<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "xhtml1-transitional.dtd">
<!-- saved from url=(0013)about:internet -->
<?xml-stylesheet type="text/xsl" href="mathml.xsl"?><html xmlns="http://www.w3.org/1999/xhtml" xmlns:pref="http://www.w3.org/2002/Math/preference" xmlns:xlink="http://www.w3.org/1999/xlink" pref:renderer="mathplayer-dl">
  <head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
    <style xmlns="" type="text/css">
    /* This style sets a margin around the entire page */
        html, body {
            margin: 10px;
        }

        p {
            font: normal 16px verdana, sans-serif;
            margin: 0;
            padding-bottom:12px;
        }

        h1 {
            font: bold 25px verdana, sans-serif;
            margin-top: 0;
            margin-bottom: 3px;
            padding-top: 0;
            padding-bottom: 0;
        }

        h2 {
            font: bold 19px verdana, sans-serif;
            margin-top: 28px;
            margin-bottom: 3px;
            padding-top: 0;
            padding-bottom: 0;
        }

        h3 {
            font: bold 19px verdana, sans-serif !important;
            margin-top: 28px;
            margin-bottom: 3px;
            padding-top: 0;
            padding-bottom: 0;
        }

        li {
            font: normal 16px verdana, sans-serif;
            margin-top: 0;
            margin-bottom: 18px;
            padding-top: 0;
            padding-bottom: 0;
        }

        .pdparam {
            font: italic 16px verdana, sans-serif;
        }

                .term {
                        font: italic 16px verdana, sans-serif;
                        font-weight: normal;
                }

                .type {
                        font: normal 16px verdana, sans-serif !important;
                }

                .parameter {
                        font-style: italic;
                        }

        a:link, a:visited {
            color: blue;
            text-decoration: none;
            font: normal 16px;
        }

        a:hover {
            background-color: #FFFF99;
            font: normal 16px;
        }

        div.funcsynopsis {
            text-align: left;
            background-color: #e6e6e6;
            font: normal 16px verdana, sans-serif;
                        padding-top: 10px;
                        padding-bottom: 10px;
        }

        div.funcsynopsis table {
            border-collapse: separate;
            font: normal 16px verdana, sans-serif;
        }

        div.funcsynopsis td {
            background-color: #e6e6e6;
            border: 0 solid #000;
            padding: 1px;
            font: normal 16px verdana, sans-serif;
        }

        div.refsect1 {
            font-family: verdana, sans-serif;
            font-size: 16px;
        }

        code.constant {
            font: normal 16px courier new, monospace !important;
        }

                span.errorname {
            font: normal 16px verdana, sans-serif !important;
        }

        code.function {
            font: bold 16px verdana, sans-serif !important;
        }

        b.fsfunc {
            font: bold 16px verdana, sans-serif !important;
        }

        code.varname {
            font: italic 16px verdana, sans-serif;
        }

        code.replaceable {
            font: italic 16px courier new, monospace;
        }

        code.funcdef {
            font: normal 16px verdana, sans-serif !important;
        }

        .citerefentry {
            font: normal 16px verdana, sans-serif !important;
        }

        .parameter {
            font-style: italic;
        }

        code.fsfunc {
            font: normal 16px verdana, sans-serif !important;
        }

        /* PARAMETER: This style controls spacing between the terms in Parameter section */
        dt {
            margin-top: 15px;
        }

        /* TABLES: These styles apply to all tables OTHER than the Synopsis and Example tables */
        div.refsect1 table {
            width: 100%;
                        margin-top: 10px;
            background-color: #FFF;
                        border-collapse: collapse;
                        border-color: #000;
            border-width: 1px;
                        font: normal 16px verdana, sans-serif;
        }

        div.refsect1 th {
                        border-collapse: collapse;
                        border-color: #000;
            border-width: 1px;
            font: bold 16px verdana, sans-serif;
        }

        div.refsect1 td {
            background-color: #FFF;
            padding: 5px;
            vertical-align: text-top;
                        border-collapse: collapse;
                        border-color: #000;
            border-width: 1px;
            font: normal 16px verdana, sans-serif;
        }

                  div.refsect1 p{
            font: normal 16px verdana, sans-serif;
            margin-top: 8px;
            margin-bottom: 8px;
            padding-top: 0;
            padding-bottom: 0;
        }


