rtf_create_handler.3

上传的是rtlinux的源码包

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.TH "rtf_create_handler" "3" 
.SH "NAME" 
rtf_create_handler \(em install a handler for realtime fifo data 
.SH "SYNOPSIS" 
.PP 
.nf 
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#include <rtl_fifo.h> 
 
int \fBrtf_create_handler\fP(unsigned int \fBfifo\fR, int (* \fBhandler\fR)()); 
.fi 
.SH "DESCRIPTION" 
.PP 
\fBrtf_create_handler\fP installs  a  handler which is executed when data is written to or read from a real-time fifo (RT-FIFO) by a user-space process.   \fBfifo\fR is an RT-FIFO that must have previously been created with a call to \fBrtf_create\fP.  \fBhandler\fR  is  then called whenever a Linux process accesses that fifo. The handler is executed with the Linux (i.e., lowest) priority. 
.PP 
\fBrtf_create_handler\fP  is  often  used  in  conjunction  with rtf_get to process data  acquired  asynchronously  from  a Linux  process.   The installed handler calls \fBrtf_get\fP when data is present.  Because the  handler  is  only  executed when  there is activity on the fifo, polling is not necessary. 
.PP 
The RT-FIFO is a mechanism,  implemented  as  a  character device,  to  communicate between realtime software components (either in threads or  handlers), 
and between realtime software and ordinary Linux processes.  The rtf_* functions are used in RT mode;  Linux  processes use standard character device access functions such  as  \fBread(2)\fP,  \fBwrite(2)\fP  and \fBselect(2)\fP. 
.SH "RETURN VALUE" 
.PP 
On success, 0 is returned.  On failure, a negative value is returned as described below. 
.SH "NOTES" 
.PP 
The handler is only called when a Linux process accesses the FIFO. To install a handler that would be called on \fBrtf_put\fP or \fBrtf_get\fP, use \fBrtf_create_rt_handler\fP. 
.SH "ERRORS" 
.IP "-EINVAL" 10 
\fBfifo\fR is greater than or equal to RTF_NO, or is not a valid RT-FIFO identifier; or \fBhandler\fR is NULL. 
.SH "SEE ALSO" 
\fIrtf_create(3) (link to URL rtf_create.3.html) \fR, \fIrtf_create_rt_handler(3) (link to URL rtf_create_rt_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_put(3) (link to URL rtf_put.3.html) \fR 
.PP 
\(co1997 Jerry Epplin. 
.PP 
Modifications for RTLinux 2.x and 3.x by Michael Barabanov. \(co2001 FSMLabs Inc. 
.PP 
All rights reserved. 
...\" created by instant / docbook-to-man, Wed 13 Jun 2001, 17:58