1993/0309/port/proc.c (diff list | history)

port/proc.c on 1990/0227
1990/0227		#include "u.h"
1992/0321		#include "../port/lib.h"
1990/0227		#include "mem.h" #include "dat.h" #include "fns.h"
1992/0111		#include "../port/error.h"
1990/0227
1992/0309		Ref pidalloc;
1992/0428		Ref noteidalloc;
1990/0227		struct { Lock; Proc *arena; Proc *free; }procalloc;
1991/0926		struct { Lock; Waitq *free; }waitqalloc;
1991/0420		typedef struct
1990/0227		{ Lock; Proc *head; Proc *tail;
1991/0420		}Schedq;
1990/0227
1991/1112		Schedq runhiq, runloq; int nrdy;
1991/0420
1992/0309		char *statename[] = { /* BUG: generate automatically */
1990/0227		"Dead", "Moribund", "Ready", "Scheding", "Running", "Queueing", "Wakeme", "Broken",
1991/0705		"Stopped",
1991/0806		"Rendez",
1990/0227		}; /* * Always splhi()'ed. */ void schedinit(void) /* never returns */ { Proc *p; setlabel(&m->sched); if(u){ m->proc = 0; p = u->p;
1990/1211		invalidateu(); /* safety first */
1990/0227		u = 0; if(p->state == Running) ready(p);
1992/0619		else if(p->state == Moribund) {
1990/0227		p->pid = 0;
1992/0620		p->state = Dead;
1991/0705		/*
1991/0717		* Holding locks from pexit:
1991/0705		* procalloc, debug, palloc */
1991/1003		mmurelease(p); simpleputpage(p->upage);
1991/0705		p->upage = 0;
1990/0227		p->qnext = procalloc.free; procalloc.free = p;
1991/0705		unlock(&palloc);
1991/1216		qunlock(&p->debug);
1990/0227		unlock(&procalloc); } p->mach = 0; } sched(); } void sched(void) { Proc *p; if(u){ splhi();
1991/0425		m->cs++;
1992/0122		procsave(u->p);
1990/0227		if(setlabel(&u->p->sched)){ /* woke up */ p = u->p; p->state = Running; p->mach = m; m->proc = p;
1992/0122		procrestore(p);
1990/0227		spllo(); return; } gotolabel(&m->sched); } p = runproc(); mapstack(p); gotolabel(&p->sched); }
1990/1227		int anyready(void) {
1991/0420		return runloq.head != 0 || runhiq.head != 0;
1990/1227		}
1990/0227		void ready(Proc *p) {
1991/0420		Schedq *rq;
1990/0227		int s; s = splhi();
1991/0501
1991/0420		if(p->state == Running) rq = &runloq; else rq = &runhiq; lock(&runhiq);
1990/0227		p->rnext = 0;
1991/0420		if(rq->tail) rq->tail->rnext = p;
1990/0227		else
1991/0420		rq->head = p; rq->tail = p;
1991/1112		nrdy++;
1990/0227		p->state = Ready;
1991/0420		unlock(&runhiq);
1990/0227		splx(s); } /*
1992/0603		* Always called splhi
1990/0227		*/ Proc* runproc(void) {
1991/0420		Schedq *rq;
1990/0227		Proc *p; loop:
1992/0603		spllo();
1991/0420		while(runhiq.head==0 && runloq.head==0)
1992/0622		;
1990/0227		splhi();
1992/0622
1991/0420		lock(&runhiq); if(runhiq.head) rq = &runhiq; else rq = &runloq; p = rq->head;
1990/0227		if(p==0 || p->mach){ /* p->mach==0 only when process state is saved */
1991/0420		unlock(&runhiq);
1990/0227		goto loop; } if(p->rnext == 0)
1991/0420		rq->tail = 0; rq->head = p->rnext;
1991/1112		nrdy--;
1990/0227		if(p->state != Ready) print("runproc %s %d %s\n", p->text, p->pid, statename[p->state]);