        /* EXAMPLE: These styles apply only to the Example section */
        div.refsect2 {
            font: normal 16px courier new, monospace !important;
        }

        div.refsect2 table {
            margin-top: 0;
            background-color: #e6e6e6;
            width: 100%;
            border: 0 solid #000;
            padding: 2px;
            font: normal 16px courier new, monospace !important;
        }

        div.refsect2 td {
            background-color: #e6e6e6;
            font: normal 16px courier new, monospace !important;
                        white-space:pre;
        }

        /* COPYRIGHT: This style formats the text of the copyright statement at the bottom of the page */
        div.refsect3 {
            font: normal 11px verdana, sans-serif;
            margin-top: 50px;
            margin-bottom: 20px;
            padding-top: 0;
            padding-bottom: 0;
        }

</style>
    <title>clEnqueueAcquireGLObjects</title>
    <meta name="generator" content="DocBook XSL Stylesheets V1.78.1" />
    <meta name="keywords" content="clEnqueueAcquireGLObjects" />
  </head>
  <body>
    <div class="refentry">
      <a id="id-1"></a>
      <div class="titlepage"></div>
      <div xmlns="" class="refnamediv">
        <a xmlns="http://www.w3.org/1999/xhtml" id="clEnqueueAcquireGLObjects"></a>
        <h1>clEnqueueAcquireGLObjects</h1>
        <p>
            Acquire OpenCL memory objects that have been created from OpenGL objects.
        </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">
                        clEnqueueAcquireGLObjects
                    </strong>
                (</code>
                <td><a xmlns="http://www.w3.org/1999/xhtml" class="link" href="abstractDataTypes.html" target="pagedisplay">cl_command_queue</a> <var xmlns="http://www.w3.org/1999/xhtml" class="pdparam">command_queue</var>, </td>
              </td>
            </tr>
            <tr valign="top">
              <td> </td>
              <td><a xmlns="http://www.w3.org/1999/xhtml" class="link" href="scalarDataTypes.html" target="pagedisplay">cl_uint</a> <var xmlns="http://www.w3.org/1999/xhtml" class="pdparam">num_objects</var>, </td>
            </tr>
            <tr valign="top">
              <td> </td>
              <td>const <a xmlns="http://www.w3.org/1999/xhtml" class="link" href="abstractDataTypes.html" target="pagedisplay">cl_mem</a> <var xmlns="http://www.w3.org/1999/xhtml" class="pdparam">*mem_objects</var>, </td>
            </tr>
            <tr valign="top">
              <td> </td>
              <td><a xmlns="http://www.w3.org/1999/xhtml" class="link" href="scalarDataTypes.html" target="pagedisplay">cl_uint</a> <var xmlns="http://www.w3.org/1999/xhtml" class="pdparam">num_events_in_wait_list</var>, </td>
            </tr>
            <tr valign="top">
              <td> </td>
              <td>const <a xmlns="http://www.w3.org/1999/xhtml" class="link" href="abstractDataTypes.html" target="pagedisplay">cl_event</a> <var xmlns="http://www.w3.org/1999/xhtml" class="pdparam">*event_wait_list</var>, </td>
            </tr>
            <tr valign="top">
              <td> </td>
              <td><a xmlns="http://www.w3.org/1999/xhtml" class="link" href="abstractDataTypes.html" target="pagedisplay">cl_event</a> <var xmlns="http://www.w3.org/1999/xhtml" class="pdparam">*event</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"> 
                        command_queue
                    </code>
                </span>
            </dt>
            <dd>
              <p> 
A valid command-queue. All devices used to create the OpenCL context
associated with <code class="varname">command_queue</code> must support acquiring shared CL/GL objects.
This constraint is enforced at context creation time.
                    </p>
            </dd>
            <dt>
              <span class="term">
                    <code class="varname"> 
                        num_objects
                    </code>
                </span>
            </dt>
            <dd>
              <p> 
The number of memory objects to be acquired in <code class="varname">mem_objects</code>.
                    </p>
            </dd>
            <dt>
              <span class="term">
                    <code class="varname"> 
                        mem_objects
                    </code>
                </span>
            </dt>
            <dd>
              <p> 
A pointer to a list of CL memory objects that correspond to GL objects.
                    </p>
            </dd>
            <dt>
              <span class="term">
                    <code class="varname"> 
                        event_wait_list
                    </code>
                , </span>
              <span class="term">
                    <code class="varname"> 
                        num_events_in_wait_list
                    </code>
                </span>
            </dt>
            <dd>
              <p> 
Specify events that need to complete before this
particular command can be executed. If <code class="varname">event_wait_list</code> is NULL, then this particular command
does not wait on any event to complete. If <code class="varname">event_wait_list</code> is NULL,
<code class="varname">num_events_in_wait_list</code>
