<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN""http://www.w3.org/TR/html4/loose.dtd"> <HTML ><HEAD ><TITLE >comedi_mark_buffer_written</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK REL="HOME" TITLE=" Comedi " HREF="index.html"><LINK REL="UP" TITLE=" Comedi Function Reference " HREF="x4629.html#FUNCTIONREFERENCE"><LINK REL="PREVIOUS" TITLE="comedi_mark_buffer_read" HREF="r6279.html"><LINK REL="NEXT" TITLE="comedi_get_buffer_offset" HREF="r6325.html"></HEAD ><BODY CLASS="REFENTRY" BGCOLOR="#FFFFFF" TEXT="#000000" LINK="#0000FF" VLINK="#840084" ALINK="#0000FF" ><DIV CLASS="NAVHEADER" ><TABLE SUMMARY="Header navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="3" ALIGN="center" >Comedi: The <SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >Control and Measurement Device Interface</I ></SPAN > handbook </TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="r6279.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="r6325.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="FUNC-REF-COMEDI-MARK-BUFFER-WRITTEN" ></A >comedi_mark_buffer_written</H1 ><DIV CLASS="REFNAMEDIV" ><A NAME="AEN6306" ></A ><H2 >Name</H2 >comedi_mark_buffer_written -- streaming buffer control</DIV ><DIV CLASS="REFSYNOPSISDIV" ><A NAME="AEN6309" ></A ><H2 >Synopsis</H2 ><DIV CLASS="FUNCSYNOPSIS" ><P ></P ><A NAME="AEN6310" ></A ><PRE CLASS="FUNCSYNOPSISINFO" >#include <comedilib.h></PRE ><P ><CODE ><CODE CLASS="FUNCDEF" >int comedi_mark_buffer_written</CODE >(comedi_t * device, unsigned int subdevice, unsigned int num_bytes);</CODE ></P ><P ></P ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN6321" ></A ><H2 > Description </H2 ><P >The function comedi_mark_buffer_written() is used on a subdevice that has a Comedi output command in progress. It should only be used if you are using a mmap() (as opposed to calling write() on the device file) to write data to Comedi's buffer, since Comedi will automatically keep track of how many bytes have been transferred via write() calls. This function is used to indicate that the next num_bytes bytes in the buffer are valid and may be sent to the device. If there is an error, -1 is returned.</P ><P > </P ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE SUMMARY="Footer navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="r6279.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="r6325.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >comedi_mark_buffer_read</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="x4629.html#FUNCTIONREFERENCE" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >comedi_get_buffer_offset</TD ></TR ></TABLE ></DIV ></BODY ></HTML >