sdk/1.1/docs/man/clCreateContextFromType.xml

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<refentry>
    <refentryinfo>
        <keywordset>
            <keyword>clCreateContextFromType</keyword>
        </keywordset>
    </refentryinfo>

    <refmeta>
        <refentrytitle>       
            clCreateContextFromType
        </refentrytitle>

        <refmiscinfo>
            <copyright>
                <year>2007-2010</year>
                <holder>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
in all copies or substantial portions of the Materials.</holder>
            </copyright>
        </refmiscinfo>
        <manvolnum>3</manvolnum>
  
    </refmeta>


<!-- ================================ SYNOPSIS -->  
    <refnamediv id="clCreateContextFromType">
        <refname>              
            clCreateContextFromType 
        </refname> 

        <refpurpose>          
            Create an OpenCL context from a device type that identifies the specific device(s) to use.
        </refpurpose>
    </refnamediv> 

    <refsynopsisdiv xmlns:xlink="http://www.w3.org/1999/xlink"><title></title>
        <funcsynopsis>
            <funcprototype>
                <funcdef>

                    <link xlink:href="scalarDataTypes.html">cl_context</link>

                    <function>      
                        clCreateContextFromType
                    </function>
                </funcdef>

                <paramdef>const <type><link xlink:href="enums.html#cl_context_properties">cl_context_properties</link></type>
                    <parameter> *properties</parameter></paramdef>
                <paramdef><link xlink:href="enums.html#cl_device_type">cl_device_type</link> 
                    <parameter>device_type</parameter></paramdef>
                <paramdef><link xlink:href="scalarDataTypes.html">void</link> 
                    <parameter>(CL_CALLBACK *pfn_notify) 
                        (const <link xlink:href="scalarDataTypes.html">char</link> *errinfo</parameter></paramdef>
                <paramdef>const <link xlink:href="scalarDataTypes.html">void</link> 
                    <parameter>*private_info</parameter></paramdef> 
                <paramdef><link xlink:href="scalarDataTypes.html">size_t</link> 
                    <parameter>cb</parameter></paramdef>  
                <paramdef><link xlink:href="scalarDataTypes.html">void</link>
                    <parameter>*user_data)</parameter></paramdef>
                <paramdef><link xlink:href="scalarDataTypes.html">void</link>
                    <parameter>*user_data</parameter></paramdef>
                <paramdef><link xlink:href="scalarDataTypes.html">cl_int</link>
                    <parameter>*errcode_ret</parameter></paramdef>     

            </funcprototype>
        </funcsynopsis>     
    </refsynopsisdiv>


<!-- ================================ PARAMETERS --> 

    <refsect1 xmlns:xlink="http://www.w3.org/1999/xlink" id="parameters">
        <title>Parameters</title>
        <variablelist>

        
<!-- ================================ PARAMETER TABLE (OPTIONAL) -->        
        <varlistentry>
            <term>properties</term>
            <listitem>
                <para>
                    Specifies a list of context property names and their corresponding values. Each property name is immediately followed by the corresponding desired value. The list is terminated with 0. <varname>properties</varname> can be NULL in which case the platform that is selected is implementation-defined. The list of supported properties is described in the table below. 
                </para>
                <informaltable frame="all"><tgroup cols="3" align="left" colsep="1" rowsep="1">
    <colspec colname="col1" colnum="1" />
    <colspec colname="col2" colnum="2" />
    <colspec colname="col3" colnum="3" />   
    <thead>
        <row>
        <entry>cl_context_properties enum</entry>
        <entry>Property value</entry>       
        <entry>Description</entry>
        </row>
    </thead>
    <tbody>
        <row>
            <entry><constant>CL_CONTEXT_PLATFORM</constant></entry>
            <entry><link xlink:href="abstractDataTypes.html">cl_platform_id</link></entry>
            <entry>Specifies the platform to use.</entry>
        </row>
        <row>
            <entry><constant>CL_CONTEXT_D3D10_DEVICE_KHR</constant></entry>
            <entry>ID3D10Device*</entry>
            <entry>If the <citerefentry><refentrytitle>cl_khr_d3d10_sharing</refentrytitle></citerefentry> 
            extension is enabled, specifies the ID3D10Device* to use for Direct3D 10 interoperability. The default value is NULL.</entry>
        </row>
        <row>
            <entry>
<literallayout><constant>CL_GL_CONTEXT_KHR</constant>
<constant>CL_EGL_DISPLAY_KHR</constant>
<constant>CL_GLX_DISPLAY_KHR</constant>
<constant>CL_WGL_HDC_KHR</constant>
<constant>CL_CGL_SHAREGROUP_KHR</constant></literallayout></entry>
            <entry></entry>
            <entry>Available if the <citerefentry><refentrytitle>cl_khr_gl_sharing</refentrytitle></citerefentry> 
            extension is enabled.</entry>
        </row>
    </tbody>    
        
