Declarations for linux fifo utilities. More...

#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <signal.h>
#include <sys/stat.h>
#include "profileutils.h"

Classes
struct	fifo_channel
	The basic fifo_channel structure. More...

struct	fifo_list
	A structure to hold a list of fifo_channels. More...

Macros
#define	MAX_FNAME_SZ 256
	The maximum allowed filename length.

#define	RWBUFF_SZ 256
	The size of the i/o buffer.

#define	ERRMSG_SZ 256
	The size of the errmsg buffers.

#define	ERRMSG(msg) fprintf(stderr, "%s (%s line %i)\n", msg,__FILE__,__LINE__)
	Error reporting macro. If not using the function __error_message(msg) then use stderr.

#define	RTSIGIO (SIGRTMIN+4)

#define	RTSIGIGN (SIGRTMIN+5)

#define	RTSIGPING (SIGRTMIN+6)

Functions
int	init_fifo_channel (fifo_channel *fc)
	Initializes the fifo_channel structure. More...

int	setup_fifo_channel (fifo_channel *fc, size_t buffsz)
	Allocate the server_response buffer. More...

int	set_fifo_channel (fifo_channel fc, const char fin, const char fout, int(inp_hand)(fifo_channel ), void adata)
	Set the details of the fifo_channel. More...

int	create_fifos (fifo_channel *fc)
	Creates the fifos if they don't already exist. More...

int	open_fifo_channel_in (fifo_channel *fc)
	Opens the input fifo channel for async reading with an exculsive lock. More...

int	open_fifo_channel_in_nolock (fifo_channel *fc)
	Opens the input fifo channel for async reading without an exculsive lock. More...

int	open_fifo_channel_out (fifo_channel *fc)
	Opens the output fifo channel for non-blocking writing with an exclusive lock. More...

int	open_fifo_channel_out_nolock (fifo_channel *fc)
	Opens the output fifo channel for non-blocking writing without an exclusive lock. More...

int	write_fifo_channel (fifo_channel fc, const char com, int comlen)
	Write data to the output channel. More...

int	write_fifo_channel_seqmsg (fifo_channel fc, const char com, int comlen, char *seqmsg)
	Write data to the output channel, including a sequence message. More...

int	read_fifo_channel (fifo_channel *fc)
	Read data from the input fifo channel. More...

int	check_if_in_locked (fifo_channel *fc)
	Checks if the output fifo of the channel is locked. More...

int	init_fifo_list (fifo_list *fl)
	Initialize the fifo_list. More...

int	setup_fifo_list (fifo_list *fl, int nch)
	Setup a fifo_list. More...

int	set_fifo_list_channel (fifo_list fl, int nch, int buffsz, const char fin, const char fout, int(inp_hand)(fifo_channel ), void adata)
	Set the details of one channel in the list. More...

int	connect_fifo_list (fifo_list *fl)
	Open each fifo in the list, with exclusive lock on the input fifo. More...

int	connect_fifo_list_nolock (fifo_list *fl)
	Open each fifo in the list, without exclusive locks. More...

int	init_fifo_list_pending_reads (fifo_list *fl)
	Populates the fd_to_fifo_ch_index array.

void	catch_fifo_response_list (int signum)
	A SIGIO handler, which uses global_fifo_list to call the appropriate handler. More...

int	set_fifo_list_rtsig (fifo_list *fl)
	Change from SIGIO to real time signals.

void	catch_fifo_pending_reads (int signum, siginfo_t siginf, void ucont)
	A handler for a R/T SIGIO, which just updates the pending reads meta data but does no actual signal handling.

void	catch_fifo_standard_sigio (int signum)
	A handler for normal SIGIO when we should have gotten the R/T SIGIO, implying signal queue overflow.

int	fifo_list_do_pending_read (fifo_list *fl)
	Runs through the pending reads, dispatching each handler in turn.

int	ropen_async (char *fname, int nolock)
	Open a file for non-blocking asynchronous reads. More...

int	wopen_nonblock (char *fname, int nolock)
	Open a file for non-blocking writes. More...

double	get_currt ()
	Returns time since the Unix epoch in double precision seconds. More...

Variables
fifo_list *	global_fifo_list
	The global fifo_list, for signal handling.

Detailed Description

Author: Jared R. Males

Definition in file fifoutils.h.

Function Documentation

int init_fifo_channel ( fifo_channel * fc )

All members are set to zero by this init. Should be called every time a fifo_channel is created.

Parameters

fc	is a pointer the fifo_channel to initialize

Return values

0	on success (always)

Definition at line 31 of file fifoutils.c.

Referenced by setup_fifo_list().

int setup_fifo_channel	(	fifo_channel *	fc,
		size_t	buffsz
	)

Checks if buffer is non-zero and free's it if it is - so you must call init_fifo_channel before setup.

Parameters

fc	is a pointer the fifo_channel to initialize
buffsz	is the size of the server_response buffer to allocate

Return values

0	on success
-1	on failure

Definition at line 47 of file fifoutils.c.

References ERRMSG.

