NaN%" id="d123197e64"> <p>N3000 </p> </th> <th class="row-nocellborder" valign="top" width="NaN%" id="d123197e70"> <p>Intel® TBB </p> </th> </tr> </thead> <tbody> <tr> <td class="cellrowborder" valign="top" width="NaN%" headers="d123197e64 "> <p><samp class="codeph">template<class Rep, class Period> std::this_thread::sleep_for(</samp> </p> <p><samp class="codeph">const chrono::duration<Rep, Period>& rel_time)</samp> </p> </td> <td class="row-nocellborder" valign="top" width="NaN%" headers="d123197e70 "> <p><samp class="codeph">std::this_thread::sleep_for( tick_count::interval_t )</samp> </p> </td> </tr> <tr> <td class="cellrowborder" valign="top" width="NaN%" headers="d123197e64 "> <p>rvalue reference parameters </p> </td> <td class="row-nocellborder" valign="top" width="NaN%" headers="d123197e70 "> <p>Parameter changed to plain value, or function removed, as appropriate. </p> </td> </tr> <tr> <td class="cellrowborder" valign="top" width="NaN%" headers="d123197e64 "> <p>constructor for <samp class="codeph">std::thread</samp> takes arbitrary number of arguments. </p> </td> <td class="row-nocellborder" valign="top" width="NaN%" headers="d123197e70 "> <p>constructor for <samp class="codeph">std::thread</samp> takes 0-3 arguments. </p> </td> </tr> </tbody> </table> </div> <p>The other changes are for compatibility with the current C++ standard or Intel® TBB. For example, constructors that have an arbitrary number of arguments require the variadic template features of C++11. </p> <div class="Note"><h3 class="NoteTipHead"> Caution</h3> <p>Threads are heavy weight entities on most systems, and running too many threads on a system can seriously degrade performance. Consider using a task based solution instead if practical. </p> </div> </div> </div> <div class="familylinks"> <div class="parentlink"><strong>Parent topic:</strong> <a href="../reference/reference.htm">Intel® Threading Building Blocks Reference Manual</a></div> </div> <div class="See Also"> <ul class="ullinks"> <li class="ulchildlink"><a href="../reference/threads/thread_cls.htm">thread Class</a><br> </li> <li class="ulchildlink"><a href="../reference/threads/thread_id.htm">thread::id</a><br> </li> <li class="ulchildlink"><a href="../reference/threads/this_thread_namespace.htm">this_thread Namespace</a><br> </li> </ul> <h2>See Also</h2> <div class="linklist"> <div><a href="general_conventions/namespaces.htm">Namespaces, std Namespace </a></div></div> </div> </body> </html>