ref: 5c1feb0ef0b795e5de71e956f9ccddcd5c4b7f21
dir: /sys/src/9/port/pgrp.c/
#include "u.h"
#include "../port/lib.h"
#include "mem.h"
#include "dat.h"
#include "fns.h"
#include "../port/error.h"
enum {
Whinesecs = 10, /* frequency of out-of-resources printing */
};
static Ref pgrpid;
static Ref mountid;
void
pgrpnote(ulong noteid, char *a, long n, int flag)
{
Proc *p, *ep;
char buf[ERRMAX];
if(n >= ERRMAX-1)
error(Etoobig);
memmove(buf, a, n);
buf[n] = 0;
p = proctab(0);
for(ep = p+conf.nproc; p < ep; p++) {
if(p->state == Dead)
continue;
if(up != p && p->noteid == noteid && p->kp == 0) {
qlock(&p->debug);
if(p->noteid == noteid)
postnote(p, 0, buf, flag);
qunlock(&p->debug);
}
}
}
Pgrp*
newpgrp(void)
{
Pgrp *p;
p = smalloc(sizeof(Pgrp));
p->ref = 1;
p->pgrpid = incref(&pgrpid);
return p;
}
Rgrp*
newrgrp(void)
{
Rgrp *r;
r = smalloc(sizeof(Rgrp));
r->ref = 1;
return r;
}
void
closergrp(Rgrp *r)
{
if(decref(r) == 0)
free(r);
}
void
closepgrp(Pgrp *p)
{
Mhead **h, **e, *f;
Mount *m;
if(decref(p))
return;
e = &p->mnthash[MNTHASH];
for(h = p->mnthash; h < e; h++) {
while((f = *h) != nil){
*h = f->hash;
wlock(&f->lock);
m = f->mount;
f->mount = nil;
wunlock(&f->lock);
mountfree(m);
putmhead(f);
}
}
free(p);
}
void
pgrpinsert(Mount **order, Mount *m)
{
Mount *f;
m->order = nil;
if(*order == nil) {
*order = m;
return;
}
for(f = *order; f != nil; f = f->order) {
if(m->mountid < f->mountid) {
m->order = f;
*order = m;
return;
}
order = &f->order;
}
*order = m;
}
/*
* pgrpcpy MUST preserve the mountid allocation order of the parent group
*/
void
pgrpcpy(Pgrp *to, Pgrp *from)
{
Mount *n, *m, **link, *order;
Mhead *f, **tom, **l, *mh;
int i;
wlock(&to->ns);
rlock(&from->ns);
order = nil;
tom = to->mnthash;
for(i = 0; i < MNTHASH; i++) {
l = tom++;
for(f = from->mnthash[i]; f != nil; f = f->hash) {
rlock(&f->lock);
mh = newmhead(f->from);
*l = mh;
l = &mh->hash;
link = &mh->mount;
for(m = f->mount; m != nil; m = m->next) {
n = smalloc(sizeof(Mount));
n->mountid = m->mountid;
n->mflag = m->mflag;
n->to = m->to;
incref(n->to);
if(m->spec != nil)
kstrdup(&n->spec, m->spec);
pgrpinsert(&order, n);
*link = n;
link = &n->next;
}
runlock(&f->lock);
}
}
/*
* Allocate mount ids in the same sequence as the parent group
*/
for(m = order; m != nil; m = m->order)
m->mountid = incref(&mountid);
runlock(&from->ns);
wunlock(&to->ns);
}
Fgrp*
dupfgrp(Fgrp *f)
{
Fgrp *new;
Chan *c;
int i;
new = smalloc(sizeof(Fgrp));
if(f == nil){
new->fd = smalloc(DELTAFD*sizeof(Chan*));
new->nfd = DELTAFD;
new->ref = 1;
return new;
}
lock(f);
/* Make new fd list shorter if possible, preserving quantization */
new->nfd = f->maxfd+1;
i = new->nfd%DELTAFD;
if(i != 0)
new->nfd += DELTAFD - i;
new->fd = malloc(new->nfd*sizeof(Chan*));
if(new->fd == nil){
unlock(f);
free(new);
error("no memory for fgrp");
}
new->ref = 1;
new->maxfd = f->maxfd;
for(i = 0; i <= f->maxfd; i++) {
if((c = f->fd[i]) != nil){
incref(c);
new->fd[i] = c;
}
}
unlock(f);
return new;
}
void
closefgrp(Fgrp *f)
{
int i;
Chan *c;
if(f == nil || decref(f))
return;
/*
* If we get into trouble, forceclosefgrp
* will bail us out.
*/
up->closingfgrp = f;
for(i = 0; i <= f->maxfd; i++)
if((c = f->fd[i]) != nil){
f->fd[i] = nil;
cclose(c);
}
up->closingfgrp = nil;
free(f->fd);
free(f);
}
/*
* Called from interrupted() because up is in the middle
* of closefgrp and just got a kill ctl message.
* This usually means that up has wedged because
* of some kind of deadly embrace with mntclose
* trying to talk to itself. To break free, hand the
* unclosed channels to the close queue. Once they
* are finished, the blocked cclose that we've
* interrupted will finish by itself.
*/
void
forceclosefgrp(void)
{
int i;
Chan *c;
Fgrp *f;
if(up->procctl != Proc_exitme || up->closingfgrp == nil){
print("bad forceclosefgrp call");
return;
}
f = up->closingfgrp;
for(i = 0; i <= f->maxfd; i++)
if((c = f->fd[i]) != nil){
f->fd[i] = nil;
ccloseq(c);
}
}
Mount*
newmount(Chan *to, int flag, char *spec)
{
Mount *m;
m = smalloc(sizeof(Mount));
m->to = to;
incref(to);
m->mountid = incref(&mountid);
m->mflag = flag;
if(spec != nil)
kstrdup(&m->spec, spec);
return m;
}
void
mountfree(Mount *m)
{
Mount *f;
while((f = m) != nil) {
m = m->next;
cclose(f->to);
free(f->spec);
free(f);
}
}
void
resrcwait(char *reason)
{
static ulong lastwhine;
ulong now;
char *p;
if(up == nil)
panic("resrcwait");
p = up->psstate;
if(reason != nil) {
if(waserror()){
up->psstate = p;
nexterror();
}
up->psstate = reason;
now = seconds();
/* don't tie up the console with complaints */
if(now - lastwhine > Whinesecs) {
lastwhine = now;
print("%s\n", reason);
}
}
tsleep(&up->sleep, return0, 0, 100+nrand(200));
if(reason != nil) {
up->psstate = p;
poperror();
}
}