Writing at multiple positions in real-time - c++

Question

I am trying to develop a console application, where I will display the system date and time in real time (or as real as I can get). This is the easy part. The hard part is that I must also have the cursor available for the user to enter information through. I can't use NCurses in my application, nor any other library that it not included in vanilla GCC 4.4 (there goes boost! Noooo....)
This is my code so far:
The realtime class, where I am incorporating the solution given by Jeremy Friesner here pthreads in c++ inside classes
#ifndef _REALTIME_H_
#define _REALTIME_H_
#include <iostream>
#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>
class MyThreadClass
{
public:
MyThreadClass() {/* empty */}
virtual ~MyThreadClass() {/* empty */}
/** Returns true if the thread was successfully started, false if there was an error starting the thread */
bool startMainThread()
{
return (pthread_create(&_mainThread, NULL, mainRunnerFunc, this) == 0);
}
bool startDisplayThread()
{
return (pthread_create(&_displayThread, NULL, displayThreadFunc, this) == 0);
}
/** Will not return until the main thread has exited. */
void waitForMainThreadToExit()
{
(void) pthread_join(_mainThread, NULL);
}
void waitForDisplayThreadToExit()
{
(void) pthread_join(_displayThread, NULL);
}
protected:
/** Implement this method in your subclass with the code you want your thread to run. */
virtual void mainRunner() = 0;
virtual void displayTime() = 0;
private:
static void * mainRunnerFunc(void * This) {((MyThreadClass *)This)->mainRunner(); return NULL;}
static void * displayThreadFunc(void * This) {((MyThreadClass *)This)->displayTime(); return NULL;}
pthread_t _mainThread;
pthread_t _displayThread;
};
class DynamicTime : public MyThreadClass
{
private:
const string currentDate();
void gotoxy(int,int);
void displayTime();
void mainRunner();
pthread_mutex_t mutex1;
public:
// pthread_mutex_t mutex1;
DynamicTime();
unsigned int lifeTime;
unsigned int updateTime;
void start();
int Exit;
};
const string DynamicTime::currentDate()
{
time_t now = time(0);
struct tm tstruct;
char buf[80];
tstruct = *localtime(&now);
strftime(buf,sizeof(buf),"%I:%M:%S %p, %d-%m-%y",&tstruct);
return buf;
}
DynamicTime::DynamicTime()
{
pthread_mutex_init(&(mutex1),NULL);
lifeTime=-1; /* 100 seconds */
updateTime = 1; /* 5 seconds interval */
Exit=1;
}
void DynamicTime::gotoxy(int x,int y)
{
/* go to location */
printf("\033[%d;%df",y,x);
}
void DynamicTime::displayTime()
{
pthread_mutex_lock(&mutex1);
/* save the cursor location */
printf("\033[s");
gotoxy(75,30);
cout << "Date : " << currentDate() << endl;
/* restore the cursor location */
printf("\033[u");
pthread_mutex_unlock(&mutex1);
}
void DynamicTime::mainRunner()
{
unsigned long iterate, iterate2;
int iret1,iret2;
if(lifeTime!=-1)
{
for(iterate=0;iterate<lifeTime*100000;iterate++)
{
if(iterate%(updateTime*50)==0)
{
iret2 = startDisplayThread();
waitForDisplayThreadToExit();
}
for(iterate2=0;iterate2<100000;iterate2++);
}
std::cout << "Ending main thread..." << endl;
}
else
{
while(1&Exit) /* infinitely */
{
iret2 = startDisplayThread();
waitForDisplayThreadToExit();
for(iterate2=0;iterate2<100000;iterate2++);
}
std::cout << "Exiting Application.... " << endl;
}
}
void DynamicTime::start()
{
//system("clear");
//cout << "Starting...." << endl;
if(startMainThread()==false)
{
std::cerr << "Coudln't start main Thread! " << endl;
}
/* call this function in the main program
* else
{
waitForMainThreadToExit();
}*/
}
/* Example
* on how to use the program
* int main()
{
DynamicTime DT;
DT.lifeTime = 100;
DT.start();
return 0;
}
*/
#endif
and my example program, where I am trying to read data from the user, while showing the time at the same time:
//#include <iostream>
#include "realtime2.h"
int main()
{
DynamicTime DT;
string temp="abcd";
DT.start();
while(temp!="exit")
{
std::cout << "$> " ;
std::cin >> temp;
}
DT.waitForMainThreadToExit();
return 0;
}
This would be called a fully-functional program, if only I could get the user to enter data without interruption from the display thread. Any ideas as to how to get around this ? Or if I can't get around this, what would be the proper way to do so ?