<?xml version='1.0'?> <!--*-nxml-*-->
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
          "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">

<!--
  Written 2012 by David Herrmann <dh.herrmann@googlemail.com>
  Dedicated to the Public Domain
-->

<refentry id="drmHandleEvent">
  <refentryinfo>
    <title>Direct Rendering Manager</title>
    <productname>libdrm</productname>
    <date>September 2012</date>
    <authorgroup>
      <author>
        <contrib>Developer</contrib>
        <firstname>David</firstname>
        <surname>Herrmann</surname>
        <email>dh.herrmann@googlemail.com</email>
      </author>
    </authorgroup>
  </refentryinfo>

  <refmeta>
    <refentrytitle>drmHandleEvent</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>drmHandleEvent</refname>
    <refpurpose>read and process pending DRM events</refpurpose>
  </refnamediv>

  <refsynopsisdiv>

    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;xf86drm.h&gt;</funcsynopsisinfo>

      <funcprototype>
        <funcdef>int <function>drmHandleEvent</function></funcdef>
        <paramdef>int <parameter>fd</parameter></paramdef>
        <paramdef>drmEventContextPtr <parameter>evctx</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>

  </refsynopsisdiv>

  <refsect1>
    <title>Description</title>
    <para><function>drmHandleEvent</function> processes outstanding DRM events
          on the DRM file-descriptor passed as <parameter>fd</parameter>. This
          function should be called after the DRM file-descriptor has polled
          readable; it will read the events and use the passed-in
          <parameter>evctx</parameter> structure to call function pointers
          with the parameters noted below:

<programlisting>
typedef struct _drmEventContext {
    int version;
    void (*vblank_handler) (int fd,
                            unsigned int sequence,
                            unsigned int tv_sec,
                            unsigned int tv_usec,
                            void *user_data)
    void (*page_flip_handler) (int fd,
                               unsigned int sequence,
                               unsigned int tv_sec,
                               unsigned int tv_usec,
                               void *user_data)
} drmEventContext, *drmEventContextPtr;
</programlisting>

          </para>

  </refsect1>

  <refsect1>
    <title>Return Value</title>
    <para><function>drmHandleEvent</function> returns <literal>0</literal> on
          success, or if there is no data to read from the file-descriptor.
          Returns <literal>-1</literal> if the read on the file-descriptor fails
          or returns less than a full event record.</para>
  </refsect1>

  <refsect1>
    <title>Reporting Bugs</title>
    <para>Bugs in this function should be reported to
      https://bugs.freedesktop.org/enter_bug.cgi?product=DRI&amp;component=libdrm
      under the "DRI" product, component "libdrm"</para>
  </refsect1>

  <refsect1>
    <title>See Also</title>
    <para>
      <citerefentry><refentrytitle>drm</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
      <citerefentry><refentrytitle>drm-kms</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
      <citerefentry><refentrytitle>drmModePageFlip</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
      <citerefentry><refentrytitle>drmWaitVBlank</refentrytitle><manvolnum>3</manvolnum></citerefentry>
    </para>
  </refsect1>
</refentry>