| |
| |
| <!DOCTYPE html> |
| <html class="writer-html5" lang="en" data-content_root="../../"> |
| <head> |
| <meta charset="utf-8" /><meta name="viewport" content="width=device-width, initial-scale=1" /> |
| |
| <meta name="viewport" content="width=device-width, initial-scale=1.0" /> |
| <title>Clock Domain API — ITT/JIT APIs Documentation documentation</title> |
| <link rel="stylesheet" type="text/css" href="../../_static/pygments.css?v=80d5e7a1" /> |
| <link rel="stylesheet" type="text/css" href="../../_static/css/theme.css?v=9edc463e" /> |
| |
| |
| <link rel="canonical" href="https://intel.github.io/ittapi/src/ittapi/clock-domain-api.html" /> |
| <script src="../../_static/jquery.js?v=5d32c60e"></script> |
| <script src="../../_static/_sphinx_javascript_frameworks_compat.js?v=2cd50e6c"></script> |
| <script src="../../_static/documentation_options.js?v=5929fcd5"></script> |
| <script src="../../_static/doctools.js?v=fd6eb6e6"></script> |
| <script src="../../_static/sphinx_highlight.js?v=6ffebe34"></script> |
| <script src="../../_static/js/theme.js"></script> |
| <link rel="index" title="Index" href="../../genindex.html" /> |
| <link rel="search" title="Search" href="../../search.html" /> |
| <link rel="next" title="Collection Control API" href="collection-control-api.html" /> |
| <link rel="prev" title="ITT API Reference" href="../itt-api-reference.html" /> |
| </head> |
| |
| <body class="wy-body-for-nav"> |
| <div class="wy-grid-for-nav"> |
| <nav data-toggle="wy-nav-shift" class="wy-nav-side"> |
| <div class="wy-side-scroll"> |
| <div class="wy-side-nav-search" > |
| |
| |
| |
| <a href="../../index.html" class="icon icon-home"> |
| ITT/JIT APIs Documentation |
| </a> |
| <div role="search"> |
| <form id="rtd-search-form" class="wy-form" action="../../search.html" method="get"> |
| <input type="text" name="q" placeholder="Search docs" aria-label="Search docs" /> |
| <input type="hidden" name="check_keywords" value="yes" /> |
| <input type="hidden" name="area" value="default" /> |
| </form> |
| </div> |
| </div><div class="wy-menu wy-menu-vertical" data-spy="affix" role="navigation" aria-label="Navigation menu"> |
| <p class="caption" role="heading"><span class="caption-text">Contents:</span></p> |
| <ul class="current"> |
| <li class="toctree-l1"><a class="reference internal" href="../overview.html">Overview</a></li> |
| <li class="toctree-l1"><a class="reference internal" href="../build.html">Build from Source Code</a></li> |
| <li class="toctree-l1 current"><a class="reference internal" href="../api-support.html">Use the ITT/JIT APIs</a><ul class="current"> |
| <li class="toctree-l2 current"><a class="reference internal" href="../api-support.html#c-c-api-usage-and-reference">C/C++ API Usage and Reference:</a><ul class="current"> |
| <li class="toctree-l3 current"><a class="reference internal" href="../itt-api-support.html">Instrumentation and Tracing Technology (ITT) API</a><ul class="current"> |
| <li class="toctree-l4 current"><a class="reference internal" href="../itt-api-support.html#itt-api-usage-and-reference">ITT API Usage and Reference</a></li> |
| </ul> |
| </li> |
| <li class="toctree-l3"><a class="reference internal" href="../jit-api-support.html">Just-In-Time (JIT) API</a></li> |
| </ul> |
| </li> |
| <li class="toctree-l2"><a class="reference internal" href="../api-support.html#other-language-api-bindings">Other Language API Bindings:</a></li> |
| </ul> |
| </li> |
| <li class="toctree-l1"><a class="reference internal" href="../ref_collector.html">ITT API Reference Collector</a></li> |
| <li class="toctree-l1"><a class="reference external" href="https://github.com/intel/ittapi">GitHub Project</a></li> |
| </ul> |
| |
| </div> |
| </div> |
| </nav> |
| |
| <section data-toggle="wy-nav-shift" class="wy-nav-content-wrap"><nav class="wy-nav-top" aria-label="Mobile navigation menu" > |
| <i data-toggle="wy-nav-top" class="fa fa-bars"></i> |
| <a href="../../index.html">ITT/JIT APIs Documentation</a> |
| </nav> |
| |
| <div class="wy-nav-content"> |
| <div class="rst-content style-external-links"> |
| <div role="navigation" aria-label="Page navigation"> |
| <ul class="wy-breadcrumbs"> |
| <li><a href="../../index.html" class="icon icon-home" aria-label="Home"></a></li> |
| <li class="breadcrumb-item"><a href="../api-support.html">Use the ITT/JIT APIs</a></li> |
