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 4f6d2bb1 2007-04-08 devnull 	int ref;
 16 056fe1ba 2003-11-23 devnull 	int hungup;
 17 056fe1ba 2003-11-23 devnull 	QLock lk;
 18 056fe1ba 2003-11-23 devnull 	Rendez r;
 19 056fe1ba 2003-11-23 devnull 	Qel *head;
 20 056fe1ba 2003-11-23 devnull 	Qel *tail;
 21 056fe1ba 2003-11-23 devnull };
 22 056fe1ba 2003-11-23 devnull 
 23 056fe1ba 2003-11-23 devnull Queue*
 24 056fe1ba 2003-11-23 devnull _vtqalloc(void)
 25 056fe1ba 2003-11-23 devnull {
 26 056fe1ba 2003-11-23 devnull 	Queue *q;
 27 056fe1ba 2003-11-23 devnull 
 28 056fe1ba 2003-11-23 devnull 	q = vtmallocz(sizeof(Queue));
 29 056fe1ba 2003-11-23 devnull 	q->r.l = &q->lk;
 30 4f6d2bb1 2007-04-08 devnull 	q->ref = 1;
 31 056fe1ba 2003-11-23 devnull 	return q;
 32 056fe1ba 2003-11-23 devnull }
 33 056fe1ba 2003-11-23 devnull 
 34 4f6d2bb1 2007-04-08 devnull Queue*
 35 4f6d2bb1 2007-04-08 devnull _vtqincref(Queue *q)
 36 4f6d2bb1 2007-04-08 devnull {
 37 4f6d2bb1 2007-04-08 devnull 	qlock(&q->lk);
 38 4f6d2bb1 2007-04-08 devnull 	q->ref++;
 39 4f6d2bb1 2007-04-08 devnull 	qunlock(&q->lk);
 40 4f6d2bb1 2007-04-08 devnull 	return q;
 41 4f6d2bb1 2007-04-08 devnull }
 42 4f6d2bb1 2007-04-08 devnull 
 43 6fc7da3c 2006-10-19 devnull void
 44 4f6d2bb1 2007-04-08 devnull _vtqdecref(Queue *q)
 45 6fc7da3c 2006-10-19 devnull {
 46 6fc7da3c 2006-10-19 devnull 	Qel *e;
 47 fa325e9b 2020-01-10 cross 
 48 4f6d2bb1 2007-04-08 devnull 	qlock(&q->lk);
 49 4f6d2bb1 2007-04-08 devnull 	if(--q->ref > 0){
 50 4f6d2bb1 2007-04-08 devnull 		qunlock(&q->lk);
 51 4f6d2bb1 2007-04-08 devnull 		return;
 52 4f6d2bb1 2007-04-08 devnull 	}
 53 4f6d2bb1 2007-04-08 devnull 	assert(q->ref == 0);
 54 4f6d2bb1 2007-04-08 devnull 	qunlock(&q->lk);
 55 4f6d2bb1 2007-04-08 devnull 
 56 6fc7da3c 2006-10-19 devnull 	/* Leaks the pointers e->p! */
 57 6fc7da3c 2006-10-19 devnull 	while(q->head){
 58 6fc7da3c 2006-10-19 devnull 		e = q->head;
 59 6fc7da3c 2006-10-19 devnull 		q->head = e->next;
 60 6fc7da3c 2006-10-19 devnull 		free(e);
 61 6fc7da3c 2006-10-19 devnull 	}
 62 6fc7da3c 2006-10-19 devnull 	free(q);
 63 6fc7da3c 2006-10-19 devnull }
 64 6fc7da3c 2006-10-19 devnull 
 65 056fe1ba 2003-11-23 devnull int
 66 056fe1ba 2003-11-23 devnull _vtqsend(Queue *q, void *p)
 67 056fe1ba 2003-11-23 devnull {
 68 056fe1ba 2003-11-23 devnull 	Qel *e;
 69 056fe1ba 2003-11-23 devnull 
 70 056fe1ba 2003-11-23 devnull 	e = vtmalloc(sizeof(Qel));
 71 056fe1ba 2003-11-23 devnull 	qlock(&q->lk);
 72 056fe1ba 2003-11-23 devnull 	if(q->hungup){
 73 056fe1ba 2003-11-23 devnull 		werrstr("hungup queue");
 74 056fe1ba 2003-11-23 devnull 		qunlock(&q->lk);
 75 056fe1ba 2003-11-23 devnull 		return -1;