1991/0420		unlock(&runhiq);
1990/0227		p->state = Scheding; return p; }
1991/0705		int canpage(Proc *p) { int ok = 0; splhi(); lock(&runhiq);
1991/0906		/* Only reliable way to see if we are Running */ if(p->mach == 0) {
1991/0705		p->newtlb = 1; ok = 1; } unlock(&runhiq); spllo(); return ok; }
1990/0227		Proc* newproc(void) { Proc *p;
1991/1110		for(;;) { lock(&procalloc); if(p = procalloc.free){ /* assign = */ procalloc.free = p->qnext; p->state = Scheding; p->psstate = "New"; unlock(&procalloc); p->mach = 0; p->qnext = 0; p->nchild = 0; p->nwait = 0; p->waitq = 0; p->pgrp = 0; p->egrp = 0; p->fgrp = 0; p->pdbg = 0; p->fpstate = FPinit; p->kp = 0; p->procctl = 0; p->notepending = 0; memset(p->seg, 0, sizeof p->seg);
1992/0309		p->pid = incref(&pidalloc);
1992/0428		p->noteid = incref(¬eidalloc); if(p->pid==0 || p->noteid==0)
1991/1110		panic("pidalloc"); return p; }
1990/0227		unlock(&procalloc);
1991/1110		resrcwait("no procs");
1990/0227		}
1992/0520		return 0; /* not reached */
1990/0227		} void procinit0(void) /* bad planning - clashes with devproc.c */ { Proc *p; int i;
1992/0619		procalloc.free = xalloc(conf.nproc*sizeof(Proc));
1990/0227		procalloc.arena = procalloc.free; p = procalloc.free;
1990/0310		for(i=0; i<conf.nproc-1; i++,p++)
1990/0227		p->qnext = p+1; p->qnext = 0; } void sleep1(Rendez *r, int (*f)(void*), void *arg) { Proc *p; int s; /* * spl is to allow lock to be called * at interrupt time. lock is mutual exclusion */ s = splhi();
1991/0727		p = u->p; p->r = r; /* early so postnote knows */
1990/0227		lock(r); /* * if condition happened, never mind */
1991/0727		if((*f)(arg)){ p->r = 0;
1990/0227		unlock(r); splx(s); return; } /* * now we are committed to * change state and call scheduler */
1991/0807		if(r->p){
1990/03013		print("double sleep %d %d\n", r->p->pid, p->pid);
1991/0807		dumpstack(); }
1990/0227		p->state = Wakeme; r->p = p; unlock(r); } void sleep(Rendez *r, int (*f)(void*), void *arg) {
1991/0727		Proc *p;
1992/0519		int s;
1991/0727		p = u->p;
1990/0227		sleep1(r, f, arg);
1991/0727		if(p->notepending == 0) sched(); /* notepending may go true while asleep */ if(p->notepending){ p->notepending = 0;
1992/0519		s = splhi();
1991/0805		lock(r); if(r->p == p) r->p = 0; unlock(r);
1992/0519		splx(s);
1990/11211		error(Eintr);
1990/0227		} }
1992/0617		int tfn(void *arg) { Proc *p; p = u->p; return MACHP(0)->ticks >= p->twhen || (*p->tfn)(arg); }
1990/0227		void
1992/0602		tsleep(Rendez *r, int (*fn)(void*), void *arg, int ms)
1990/0227		{
1992/0602		ulong when;
1992/0701		Proc *p, *f, **l;
1990/0227
1991/0727		p = u->p;
1992/0602		when = MS2TK(ms)+MACHP(0)->ticks; lock(&talarm);
1992/0701		/* take out of list if checkalarm didn't */ if(p->trend) { l = &talarm.list; for(f = *l; f; f = f->tlink) { if(f == p) { *l = p->tlink; break; } l = &f->tlink; } } /* insert in increasing time order */