must be 0. If <code class="varname">event_wait_list</code> is not NULL,
the list of events pointed to by <code class="varname">event_wait_list</code> must
be valid and <code class="varname">num_events_in_wait_list</code> must be greater than 0.
The events specified in
<code class="varname">event_wait_list</code> act as synchronization points.
                    </p>
            </dd>
            <dt>
              <span class="term">
                    <code class="varname"> 
                        event
                    </code>
                </span>
            </dt>
            <dd>
              <p>
                       Returns an event object that identifies
                      this command and can be used to query or queue a wait for the command
                      to complete. <code class="varname">event</code> can be NULL in which case
                      it will not be possible for the application to query the status of
                      this command or queue a wait for this command to complete.  If the
                      <code class="varname">event_wait_list</code> and the <code class="varname">event</code>
                      arguments are not NULL, the <code class="varname">event</code> argument should not
                      refer to an element of the <code class="varname">event_wait_list</code> array
                    </p>
              <p>
                       If the
                      <a class="citerefentry" href="cl_khr_gl_sharing.html"><span class="citerefentry"><span class="refentrytitle">cl_khr_gl_sharing</span></span></a>
                      extension is supported, if an OpenGL context is bound to the current
                      thread, then any OpenGL commands which
                    </p>
              <div class="itemizedlist">
                <ul class="itemizedlist" style="list-style-type: disc; ">
                  <li class="listitem" style="list-style-type: disc">
                              affect or access the contents of a memory object listed in the
                              <code class="varname">mem_objects</code> list, and
                            </li>
                  <li class="listitem" style="list-style-type: disc">
                              were issued on that OpenGL context prior to the call to
                              <code class="function">clEnqueueAcquireGLObjects</code></li>
                </ul>
              </div>
              <p>
                          will complete before execution of any OpenCL commands following the
                          <code class="function">clEnqueueAcquireGLObjects</code> which affect or access
                          any of those memory objects. If a non-NULL event object is returned,
                          it will report completion only after completion of such OpenGL commands.
                        </p>
            </dd>
          </dl>
        </div>
      </div>
      <div class="refsect1">
        <a id="description"></a>
        <h2>Description</h2>
        <p>
          These objects need to be acquired before they can be used by any OpenCL commands
          queued to a command-queue. The OpenGL objects are acquired by the OpenCL context
          associated with <code class="varname">command_queue</code> and can therefore be used by all
          command-queues associated with the OpenCL context.
        </p>
      </div>
      <div class="refsect1">
        <a id="notes"></a>
        <h2>Notes</h2>
        <p>
       In order to ensure data integrity, the application is responsible
      for synchronizing access to shared CL/GL objects by their respective APIs.  Failure to
      provide such synchronization may result in race conditions and other undefined behavior
      including non-portability between implementations.
    </p>
        <p>
       Prior to calling <code class="function">clEnqueueAcquireGLObjects</code>,
      the application must ensure that any pending GL operations which access the objects
      specified in <code class="varname">mem_objects</code>  have completed.  This may be accomplished
      portably by issuing and waiting for completion of a <code class="function">glFinish</code>
      command on all GL contexts with pending references to these objects.  Implementations
      may offer more efficient synchronization methods; for example on some platforms calling
      <code class="function">glFlush</code> may be sufficient, or synchronization may be implicit within
      a thread, or there may be vendor-specific extensions that enable placing a fence in the
      GL command stream and waiting for completion of that fence in the CL command queue. Note
      that no synchronization methods other than <code class="function">glFinish</code> are portable
      between OpenGL implementations at this time.
    </p>
        <p>
       Similarly, after calling
      <code class="function">clEnqueueReleaseGLObjects</code>, the application is responsible
      for ensuring that any pending OpenCL operations which access the objects specified
      in <code class="varname">mem_objects</code> have completed prior to executing subsequent GL
      commands which reference these objects. This may be accomplished portably by calling