Referenced by set_fifo_list_channel().

int set_fifo_channel	(	fifo_channel *	fc,
		const char *	fin,
		const char *	fout,
		int()(fifo_channel )	inp_hand,
		void *	adata
	)

Allocates and assigns the file name strings, you must call init_fifo_channel before using this function. Also installs the handler pointer. This function calls create_fifos, thus creating them if they don't already exist. This function does not actually open the fifos.

Parameters

fc	is a pointer the fifo_channel to initialize
fin	is the file name of the input fifo
fout	is the file name of the output fifo
inp_hand	is a pointer to the input handler function for this channel
adata	a pointer to auxiliary data.

Return values

0	on success
-1	on failure

Definition at line 63 of file fifoutils.c.

References create_fifos(), and ERRMSG.

Referenced by set_fifo_list_channel().

int create_fifos ( fifo_channel * fc )

Parameters

fc	is a pointer the fifo_channel to initialize

Return values

0	on success
-1	on failure (check errno)

Definition at line 92 of file fifoutils.c.

References ERRMSG.

Referenced by set_fifo_channel().

int open_fifo_channel_in ( fifo_channel * fc )

Clears the fifo, ignoring any pending input, so open before listening for SIGIO

Parameters

fc	is a pointer the fifo_channel to initialize

Return values

0	on success
-1	on failure

Definition at line 119 of file fifoutils.c.

References ERRMSG, and ropen_async().

Referenced by connect_fifo_list().

int open_fifo_channel_in_nolock ( fifo_channel * fc )

Clears the fifo, ignoring any pending input, so open before listening for SIGIO

Parameters

fc	is a pointer the fifo_channel to initialize

Return values

0	on success
-1	on failure

Definition at line 144 of file fifoutils.c.

References ERRMSG, and ropen_async().

Referenced by connect_fifo_list_nolock().

int open_fifo_channel_out ( fifo_channel * fc )

Parameters

fc	is a pointer the fifo_channel to initialize

Return values

0	on success
-1	on failure

Definition at line 166 of file fifoutils.c.

References ERRMSG, and wopen_nonblock().

int open_fifo_channel_out_nolock ( fifo_channel * fc )

Parameters

fc	is a pointer the fifo_channel to initialize

Return values

0	on success
-1	on failure

Definition at line 180 of file fifoutils.c.

References ERRMSG, and wopen_nonblock().

Referenced by connect_fifo_list(), and connect_fifo_list_nolock().

int write_fifo_channel	(	fifo_channel *	fc,
		const char *	com,
		int	comlen
	)

Parameters

fc	is a pointer the fifo_channel to initialize
com	the buffer to write
comlen	length of the buffer

Return values

nbytes	the number of bytes written, on success
-1	on failure

Definition at line 194 of file fifoutils.c.

References ERRMSG, and RWBUFF_SZ.

Referenced by VisAO::com_auto_handler(), VisAO::com_local_handler(), VisAO::com_remote_handler(), VisAO::com_script_handler(), VisAO::read_diofifo(), and VisAO::framegrabber< dataT >::send_ping().

int write_fifo_channel_seqmsg	(	fifo_channel *	fc,
		const char *	com,
		int	comlen,
		char *	seqmsg
	)

Parameters

fc	is a pointer the fifo_channel to initialize
com	the buffer to write
comlen	length of the buffer
seqmsg	the 6 byte sequence message.

Return values

nbytes	the number of bytes written, on success
-1	on failure

Definition at line 218 of file fifoutils.c.

References ERRMSG, and RWBUFF_SZ.

Referenced by VisAO::VisAOApp_base::write_fifo_channel().

int read_fifo_channel ( fifo_channel * fc )

Parameters

fc	is a pointer the fifo_channel to initialize

Return values

0	on success
1	if read not complete before filling __fifo_channel::server_response.

Definition at line 246 of file fifoutils.c.

References ERRMSG, and RWBUFF_SZ.

Referenced by VisAO::com_auto_handler(), VisAO::com_local_handler(), VisAO::com_remote_handler(), VisAO::com_script_handler(), VisAO::VisAOApp_base::get_fifo_channel_response(), VisAO::read_diofifo(), VisAO::frameselector::Run(), VisAO::reconstructor::Run(), VisAO::frameserver::send_frame(), and VisAO::JoeCtrl::TestCCD47CtrlLink().

int check_if_in_locked ( fifo_channel * fc )

Normally a process obtains an exclusive lock on the input of its fifo channels. That is it wants to be the only process which can receive commands on that channel. This function checks for the presence of such a lock on the output fifo of a channel, as a way to test if anybody is listening. This can be used to prevent writing to a fifo that isn't being read. See VisApp_base::write_fifo_channel for an example.

Parameters

fc	the relevant fifo_channel

Return values

0	if there is not lock
1	if there is a lock

Definition at line 316 of file fifoutils.c.

int init_fifo_list ( fifo_list * fl )

All members set to 0.

Parameters

fl	is a pointer to the fifo_list to initialize

Return values

0	on success (always)

Definition at line 341 of file fifoutils.c.

