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#define NUM_ARGS 0
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/stat.h>
#include <unistd.h>
#include <fcntl.h>
#include <dirent.h>
#include <string.h>
#include <time.h>
#include <pthread.h>
#include <semaphore.h>
#include <sys/time.h>
long condTotal = 0;
struct queue {
int vals[100];
int index; //indicates the next available spot
};
struct condQueue {
struct queue* q;
pthread_cond_t* cond;
pthread_mutex_t* mutex;
};
void insert(struct queue* q, int val) {
q->vals[q->index] = val;
++q->index;
}
int delete(struct queue* q) {
--q->index;
int val = q->vals[q->index];
return val;
}
// TODO: Insert code to use a condition variable.
void *condProducer(void* arg) {
// Random delay. DO NOT REMOVE!
usleep(rand() % 1000);
struct condQueue* cq = (struct condQueue*) arg;
pthread_mutex_lock(cq->mutex);
// Counter.
static int in = 0;
++in;
// Add an element to the queue.
insert(cq->q, in);
pthread_cond_signal(cq->cond); //to send signal to any waiting consumer
pthread_mutex_unlock(cq->mutex);
}
// TODO: Insert code to use a condition variable.
void *condConsumer(void* arg) {
// Random delay. DO NOT REMOVE!
usleep(rand() % 1000);
struct condQueue* cq = (struct condQueue*) arg;
pthread_mutex_lock(cq->mutex);
while (cq->q->index < 1) pthread_cond_wait(cq->cond, cq->mutex);//wait if buffer is empty
// Remove an element from the queue.
condTotal += delete(cq->q);
pthread_mutex_unlock(cq->mutex);
}
int main(int argc, char** argv) {
if (argc != NUM_ARGS + 1) {
printf("Wrong number of args, expected %d, given %d\n", NUM_ARGS, argc - 1);
exit(1);
}
// Seed the random generator.
srand(time(NULL));
// Create threads.
pthread_t condPool[100];
struct timeval start;
gettimeofday(&start, NULL);
// Create the cond variable controlled task queue.
struct condQueue* cq = (struct condQueue*) malloc(sizeof(struct condQueue));
cq->q = (struct queue*) malloc(sizeof(struct queue));
cq->q->index=0;
// Allocate memory and initialize condition variable and mutex
cq->cond = (pthread_cond_t*) malloc(sizeof(pthread_cond_t));
cq->mutex = (pthread_mutex_t*) malloc(sizeof(pthread_mutex_t));
pthread_cond_init(cq->cond, NULL);
pthread_mutex_init(cq->mutex, NULL);
// Launch them.
for (int i=0; i < 50; ++i) {
pthread_create(&condPool[i], NULL, condProducer, (void*) cq); //start 50 producer threads
pthread_create(&condPool[50 + i], NULL, condConsumer, (void*) cq); //start 50 consumer threads
}
for (int i=0; i < 100; ++i) pthread_join(condPool[i], NULL); //wait for all the threads to be finished
struct timeval end;
gettimeofday(&end, NULL);
printf("Cond Test: \nTotal of buffer = %ld\n", condTotal);
printf("Time (in us) to run = %ld\n\n", ((end.tv_sec - start.tv_sec) * 1000000) + (end.tv_usec - start.tv_usec));
}
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