      <a class="citerefentry" href="clWaitForEvents.html"><span class="citerefentry"><span class="refentrytitle">clWaitForEvents</span></span></a> with the
      event object returned by <code class="function">clEnqueueReleaseGLObjects</code>, or by calling
      <a class="citerefentry" href="clFinish.html"><span class="citerefentry"><span class="refentrytitle">clFinish</span></span></a>.  As above, some
      implementations may offer more efficient methods.
    </p>
        <p>
       The application is responsible for maintaining the proper order
      of operations if the CL and GL contexts are in separate threads.
    </p>
        <p>
       If a GL context is bound to a thread other than the one in which
      <code class="function">clEnqueueReleaseGLObjects</code> is called, changes to any of the objects in
      <code class="varname">mem_objects</code> may not be visible to that context without additional steps
      being taken by the application. For an OpenGL 3.1 (or later) context, the requirements
      are described in Appendix D ("Shared Objects and Multiple Contexts") of the OpenGL 3.1
      Specification. For prior versions of OpenGL, the requirements are implementation-dependent.
    </p>
        <p>
       Attempting to access the data store of an OpenGL object after
      it has been acquired by OpenCL and before it has been released will result in undefined
      behavior.  Similarly, attempting to access a shared CL/GL object from OpenCL before it
      has been acquired by the OpenCL command queue, or after it has been released, will result
      in undefined behavior.
    </p>
        <p>
       If the
      <a class="citerefentry" href="cl_khr_gl_event.html"><span class="citerefentry"><span class="refentrytitle">cl_khr_gl_event</span></span></a> extension
      is supported, then the OpenCL implementation will ensure that any such pending OpenGL
      operations are complete for an OpenGL context bound to the same thread as the OpenCL
      context. This is referred to as implicit synchronization.
    </p>
      </div>
      <div class="refsect1">
        <a id="errors"></a>
        <h2>Errors</h2>
        <p>
          Returns <span class="errorname">CL_SUCCESS</span> if the function is executed successfully. If
          <code class="varname">num_objects</code> is 0 and <code class="varname">mem_objects</code> is NULL the
          function does nothing and returns <span class="errorname">CL_SUCCESS</span>.  Otherwise,
          it returns one of the following errors:
        </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_VALUE</span> if <code class="varname">num_objects</code>
              is zero and <code class="varname">mem_objects</code> is not a NULL value or if
              <code class="varname">num_objects</code> &gt; 0 and <code class="varname">mem_objects</code> is NULL.
            </li>
            <li class="listitem" style="list-style-type: disc"><span class="errorname">CL_INVALID_MEM_OBJECT</span> if memory objects in
              <code class="varname">mem_objects</code> are not valid OpenCL memory objects.
            </li>
            <li class="listitem" style="list-style-type: disc"><span class="errorname">CL_INVALID_COMMAND_QUEUE</span> if <code class="varname">command_queue</code>
              is not a valid command-queue.
            </li>
            <li class="listitem" style="list-style-type: disc"><span class="errorname">CL_INVALID_CONTEXT</span> if context associated with
              <code class="varname">command_queue</code> was not created from an OpenGL context.
            </li>
            <li class="listitem" style="list-style-type: disc"><span class="errorname">CL_INVALID_GL_OBJECT</span> if memory objects in
              <code class="varname">mem_objects</code> have not been created from a GL object(s).
            </li>
            <li class="listitem" style="list-style-type: disc"><span class="errorname">CL_INVALID_EVENT_WAIT_LIST</span>
              if <code class="varname">event_wait_list</code> is NULL and
              <code class="varname">num_events_in_wait_list</code> &gt; 0,
              or <code class="varname">event_wait_list</code> is not NULL and
              <code class="varname">num_events_in_wait_list</code> is 0, or if event objects in
              <code class="varname">event_wait_list</code> are not valid events.
            </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="http://www.khronos.org/registry/cl/specs/opencl-1.2-extensions.pdf#page=56" target="OpenCL Spec">OpenCL Specification</a>
        </p>
      </div>
      <div class="refsect1">
        <a id="seealso"></a>
        <h2>Also see</h2>
        <p>
            <a class="citerefentry" href="cl_khr_gl_sharing.html"><span class="citerefentry"><span class="refentrytitle">cl_khr_gl_sharing</span></span></a>,
            <a class="citerefentry" href="clEnqueueReleaseGLObjects.html"><span class="citerefentry"><span class="refentrytitle">clEnqueueReleaseGLObjects</span></span></a>,
            <a class="citerefentry" href="cl_khr_gl_event.html"><span class="citerefentry"><span class="refentrytitle">cl_khr_gl_event</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 © 2007-2011 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.
</div>
    </div>
  </body>
</html>