ref: 02ac617541ca1a7bf82b1615fb5a58235469b5d3
dir: /emu/Plan9/os.c/
#include "dat.h"
#include "fns.h"
#include "error.h"
enum
{
KSTACK = 16*1024,
DELETE = 0x7F,
};
Proc **Xup;
extern void killrefresh(void);
extern void tramp(char*, void (*)(void*), void*);
extern int usenewwin;
int *ustack; /* address on unshared stack: see vstack in asm*.s */
extern int dflag;
char *hosttype = "Plan9";
char *cputype;
void
osblock(void)
{
rendezvous(up, nil);
}
void
osready(Proc *p)
{
rendezvous(p, nil);
}
void
pexit(char *msg, int)
{
Osenv *e;
USED(msg);
lock(&procs.l);
if(up->prev)
up->prev->next = up->next;
else
procs.head = up->next;
if(up->next)
up->next->prev = up->prev;
else
procs.tail = up->prev;
unlock(&procs.l);
/* print("pexit: %s: %s\n", up->text, msg); /**/
e = up->env;
if(e != nil) {
closefgrp(e->fgrp);
closepgrp(e->pgrp);
closeegrp(e->egrp);
closesigs(e->sigs);
}
free(e->user);
free(up->prog);
up->prog = nil;
up->type = Moribund;
longjmp(up->privstack, 1);
}
int
kproc1(char *name, void (*func)(void*), void *arg, int flags)
{
int pid;
Proc *p;
Pgrp *pg;
Fgrp *fg;
Egrp *eg;
p = newproc();
if(p == nil)
panic("kproc: no memory");
p->kstack = mallocz(KSTACK, 0);
if(p->kstack == nil)
panic("kproc: no memory");
if(flags & KPDUPPG) {
pg = up->env->pgrp;
incref(&pg->r);
p->env->pgrp = pg;
}
if(flags & KPDUPFDG) {
fg = up->env->fgrp;
incref(&fg->r);
p->env->fgrp = fg;
}
if(flags & KPDUPENVG) {
eg = up->env->egrp;
incref(&eg->r);
p->env->egrp = eg;
}
p->env->uid = up->env->uid;
p->env->gid = up->env->gid;
kstrdup(&p->env->user, up->env->user);
strcpy(p->text, name);
p->func = func;
p->arg = arg;
lock(&procs.l);
if(procs.tail != nil) {
p->prev = procs.tail;
procs.tail->next = p;
}
else {
procs.head = p;
p->prev = nil;
}
procs.tail = p;
unlock(&procs.l);
/*
* switch back to the unshared stack to do the fork
* only the parent returns from kproc
*/
up->kid = p;
up->kidsp = p->kstack;
pid = setjmp(up->sharestack);
if(pid == 0)
longjmp(up->privstack, 1);
return pid;
}
void
kproc(char *name, void (*func)(void*), void *arg, int flags)
{
kproc1(name, func, arg, flags);
}
void
traphandler(void *reg, char *msg)
{
int intwait;
intwait = up->intwait;
up->intwait = 0;
/* Ignore pipe writes from devcmd */
if(strstr(msg, "write on closed pipe") != nil)
noted(NCONT);
if(sflag) {
if(intwait && strcmp(msg, Eintr) == 0)
noted(NCONT);
else
noted(NDFLT);
}
if(intwait == 0)
disfault(reg, msg);
noted(NCONT);
}
int
readfile(char *path, char *buf, int n)
{
int fd;
fd = open(path, OREAD);
if(fd >= 0) {
n = read(fd, buf, n-1);
if(n > 0) /* both calls to readfile() have a ``default'' */
buf[n] = '\0';
close(fd);
return n;
}
return 0;
}
static void
dobinds(void)
{
char dir[MAXROOT+9];
snprint(dir, sizeof(dir), "%s/net", rootdir);
bind("/net", dir, MREPL);
snprint(dir, sizeof(dir), "%s/net.alt", rootdir);
bind("/net.alt", dir, MREPL);
snprint(dir, sizeof(dir), "%s/dev", rootdir);
bind("#t", dir, MAFTER);
bind("#A", dir, MAFTER);
}
void
libinit(char *imod)
{
char *sp;
Proc *xup, *p;
int fd, n, pid;
char nbuf[64];
xup = nil;
Xup = &xup;
/*
* setup personality
*/
if(readfile("/dev/user", nbuf, sizeof nbuf))
kstrdup(&eve, nbuf);
if(readfile("/dev/sysname", nbuf, sizeof nbuf))
kstrdup(&ossysname, nbuf);
if(readfile("/env/cputype", nbuf, sizeof nbuf))
kstrdup(&cputype, nbuf);
/*
* guess at a safe stack for vstack
*/
ustack = &fd;
rfork(RFNAMEG|RFREND);
if(!dflag){
fd = open("/dev/consctl", OWRITE);
if(fd < 0)
fprint(2, "libinit: open /dev/consctl: %r\n");
n = write(fd, "rawon", 5);
if(n != 5)
fprint(2, "keyboard rawon (n=%d, %r)\n", n);
}
osmillisec(); /* set the epoch */
dobinds();
notify(traphandler);
/*
* dummy up a up and stack so the first proc
* calls emuinit after setting up his private jmp_buf
*/
p = newproc();
p->kstack = mallocz(KSTACK, 0);
if(p == nil || p->kstack == nil)
panic("libinit: no memory");
sp = p->kstack;
p->func = emuinit;
p->arg = imod;
/*
* set up a stack for forking kids on separate stacks.
