sdk/1.2/docs/man/accessQualifiers.xml

<?xml version="1.0" encoding="UTF-8"?>
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<refentry>
    <refentryinfo>
        <keywordset>
            <keyword>accessQualifiers</keyword>
        </keywordset>
    </refentryinfo>

    <refmeta>                                    
        <refentrytitle>accessQualifiers</refentrytitle>

        <refmiscinfo>
            <copyright>
                <year>2007-2011</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="accessQualifiers">             
        <refname>Access Qualifiers</refname>

        <refpurpose>
            Access Qualifiers for image memory objects.
        </refpurpose>
    </refnamediv>


    <!-- ALTERNATIVE SYNTAX SYNOPSIS (NON-FUNCTION) -->
    <refsect2 id="synopsis">
        <title>
        </title>

        <informaltable frame="none">
            <tgroup cols="1" align="left" colsep="0" rowsep="0">
                <colspec colname="col1" colnum="1" />
                <tbody>
                    <row>
                        <entry>
__read_only
__write_only
read_only
write_only
                        </entry>
                    </row>
                </tbody>
            </tgroup>
        </informaltable>
    </refsect2>


<!-- ================================ DESCRIPTION  -->

    <refsect1 id="description"><title>Description</title>
        <para>
Image objects specified as arguments to a kernel can be declared to be read-only or
write-only. A kernel cannot read from and write to the same image object. The
<function>__read_only</function> (or <function>read_only</function>) and
<function>__write_only</function> (or <function>write_only</function>) qualifiers
must be used with image object arguments to declare if the image object is
being read or written by a kernel. The default qualifier is <function>__read_only</function>.
        </para>
    </refsect1>


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

    <refsect1 id="notes"><title>Notes</title>
        <para>
        The <function>__read_only</function>, <function>__write_only</function>, 
        <function>__read_write</function>, <function>read_only</function>, 
        <function>write_only</function> and <function>read_write</function> names are reserved 
        for use as access qualifiers and shall not be used otherwise.
        </para>
    </refsect1> 

<!-- ================================ EXAMPLE  -->

    <refsect2 id="example1">
        <title>
            Example
        </title>
        <para>
In the example below, <constant>imageA</constant> is a read-only 2D image object, and 
<constant>imageB</constant> is a write-only 2D image object.
        </para>
        <informaltable frame="none">
            <tgroup cols="1" align="left" colsep="0" rowsep="0">
                <colspec colname="col1" colnum="1" />
                <tbody>
                    <row>
                        <entry>
__kernel void
foo (read_only image2d_t imageA,
     write_only image2d_t imageB)
{
     ... 
}
                        </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="accessQualifiers">OpenCL Specification</olink>
        </para>
    </refsect1>


<!-- ================================ ALSO SEE  -->
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     <citerefentry href="thatPage"><refentrytitle>clGetDeviceInfo</refentrytitle></citerefentry>


    <refsect1 id="seealso"><title>Also see</title>
        <para>
            <citerefentry><refentrytitle>addressSpaceQualifiers</refentrytitle></citerefentry>, 
            <citerefentry><refentrytitle>imageAccessQualifiers</refentrytitle></citerefentry>, 
            <citerefentry><refentrytitle>functionQualifiers</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>
<!-- 11-Oct-11 -->
</refentry>