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Merged
pradeeban merged 2 commits into from
Jun 23, 2023
Merged

Shared Memory v1.0.0 #76

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cc6cc49
Implement v1.0.0 of Shared Memory
shivangvijay Jun 22, 2023
964855f
commented not required print
shivangvijay Jun 22, 2023
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228 changes: 224 additions & 4 deletions concore.hpp
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Original file line number Diff line number Diff line change
Expand Up @@ -12,15 +12,25 @@
//libraries for platform independent delay. Supports C++11 upwards
#include <chrono>
#include <thread>
#include <sys/ipc.h>
#include <sys/shm.h>
#include <unistd.h>
#include <cstring>
#include <cctype>

using namespace std;

class Concore{

private:
//private variables
string s="",olds="";
string inpath = "./in";
string outpath = "./out";
int shmId_;
char* sharedData_;
// File sharing:- 0, Shared Memory:- 1
int communication_ = 0;

public:
double delay = 1;
Expand All @@ -32,9 +42,96 @@ class Concore{
//Constructor to put in iport and oport values in map
Concore(){
iport = mapParser("concore.iport");
oport = mapParser("concore.oport");
oport = mapParser("concore.oport");
std::map<std::string, int>::iterator it_iport = iport.begin();
std::map<std::string, int>::iterator it_oport = oport.begin();
int iport_number = AlphanumericSM(it_iport->first);
int oport_number = AlphanumericSM(it_oport->first);

if(iport_number != -1 || oport_number != -1)
{
communication_ = 1;
if(iport_number > oport_number)
{
this->createSharedMemory();
}
else
{
this->getSharedMemory();
}
}
}

/**
* return number if number is greater than zero
* and alphanumeric
*/
int AlphanumericSM(const std::string& input) {
bool isPureAlphabetic = true;
for (char c : input) {
if (!std::isalpha(c)) {
isPureAlphabetic = false;
break;
}
}

if (isPureAlphabetic) {
return -1;
} else {
if (int(input[0]))
{
return int(input[0]);
}
return -1;
}
}

~Concore()
{
// Detach the shared memory segment from the process
shmdt(sharedData_);

// Remove the shared memory segment
shmctl(shmId_, IPC_RMID, nullptr);
}


void createSharedMemory()
{
std::cout << "create SM" << std::endl;
shmId_ = shmget(1237, 256, IPC_CREAT | 0666);
if (shmId_ == -1) {
std::cerr << "Failed to create shared memory segment." << std::endl;
}

// Attach the shared memory segment to the process's address space
sharedData_ = static_cast<char*>(shmat(shmId_, NULL, 0));
if (sharedData_ == reinterpret_cast<char*>(-1)) {
std::cerr << "Failed to attach shared memory segment." << std::endl;
}
}

void getSharedMemory()
{
std::cout << "get SM" << std::endl;
while (true) {
// Get the shared memory segment created by Writer
shmId_ = shmget(1237, 256, 0666);

// Check if shared memory exists
if (shmId_ != -1) {
break; // Break the loop if shared memory exists
}

std::cout << "Shared memory does not exist. Make sure the writer process is running." << std::endl;
sleep(1); // Sleep for 1 second before checking again
}

// Attach the shared memory segment to the process's address space
sharedData_ = static_cast<char*>(shmat(shmId_, NULL, 0));
}


map<string,int> mapParser(string filename){
map<string,int> ans;

Expand Down Expand Up @@ -112,8 +209,18 @@ class Concore{
return temp;
}

vector<double> read(int port, string name, string initstr)
{
if(communication_ == 1)
{
return read_SM(port, name, initstr);
}

return read_FM(port, name, initstr);
}

//accepts the file name as string and returns a string of file content
vector<double> read(int port, string name, string initstr){
vector<double> read_FM(int port, string name, string initstr){
chrono::milliseconds timespan((int)(1000*delay));
this_thread::sleep_for(timespan);
string ins;
Expand Down Expand Up @@ -159,6 +266,60 @@ class Concore{
}
s += ins;

vector<double> inval = parser(ins);
simtime = simtime > inval[0] ? simtime : inval[0];

//returning a string with data excluding simtime
inval.erase(inval.begin());
return inval;

}

//accepts the file name as string and returns a string of file content
vector<double> read_SM(int port, string name, string initstr){
chrono::milliseconds timespan((int)(1000*delay));
this_thread::sleep_for(timespan);
string ins = "";
try {
if (shmId_ != -1) {
if (sharedData_ && sharedData_[0] != '\0') {
std::string message(sharedData_, strnlen(sharedData_, 256));
ins = message;
// std::cout << "Received message: " << message << " ins " << ins.length() << std::endl;
}
else
{
throw 505;
}
}
else
{
throw 505;
}
} catch (...) {
ins = initstr;
}

while ((int)ins.length()==0){
this_thread::sleep_for(timespan);
try{
if(shmId_ != -1) {
std::cout << "in read while\n";
std::string message(sharedData_, strnlen(sharedData_, 256));
ins = message;
retrycount++;
}
else{
retrycount++;
throw 505;
}
}
//observed retry count in C++ from various tests is approx 80.
catch(...){
cout<<"Read error";
}
}
s += ins;

vector<double> inval = parser(ins);
simtime = simtime > inval[0] ? simtime : inval[0];
Expand All @@ -169,8 +330,28 @@ class Concore{

}

void write(int port, string name, vector<double> val, int delta=0)
{
if(communication_ == 1)
{
return write_SM(port, name, val, delta);
}

return write_FM(port, name, val, delta);
}

void write(int port, string name, string val, int delta=0)
{
if(communication_ == 1)
{
return write_SM(port, name, val, delta);
}

return write_FM(port, name, val, delta);
}

//write method, accepts a vector double and writes it to the file
void write(int port, string name, vector<double> val, int delta=0){
void write_FM(int port, string name, vector<double> val, int delta=0){

try {
ofstream outfile;
Expand All @@ -194,7 +375,7 @@ class Concore{
}

//write method, accepts a string and writes it to the file
void write(int port, string name, string val, int delta=0){
void write_FM(int port, string name, string val, int delta=0){
chrono::milliseconds timespan((int)(2000*delay));
this_thread::sleep_for(timespan);
try {
Expand All @@ -211,6 +392,45 @@ class Concore{
cout<<"skipping +"<<outpath<<port<<" /"<<name;
}
}

//write method, accepts a vector double and writes it to the file
void write_SM(int port, string name, vector<double> val, int delta=0){

try {
std::ostringstream outfile;
if(shmId_ != -1){
val.insert(val.begin(),simtime+delta);
outfile<<'[';
for(int i=0;i<val.size()-1;i++)
outfile<<val[i]<<',';
outfile<<val[val.size()-1]<<']';
std::string result = outfile.str();
std::strncpy(sharedData_, result.c_str(), 256 - 1);
}
else{
throw 505;
}
}

catch(...){
cout<<"skipping +"<<outpath<<port<<" /"<<name;
}
}

//write method, accepts a string and writes it to the file
void write_SM(int port, string name, string val, int delta=0){
chrono::milliseconds timespan((int)(2000*delay));
this_thread::sleep_for(timespan);
try {
if(shmId_ != -1){
std::strncpy(sharedData_, val.c_str(), 256 - 1);
}
else throw 505;
}
catch(...){
cout<<"skipping +"<<outpath<<port<<" /"<<name;
}
}

//Initialising
vector<double> initval(string f){
Expand Down