1COMEDI_MARK_BUFFER_W(3)        Comedi reference        COMEDI_MARK_BUFFER_W(3)
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NAME

6       comedi_mark_buffer_written - streaming buffer control
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SYNOPSIS

9       #include <comedilib.h>
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11       int comedi_mark_buffer_written(comedi_t * device,
12                                      unsigned int subdevice,
13                                      unsigned int num_bytes);
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DESCRIPTION

16       The function comedi_mark_buffer_written is used on a subdevice that has
17       a Comedi output command in progress. It should only be used if you are
18       using a mmap mapping to write data to Comedi's buffer (as opposed to
19       calling write on the device file descriptor), since Comedi will
20       automatically keep track of how many bytes have been transferred via
21       write calls. This function is used to indicate that the next num_bytes
22       bytes in the buffer are valid and may be sent to the device.
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RETURN VALUE

25       On success, comedi_mark_buffer_written returns the number of bytes
26       successfully marked as written. The return value may be less than the
27       num_bytes. On failure, -1 is returned.
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AUTHORS

30       David Schleef <ds@schleef.org>
31           Author.
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33       Frank Mori Hess <fmhess@users.sourceforge.net>
34           Author.
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36       Herman Bruyninckx <Herman.Bruyninckx@mech.kuleuven.ac.be>
37           Author.
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39       Bernd Porr <tech@linux-usb-daq.co.uk>
40           Author.
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42       Ian Abbott <abbotti@mev.co.uk>
43           Author.
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45       Éric Piel <piel@delmic.com>
46           Author.
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49       Copyright © 1998-2003 David Schleef
50       Copyright © 2001-2003, 2005, 2008 Frank Mori Hess
51       Copyright © 2002-2003 Herman Bruyninckx
52       Copyright © 2012 Bernd Porr
53       Copyright © 2012 Ian Abbott
54       Copyright © 2012, 2015 Éric Piel
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56       This document is part of Comedilib. In the context of this document,
57       the term "source code" as defined by the license is interpreted as the
58       XML source.
59
60       This library is free software; you can redistribute it and/or modify it
61       under the terms of the GNU Lesser General Public License as published
62       by the Free Software Foundation, version 2.1 of the License.
63
64       This library is distributed in the hope that it will be useful, but
65       WITHOUT ANY WARRANTY; without even the implied warranty of
66       MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
67       General Public License for more details.
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69       You should have received a copy of the GNU Lesser General Public
70       License along with this library; if not, write to the Free Software
71       Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
72       USA.
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77Comedi                            05/11/2017           COMEDI_MARK_BUFFER_W(3)
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