Part 3: Devise an OpenMP solution for the Queue Scheduling problem described in Task 1.3

Please use OpenMP directives and OpenMP synchronization primitives ONLY as appropriate

Task 1.3 Code listed below:

#include #include #include #include #include

int num_students; int office_capacity; int current_student_id;

sem_t OfficeSpots; sem_t StudentCanAskQuestion; sem_t ProfessorCanSpeak; sem_t StudentCanSpeak;

void * Professor(); void * Student(void *id);

void AnswerStart(int student_id); void AnswerDone(int student_id); void EnterOffice(int id); void LeaveOffice(int id); void QuestionStart(int id); void QuestionDone(int id);

int main(int argc, char *argv[]) { // Input Validation if (argc <= 2) { printf("Error: Please specify a number of students and office capacity. "); return 0; }

num_students = atoi(argv[1]); office_capacity = atoi(argv[2]); if (!num_students || !office_capacity) { printf("Arguments are not valid. "); return 0; } printf("num_students: %d, capacity: %d ", num_students, office_capacity);

sem_init(&OfficeSpots, 0, office_capacity); sem_init(&StudentCanAskQuestion, 0, 1); sem_init(&ProfessorCanSpeak, 0, 0); sem_init(&StudentCanSpeak, 0, 0);

pthread_t professor_thread; pthread_create(&professor_thread, NULL, Professor, NULL);

int student_num; pthread_t student_threads[num_students]; int student_ids[num_students];

for (student_num = 0; student_num < num_students; student_num++) { student_ids[student_num] = student_num; pthread_create(&student_threads[student_num], NULL, Student, (void *)&student_ids[student_num]); }

for (student_num = 0; student_num < num_students; student_num++) { pthread_join(student_threads[student_num], NULL); }

printf("Simulation completed. No more students left. ");

return 0; }

void * Professor() { while(1) { sem_post(&StudentCanSpeak); sem_wait(&ProfessorCanSpeak); AnswerStart(current_student_id); AnswerDone(current_student_id); sem_post(&StudentCanSpeak); } }

void * Student(void *id) { int student_id = *((int *) id); int n_questions = (student_id % 4) + 1; int quest;

sem_wait(&OfficeSpots); // Wait for a spot in the office EnterOffice(student_id);

for(quest = 0; quest < n_questions; quest++) { sem_wait(&StudentCanAskQuestion); // Wait for turn current_student_id = student_id; sem_wait(&StudentCanSpeak); QuestionStart(student_id); sem_post(&ProfessorCanSpeak); // Let professor answer

sem_wait(&StudentCanSpeak); QuestionDone(student_id);

sem_post(&StudentCanAskQuestion); // Let another student ask }

sem_post(&OfficeSpots); // Let another student in the office LeaveOffice(student_id); }

// Professor Actions void AnswerStart(int student_id) { printf("Professor starts to answer question for student %d. ", student_id); } void AnswerDone(int student_id) { printf("Professor is done with answer for student %d. ", student_id); }

// Student Actions void EnterOffice(int id) { printf("Student %d enters the office. ", id); } void LeaveOffice(int id) { printf("Student %d leaves the office. ", id); } void QuestionStart(int id) { printf("Student %d asks a question. ", id); } void QuestionDone(int id) { printf("Student %d is satisfied. ", id); }