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    <title>clReleaseEvent</title>
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      <div xmlns="" class="refnamediv">
        <a xmlns="http://www.w3.org/1999/xhtml" id="clReleaseEvent"></a>
        <h1>
            clReleaseEvent
        </h1>
        <p>
            Decrements the <code xmlns="http://www.w3.org/1999/xhtml" class="varname">event</code> reference count.
        </p>
      </div>
      <div class="refsynopsisdiv">
        <h2></h2>
        <div class="funcsynopsis">
          <table xmlns="" border="0" summary="Function synopsis" cellspacing="0" cellpadding="0">
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              <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">clReleaseEvent</strong>
                (</code>
                <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>
              </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">event</code>
              </span>
            </dt>
            <dd>
              <p>Event object being released.</p>
            </dd>
          </dl>
        </div>
      </div>
      <div class="refsect1">
        <a id="notes"></a>
        <h2>Notes</h2>
        <p>
            Decrements the <code class="varname">event</code> reference count.
        </p>
        <p>
          The event object is deleted once the reference count becomes zero, the specific command
          identified by this event has completed (or terminated) and there are no commands in
          the command-queues of a context that require a wait for this event to complete.
          Using this function
          to release a reference that was not obtained by creating the object or by calling 
          <a class="citerefentry" href="clRetainEvent.html"><span class="citerefentry"><span class="refentrytitle">clRetainEvent</span></span></a>
          causes undefined behavior.
        </p>
        <p>
          Developers should be careful when releasing their last reference count on events
          created by <a class="citerefentry" href="clCreateUserEvent.html"><span class="citerefentry"><span class="refentrytitle">clCreateUserEvent</span></span></a>
          that have not yet been set to status of <code class="constant">CL_COMPLETE</code> or an error.
          If the user event was used in the <code class="varname">event_wait_list</code> argument passed to
          a <code class="function">clEnqueue***</code> API or another application host thread is waiting
          for it in <a class="citerefentry" href="clWaitForEvents.html"><span class="citerefentry"><span class="refentrytitle">clWaitForEvents</span></span></a>,
          those commands and host threads will continue to wait for the event status to reach
          <code class="constant">CL_COMPLETE</code> or error, even after the user has released the object.
          Since in this scenario the developer has released his last reference count to the
          user event, it would be in principle no longer valid for him to change the status
          of the event to unblock all the other machinery.  As a result the waiting tasks will
          wait forever, and associated events, <span class="type">cl_mem</span> objects, command queues and
          contexts are likely to leak.  In-order command queues caught up in this deadlock may
          cease to do any work.
        </p>
      </div>
      <div class="refsect1">
        <a id="errors"></a>
        <h2>Errors</h2>
        <p>
          Returns <span class="errorname">CL_SUCCESS</span> if the function executed
          successfully. 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_EVENT</span> if <code class="varname">event</code> is not a
              valid event object.
            </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=clReleaseEvent" target="OpenCL Spec">OpenCL Specification</a>
        </p>
      </div>
      <div class="refsect1">
        <a id="seealso"></a>
        <h2>Also see</h2>
        <p>
            <a class="citerefentry" href="clGetEventInfo.html"><span class="citerefentry"><span class="refentrytitle">clGetEventInfo</span></span></a>,
            <a class="citerefentry" href="clRetainEvent.html"><span class="citerefentry"><span class="refentrytitle">clRetainEvent</span></span></a>,
            <a class="citerefentry" href="clWaitForEvents.html"><span class="citerefentry"><span class="refentrytitle">clWaitForEvents</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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