<!DOCTYPE refentry [ <!ENTITY % mathent SYSTEM "math.ent"> %mathent; ]>

<!-- Converted by db4-upgrade version 1.1 -->

<refentry xmlns="http://docbook.org/ns/docbook" version="5.0" xml:id="memoryBarrier">
    <info>
        <copyright>
            <year>2011-2015</year>
            <holder>Khronos Group</holder>
        </copyright>
    </info>
    <refmeta>
            <refentrytitle>memoryBarrier</refentrytitle>
        <manvolnum>3G</manvolnum>
    </refmeta>
    <refnamediv>
        <refname>memoryBarrier</refname>
        <refpurpose>controls the ordering of memory transactions issued by a single shader invocation</refpurpose>
    </refnamediv>
    <refsynopsisdiv>
        <title>Declaration</title>
        <funcsynopsis>
            <funcprototype>
                <funcdef>void <function>memoryBarrier</function></funcdef>
                <paramdef>void</paramdef>
            </funcprototype>
        </funcsynopsis>
    </refsynopsisdiv>
    <refsect1 xml:id="description"><title>Description</title>
        <para>
            <function>memoryBarrier</function> waits on the completion of all memory accesses resulting from the use of
            image variables or atomic counters and then returns with no other effect.  When this function returns, the
            results of any memory stores performed using coherent variables performed prior to the call will be visible
            to any future coherent memory access to the same addresses from other shader invocations.  In particular,
            the values written this way in one shader stage are guaranteed to be visible to coherent memory accesses
            performed by shader invocations in subsequent stages when those invocations were triggered by the
            execution of the original shader invocation (e.g., fragment shader invocations for a primitive resulting
            from a particular geometry shader invocation).
        </para>
    </refsect1>
    <refsect1 xml:id="versions">
        <title>Version Support</title>
        <informaltable>
            <tgroup cols="5" align="left">
                <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="funchead.xml" xpointer="xpointer(/*/*)"/>
                <tbody>
                    <row>
                        <entry><function>memoryBarrier</function></entry>
                        <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="version.xml" xpointer="xpointer(/*/*[@role='es31']/*)"/>
                    </row>
                </tbody>
            </tgroup>
        </informaltable>
    </refsect1>
    <refsect1 xml:id="seealso"><title>See Also</title>
        <para>
            <citerefentry><refentrytitle>imageLoad</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>imageStore</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>imageAtomicAdd</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>imageAtomicMin</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>imageAtomicMax</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>imageAtomicXor</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>imageAtomicOr</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>imageAtomicAnd</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>imageAtomicExchange</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>imageAtomicCompSwap</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>memoryBarrier</refentrytitle></citerefentry>
        </para>
    </refsect1>
    <refsect1 xml:id="Copyright"><title>Copyright</title>
        <para>
            Copyright <trademark class="copyright"/> 2011-2015 Khronos Group. 
            This material may be distributed subject to the terms and conditions set forth in 
            the Open Publication License, v 1.0, 8 June 1999.
            <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://opencontent.org/openpub/">http://opencontent.org/openpub/</link>.
        </para>
    </refsect1>
</refentry>
