NAME
comedi_mark_buffer_written - streaming buffer control
SYNOPSIS
#include <comedilib.h>
int comedi_mark_buffer_written (comedi_t * device, unsigned int
subdevice, unsigned int num_bytes);
DESCRIPTION
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.
28 October 2007