    </tgroup></informaltable>   
            </listitem>
        </varlistentry>
<!-- ================================ END PARAMETER TABLE  -->             

<!-- ================================ PARAMETER TABLE (OPTIONAL) -->        
        <varlistentry>
            <term>device_type</term>
            <listitem>
                <para>
                    A bit-field that identifies the type of device and is described in the table below. 
                </para>
                <informaltable frame="all"><tgroup cols="2" align="left" colsep="1" rowsep="1">
    <colspec colname="col1" colnum="1" />
    <colspec colname="col2" colnum="2" />
    <thead>
        <row>
        <entry>cl_device_type</entry>
        <entry>Description</entry>
        </row>
    </thead>
    <tbody>
        <row>
            <entry><constant>CL_DEVICE_TYPE_CPU</constant></entry>
            <entry>An OpenCL device that is the host processor. The host
processor runs the OpenCL implementations and is a
single or multi-core CPU.</entry>
        </row>
        <row>
            <entry><constant>CL_DEVICE_TYPE_GPU</constant></entry>
            <entry>An OpenCL device that is a GPU. By this we mean that
the device can also be used to accelerate a 3D API such
as OpenGL or DirectX.</entry>
        </row>
        <row>
            <entry><constant>CL_DEVICE_TYPE_ACCELERATOR</constant></entry>
            <entry>Dedicated OpenCL accelerators (for example the IBM
CELL Blade). These devices communicate with the host
processor using a peripheral interconnect such as PCIe.</entry>
        </row>
        
        <row>
            <entry><constant>CL_DEVICE_TYPE_DEFAULT</constant></entry>
            <entry>The default OpenCL device in the system.</entry>
        </row>
        <row>
            <entry><constant>CL_DEVICE_TYPE_ALL</constant></entry>
            <entry>All OpenCL devices available in the system.</entry>
        </row>
    </tbody>    
        
    </tgroup></informaltable>
            </listitem>
        </varlistentry>
<!-- ================================ END PARAMETER TABLE  -->

            <varlistentry>
            <term><varname>pfn_notify</varname></term>
            <listitem>
                <para>
                    A callback function that can be registered by the application. This callback function will be used by the OpenCL implementation to report information on errors that occur in this context. This callback function may be called asynchronously by the OpenCL implementation.
It is the application's responsibility to ensure that the callback function is thread-safe. If <varname>pfn_notify</varname> is NULL, no callback function is registered. The parameters to this callback function are:
                </para>
                
                <para><varname>errinfo</varname> is a pointer to an error string.</para>
<para><varname>private_info</varname> and <varname>cb</varname> represent a pointer to binary data that is returned by the OpenCL implementation that can be used to log additional information helpful in debugging the error.</para>
<para><varname>user_data</varname> is a pointer to user supplied data.</para>

                <para>
                    There are a number of cases where error notifications need to be delivered due to an error that occurs outside a context. Such notifications may not be delivered through the <varname>pfn_notify</varname> callback. Where these notifications go is implementation-defined.
                </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><varname>user_data</varname></term>
            <listitem>
                <para>
                    Passed as the <varname>user_data</varname> argument when <varname>pfn_notify</varname> is called. user_data can be NULL.
                </para>
            </listitem>
        </varlistentry>

            <varlistentry>
                <term>
                    <varname> <!-- parameter name -->
                        errcode_ret
                    </varname>
                </term>

                <listitem>
                    <para> <!-- parameter description -->
                        Return an appropriate error code. If errcode_ret is NULL, no error code is returned.
                    </para>
                </listitem>
            </varlistentry>
        </variablelist>
    </refsect1>


