Hello I am having trouble with strtol
(specifically, that implicit conversion loses integer precision)
as well as with sem_open incompatible pointer types passing sem_t
I have tried to use named semaphores instead of unnamed semaphores, use sem_open instead of sem_init, and use sem_close and sem_unlink instead of sem_destroy, but still getting errors.
#include <stdio.h>
#include <string.h>
#include <pthread.h>
#include <ctype.h>
#include <stdlib.h>
#include <unistd.h>
#include <time.h>
#include <fcntl.h> /* For O_* constants */
#include <sys/stat.h> /* For mode constants */
#include <semaphore.h>
// Global mutex and semaphores
pthread_mutex_t lock;
sem_t full;
sem_t empty;
// Global item to be incremented and enqueued
int global_value = 1;
// Queue
int* buffer;
int in_index;
int out_index;
// Producer and consumer arrays for comparing
int* producer_arr;
int* consumer_arr;
int p_idx = 0;
int c_idx = 0;
// Global args
int num_buffers;
int num_producers;
int num_consumers;
int items_produced;
int items_consumed;
int over_consume;
int over_consume_amount;
int p_time;
int c_time;
/*
* Function to remove item.
* Item removed is returned
*/
int dequeue_item() {
int item = buffer[out_index];
buffer[out_index] = 0;
out_index = (out_index + 1) % num_buffers;
return item;
}
/*
* Function to add item.
* Item added is returned.
* It is up to you to determine
* how to use the ruturn value.
* If you decide to not use it, then ignore
* the return value, do not change the
* return type to void.
*/
int enqueue_item(int item) {
buffer[in_index] = item;
in_index = (in_index + 1) % num_buffers;
return item;
}
void* producer(void* arg) {
int tid = *((int*) arg);
int item;
for (int i = 0; i < items_produced; i++) {
// Increment global item
item = global_value++;
// Lock semaphore and mutex
sem_wait(&empty);
pthread_mutex_lock(&lock);
// Produce item onto queue
enqueue_item(item);
producer_arr[p_idx++] = item;
printf( "%5d was produced by producer->\t%5d\n" , item, tid);
// Unlock mutex and semaphore
pthread_mutex_unlock(&lock);
sem_post(&full);
// Sleep
sleep(p_time);
}
pthread_exit(0);
}
void* consumer(void* arg) {
int tid = *((int*) arg);
int item;
if (!over_consume) {
// Either over or not required
for (int i = 0; i < items_consumed; i++) {
// Lock semaphore and mutex
sem_wait(&full);
pthread_mutex_lock(&lock);
// Consume item from queue
item = dequeue_item();
consumer_arr[c_idx++] = item;
printf( "%5d was consumed by consumer->\t%5d\n" , item, tid);
// Unlock mutex and semaphore
pthread_mutex_unlock(&lock);
sem_post(&empty);
// Sleep
sleep(c_time);
}
} else {
// Over consume if needed at the beginning of the program
over_consume = 0;
for (int i = 0; i < items_consumed + over_consume_amount; i++) {
// Lock semaphore and mutex
sem_wait(&full);
pthread_mutex_lock(&lock);
// Consume item from queue
item = dequeue_item();
consumer_arr[c_idx++] = item;
printf( "%5d was consumed by consumer->\t%5d\n" , item, tid);
// Unlock mutex and semaphore
pthread_mutex_unlock(&lock);
sem_post(&empty);
// Sleep
sleep(c_time);
}
}
pthread_exit(0);
}
/*
* $ ./pandc <N> <P> <C> <X> <Ptime> <Ctime>
* N = number of buffers to maintain
* P = number of producer threads
* C = number of consumer threads
* X = number of items each producer thread will produce
* Ptime = how long each producer thread will sleep after producing an item in seconds
