ex07.c

ex07.c

#include <errno.h>
#include <fcntl.h>
#include <pthread.h>
#include <semaphore.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <time.h>
#include <unistd.h>

#define CHUNK_SIZE 1000

#define NUMBER_OF_KEYS 10000

#define NUMBER_OR_THREADS 10

typedef struct {
    int normal[5];
    int special;
} Key;

// Keys
Key keys[NUMBER_OF_KEYS];
// Mutex
pthread_mutex_t mutex;

int getRandomIntBetween(int min, int max) {
    return (rand() % max) + min;
}

void* generateKeys(void* arg) {
    int index = *((int*)arg);

    printf("Thread with id %lu is now running...\n", pthread_self());
    fflush(stdout);

    int start = index * CHUNK_SIZE;
    int finish = (index + 1) * CHUNK_SIZE;

    if (pthread_mutex_lock(&mutex) != 0) {
        perror("Error at pthread_mutex_lock()\n");
    }

    int i;
    for (i = start; i < finish; i++) {
        int n;
        for (n = 0; n < 5; n++) {
            keys[i].normal[n] = getRandomIntBetween(1, 49);
        }
        keys[i].special = getRandomIntBetween(1, 5);
    }

    if (pthread_mutex_unlock(&mutex) != 0) {
        perror("Error at pthread_mutex_unlock()\n");
    }

    pthread_exit((void*)NULL);
}

int main(int argc, char* agrv[]) {
    // Randomize Seed
    srand(time(NULL));
    // Threads
    pthread_t threads[NUMBER_OR_THREADS];
    // Initialize mutex
    pthread_mutex_init(&mutex, NULL);

    // Make each thread fill their corresponding part of the array of keys
    int i;
    for (i = 0; i < NUMBER_OR_THREADS; i++) {
        int index = i;
        pthread_create(&threads[i], NULL, generateKeys, (void*)&index);
    }

    // Wait for all threads to finish their job
    int k;
    for (k = 0; k < NUMBER_OR_THREADS; k++) {
        pthread_join(threads[k], NULL);
    }

    // Destroy mutex
    pthread_mutex_destroy(&mutex);

    // Print generated numbers
    int j;
    for (j = 0; j < 15; j++) {
        int num1 = keys[j].normal[0];
        int num2 = keys[j].normal[1];
        int num3 = keys[j].normal[2];
        int num4 = keys[j].normal[3];
        int num5 = keys[j].normal[4];
        int special = keys[j].special;
        printf("%d %d %d %d %d : %d\n", num1, num2, num3, num4, num5, special);
        fflush(stdout);
    }

    return 0;
}