1 d3df3087 2003-12-06 devnull /* Copyright (C) 2003 Russ Cox, Massachusetts Institute of Technology */
  2 d3df3087 2003-12-06 devnull /* See COPYRIGHT */
  3 d3df3087 2003-12-06 devnull 
  4 d3df3087 2003-12-06 devnull #include <u.h>
  5 d3df3087 2003-12-06 devnull #include <libc.h>
  6 d3df3087 2003-12-06 devnull #include <mux.h>
  7 d3df3087 2003-12-06 devnull 
  8 d3df3087 2003-12-06 devnull typedef struct Qel Qel;
  9 d3df3087 2003-12-06 devnull struct Qel
 10 d3df3087 2003-12-06 devnull {
 11 d3df3087 2003-12-06 devnull 	Qel *next;
 12 d3df3087 2003-12-06 devnull 	void *p;
 13 d3df3087 2003-12-06 devnull };
 14 d3df3087 2003-12-06 devnull 
 15 d3df3087 2003-12-06 devnull struct Muxqueue
 16 d3df3087 2003-12-06 devnull {
 17 d3df3087 2003-12-06 devnull 	int hungup;
 18 d3df3087 2003-12-06 devnull 	QLock lk;
 19 d3df3087 2003-12-06 devnull 	Rendez r;
 20 d3df3087 2003-12-06 devnull 	Qel *head;
 21 d3df3087 2003-12-06 devnull 	Qel *tail;
 22 d3df3087 2003-12-06 devnull };
 23 d3df3087 2003-12-06 devnull 
 24 d3df3087 2003-12-06 devnull Muxqueue*
 25 d3df3087 2003-12-06 devnull _muxqalloc(void)
 26 d3df3087 2003-12-06 devnull {
 27 d3df3087 2003-12-06 devnull 	Muxqueue *q;
 28 d3df3087 2003-12-06 devnull 
 29 d3df3087 2003-12-06 devnull 	q = mallocz(sizeof(Muxqueue), 1);
 30 d3df3087 2003-12-06 devnull 	if(q == nil)
 31 d3df3087 2003-12-06 devnull 		return nil;
 32 d3df3087 2003-12-06 devnull 	q->r.l = &q->lk;
 33 d3df3087 2003-12-06 devnull 	return q;
 34 d3df3087 2003-12-06 devnull }
 35 d3df3087 2003-12-06 devnull 
 36 d3df3087 2003-12-06 devnull int
 37 d3df3087 2003-12-06 devnull _muxqsend(Muxqueue *q, void *p)
 38 d3df3087 2003-12-06 devnull {
 39 d3df3087 2003-12-06 devnull 	Qel *e;
 40 d3df3087 2003-12-06 devnull 
 41 d3df3087 2003-12-06 devnull 	e = malloc(sizeof(Qel));
 42 d3df3087 2003-12-06 devnull 	if(e == nil)
 43 d3df3087 2003-12-06 devnull 		return -1;
 44 d3df3087 2003-12-06 devnull 	qlock(&q->lk);
 45 d3df3087 2003-12-06 devnull 	if(q->hungup){
 46 d3df3087 2003-12-06 devnull 		werrstr("hungup queue");
 47 d3df3087 2003-12-06 devnull 		qunlock(&q->lk);
 48 ac244f8d 2003-12-09 devnull 		free(e);
 49 d3df3087 2003-12-06 devnull 		return -1;
 50 d3df3087 2003-12-06 devnull 	}
 51 d3df3087 2003-12-06 devnull 	e->p = p;
 52 d3df3087 2003-12-06 devnull 	e->next = nil;
 53 d3df3087 2003-12-06 devnull 	if(q->head == nil)
 54 d3df3087 2003-12-06 devnull 		q->head = e;
 55 d3df3087 2003-12-06 devnull 	else
 56 d3df3087 2003-12-06 devnull 		q->tail->next = e;
