main.cpp File Reference

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <signal.h>
#include <sys/time.h>
#include <time.h>
#include "mudpi.h"
#include "math.h"
#include <vector>
#include <sstream>
#include <fcntl.h>
#include <sys/mman.h>
#include <sys/shm.h>
#include <sys/stat.h>

Macros
#define	IFNAMSIZ   16
#define	LINESIZE   1024*500

Functions
void	error (const char *msg)
void	sig_int (int sig)
int	bind_src (int sockfd, char const *ifName)
int	parse_args (int argc, char **argv, char *&hostname, int &portno, int &topicId, int &nframes, long &delayUs, char *&data_file, int &bufSize, bool &waitTrigger, bool &rollingRamp, int &sampleSize, int &limit)
void	fillSample (int samplePayloadFloats, int sampleId)
void	readSamples (char *filename, int samplePayloadFloats)
void	create_shm ()
void	remove_shm ()
void	signal_shm (int value)
void	wait_shm (int value)
int	main (int argc, char **argv)

Variables
int	time_to_die =0
std::vector< std::vector< float > >	samplesVector
int	shm_fd
int *	shm_ptr

Macro Definition Documentation

IFNAMSIZ

#define IFNAMSIZ   16

LINESIZE

#define LINESIZE   1024*500

Function Documentation

bind_src()

int bind_src	(	int	sockfd,
		char const *	ifName
	)

create_shm()

void create_shm

(

)

we want the shm to be writeable by all so disable the umask

open or create

error()

void error

(

const char *

msg

)

fillSample()

void fillSample	(	int	samplePayloadFloats,
		int	sampleId
	)

If we just ramp forever with increasing sample Id we will run out of numerical precision so when we get to 1000 increments start again

main()

int main	(	int	argc,
		char **	argv
	)

Announce the amount of data we are sending

Either read sample values from a file or generate a ramp if no file is given

Access mudpi { int32_t topicId; uint16_t componentId; uint16_t applicationTag; uint16_t reserved; uint16_t version; uint32_t sampleId; timestamp_t timestamp; uint16_t frameId; uint16_t numFrames; uint16_t payloadSize; uint16_t reserved2; }mudpiHeader;

Fill in some fixed values for MUDPI constant fields

Create the shm seg where we coordinate instances

terminate on signal

If waiting for a trigger process, them wait, otherwise signal

If the rollingRamp flag is set then update the ramp for this sampleId if not coming from a file

Fill in some of the more interesting MUDPI fields

fill in this frame of data from the relevant part of the sample

move to the next sample and wrap around if needed

parse_args()

int parse_args	(	int	argc,
		char **	argv,
		char *&	hostname,
		int &	portno,
		int &	topicId,
		int &	nframes,
		long &	delayUs,
		char *&	data_file,
		int &	bufSize,
		bool &	waitTrigger,
		bool &	rollingRamp,
		int &	sampleSize,
		int &	limit
	)

If the sample size is set, we need to work out how many frames of buffsize we need to transport the sample

For some reason the way I would have done this in the past does not seem to work with the implementation of round on eltrtctk40 which "rounds away from 0" so that round 2.5 is 3 not 2 so the first check catches the case where sampleSize is a multiple of payloadsize

If the sample size is not set, then it's just nframes * payload

readSamples()

void readSamples	(	char *	filename,
		int	samplePayloadFloats
	)

Read one line at a time with a big LINESIZE

Space separated floats up to the maximum allowed

Add to the vector of samples

remove_shm()

void remove_shm

(

)

sig_int()

void sig_int

(

int

sig

)

signal_shm()

void signal_shm

(

int

value

)

Just write the value into the shm after checking the segment is good

wait_shm()

void wait_shm

(

int

value

)

Wait for a value(sampleId) to be present in the shm or bail out if we get a signal

Variable Documentation

samplesVector

std::vector<std::vector<float> > samplesVector

shm_fd

int shm_fd

shm_ptr

int* shm_ptr

time_to_die

int time_to_die =0