void sem_signal(struct Semaphore *s)
{
lock_acquire(&s->locksem);
if(!empty_q(&s->t_q))
{
twakeup(pop_q(&s->t_q));
}
else
{
s->count++;
}
lock_release(&s->locksem);
}
PROC *get_next_from_pid_q(PIDQ_HEAD *q)
{
PROC *p;
PIDQ *tmp = q->head;
if (!empty_q(q)) {
p = q->head->proc;
q->head = tmp->next;
free(tmp);
return p;
}
return NULL;
}
static inline PROC *get_next_from_pid_q(PIDQ *q)
{
PROC *p;
PIDQ *tmp = q->front;
if (!empty_q(q)) {
p = q->front->proc;
q->front = tmp->next;
free(tmp);
return p;
}
return NULL;
}
void sem_signal(struct Semaphore *s) {
lock_acquire(&s->lock);
if (s->count > 0) {
s->count++;
lock_release(&s->lock);
}
else {
if (empty_q(&s->q) == 1)
s->count++;
else
twakeup(pop_q(&s->q));
lock_release(&s->lock);
}
}
int pop_q(struct queue *q){
int val;
struct node *destroy;
if(!empty_q(q)){
val = q->head->value;
destroy = q->head;
q->head = q->head->next;
free(destroy);
q->size--;
if(q->size == 0){
q->head = 0;
q->tail = 0;
}
return val;
}
return -1;
}
int travel(){
int i,j;
Point p;
for(i=0;i<n;i++){
for(j=0;j<m;j++){
count[i][j] = wand[i][j] = visited[i][j] = 0;
}
}
init_q();
enqueue(hermione);
visited[hermione.x][hermione.y] = 1;
while(!empty_q()){
p = dequeue();
if(forest[p.x][p.y] == '*')
break;
isvalid(p);
}
}
int add_pid_to_q(PIDQ_HEAD *q, PROC *p)
{
PIDQ *tmp;
tmp = (PIDQ *)xmalloc(sizeof(PIDQ));
tmp->proc = p;
tmp->next = NULL;
if (empty_q(q)) {
q->head = tmp;
q->tail = tmp;
} else {
q->tail->next = tmp;
q->tail = tmp;
}
return 0;
}
static inline int add_pid_to_q(PIDQ *q, PROC *p)
{
PIDQ *tmp;
tmp = (PIDQ *)malloc(sizeof(PIDQ));
tmp->proc = p;
tmp->next = NULL;
if (empty_q(q)) {
q->front = tmp;
q->rear = tmp;
} else {
q->rear->next = tmp;
q->rear = tmp;
}
return 0;
}
Point dequeue(){
if(!empty_q()){
return queue[front++];
}
}
