/* * This file is part of the UCB release of Plan 9. It is subject to the license * terms in the LICENSE file found in the top-level directory of this * distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No * part of the UCB release of Plan 9, including this file, may be copied, * modified, propagated, or distributed except according to the terms contained * in the LICENSE file. */ #include <u.h>#include <libc.h>#include <venti.h>#include "queue.h" typedef struct Qel Qel;struct Qel{ Qel *next; void *p;}; struct Queue{ int ref; int hungup; QLock lk; Rendez r; Qel *head; Qel *tail;}; Queue*_vtqalloc(void){ Queue *q; q = vtmallocz(sizeof(Queue)); q->r.l = &q->lk; q->ref = 1; return q;} Queue*_vtqincref(Queue *q){ qlock(&q->lk); q->ref++; qunlock(&q->lk); return q;} void_vtqdecref(Queue *q){ Qel *e; qlock(&q->lk); if(--q->ref > 0){ qunlock(&q->lk); return; } assert(q->ref == 0); qunlock(&q->lk); /* Leaks the pointers e->p! */ while(q->head){ e = q->head; q->head = e->next; free(e); } free(q);} int_vtqsend(Queue *q, void *p){ Qel *e; e = vtmalloc(sizeof(Qel)); qlock(&q->lk); if(q->hungup){ werrstr("hungup queue"); qunlock(&q->lk); return -1; } e->p = p; e->next = nil; if(q->head == nil) q->head = e; else q->tail->next = e; q->tail = e; rwakeup(&q->r); qunlock(&q->lk); return 0;} void*_vtqrecv(Queue *q){ void *p; Qel *e; qlock(&q->lk); while(q->head == nil && !q->hungup) rsleep(&q->r); if(q->hungup){ qunlock(&q->lk); return nil; } e = q->head; q->head = e->next; qunlock(&q->lk); p = e->p; vtfree(e); return p;} void*_vtnbqrecv(Queue *q){ void *p; Qel *e; qlock(&q->lk); if(q->head == nil){ qunlock(&q->lk); return nil; } e = q->head; q->head = e->next; qunlock(&q->lk); p = e->p; vtfree(e); return p;} void_vtqhangup(Queue *q){ qlock(&q->lk); q->hungup = 1; rwakeupall(&q->r); qunlock(&q->lk);}
/*
* This file is part of the UCB release of Plan 9. It is subject to the license
* terms in the LICENSE file found in the top-level directory of this
* distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No
* part of the UCB release of Plan 9, including this file, may be copied,
* modified, propagated, or distributed except according to the terms contained
* in the LICENSE file.
*/
#include <u.h>
#include <libc.h>
#include <venti.h>
#include "queue.h"
typedef struct Qel Qel;
struct Qel
{
Qel *next;
void *p;
};
struct Queue
{
int ref;
int hungup;
QLock lk;
Rendez r;
Qel *head;
Qel *tail;
};
Queue*
_vtqalloc(void)
{
Queue *q;
q = vtmallocz(sizeof(Queue));
q->r.l = &q->lk;
q->ref = 1;
return q;
}
Queue*
_vtqincref(Queue *q)
{
qlock(&q->lk);
q->ref++;
qunlock(&q->lk);
return q;
}
void
_vtqdecref(Queue *q)
{
Qel *e;
qlock(&q->lk);
if(--q->ref > 0){
qunlock(&q->lk);
return;
}
assert(q->ref == 0);
qunlock(&q->lk);
/* Leaks the pointers e->p! */
while(q->head){
e = q->head;
q->head = e->next;
free(e);
}
free(q);
}
int
_vtqsend(Queue *q, void *p)
{
Qel *e;
e = vtmalloc(sizeof(Qel));
qlock(&q->lk);
if(q->hungup){
werrstr("hungup queue");
qunlock(&q->lk);
return -1;
}
e->p = p;
e->next = nil;
if(q->head == nil)
q->head = e;
else
q->tail->next = e;
q->tail = e;
rwakeup(&q->r);
qunlock(&q->lk);
return 0;
}
void*
_vtqrecv(Queue *q)
{
void *p;
Qel *e;
qlock(&q->lk);
while(q->head == nil && !q->hungup)
rsleep(&q->r);
if(q->hungup){
qunlock(&q->lk);
return nil;
}
e = q->head;
q->head = e->next;
qunlock(&q->lk);
p = e->p;
vtfree(e);
return p;
}
void*
_vtnbqrecv(Queue *q)
{
void *p;
Qel *e;
qlock(&q->lk);
if(q->head == nil){
qunlock(&q->lk);
return nil;
}
e = q->head;
q->head = e->next;
qunlock(&q->lk);
p = e->p;
vtfree(e);
return p;
}
void
_vtqhangup(Queue *q)
{
qlock(&q->lk);
q->hungup = 1;
rwakeupall(&q->r);
qunlock(&q->lk);
}