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    <title>clGetContextInfo</title>
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        <a xmlns="http://www.w3.org/1999/xhtml" id="clGetDeviceIDs"></a>
        <h1>clGetContextInfo</h1>
        <p>
            Query information about a context.
        </p>
      </div>
      <div class="refsynopsisdiv">
        <h2></h2>
        <div class="funcsynopsis">
          <table xmlns="" border="0" summary="Function synopsis" cellspacing="0" cellpadding="0">
            <tr valign="bottom">
              <td>
                <code xmlns="http://www.w3.org/1999/xhtml" class="funcdef">
                    <a class="link" href="scalarDataTypes.html" target="pagedisplay">cl_int</a>
                    <strong class="fsfunc">
                        clGetContextInfo
                    </strong>
                (</code>
                <td>
                    <a xmlns="http://www.w3.org/1999/xhtml" class="link" href="abstractDataTypes.html" target="pagedisplay">cl_context</a>
                     <var xmlns="http://www.w3.org/1999/xhtml" class="pdparam">context</var>
                , </td>
              </td>
            </tr>
            <tr valign="top">
              <td> </td>
              <td>
                    <a xmlns="http://www.w3.org/1999/xhtml" class="link" href="enums.html#cl_context_info" target="pagedisplay">cl_context_info</a>
                     <var xmlns="http://www.w3.org/1999/xhtml" class="pdparam">param_name</var>
                , </td>
            </tr>
            <tr valign="top">
              <td> </td>
              <td>
                    <a xmlns="http://www.w3.org/1999/xhtml" class="link" href="scalarDataTypes.html" target="pagedisplay">size_t</a>
                     <var xmlns="http://www.w3.org/1999/xhtml" class="pdparam">param_value_size</var>
                , </td>
            </tr>
            <tr valign="top">
              <td> </td>
              <td>
                    <a xmlns="http://www.w3.org/1999/xhtml" class="link" href="scalarDataTypes.html" target="pagedisplay">void</a>
                     <var xmlns="http://www.w3.org/1999/xhtml" class="pdparam">*param_value</var>
                , </td>
            </tr>
            <tr valign="top">
              <td> </td>
              <td>
                    <a xmlns="http://www.w3.org/1999/xhtml" class="link" href="scalarDataTypes.html" target="pagedisplay">size_t</a>
                     <var xmlns="http://www.w3.org/1999/xhtml" class="pdparam">*param_value_size_ret</var>
                <code>)</code></td>
            </tr>
          </table>
        </div>
      </div>
      <div class="refsect1">
        <a id="parameters"></a>
        <h2>Parameters</h2>
        <div class="variablelist">
          <dl class="variablelist">
            <dt>
              <span class="term"> <code class="varname">context </code> </span>
            </dt>
            <dd>
              <p>
                        Specifies the OpenCL context being queried.
                    </p>
            </dd>
            <dt>
              <span class="term"> <code class="varname"> param_name </code> </span>
            </dt>
            <dd>
              <p>
                        An enumeration constant that specifies the information to query.
                        The valid values for <code class="varname">param_name</code> are:
                    </p>
              <div class="informaltable">
                <table border="1">
                  <colgroup>
                    <col align="left" class="col1" />
                    <col align="left" class="col2" />
                    <col align="left" class="col3" />
                  </colgroup>
                  <thead>
                    <tr>
                      <th align="left">cl_context_info</th>
                      <th align="left">Return Type</th>
                      <th align="left">Information returned in param_value</th>
                    </tr>
                  </thead>
                  <tbody>
                    <tr>
                      <td align="left">
                        <code class="constant">CL_CONTEXT_REFERENCE_COUNT</code>
                      </td>
                      <td align="left">cl_uint</td>
                      <td align="left">
                              Return the <code class="varname">context</code> reference count. The reference
                              count returned should be considered immediately stale. It is
                              unsuitable for general use in applications. This feature is
                              provided for identifying memory leaks.
