OS Project 2

/**
 * Project 2
 * Hyung Jun Hahn
 **/

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

#define NUM_OF_SORTING_THREADS 2

int *master_list;
int size;

typedef struct {
    int start;
    int end;
} param;

void *sorter(void *param); /* the thread */
void *merger(void *param); /* the thread */

int main(int argc, char *argv[]) {
    pthread_t tid[NUM_OF_SORTING_THREADS + 1]; // One thread is used for merging.
    pthread_attr_t attr;
    if (argc < 2) {
        printf("Usage: sorter <numbers delimited with space>");
        return -1;
    }

    size = argc - 1;
    master_list = malloc(size * sizeof(master_list[0]));

    int i;
    for (i = 1; i < argc; i++) {
        char *endptr;
        int val = strtol(argv[i], &endptr, 10);
        master_list[i - 1] = val;
    }

    for(i = 0; i < size; i++) {
        printf("Index %d: %d\n", i, master_list[i]);
    }

    for (i = 0; i < NUM_OF_SORTING_THREADS; i++) {
        param *data = (param *)malloc(sizeof(param));
        data->start = i * size / 2;
        data->end = (size/ 2 * (i + 1)) - 1;
        pthread_attr_init(&attr);
        pthread_create(&tid[i], &attr, sorter, data);
    }
    for (i = 0; i < NUM_OF_SORTING_THREADS; i++) {
        pthread_join(tid[i], NULL);
        printf("\n");
    }

    // Merging lists.
    param *data = (param *)malloc(sizeof(param));
    data->start = 0;
    data->end = size / 2;
    pthread_attr_init(&attr);
    pthread_create(&tid[2], &attr, merger, data);
    pthread_join(tid[2], NULL);

    printf("FINAL RESULT: \n");
    while (*master_list) {
        printf("%d ", *master_list++);
    }
    printf("\n");
    return 0;
}

void * sorter(void *params) {
    param* data = (param *)params;
    int start = data->start;
    int end = data->end + 1;
    int temp = 0;
    for (int i = start; i< end; i++) {
        for (int j = start; j< end - 1; j++) {
            if (master_list[j] > master_list[j + 1]) {
                temp = master_list[j];
                master_list[j] = master_list[j + 1];
                master_list[j + 1] = temp;
            }
        }
    }

    for (int k = start; k < end; k++) {
        printf("Sorted Array: %d\n", master_list[k]);
    }
    pthread_exit(NULL);
}

void * merger(void *params) {
    param* data = (param *)params;
    int start1 = data->start;
    int start2 = data->end;

    int s1 = data->end;
    int s2 = size - s1;
    int list1[s1], list2[s2];

    int i, j;
    for (i = 0; i < s1; i++) {
        list1[i] = master_list[start1 + i];
        printf("list1: %d\n", list1[i]);
    }
    for (j = 0; j < s2; j++) {
        list2[j] = master_list[start2 + j];
        printf("list2: %d\n", list2[j]);
    }
    i = 0;
    j = 0;
    int k = 0;
    while(i < s1 && j < s2) {
        if(list1[i] < list2[j]) {
            master_list[k] = list1[i];
            i++;
        } else {
            master_list[k] = list2[j];
            j++;
        }
        k++;
    }

    while(i < s1) {
        master_list[k] = list1[i];
        k++;
        i++;
    }
    while(j < s2) {
        master_list[k] = list2[j];
        k++;
        j++;
    }
    pthread_exit(NULL);
}