<!-- ================================ NOTES  -->        
 

    <refsect1 id="notes"><title>Notes</title>
        <para>
            <function>clCreateContextFromType</function> may return all or a subset of the actual physical devices present in the platform and that match <varname>device_type</varname>.
        </para>
        <para>
            <function>clCreateContextFromType</function> and <citerefentry><refentrytitle>clCreateContext</refentrytitle></citerefentry> perform an implicit retain. This is very helpful for 3rd party libraries, which typically get a context passed to them by the application.
However, it is possible that the application may delete the context without informing the library.
Allowing functions to attach to (i.e. retain) and release a context solves the problem of a context
being used by a library no longer being valid.
        </para>
    </refsect1>
 
    
<!-- ================================ ERRORS  -->       
 

    <refsect1 id="errors"><title>Errors</title>
        <para>
            <function>clCreateContextFromType</function> returns a valid non-zero context and <varname>errcode_ret</varname> is set 
            to <errorname>CL_SUCCESS</errorname> if the context is created successfully. Otherwise, it returns a NULL value with the following 
            error vlaues returned in <varname>errcode_ret</varname>:
        </para>

        <itemizedlist mark="disc">
            <listitem>
                <errorname>CL_INVALID_PLATFORM</errorname> if <varname>properties</varname> is NULL and no platform could be selected or 
                if platform value specified in <varname>properties</varname> is not a valid platform. (If the extension <citerefentry><refentrytitle>cl_khr_gl_sharing</refentrytitle></citerefentry> is enabled, then see error "CL_INVALID_GL_SHAREGROUP_REFERENCE_KHR" below.)
            </listitem>
            
            <listitem>
                <errorname>CL_INVALID_PROPERTY</errorname> if context property name in <varname>properties</varname> is not a supported property 
                name, or if the value specified for a supported property name is not valid, or if the same property name is specified more than once.
            </listitem>
            
            <listitem>
                <errorname>CL_INVALID_VALUE</errorname> if <varname>pfn_notify</varname> is NULL but <varname>user_data</varname> is not NULL.
            </listitem>
 
            <listitem>
                <errorname>CL_INVALID_DEVICE_TYPE</errorname> if <varname>device_type</varname> is not a valid value.
            </listitem>
            
            <listitem>
                <errorname>CL_INVALID_OPERATION</errorname> if Direct3D 10 interoperability is specified by setting CL_INVALID_D3D10_DEVICE_KHR 
                to a non-NULL value, and interoperability with another graphics API is also specified (if the 
                <citerefentry><refentrytitle>cl_khr_d3d10_sharing</refentrytitle></citerefentry> extension is enabled).
            </listitem>
            <listitem>
                <errorname>CL_DEVICE_NOT_AVAILABLE</errorname> if no devices that match <varname>device_type</varname> and property values 
                specified in <varname>properties</varname> are currently available.
            </listitem>

            <listitem>
                <errorname>CL_DEVICE_NOT_FOUND</errorname> if no devices that match <varname>device_type</varname> and property values 
                specified in <varname>properties</varname> were found.
            </listitem>
            
            <listitem>
                <errorname>CL_OUT_OF_RESOURCES</errorname> if there is a failure to allocate resources required by the OpenCL 
                implementation on the device.
            </listitem>
            
            <listitem>
                <errorname>CL_OUT_OF_HOST_MEMORY</errorname> if there is a failure to allocate resources required by the 
                OpenCL implementation on the host.
            </listitem>
            