| <li class="breadcrumb-item"><a href="../itt-api-support.html">Instrumentation and Tracing Technology (ITT) API</a></li> |
| <li class="breadcrumb-item"><a href="../itt-api-reference.html">ITT API Reference</a></li> |
| <li class="breadcrumb-item active">Clock Domain API</li> |
| <li class="wy-breadcrumbs-aside"> |
| <a href="../../_sources/src/ittapi/clock-domain-api.rst.txt" rel="nofollow"> View page source</a> |
| </li> |
| </ul> |
| <hr/> |
| </div> |
| <div role="main" class="document" itemscope="itemscope" itemtype="http://schema.org/Article"> |
| <div itemprop="articleBody"> |
| |
| <section id="clock-domain-api"> |
| <span id="id1"></span><h1>Clock Domain API<a class="headerlink" href="#clock-domain-api" title="Link to this heading"></a></h1> |
| <p>Some applications require the capability to trace events with user-defined |
| timestamps and frequencies that are different from the ones generated by a |
| CPU. For example, you may want to instrument events that occur on a GPU. |
| To do this, you can create a clock domain.</p> |
| <p>To create a clock domain, use this following primitive:</p> |
| <div class="highlight-cpp notranslate"><div class="highlight"><pre><span></span><span class="n">__itt_clock_domain</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="n">ITTAPI</span><span class="w"> </span><span class="n">__itt_clock_domain_create</span><span class="p">(</span><span class="n">__itt_get_clock_info_fn</span><span class="w"> </span><span class="n">fn</span><span class="p">,</span><span class="w"> </span><span class="kt">void</span><span class="o">*</span><span class="w"> </span><span class="n">fn_data</span><span class="p">)</span> |
| </pre></div> |
| </div> |
| <p><strong>Parameters of the primitive:</strong></p> |
| <table class="docutils align-default"> |
| <tbody> |
| <tr class="row-odd"><td><p>[in]</p></td> |
| <td><p><code class="docutils literal notranslate"><span class="pre">fn</span></code></p></td> |
| <td><p>Pointer to a callback function that retrieves alternative |
| CPU timestamps and frequencies and stores them in the |
| clock domain structure field <code class="docutils literal notranslate"><span class="pre">__itt_clock_info</span></code>.</p></td> |
| </tr> |
| <tr class="row-even"><td><p>[in]</p></td> |
| <td><p><code class="docutils literal notranslate"><span class="pre">fn_data</span></code></p></td> |
| <td><p>Argument passed to the callback function. Can be <code class="docutils literal notranslate"><span class="pre">NULL</span></code>.</p></td> |
| </tr> |
| </tbody> |
| </table> |
| <p>Tasks issued from different clock domains display on the same timeline. This |
| happens by the synchronization of a referenced clock domain base timestamp |
| (captured at the instant when the clock domain was created) and a CPU timestamp |
| (captured in the same instant).</p> |
| <p>To recalculate clock domain base timestamps and frequencies, if necessary, |
| for example, when a GPU frequency changes, use the following primitive:</p> |
| <div class="highlight-cpp notranslate"><div class="highlight"><pre><span></span><span class="n">__itt_clock_domain_reset</span><span class="p">()</span> |
| </pre></div> |
| </div> |
| </section> |
| |
| |
| </div> |
| </div> |
| <footer><div class="rst-footer-buttons" role="navigation" aria-label="Footer"> |
| <a href="../itt-api-reference.html" class="btn btn-neutral float-left" title="ITT API Reference" accesskey="p" rel="prev"><span class="fa fa-arrow-circle-left" aria-hidden="true"></span> Previous</a> |
| <a href="collection-control-api.html" class="btn btn-neutral float-right" title="Collection Control API" accesskey="n" rel="next">Next <span class="fa fa-arrow-circle-right" aria-hidden="true"></span></a> |
| </div> |
| |
| <hr/> |
| |
| <div role="contentinfo"> |
| <p>© Copyright 2026 Intel Corporation.</p> |
| </div> |
| |
| Built with <a href="https://www.sphinx-doc.org/">Sphinx</a> using a |
| <a href="https://github.com/readthedocs/sphinx_rtd_theme">theme</a> |
| provided by <a href="https://readthedocs.org">Read the Docs</a>. |
| |
| |
| </footer> |
| </div> |
| </div> |
| </section> |
| </div> |
| <script> |
| jQuery(function () { |
| SphinxRtdTheme.Navigation.enable(true); |
| }); |
| </script> |
| |
| </body> |
| </html> |