* longjmp back here from kproc.
*/
while(setjmp(p->privstack)){
if(up->type == Moribund){
free(up->kstack);
free(up);
_exits("");
}
p = up->kid;
sp = up->kidsp;
up->kid = nil;
switch(pid = rfork(RFPROC|RFMEM|RFNOWAIT)){
case 0:
/*
* send the kid around the loop to set up his private jmp_buf
*/
break;
default:
/*
* parent just returns to his shared stack in kproc
*/
longjmp(up->sharestack, pid);
panic("longjmp failed");
}
}
/*
* you get here only once per Proc
* go to the shared memory stack
*/
up = p;
up->pid = up->sigid = getpid();
tramp(sp+KSTACK, up->func, up->arg);
panic("tramp returned");
}
void
oshostintr(Proc *p)
{
postnote(PNPROC, p->sigid, Eintr);
}
void
oslongjmp(void *regs, osjmpbuf env, int val)
{
if(regs != nil)
notejmp(regs, env, val);
else
longjmp(env, val);
}
void
osreboot(char*, char**)
{
}
void
cleanexit(int x)
{
USED(x);
killrefresh();
postnote(PNGROUP, getpid(), "interrupt");
exits("interrupt");
}
int
readkbd(void)
{
int n;
char buf[1];
n = read(0, buf, sizeof(buf));
if(n < 0)
fprint(2, "emu: keyboard read error: %r\n");
if(n <= 0)
pexit("keyboard", 0);
switch(buf[0]) {
case DELETE:
cleanexit(0);
case '\r':
buf[0] = '\n';
}
return buf[0];
}
static vlong
b2v(uchar *p)
{
int i;
vlong v;
v = 0;
for(i=0; i<sizeof(uvlong); i++)
v = (v<<8)|p[i];
return v;
}
vlong
nsec(void)
{
int n;
static int nsecfd = -1;
uchar buf[sizeof(uvlong)];
if(nsecfd < 0){
nsecfd = open("/dev/bintime", OREAD|OCEXEC); /* never closed */
if(nsecfd<0){
fprint(2,"can't open /dev/bintime: %r\n");
return 0;
}
}
n = read(nsecfd, buf, sizeof(buf));
if(n!=sizeof(buf)) {
fprint(2,"read err on /dev/bintime: %r\n");
return 0;
}
return b2v(buf);
}
long
osmillisec(void)
{
static vlong nsec0 = 0;
if(nsec0 == 0){
nsec0 = nsec();
return 0;
}
return (nsec()-nsec0)/1000000;
}
/*
* Return the time since the epoch in microseconds
* The epoch is defined at 1 Jan 1970
*/
vlong
osusectime(void)
{
return nsec()/1000;
}
int
osmillisleep(ulong milsec)
{
sleep(milsec);
return 0;
}
int
limbosleep(ulong milsec)
{
return osmillisleep(milsec);
}
void
osyield(void)
{
sleep(0);
}
void
ospause(void)
{
for(;;)
sleep(1000000);
}
void
oslopri(void)
{
int fd;
char buf[32];
snprint(buf, sizeof(buf), "/proc/%d/ctl", getpid());
if((fd = open(buf, OWRITE)) >= 0){
fprint(fd, "pri 8");
close(fd);
}
}