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.\" This -*- nroff -*- file has been generated from
.\" DocBook SGML with docbook-to-man on Debian GNU/Linux.
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.TH "rtf_make_user_pair" "3"
.SH "NAME"
rtf_make_user_pair \(em make a pair of RT-FIFOs act like a bidirectional FIFO
.SH "SYNOPSIS"
.PP
.nf
.ta 8n 16n 24n 32n 40n 48n 56n 64n 72n
#include <rtl_fifo.h>
int \fBrtf_make_user_pair\fP(unsigned int \fBN\fR, unsigned int \fBP\fR);
.fi
.SH "DESCRIPTION"
.PP
\fBrtf_make_user_pair\fP modifies the behaviour of the RT-FIFO
\fBN\fR: user-space reads of the
\fB/dev/rtfN\fR are now routed to RT-FIFO
\fBP\fR. User-space writes to
\fB/dev/rtfN\fR continue communicating with fifo
\fBN\fR. This essentially makes
\fB/dev/rtfN\fR bidirectional: data sent with
\fBrtf_put\fP to FIFO \fBP\fR will be read from
\fB/dev/rtfN\fR; rtf_get on FIFO \fBN\fR gets
data written to \fB/dev/rtfN\fR.
RT-FIFO handlers are affected similarly.
.PP
The RT-FIFO is a mechanism, implemented as a character device, to communicate between realtime tasks and ordinary Linux processes. The rtf_* functions are used by the realtime tasks; Linux processes use standard character device access functions such as \fBread(2)\fP, \fBwrite(2\fP) and \fBselect(2)\fP.
.SH "RETURN VALUE"
.PP
This function returns 0 on success and a negative error code on error.
.SH "ERRORS"
.IP "-ENODEV" 10
\fBN\fR or \fBP\fR is greater than or equal to RTF_NO.
.IP "-EINVAL" 10
\fBN\fR or \fBP\fR is not a valid RT-FIFO identifier.
.SH "NOTES"
.PP
This function is useful when implementing Linux character device drivers on
top of RT-FIFOs.
.SH "SEE ALSO"
\fIread(2) (link to URL ../susv2/xns/read.html) \fR, \fIrtf_create(3) (link to URL rtf_create.3.html) \fR, \fIrtf_create_handler(3) (link to URL rtf_create_handler.3.html) \fR, \fIrtf_destroy(3) (link to URL rtf_destroy.3.html) \fR, \fIrtf_get(3) (link to URL rtf_get.3.html) \fR, \fIrtf_link_user_ioctl(3) (link to URL rtf_link_user_ioctl.3.html) \fR, \fIwrite(2) (link to URL ../susv2/xns/write.html) \fR
.PP
\(co2001 FSMLabs Inc.
.PP
All rights reserved.
...\" created by instant / docbook-to-man, Wed 13 Jun 2001, 17:58
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