            <listitem>
                <errorname>CL_INVALID_D3D10_DEVICE_KHR</errorname> if the Direct3D 10 device specified for interoperability is not 
                compatible with the devices against which the context is to be created (if the 
                <citerefentry><refentrytitle>cl_khr_d3d10_sharing</refentrytitle></citerefentry> extension is enabled).
            </listitem>
            <listitem>
                <errorname>CL_INVALID_D3D10_DEVICE_KHR</errorname> if the value of the property CL_CONTEXT_D3D10_DEVICE_KHR is non-NULL 
                and does not specify a valid Direct3D 10 device with which the <varname>cl_device_ids</varname> against which this context 
                is to be created may interoperate (if the 
                <citerefentry><refentrytitle>cl_khr_d3d10_sharing</refentrytitle></citerefentry> extension is enabled).
            </listitem>
            <listitem>
                <errorname>CL_INVALID_GL_SHAREGROUP_REFERENCE_KHR</errorname> when an invalid OpenGL context or share group 
                object handle is specified in <varname>properties</varname> if the <citerefentry><refentrytitle>cl_khr_gl_sharing</refentrytitle></citerefentry> extension is enabled.
            </listitem>
            <listitem>
            <errorname>CL_INVALID_GL_SHAREGROUP_REFERENCE_KHR</errorname> if the
            <citerefentry><refentrytitle>cl_khr_gl_sharing</refentrytitle></citerefentry> extension is enabled and if a context was specified by any of the following means:
                <itemizedlist mark="disc">
                    <listitem>
                        Context specified for an EGL-based OpenGL ES or OpenGL implementation by 
                        setting the attributes CL_GL_CONTEXT_KHR and CL_EGL_DISPLAY_KHR. 
                    </listitem>
                    <listitem>
                        Context was specified for a GLX-based OpenGL implementation by setting the 
                        attributes CL_GL_CONTEXT_KHR and CL_GLX_DISPLAY_KHR.
                    </listitem>
                    <listitem>
                        Context was specified for a WGL-based OpenGL implementation by setting the 
                        attributes CL_GL_CONTEXT_KHR and CL_WGL_HDC_KHR.
                    </listitem>
                </itemizedlist>
            and any of the following conditions hold:
                <itemizedlist mark="disc">
                    <listitem>
                        The specified display and context attributes do not identify a valid OpenGL or 
                        OpenGL ES context.
                    </listitem>
                    <listitem>  
                        The specified context does not support buffer and renderbuffer objects.
                    </listitem>
                    <listitem>      
                        The specified context is not compatible with the OpenCL context being 
                        created (for example, it exists in a physically distinct address space, 
                        such as another hardware device, or does not support sharing data with OpenCL 
                        due to implementation restrictions).
                    </listitem>
                </itemizedlist> 
        </listitem>
        <listitem>
            <errorname>CL_INVALID_GL_SHAREGROUP_REFERENCE_KHR</errorname> if a share group was specified 
            for a CGL-based OpenGL implementation by setting the attribute CL_CGL_SHAREGROUP_KHR, and the 
            specified share group does not identify a valid CGL share group object (only if the
            <citerefentry><refentrytitle>cl_khr_gl_sharing</refentrytitle></citerefentry> extension is enabled).
        </listitem>
            
        </itemizedlist>
    </refsect1>
    

<!-- ================================ EXAMPLE  -->  
<!-- DO NOT DELETE IN CASE AN EXAMPLE IS ADDED IN THE FUTURE -->
<!--    --> 
    <refsect2 id="example1">
        <title>
            Example
        </title>

        <informaltable frame="none">
            <tgroup cols="1" align="left" colsep="0" rowsep="0">
                <colspec colname="col1" colnum="1" />
                <tbody>
                    <row>
                        <entry>Example goes here - it will be set in "code" type with white space preserved.</entry>
                    </row>
                </tbody>
            </tgroup>
        </informaltable>   
    </refsect2>  



<!-- ================================ SPECIFICATION  -->        
<!-- Set the "uri" attribute in the <olink /> element to the "named destination" for the PDF page
-->     
    <refsect1 id="specification"><title>Specification</title>     
        <para>
            <imageobject>
                <imagedata fileref="pdficon_small1.gif" format="gif" />
            </imageobject>
                            
            <olink uri="clCreateContextFromType">OpenCL Specification</olink>
        </para>
    </refsect1>     


<!-- ================================ ALSO SEE  -->       

    <refsect1 id="seealso"><title>Also see</title>
        <para>
<citerefentry><refentrytitle>clCreateContext</refentrytitle></citerefentry>,   <citerefentry><refentrytitle>clGetContextInfo</refentrytitle></citerefentry>,  <citerefentry><refentrytitle>clReleaseContext</refentrytitle></citerefentry>,      <citerefentry><refentrytitle>clRetainContext</refentrytitle></citerefentry>,   
<citerefentry><refentrytitle>clGetContextInfo</refentrytitle></citerefentry>,
            <citerefentry href="classDiagram"><refentrytitle>Cardinality Diagram</refentrytitle></citerefentry>
        </para>
    </refsect1>

<!-- ================================ COPYRIGHT  -->  
<!-- Content included from copyright.inc.xsl -->

    <refsect3 id="Copyright"><title></title>
        <imageobject>
                <imagedata fileref="KhronosLogo.jpg" format="jpg" />
        </imageobject>
        <para />
    </refsect3>

</refentry>