                            </td>
                    </tr>
                    <tr>
                      <td align="left">
                        <code class="constant">CL_CONTEXT_NUM_DEVICES</code>
                      </td>
                      <td align="left">cl_uint</td>
                      <td align="left">
                              Return the number of devices in <code class="varname">context</code>.
                            </td>
                    </tr>
                    <tr>
                      <td align="left">
                        <code class="constant">CL_CONTEXT_DEVICES</code>
                      </td>
                      <td align="left">cl_device_id[]</td>
                      <td align="left">
                              Return the list of devices in <code class="varname">context</code>.
                            </td>
                    </tr>
                    <tr>
                      <td align="left">
                        <code class="constant">CL_CONTEXT_PROPERTIES</code>
                      </td>
                      <td align="left">cl_context_-
properties[]</td>
                      <td align="left">
                              Return the <code class="varname">properties</code> argument specified in
                              <a class="citerefentry" href="clCreateContext.html"><span class="citerefentry"><span class="refentrytitle">clCreateContext</span></span></a>
                              or
                              <a class="citerefentry" href="clCreateContextFromType.html"><span class="citerefentry"><span class="refentrytitle">clCreateContextFromType</span></span></a>.
                              <p>If the <code class="varname">properties</code> argument specified in
                              <a class="citerefentry" href="clCreateContext.html"><span class="citerefentry"><span class="refentrytitle">clCreateContext</span></span></a>
                              or
                              <a class="citerefentry" href="clCreateContextFromType.html"><span class="citerefentry"><span class="refentrytitle">clCreateContextFromType</span></span></a>
                              used to create <code class="varname">context</code> is not NULL,
                              the implementation must return the values specified in the
                              <code class="varname">properties</code> argument.  </p>
                              <p> If the <code class="varname">properties</code> argument specified in
                              <a class="citerefentry" href="clCreateContext.html"><span class="citerefentry"><span class="refentrytitle">clCreateContext</span></span></a>
                              or
                              <a class="citerefentry" href="clCreateContextFromType.html"><span class="citerefentry"><span class="refentrytitle">clCreateContextFromType</span></span></a>
                              used to create <code class="varname">context</code> is NULL, the implementation
                              may return either a <code class="varname">param_value_size_ret</code>
                              of 0, i.e. there is no context property value to be returned
                              or can return a context property value of 0 (where 0 is used
                              to terminate the context properties list) in the memory that
                              <code class="varname">param_value</code> points to.  </p>
                            </td>
                    </tr>
                    <tr>
                      <td align="left">
                        <code class="constant">CL_CONTEXT_D3D10_PREFER_-
SHARED_RESOURCES_KHR</code>
                      </td>
                      <td align="left">cl_bool</td>
                      <td align="left">
                              If the
                              <a class="citerefentry" href="cl_khr_d3d10_sharing.html"><span class="citerefentry"><span class="refentrytitle">cl_khr_d3d10_sharing</span></span></a>
                              extension is enabled, returns <code class="constant">CL_TRUE</code>
                              if Direct3D 10 resources created as shared by
                              setting <code class="varname">MiscFlags</code> to include
                              <code class="constant">D3D10_RESOURCE_MISC_SHARED</code> will perform faster
                              when shared with OpenCL, compared with resources which have not
                              set this flag. Otherwise returns <code class="constant">CL_FALSE</code>.
                            </td>
                    </tr>
                    <tr>
                      <td align="left">
                        <code class="constant">CL_CONTEXT_D3D11_PREFER_-
SHARED_RESOURCES_KHR</code>
                      </td>
                      <td align="left">cl_bool</td>
                      <td align="left">
                              If the <a class="citerefentry" href="cl_khr_d3d11_sharing.html"><span class="citerefentry"><span class="refentrytitle">cl_khr_d3d11_sharing</span></span></a> 
                              extension is enabled, returns
                              <code class="constant">CL_TRUE</code> if Direct3D 11 resources created
                              as shared by setting <code class="varname">MiscFlags</code> to include
                              <code class="constant">D3D11_RESOURCE_MISC_SHARED</code> will perform faster
                              when shared with OpenCL, compared with resources which have not
                              set this flag. Otherwise returns <code class="constant">CL_FALSE</code>.
