Course Objective:

Students in this course will learn about the use and design of modern operating systems, focusing on Linux. On the "use" side, students will learn the Linux command line, to write shell scripts, and to build programs with GNU utilities like awk, sed and make. On the "design" side, students will develop a deep understanding of process management, memory management, file systems, and concurrency, and how they apply to modern technologies like virtualization and cloud computing.

Class Project:

This program generates two matrices of size 1024 and incorporates multithreading to multiply them together.

    /*
    # Name: Luis Jimenez
    # Date: April 5, 2022
    # Title: Lab5 - Step 3
    # Description : Used multi threading to multiply two matrices
    */

    #include <stdlib.h>
    #include <pthread.h>
    #include <stdio.h>

    #define N 1024 //# rows of matrix A
    #define M 1024//# columns  matrix A & # rows matrix B
    #define L 1024 //# colummns matrix B
    #define NTHREADS N //# threads
    pthread_t threads[NTHREADS];

    double matrixA[N][M]; //initialize matrix A
    double matrixB[M][L]; //initialize matrix B
    double matrixC[N][L]; //initialize result matrix C

    //this function references int i and calculates 
    //the product of matrixA*matrixB which is matrixC.
    void* matrixCalculation(void* arg)
    {
    int i = *((int*)arg);
    //calculates row * column for each
    for (int j = 0; j < L; j++)
    {
        double temp = 0;
        for (int k = 0; k < M; k++)
        {
            temp += matrixA[i][k] * matrixB[k][j];
        } 
        matrixC[i][j] = temp;
    }
    pthread_exit(NULL);
    }

    //main function that prints out matrixA, matrixB, then calculates
    // and displays matrixC.
    int main() {
    srand(time(NULL));
    int pass[NTHREADS];
    //randomly generates two matrices with numbers between 0-9
    for(int i = 0; i < N; i++)
        for(int j = 0; j < M; j++)
        {
            matrixA[i][j] = rand() % 10;
            matrixB[i][j] = rand() % 10;
        }
    //prints out matrixA
    printf("\n");
    for(int i = 0; i < N; i++)
    {
        for(int j=0; j<M; ++j) 
        {
            if(j ==(M-1))
            {
                printf(" %g  ", matrixA[i][j]);
                printf("\n");
            } else {
            printf(" %g ", matrixA[i][j]);
            }
        }
    }

    //prints out matrixB
    printf("\n");
    for(int i = 0; i < M; i++)
    {
        for(int j = 0; j < L; ++j) 
        {
            if(j==(L-1))
            {
                printf(" %g  ", matrixB[i][j]);
                printf("\n");
            }
            else{
                printf(" %g ", matrixB[i][j]);
            }
        } 
    }

    //Make threads
    for(int i = 0; i<NTHREADS; i++)
    {
        pass[i]=i;
        pthread_create(&threads[i], NULL, matrixCalculation, &pass[i]);
    }

    //join threads
    for(int i = 0; i<NTHREADS; i++)
    {
        pthread_join(threads[i], NULL);
    } 

    //print out matrix C
    printf("\n");
    for(int i = 0; i < N; i++)
    {
        for(int j = 0; j < L; j++)
        {
            if(j==(L-1)){
                printf(" %g ", matrixC[i][j]);
                printf("\n");
            }
            else{
                printf(" %g ", matrixC[i][j]);
            }
        }
    }
    }