 76 056fe1ba 2003-11-23 devnull 	}
 77 056fe1ba 2003-11-23 devnull 	e->p = p;
 78 056fe1ba 2003-11-23 devnull 	e->next = nil;
 79 056fe1ba 2003-11-23 devnull 	if(q->head == nil)
 80 056fe1ba 2003-11-23 devnull 		q->head = e;
 81 056fe1ba 2003-11-23 devnull 	else
 82 056fe1ba 2003-11-23 devnull 		q->tail->next = e;
 83 056fe1ba 2003-11-23 devnull 	q->tail = e;
 84 056fe1ba 2003-11-23 devnull 	rwakeup(&q->r);
 85 056fe1ba 2003-11-23 devnull 	qunlock(&q->lk);
 86 056fe1ba 2003-11-23 devnull 	return 0;
 87 056fe1ba 2003-11-23 devnull }
 88 056fe1ba 2003-11-23 devnull 
 89 056fe1ba 2003-11-23 devnull void*
 90 056fe1ba 2003-11-23 devnull _vtqrecv(Queue *q)
 91 056fe1ba 2003-11-23 devnull {
 92 056fe1ba 2003-11-23 devnull 	void *p;
 93 056fe1ba 2003-11-23 devnull 	Qel *e;
 94 056fe1ba 2003-11-23 devnull 
 95 056fe1ba 2003-11-23 devnull 	qlock(&q->lk);
 96 056fe1ba 2003-11-23 devnull 	while(q->head == nil && !q->hungup)
 97 056fe1ba 2003-11-23 devnull 		rsleep(&q->r);
 98 056fe1ba 2003-11-23 devnull 	if(q->hungup){
 99 056fe1ba 2003-11-23 devnull 		qunlock(&q->lk);
100 056fe1ba 2003-11-23 devnull 		return nil;
101 056fe1ba 2003-11-23 devnull 	}
102 056fe1ba 2003-11-23 devnull 	e = q->head;
103 056fe1ba 2003-11-23 devnull 	q->head = e->next;
104 056fe1ba 2003-11-23 devnull 	qunlock(&q->lk);
105 056fe1ba 2003-11-23 devnull 	p = e->p;
106 056fe1ba 2003-11-23 devnull 	vtfree(e);
107 056fe1ba 2003-11-23 devnull 	return p;
108 056fe1ba 2003-11-23 devnull }
109 056fe1ba 2003-11-23 devnull 
110 056fe1ba 2003-11-23 devnull void*
111 056fe1ba 2003-11-23 devnull _vtnbqrecv(Queue *q)
112 056fe1ba 2003-11-23 devnull {
113 056fe1ba 2003-11-23 devnull 	void *p;
114 056fe1ba 2003-11-23 devnull 	Qel *e;
115 056fe1ba 2003-11-23 devnull 
116 056fe1ba 2003-11-23 devnull 	qlock(&q->lk);
117 056fe1ba 2003-11-23 devnull 	if(q->head == nil){
118 056fe1ba 2003-11-23 devnull 		qunlock(&q->lk);
119 056fe1ba 2003-11-23 devnull 		return nil;
120 056fe1ba 2003-11-23 devnull 	}
121 056fe1ba 2003-11-23 devnull 	e = q->head;
122 056fe1ba 2003-11-23 devnull 	q->head = e->next;
123 056fe1ba 2003-11-23 devnull 	qunlock(&q->lk);
124 056fe1ba 2003-11-23 devnull 	p = e->p;
125 056fe1ba 2003-11-23 devnull 	vtfree(e);
126 056fe1ba 2003-11-23 devnull 	return p;
127 056fe1ba 2003-11-23 devnull }
128 056fe1ba 2003-11-23 devnull 
129 056fe1ba 2003-11-23 devnull void
130 056fe1ba 2003-11-23 devnull _vtqhangup(Queue *q)
131 056fe1ba 2003-11-23 devnull {
132 056fe1ba 2003-11-23 devnull 	qlock(&q->lk);
133 056fe1ba 2003-11-23 devnull 	q->hungup = 1;
134 056fe1ba 2003-11-23 devnull 	rwakeupall(&q->r);
135 056fe1ba 2003-11-23 devnull 	qunlock(&q->lk);
136 056fe1ba 2003-11-23 devnull }