1 056fe1ba 2003-11-23 devnull #include <u.h>
  2 056fe1ba 2003-11-23 devnull #include <libc.h>
  3 056fe1ba 2003-11-23 devnull #include <venti.h>
  4 056fe1ba 2003-11-23 devnull #include "queue.h"
  5 056fe1ba 2003-11-23 devnull 
  6 056fe1ba 2003-11-23 devnull typedef struct Qel Qel;
  7 056fe1ba 2003-11-23 devnull struct Qel
  8 056fe1ba 2003-11-23 devnull {
  9 056fe1ba 2003-11-23 devnull 	Qel *next;
 10 056fe1ba 2003-11-23 devnull 	void *p;
 11 056fe1ba 2003-11-23 devnull };
 12 056fe1ba 2003-11-23 devnull 
 13 056fe1ba 2003-11-23 devnull struct Queue
 14 056fe1ba 2003-11-23 devnull {
 15 056fe1ba 2003-11-23 devnull 	int hungup;
 16 056fe1ba 2003-11-23 devnull 	QLock lk;
 17 056fe1ba 2003-11-23 devnull 	Rendez r;
 18 056fe1ba 2003-11-23 devnull 	Qel *head;
 19 056fe1ba 2003-11-23 devnull 	Qel *tail;
 20 056fe1ba 2003-11-23 devnull };
 21 056fe1ba 2003-11-23 devnull 
 22 056fe1ba 2003-11-23 devnull Queue*
 23 056fe1ba 2003-11-23 devnull _vtqalloc(void)
 24 056fe1ba 2003-11-23 devnull {
 25 056fe1ba 2003-11-23 devnull 	Queue *q;
 26 056fe1ba 2003-11-23 devnull 
 27 056fe1ba 2003-11-23 devnull 	q = vtmallocz(sizeof(Queue));
 28 056fe1ba 2003-11-23 devnull 	q->r.l = &q->lk;
 29 056fe1ba 2003-11-23 devnull 	return q;
 30 056fe1ba 2003-11-23 devnull }
 31 056fe1ba 2003-11-23 devnull 
 32 056fe1ba 2003-11-23 devnull int
 33 056fe1ba 2003-11-23 devnull _vtqsend(Queue *q, void *p)
 34 056fe1ba 2003-11-23 devnull {
 35 056fe1ba 2003-11-23 devnull 	Qel *e;
 36 056fe1ba 2003-11-23 devnull 
 37 056fe1ba 2003-11-23 devnull 	e = vtmalloc(sizeof(Qel));
 38 056fe1ba 2003-11-23 devnull 	qlock(&q->lk);
 39 056fe1ba 2003-11-23 devnull 	if(q->hungup){
 40 056fe1ba 2003-11-23 devnull 		werrstr("hungup queue");
 41 056fe1ba 2003-11-23 devnull 		qunlock(&q->lk);
 42 056fe1ba 2003-11-23 devnull 		return -1;
 43 056fe1ba 2003-11-23 devnull 	}
 44 056fe1ba 2003-11-23 devnull 	e->p = p;
 45 056fe1ba 2003-11-23 devnull 	e->next = nil;
 46 056fe1ba 2003-11-23 devnull 	if(q->head == nil)
 47 056fe1ba 2003-11-23 devnull 		q->head = e;
 48 056fe1ba 2003-11-23 devnull 	else
 49 056fe1ba 2003-11-23 devnull 		q->tail->next = e;
 50 056fe1ba 2003-11-23 devnull 	q->tail = e;
 51 056fe1ba 2003-11-23 devnull 	rwakeup(&q->r);
 52 056fe1ba 2003-11-23 devnull 	qunlock(&q->lk);
 53 056fe1ba 2003-11-23 devnull 	return 0;
 54 056fe1ba 2003-11-23 devnull }
 55 056fe1ba 2003-11-23 devnull 
 56 056fe1ba 2003-11-23 devnull void*
 57 056fe1ba 2003-11-23 devnull _vtqrecv(Queue *q)
 58 056fe1ba 2003-11-23 devnull {
 59 056fe1ba 2003-11-23 devnull 	void *p;
 60 056fe1ba 2003-11-23 devnull 	Qel *e;
 61 056fe1ba 2003-11-23 devnull 
 62 056fe1ba 2003-11-23 devnull 	qlock(&q->lk);
 63 056fe1ba 2003-11-23 devnull 	while(q->head == nil && !q->hungup)
 64 056fe1ba 2003-11-23 devnull 		rsleep(&q->r);
 65 056fe1ba 2003-11-23 devnull 	if(q->hungup){
 66 056fe1ba 2003-11-23 devnull 		qunlock(&q->lk);
 67 056fe1ba 2003-11-23 devnull 		return nil;
 68 056fe1ba 2003-11-23 devnull 	}
 69 056fe1ba 2003-11-23 devnull 	e = q->head;
 70 056fe1ba 2003-11-23 devnull 	q->head = e->next;
 71 056fe1ba 2003-11-23 devnull 	qunlock(&q->lk);
 72 056fe1ba 2003-11-23 devnull 	p = e->p;
 73 056fe1ba 2003-11-23 devnull 	vtfree(e);
 74 056fe1ba 2003-11-23 devnull 	return p;
 75 056fe1ba 2003-11-23 devnull }
 76 056fe1ba 2003-11-23 devnull 
 77 056fe1ba 2003-11-23 devnull void*
 78 056fe1ba 2003-11-23 devnull _vtnbqrecv(Queue *q)
 79 056fe1ba 2003-11-23 devnull {
 80 056fe1ba 2003-11-23 devnull 	void *p;
 81 056fe1ba 2003-11-23 devnull 	Qel *e;
 82 056fe1ba 2003-11-23 devnull 
 83 056fe1ba 2003-11-23 devnull 	qlock(&q->lk);
 84 056fe1ba 2003-11-23 devnull 	if(q->head == nil){
 85 056fe1ba 2003-11-23 devnull 		qunlock(&q->lk);
 86 056fe1ba 2003-11-23 devnull 		return nil;
 87 056fe1ba 2003-11-23 devnull 	}
 88 056fe1ba 2003-11-23 devnull 	e = q->head;
 89 056fe1ba 2003-11-23 devnull 	q->head = e->next;
 90 056fe1ba 2003-11-23 devnull 	qunlock(&q->lk);
 91 056fe1ba 2003-11-23 devnull 	p = e->p;
 92 056fe1ba 2003-11-23 devnull 	vtfree(e);
 93 056fe1ba 2003-11-23 devnull 	return p;
 94 056fe1ba 2003-11-23 devnull }
 95 056fe1ba 2003-11-23 devnull 
 96 056fe1ba 2003-11-23 devnull void
 97 056fe1ba 2003-11-23 devnull _vtqhangup(Queue *q)
 98 056fe1ba 2003-11-23 devnull {
 99 056fe1ba 2003-11-23 devnull 	qlock(&q->lk);
100 056fe1ba 2003-11-23 devnull 	q->hungup = 1;
101 056fe1ba 2003-11-23 devnull 	rwakeupall(&q->r);
102 056fe1ba 2003-11-23 devnull 	qunlock(&q->lk);
103 056fe1ba 2003-11-23 devnull }