multithreadedMenu/main.cpp at master · eribeiroClassroom/multithreadedMenu · GitHub

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//
//
// Compilation:
//
//       g++ main.cpp -lpthread -o serial -lm
//
//
//
/* Includes */

#include <cmath>
#include <iostream>     // std::cin, std::cout


/* global vars */
#define N 1000000      // length of measurement array


// Matrix of measurements
double Measurements[N];


// Populate the measurement matrix with some numbers
void generateMeasurements(void)
{

    double period      = N/4;       // Signal period
    double maxminTemperature = 200; // Range of values

    for(long int i = 0; i < N; i++ ){

        // Standard deviation of noise distribution
        double std = 10.0;

        // Generate random number in [0,1]
        double noise = std * ((double) rand() / (RAND_MAX));

        // Calculate noiseless measurement from a cosine curve in [-1,1]
        double temperatureClean =  maxminTemperature * cos( 2.0 * M_PI * (1.0/period) * (double)i);

        // Generate final (noisy) measurement
        double temperature = temperatureClean + noise;

        //printf("Temperature: %f\n", temperature );
        //fflush(stdout);

        // Store measurement into global array
        Measurements[ i ] = temperature;

    }
}


void *calculateAverage (void *)
{

    // TODO
    double avgValue = 0;
    for(long int i = 0; i < N; i++ )
        avgValue = avgValue + Measurements[ i ] / N;

    printf("Average value: %f\n", avgValue );
    fflush(stdout);

    pthread_exit(0); /* exit thread */
}


int main()
{


    // Generate measurements. All values stored in the global array Measurements.
    generateMeasurements();


    pthread_t worker1;


    // Menu selection
    int input;
    do{
         /*Displays the menu to user*/
        printf("Main menu\n");
        printf("1. Calculate Average\n");
        printf("2. Display Maximum\n");
        printf("3. Display Minimum:\n");
        printf("0. Exit:\n");
        scanf("%d",&input);

        switch(input){
            case 1:
                pthread_create (&worker1, NULL, calculateAverage,   (void *)NULL );
                break;
            case 2 :
                printf("TBD\n");
                break;
            case 3:
                printf("TBD\n");
                break;
            default:
                printf("invalid\n");
                break;
        }

    } while(input != 0);


    /* exit */
    exit(0);

} /* main() */