                            </td>
                    </tr>
                  </tbody>
                </table>
              </div>
            </dd>
            <dt>
              <span class="term">
                    <code class="varname">param_value</code>
                </span>
            </dt>
            <dd>
              <p>
                         A pointer to memory where the appropriate result being queried is returned.
                         If <code class="varname">param_value</code> is NULL, it is ignored.
                    </p>
            </dd>
            <dt>
              <span class="term">
                    <code class="varname">param_value_size</code>
                </span>
            </dt>
            <dd>
              <p>
                      Specifies the size in bytes of memory
                      pointed to by <code class="varname">param_value</code>.  This size must be greater
                      than or equal to the size of return type as described in the table above.
                    </p>
            </dd>
            <dt>
              <span class="term">
                    <code class="varname">param_value_size_ret</code>
                </span>
            </dt>
            <dd>
              <p>
                      Returns the actual size in bytes
                      of data being queried by <code class="varname">param_value</code>. If
                      <code class="varname">param_value_size_ret</code> is NULL, it is ignored.
                    </p>
            </dd>
          </dl>
        </div>
      </div>
      <div class="refsect1">
        <a id="errors"></a>
        <h2>Errors</h2>
        <p>
          Returns <span class="errorname">CL_SUCCESS</span> if the function executed successfully,
          or one of the errors below:
        </p>
        <div class="itemizedlist">
          <ul class="itemizedlist" style="list-style-type: disc; ">
            <li class="listitem" style="list-style-type: disc"><span class="errorname">CL_INVALID_CONTEXT</span> if <code class="varname">context</code>
                is not a valid context.
            </li>
            <li class="listitem" style="list-style-type: disc"><span class="errorname">CL_INVALID_VALUE</span> if <code class="varname">param_name</code>
              is not one of the supported values or if size in bytes specified by
              <code class="varname">param_value_size</code> is &lt; size of return type as specified in the
              table above and <code class="varname">param_value</code> is not a <span class="errorname">NULL</span>
              value.
            </li>
            <li class="listitem" style="list-style-type: disc"><span class="errorname">CL_OUT_OF_RESOURCES</span> if there is a failure to allocate
                resources required by the OpenCL implementation on the device.
            </li>
            <li class="listitem" style="list-style-type: disc"><span class="errorname">CL_OUT_OF_HOST_MEMORY</span> if there is a failure to allocate
                resources required by the OpenCL implementation on the host.
            </li>
          </ul>
        </div>
      </div>
      <div class="refsect1">
        <a id="specification"></a>
        <h2>Specification</h2>
        <p>
            <img src="pdficon_small1.gif" />

            <a href="https://www.khronos.org/registry/cl/specs/opencl-2.1.pdf#page=94" target="OpenCL Spec">OpenCL Specification</a>
        </p>
      </div>
      <div class="refsect1">
        <a id="seealso"></a>
        <h2>Also see</h2>
        <p>
            <a class="citerefentry" href="clGetDeviceInfo.html"><span class="citerefentry"><span class="refentrytitle">clGetDeviceInfo</span></span></a>
        </p>
      </div>
      <div xmlns="" class="refsect3" lang="en" xml:lang="en"><a xmlns="http://www.w3.org/1999/xhtml" id="Copyright"></a><h4 xmlns="http://www.w3.org/1999/xhtml"></h4><img xmlns="http://www.w3.org/1999/xhtml" src="KhronosLogo.jpg" /><p xmlns="http://www.w3.org/1999/xhtml"></p>Copyright © 2007-2015 The Khronos Group Inc.
Permission is hereby granted, free of charge, to any person obtaining a
copy of this software and/or associated documentation files (the
"Materials"), to deal in the Materials without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Materials, and to
permit persons to whom the Materials are furnished to do so, subject to
the condition that this copyright notice and permission notice shall be included
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