Help Finding Error in Thread Prime Number
My assignment is to write a program that finds the prime numbers using threads for number filters. My program compiles, but it does not even reach the test messages I'm printing in the very beginning of my main. It just sits there when I run the a.out file. Can anyone pinpoint what I've done wrong?
Code:
// Homework 8
// Threaded Primes
#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>
#include <math.h>
#include <semaphore.h>
#include <fcntl.h>
#define Q_SIZE 10
struct queue {
int queue[Q_SIZE];
int front; int back;
sem_t *mutex;
sem_t *slots;
sem_t *items;
};
struct filter {
struct queue *input;
struct queue *output;
int p;
};
void *numberFilter(void *filterStruct) { // check #s
struct filter *temp = (struct filter *)filterStruct;
int number = temp->p;
struct queue *inputQ = temp->input;
struct queue *outputQ = temp->output;
printf(" %d",88);
while(1) {
int nextNumber = dequeue(inputQ);
printf(" %d ", nextNumber);
if(nextNumber == -1) {
enqueue(number, outputQ);
return; // stop executing. poison pill received.
}
if(nextNumber == number) enqueue(number, outputQ);
if(nextNumber%number != 0) enqueue(nextNumber, outputQ);
}
}
void *generator(struct queue *q) { // generate #'s 2 thru 1000
struct queue *queue1 = q;
int counter = 2;
while(counter<1001) {
enqueue(counter, queue1);
counter++;
}
enqueue(-1, queue1); // send poison pill
}
void *finalCheck(void *inputQ) { // final checker, 13 thru sqrt of #
struct queue *temp = (struct queue *)inputQ;
int nextNumber;
while(1) {
nextNumber = dequeue(temp);
if(nextNumber == -1) {
return; // stop executing. poison pill received.
}
int prime = 1; int i;
for(i = 13; i<=sqrt(nextNumber); i+=2) {
if(nextNumber%i == 0) prime = 0;
}
if(prime == 1) printf("%d ", nextNumber);
}
}
void *initQueue(struct queue *q) {
q->queue[0] = 0;
q->front = 0; q->back = 0;
q->mutex = sem_open("QueueMutex", O_CREAT, 0700, 1); // init mutex sem
if (!q->mutex) {
perror("semaphore create error");
exit(4);
}
q->slots = sem_open("QueueSlots", O_CREAT, 0700, 10); // init slots sem
if (!q->slots) {
perror("semaphore create error");
exit(4);
}
q->items = sem_open("QueueItems", O_CREAT, 0700, 0); // init items sem
if (!q->items) {
perror("semaphore create error");
exit(4);
}
sem_unlink("QueueMutex");
sem_unlink("QueueSlots");
sem_unlink("QueueItems");
}
void enqueue(int newElement, struct queue *q) {
sem_wait(q->slots); // P(slots) operation.
sem_wait(q->mutex); // P(mutex) operation.
q->queue[q->back] = newElement;
q->back = (q->back+1) % Q_SIZE;
sem_post(q->mutex); // V(mutex) operation.
sem_post(q->items); // V(items) operation.
}
int dequeue(struct queue *q) {
sem_wait(q->items); // P(items) operation.
sem_wait(q->mutex); // P(mutex) operation.
int value = q->queue[q->front];
q->front = (q->front+1) % Q_SIZE;
sem_post(q->mutex); // V(mutex) operation.
sem_post(q->slots); // V(slots) operation.
return value;
}
int main() {
printf("anything???");
struct queue *queue1, *queue2, *queue3, *queue4, *queue5, *queue6;
printf("justbeforemalloc");
queue1 = (struct queue *) malloc(sizeof(struct queue));
printf("we did one");
queue2 = (struct queue *) malloc(sizeof(struct queue));
queue3 = (struct queue *) malloc(sizeof(struct queue));
queue4 = (struct queue *) malloc(sizeof(struct queue));
queue5 = (struct queue *) malloc(sizeof(struct queue));
queue6 = (struct queue *) malloc(sizeof(struct queue));
printf("We got to here.");
initQueue(queue1);
initQueue(queue2);
initQueue(queue3);
initQueue(queue4);
initQueue(queue5);
initQueue(queue6);
struct filter filter2 = {queue1, queue2, 2};
struct filter filter3 = {queue2, queue3, 3};
struct filter filter5 = {queue3, queue4, 5};
struct filter filter7 = {queue4, queue5, 7};
struct filter filter11 = {queue5, queue6, 11};
generator(queue1);
pthread_t thread2;
pthread_create(&thread2, NULL, numberFilter, &filter2);
printf("Checkpoint");
// creates thread for sorting through 2's.
pthread_t thread3;
pthread_create(&thread3, NULL, numberFilter, &filter3);
printf("Checkpoint2");
// creates thread for sorting through 3's.
pthread_t thread5;
pthread_create(&thread5, NULL, numberFilter, &filter5);
printf("Checkpoint3");
// creates thread for sorting through 5's.
pthread_t thread7;
pthread_create(&thread7, NULL, numberFilter, &filter7);
printf("Checkpoint4");
// creates thread for sorting through 7's.
pthread_t thread11;
pthread_create(&thread11, NULL, numberFilter, &filter11);
printf("Checkpoint5");
// creates thread for sorting through 11's.
pthread_t threadFinal;
pthread_create(&threadFinal, NULL, finalCheck, &queue6);
printf("Done");
// creates thread for final check.
free(queue1);
free(queue2);
free(queue3);
free(queue4);
free(queue5);
free(queue6);
}
