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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 class="informaltable" 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#namedest=clGetContextInfo" 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
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