static void
pipeclose(Chan *c)
{
Pipe *p;
p = c->aux;
qlock(&p->l);
if(c->flag & COPEN){
/*
* closing either side hangs up the stream
*/
switch(NETTYPE(c->qid.path)){
case Qdata0:
p->qref[0]--;
if(p->qref[0] == 0){
qhangup(p->q[1], 0);
qclose(p->q[0]);
}
break;
case Qdata1:
p->qref[1]--;
if(p->qref[1] == 0){
qhangup(p->q[0], 0);
qclose(p->q[1]);
}
break;
}
}
/*
* if both sides are closed, they are reusable
*/
if(p->qref[0] == 0 && p->qref[1] == 0){
qreopen(p->q[0]);
qreopen(p->q[1]);
}
/*
* free the structure on last close
*/
p->ref--;
if(p->ref == 0){
qunlock(&p->l);
freepipe(p);
} else
qunlock(&p->l);
}
/*
* create a pipe, no streams are created until an open
*/
static struct chan *pipeattach(char *spec)
{
ERRSTACK(2);
Pipe *p;
struct chan *c;
c = devattach(devname(), spec);
p = kzmalloc(sizeof(Pipe), 0);
if (p == 0)
error(ENOMEM, ERROR_FIXME);
if (waserror()) {
freepipe(p);
nexterror();
}
p->pipedir = kzmalloc(sizeof(pipedir), 0);
if (p->pipedir == 0)
error(ENOMEM, ERROR_FIXME);
memmove(p->pipedir, pipedir, sizeof(pipedir));
kstrdup(&p->user, current->user);
kref_init(&p->ref, pipe_release, 1);
qlock_init(&p->qlock);
p->q[0] = qopen(pipealloc.pipeqsize, Qcoalesce, 0, 0);
if (p->q[0] == 0)
error(ENOMEM, ERROR_FIXME);
p->q[1] = qopen(pipealloc.pipeqsize, Qcoalesce, 0, 0);
if (p->q[1] == 0)
error(ENOMEM, ERROR_FIXME);
poperror();
spin_lock(&(&pipealloc)->lock);
p->path = ++pipealloc.path;
spin_unlock(&(&pipealloc)->lock);
c->qid.path = NETQID(2 * p->path, Qdir);
c->qid.vers = 0;
c->qid.type = QTDIR;
c->aux = p;
c->dev = 0;
/* taps. */
SLIST_INIT(&p->data_taps[0]); /* already = 0; set to be futureproof */
SLIST_INIT(&p->data_taps[1]);
spinlock_init(&p->tap_lock);
return c;
}
/*
* create a pipe, no streams are created until an open
*/
static Chan*
pipeattach(char *spec)
{
Pipe *p;
Chan *c;
c = devattach('|', spec);
p = malloc(sizeof(Pipe));
if(p == 0)
error(Enomem);
if(waserror()){
freepipe(p);
nexterror();
}
p->pipedir = malloc(sizeof(pipedir));
if (p->pipedir == 0)
error(Enomem);
memmove(p->pipedir, pipedir, sizeof(pipedir));
kstrdup(&p->user, up->env->user);
p->ref = 1;
p->q[0] = qopen(pipealloc.pipeqsize, 0, 0, 0);
if(p->q[0] == 0)
error(Enomem);
p->q[1] = qopen(pipealloc.pipeqsize, 0, 0, 0);
if(p->q[1] == 0)
error(Enomem);
poperror();
lock(&pipealloc.l);
p->path = ++pipealloc.path;
unlock(&pipealloc.l);
c->qid.path = NETQID(2*p->path, Qdir);
c->qid.vers = 0;
c->qid.type = QTDIR;
c->aux = p;
c->dev = 0;
return c;
}
static void pipe_release(struct kref *kref)
{
Pipe *pipe = container_of(kref, Pipe, ref);
freepipe(pipe);
}