 57 d3df3087 2003-12-06 devnull 	q->tail = e;
 58 d3df3087 2003-12-06 devnull 	rwakeup(&q->r);
 59 d3df3087 2003-12-06 devnull 	qunlock(&q->lk);
 60 d3df3087 2003-12-06 devnull 	return 0;
 61 d3df3087 2003-12-06 devnull }
 62 d3df3087 2003-12-06 devnull 
 63 d3df3087 2003-12-06 devnull void*
 64 d3df3087 2003-12-06 devnull _muxqrecv(Muxqueue *q)
 65 d3df3087 2003-12-06 devnull {
 66 d3df3087 2003-12-06 devnull 	void *p;
 67 d3df3087 2003-12-06 devnull 	Qel *e;
 68 d3df3087 2003-12-06 devnull 
 69 d3df3087 2003-12-06 devnull 	qlock(&q->lk);
 70 d3df3087 2003-12-06 devnull 	while(q->head == nil && !q->hungup)
 71 d3df3087 2003-12-06 devnull 		rsleep(&q->r);
 72 d3df3087 2003-12-06 devnull 	if(q->hungup){
 73 d3df3087 2003-12-06 devnull 		qunlock(&q->lk);
 74 d3df3087 2003-12-06 devnull 		return nil;
 75 d3df3087 2003-12-06 devnull 	}
 76 d3df3087 2003-12-06 devnull 	e = q->head;
 77 d3df3087 2003-12-06 devnull 	q->head = e->next;
 78 d3df3087 2003-12-06 devnull 	qunlock(&q->lk);
 79 d3df3087 2003-12-06 devnull 	p = e->p;
 80 d3df3087 2003-12-06 devnull 	free(e);
 81 d3df3087 2003-12-06 devnull 	return p;
 82 d3df3087 2003-12-06 devnull }
 83 d3df3087 2003-12-06 devnull 
 84 3a194702 2006-11-04 devnull int
 85 3a194702 2006-11-04 devnull _muxnbqrecv(Muxqueue *q, void **vp)
 86 d3df3087 2003-12-06 devnull {
 87 d3df3087 2003-12-06 devnull 	void *p;
 88 d3df3087 2003-12-06 devnull 	Qel *e;
 89 d3df3087 2003-12-06 devnull 
 90 d3df3087 2003-12-06 devnull 	qlock(&q->lk);
 91 d3df3087 2003-12-06 devnull 	if(q->head == nil){
 92 d3df3087 2003-12-06 devnull 		qunlock(&q->lk);
 93 3a194702 2006-11-04 devnull 		*vp = nil;
 94 3a194702 2006-11-04 devnull 		return q->hungup;
 95 d3df3087 2003-12-06 devnull 	}
 96 d3df3087 2003-12-06 devnull 	e = q->head;
 97 d3df3087 2003-12-06 devnull 	q->head = e->next;
 98 d3df3087 2003-12-06 devnull 	qunlock(&q->lk);
 99 d3df3087 2003-12-06 devnull 	p = e->p;
100 d3df3087 2003-12-06 devnull 	free(e);
101 3a194702 2006-11-04 devnull 	*vp = p;
102 3a194702 2006-11-04 devnull 	return 1;
103 d3df3087 2003-12-06 devnull }
104 d3df3087 2003-12-06 devnull 
105 d3df3087 2003-12-06 devnull void
106 d3df3087 2003-12-06 devnull _muxqhangup(Muxqueue *q)
107 d3df3087 2003-12-06 devnull {
108 d3df3087 2003-12-06 devnull 	qlock(&q->lk);
109 d3df3087 2003-12-06 devnull 	q->hungup = 1;
110 d3df3087 2003-12-06 devnull 	rwakeupall(&q->r);
111 d3df3087 2003-12-06 devnull 	qunlock(&q->lk);
112 d3df3087 2003-12-06 devnull }