References fifo_list::fds, fifo_list::fifo_ch, fifo_list::maxfile, fifo_list::nchan, fifo_list::rq_sz, and fifo_list::RTSIGIO_overflow.

Referenced by VisAO::VisAOApp_base::VisAOApp_base().

int setup_fifo_list	(	fifo_list *	fl,
		int	nch
	)

Allocates the fifo_ch array, then initializes each fifo_channel

Parameters

fl	is a pointer to the initialized fifo_list to setup
nch	is the number of channels in the list

Return values

0	on success
-1	on failure

Definition at line 354 of file fifoutils.c.

References ERRMSG, fifo_list::fifo_ch, init_fifo_channel(), and fifo_list::nchan.

Referenced by VisAO::framegrabber< dataT >::Create(), and VisAO::VisAOApp_base::setup_fifo_list().

int set_fifo_list_channel	(	fifo_list *	fl,
		int	nch,
		int	buffsz,
		const char *	fin,
		const char *	fout,
		int()(fifo_channel )	inp_hand,
		void *	adata
	)

First calls setup_fifo_channel Then calls set_fifo_channel

Parameters

fl	is a pointer to the initialized fifo_list to setup
nch	is the channel number to set
buffsz	is the size of the server_reponse buvver for this channel
fin	is the file name of the input fifo
fout	is the file name of the output fifo
inp_hand	is a pointer to the input handler function for this channel
adata	a pointer to auxiliary data.

Return values

0	on success
-1	on failure

Definition at line 373 of file fifoutils.c.

References fifo_list::fifo_ch, set_fifo_channel(), and setup_fifo_channel().

Referenced by VisAO::framegrabber< dataT >::Create(), VisAO::reconstructor::Create(), VisAO::JoeCtrl::Create(), VisAO::CCD47Ctrl::init_VisAOApp(), VisAO::FocusMotorCtrl::initapp(), VisAO::VisAOApp_base::setup_baseApp(), and VisAO::dioserver::setup_dioserver().

int connect_fifo_list ( fifo_list * fl )

The input channel is locked so that no other process will intercept communications intended for the calling process. Output fifos are not locked, as multiple processes could conceivable write to the same channel (e.g. a ping or watchdog). Both channels can't be locked, as then nobody could establish a connection.

Parameters

fl	is a pointer to the initialized fifo_list to setup

Return values

0	on success
-1	on failure

Definition at line 379 of file fifoutils.c.

References ERRMSG, ERRMSG_SZ, fifo_list::fds, fifo_list::fifo_ch, init_fifo_list_pending_reads(), fifo_list::maxfile, fifo_list::nchan, open_fifo_channel_in(), and open_fifo_channel_out_nolock().

Referenced by VisAO::VisAOApp_base::connect_fifo_list().

int connect_fifo_list_nolock ( fifo_list * fl )

Parameters

fl	is a pointer to the initialized fifo_list to setup

Return values

0	on success
-1	on failure

Definition at line 415 of file fifoutils.c.

References ERRMSG, ERRMSG_SZ, fifo_list::fds, fifo_list::fifo_ch, init_fifo_list_pending_reads(), fifo_list::maxfile, fifo_list::nchan, open_fifo_channel_in_nolock(), and open_fifo_channel_out_nolock().

Referenced by VisAO::VisAOApp_base::connect_fifo_list_nolock().

void catch_fifo_response_list ( int signum )

This means you must define global_fifo_list and point it at your fifo_list or this will segfault.

Referenced by VisAO::VisAOApp_base::check_fifo_list_RTpending(), and VisAO::VisAOApp_base::setup_sigio().

int ropen_async	(	char *	fname,
		int	nolock
	)

The nolock parameter controls whether or not to attempt an exclusive lock.

Parameters

fname	is the name of the file to open
nolock	if 0 attempt to get an exclusive lock (WRLCK) and close file if rejected. if 1 do not lock.

Return values

>0	(the file descriptor) on success
0	on failure
-1	on failure to lock

Definition at line 607 of file fifoutils.c.

References ERRMSG, and ERRMSG_SZ.

Referenced by open_fifo_channel_in(), and open_fifo_channel_in_nolock().

int wopen_nonblock	(	char *	fname,
		int	nolock
	)

The nolock parameter controls whether or not to attempt an exclusive lock.

Parameters

fname	is the name of the file to open
nolock	if 0 attempt to get an exclusive lock (WRLCK) and close file if rejected. if 1 do not lock.

Return values

>0	(the file descriptor) on success
0	on failure
-1	on failure to lock

Definition at line 649 of file fifoutils.c.

References ERRMSG, and ERRMSG_SZ.

Referenced by open_fifo_channel_out(), open_fifo_channel_out_nolock(), and VisAO::VisAOApp_base::write_fifo_channel().

double get_currt ( )

Uses clock_gettime, CLOCK_REALTIME, and the attendant timespec, so it has precision of nanoseconds.

Definition at line 23 of file fifoutils.c.

Classes

Macros

Functions

Variables

Detailed Description

Function Documentation