/*
* Copyright 2021 Jeisson Hidalgo-Cespedes - Universidad de Costa Rica
* Creates a secondary thread that greets in the standard output
*/
#include <assert.h>
#include <inttypes.h>
#include <pthread.h>
#include <semaphore.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
typedef struct shared_thread_data {
size_t buffer_size;
double* buffer;
size_t rounds;
useconds_t min_producer_delay;
useconds_t max_producer_delay;
useconds_t min_consumer_delay;
useconds_t max_consumer_delay;
sem_t can_produce;
sem_t can_consume;
pthread_mutex_t stdout_mutex;
} shared_thread_data_t;
int analyze_arguments(int argc, char* argv[]
, shared_thread_data_t* shared_thread_data);
int simulate_producer_consumer(shared_thread_data_t* shared_thread_data);
int create_threads(shared_thread_data_t* shared_thread_data);
void* produce(void* data);
void* consume(void* data);
/**
* @param min must be less than @a max
* @param max must be greater than @a min
*/
void random_delay(useconds_t min, useconds_t max);
int main(int argc, char* argv[]) {
int error = 0;
struct timespec time;
clock_gettime(/*clk_id*/CLOCK_MONOTONIC, &time);
srand(time.tv_nsec);
shared_thread_data_t* shared_thread_data = (shared_thread_data_t*)
calloc(1, sizeof(shared_thread_data_t));
error = analyze_arguments(argc, argv, shared_thread_data);
if (error == EXIT_SUCCESS) {
error = simulate_producer_consumer(shared_thread_data);
}
return error;
}
int analyze_arguments(int argc, char* argv[]
, shared_thread_data_t* shared_thread_data) {
int error = 0;
if (argc == 7) {
if (sscanf(argv[1], "%zu", &shared_thread_data->buffer_size) != 1
|| shared_thread_data->buffer_size == 0) {
fprintf(stderr, "error: invalid buffer size\n");
error = 2;
} else if (sscanf(argv[2], "%zu", &shared_thread_data->rounds) != 1
|| shared_thread_data->rounds == 0) {
fprintf(stderr, "error: invalid round count\n");
error = 3;
} else if (sscanf(argv[3], "%u"
, &shared_thread_data->min_producer_delay) != 1) {
fprintf(stderr, "error: invalid min producer delay\n");
error = 4;
} else if (sscanf(argv[4], "%u"
, &shared_thread_data->max_producer_delay) != 1) {
fprintf(stderr, "error: invalid max producer delay\n");
error = 5;
} else if (sscanf(argv[5], "%u"
, &shared_thread_data->min_consumer_delay) != 1) {
fprintf(stderr, "error: invalid min consumer delay\n");
error = 6;
} else if (sscanf(argv[6], "%u"
, &shared_thread_data->max_consumer_delay) != 1) {
fprintf(stderr, "error: invalid max consumer delay\n");
error = 7;
}
} else {
fprintf(stderr, "usage: producer_consumer buffer_size rounds"
" min_producer_delay max_producer_delay"
" min_consumer_delay max_consumer_delay\n");
error = 1;
}
return error;
}
int simulate_producer_consumer(shared_thread_data_t* shared_thread_data) {
assert(shared_thread_data);
int error = 0;
if (shared_thread_data) {
shared_thread_data->buffer = (double*)
calloc(shared_thread_data->buffer_size, sizeof(double));
if (shared_thread_data->buffer) {
error = sem_init(&shared_thread_data->can_produce, /*pshared*/0
, shared_thread_data->buffer_size);
error += sem_init(&shared_thread_data->can_consume, /*pshared*/0, 0);
error += pthread_mutex_init(&shared_thread_data->stdout_mutex
, /*attr*/NULL);
if (error == 0) {
struct timespec start_time, finish_time;
clock_gettime(/*clk_id*/CLOCK_MONOTONIC, &start_time);
error = create_threads(shared_thread_data);
clock_gettime(/*clk_id*/CLOCK_MONOTONIC, &finish_time);
double elapsed_time = finish_time.tv_sec - start_time.tv_sec +
(finish_time.tv_nsec - start_time.tv_nsec) * 1e-9;
printf("execution time: %.9lfs\n", elapsed_time);
pthread_mutex_destroy(&shared_thread_data->stdout_mutex);
} else {
fprintf(stderr, "error: could not init mutex\n");
error = 11;
}
} else {
fprintf(stderr, "error: could not allocated shared memory\n");
error = 13;
}
free(shared_thread_data->buffer);
free(shared_thread_data);
} else {
fprintf(stderr, "error: could not allocated shared memory\n");
error = 12;
}
return error;
}
int create_threads(shared_thread_data_t* shared_thread_data) {
assert(shared_thread_data);
int error = 0;
pthread_t producer_thread;
pthread_t consumer_thread;
error = pthread_create(&producer_thread, NULL, produce, shared_thread_data);
if (error == 0) {
error = pthread_create(&consumer_thread, NULL, consume, shared_thread_data);
if (error == 0) {
pthread_join(consumer_thread, NULL);
} else {
fprintf(stderr, "error: could not create consumer thread\n");
error = 22;
}
pthread_join(producer_thread, NULL);
} else {
fprintf(stderr, "error: could not create producer thread\n");
error = 21;
}
return error;
}
void* produce(void* data) {
assert(data);
shared_thread_data_t* shared_data = (shared_thread_data_t*)data;
for (size_t round = 1; round <= shared_data->rounds; ++round) {
for (size_t index = 0; index < shared_data->buffer_size; ++index) {
sem_wait(&shared_data->can_produce);
random_delay(shared_data->min_producer_delay
, shared_data->max_producer_delay);
shared_data->buffer[index] = round + (index + 1) / 100.0;
pthread_mutex_lock(&shared_data->stdout_mutex);
printf("Produced %.2lf\n", shared_data->buffer[index]);
pthread_mutex_unlock(&shared_data->stdout_mutex);
sem_post(&shared_data->can_consume);
}
}
return NULL;
}
void* consume(void* data) {
assert(data);
shared_thread_data_t* shared_data = (shared_thread_data_t*)data;
for (size_t round = 1; round <= shared_data->rounds; ++round) {
for (size_t index = 0; index < shared_data->buffer_size; ++index) {
sem_wait(&shared_data->can_consume);
random_delay(shared_data->min_consumer_delay
, shared_data->max_consumer_delay);
double value = shared_data->buffer[index];
pthread_mutex_lock(&shared_data->stdout_mutex);
printf("\t\tConsumed %.2lf\n", value);
pthread_mutex_unlock(&shared_data->stdout_mutex);
sem_post(&shared_data->can_produce);
}
}
return NULL;
}
void random_delay(useconds_t min, useconds_t max) {
assert(min <= max);
useconds_t milliseconds = min;
if (max > min) {
milliseconds += rand() % (max - min);
}
usleep(milliseconds * 1000);
}