* Ctime = how long each consumer thread will sleep after consuming an item in seconds
*/
int main(int argc, char** argv) {
// argv[0] is the program itself ("./pandc")
if (argc != 7) {
printf("Enter 6 arguments: \"$ ./pandc <N> <P> <C> <X> <Ptime> <Ctime>\"\n");
exit(EXIT_FAILURE);
}
// Print current time
time_t start_time = time(0);
printf( "Current time: %s\n" , ctime(&start_time));
// Read command-line args
num_buffers = strtol(argv[1], NULL, 10);
num_producers = strtol(argv[2], NULL, 10);
num_consumers = strtol(argv[3], NULL, 10);
items_produced = strtol(argv[4], NULL, 10);
items_consumed = (num_producers * items_produced) / num_consumers;
over_consume = (num_producers * items_produced) % num_consumers > 0 ? 1 : 0;
over_consume_amount = (num_producers * items_produced) - (num_consumers * items_consumed);
p_time = strtol(argv[5], NULL, 10);
c_time = strtol(argv[6], NULL, 10);
// Print producer-consumer problem information
printf("\t Number of Buffers : %5d\n", num_buffers);
printf("\t Number of Producers : %5d\n", num_producers);
printf("\t Number of Consumers : %5d\n", num_consumers);
printf("\tNumber of items Produced by each producer : %5d\n", items_produced);
printf("\tNumber of items Consumed by each consumer : %5d\n", items_consumed);
printf("\t Over consume on? : %5s\n", (over_consume) ? "yes" : "no");
printf("\t Over consume amount : %5d\n", over_consume_amount);
printf("\t Time each Producer Sleeps (seconds) : %5d\n", p_time);
printf("\t Time each Consumer Sleeps (seconds) : %5d\n", c_time);
printf("\n");
// Initialize mutex, semaphore, buffer, arrays
pthread_mutex_init(&lock, NULL); // mutex lock = 1;
sem_open( &full, 0, 0); // semaphore full = 0;
sem_open( &empty, 0, num_buffers); // semaphore empty = N;
buffer = malloc(sizeof(int*) * num_buffers); // buffer[N];
producer_arr = malloc(sizeof(int*) * num_producers * items_produced);
consumer_arr = malloc(sizeof(int*) * num_producers * items_produced);
// consumer_arr = malloc(sizeof(int*) * num_consumers * items_consumed);
in_index = 0;
out_index = 0;
// New threads
pthread_t producer_ids[num_producers];
pthread_t consumer_ids[num_consumers];
// Create producer and consumer threads
for (int i = 0; i < num_producers; i++) {
int id = i + 1;
pthread_create(&producer_ids[i], NULL, &producer, (void*) &id);
}
for (int i = 0; i < num_consumers; i++) {
int id = i + 1;
pthread_create(&consumer_ids[i], NULL, &consumer, (void*) &id);
}
// Join producer and consumer threads
for (int i = 0; i < num_producers; i++) {
pthread_join(producer_ids[i], NULL);
printf( "Producer thread joined:%5d\n" , i);
}
for (int i = 0; i < num_consumers; i++) {
pthread_join(consumer_ids[i], NULL);
printf( "Consumer thread joined:%5d\n" , i);
}
time_t end_time = time(0);
printf( "Current time: %s\n" , ctime(&end_time));
// Compare and match producer and consumer arrays
int match = 1; // Start out as true
fprintf(stderr, "Producer Array\t| Consumer Array\n");
for (int i = 0; i < num_producers * items_produced; i++) {
fprintf(stderr, "%d\t\t\t\t| %d\n", producer_arr[i], consumer_arr[i]);
if (producer_arr[i] != consumer_arr[i]) {
match = 0; // False when mismatch detected
}
}
fprintf(stderr, "\nConsume and Produce Arrays %s!\n", (match) ? "Match" : "DO NOT Match");
fprintf(stderr, "\nTotal Runtime: %d secs\n", (int) (end_time - start_time));
// Cleanup
pthread_mutex_destroy(&lock);
sem_unlink(&full);
sem_unlink(&empty);
free(buffer);
return 0;
}