1992/0602		l = &talarm.list;
1992/0701		for(f = *l; f; f = f->tlink) { if(f->twhen >= when) break;
1992/0602		l = &f->tlink;
1991/0727		}
1992/0602		p->trend = r; p->twhen = when;
1992/0617		p->tfn = fn;
1992/0701		p->tlink = *l; *l = p;
1992/0602		unlock(&talarm);
1992/0617		sleep(r, tfn, arg);
1992/0602		p->twhen = 0;
1990/0227		}
1992/0909		/* * Expects that only one process can call wakeup for any given Rendez */
1990/0227		void wakeup(Rendez *r) { Proc *p; int s; s = splhi(); lock(r); p = r->p; if(p){ r->p = 0;
1991/0705		if(p->state != Wakeme) panic("wakeup: state");
1990/0227		p->r = 0; ready(p); } unlock(r); splx(s);
1990/03091		}
1990/0227		int postnote(Proc *p, int dolock, char *n, int flag) { User *up;
1990/0617		KMap *k;
1991/1120		int s, ret;
1990/0227		Rendez *r;
1991/0806		Proc *d, **l;
1990/0227		if(dolock)
1991/1216		qlock(&p->debug);
1991/0430
1993/0112		if(p->kp) print("sending %s to kproc %d %s\n", n, p->pid, p->text);
1991/0810		if(p->upage == 0){ if(dolock)
1991/1216		qunlock(&p->debug);
1992/0527		return 0;
1991/0810		}
1991/0425
1991/1115		SET(k);
1991/0523		if(u == 0 || p != u->p){
1991/0109		k = kmap(p->upage); up = (User*)VA(k);
1991/1115		}else
1991/0109		up = u;
1991/1127		USED(k);
1991/0523
1990/0227		if(flag!=NUser && (up->notify==0 || up->notified)) up->nnote = 0; /* force user's hand */
1991/1120		ret = 0; if(up->nnote < NNOTE){ strcpy(up->note[up->nnote].msg, n); up->note[up->nnote++].flag = flag; ret = 1;
1990/0617		}
1991/0727		p->notepending = 1;
1991/0109		if(up != u) kunmap(k);
1990/0227		if(dolock)
1991/1216		qunlock(&p->debug);
1991/0705
1991/0727		if(r = p->r){ /* assign = */ /* wake up; can't call wakeup itself because we're racing with it */
1992/0909		for(;;) { s = splhi(); if(canlock(r)) break; splx(s); } if(p->r==r && r->p==p && p->state==Wakeme){ /* check we won the race */ r->p = 0; p->r = 0; ready(p);
1990/0227		} unlock(r); splx(s); }
1991/0807
1992/1206		if(p->state != Rendezvous) return ret; /* Try and pull out of a rendezvous */ lock(p->pgrp);
1991/0806		if(p->state == Rendezvous) {
1992/1206		p->rendval = ~0; l = &REND(p->pgrp, p->rendtag); for(d = *l; d; d = d->rendhash) { if(d == p) { *l = p->rendhash;
1993/0216		ready(p);
1992/1206		break;
1991/0806		}
1992/1206		l = &d->rendhash;
1991/0806		} }
1992/1206		unlock(p->pgrp);
1991/1120		return ret;
1990/0227		}
1990/1101		/* * weird thing: keep at most NBROKEN around */ #define NBROKEN 4
1992/1206		struct { QLock;
1990/1101		int n; Proc *p[NBROKEN]; }broken;
1990/0227		void
1992/1206		addbroken(Proc *p)
1990/1101		{
1992/1206		qlock(&broken); if(broken.n == NBROKEN) {
1990/1101		ready(broken.p[0]);
1991/0318		memmove(&broken.p[0], &broken.p[1], sizeof(Proc*)*(NBROKEN-1));
1990/1101		--broken.n; }
1992/1206		broken.p[broken.n++] = p; qunlock(&broken); p->state = Broken; p->psstate = 0; sched();
1990/1101		}
1992/1206		void unbreak(Proc *p) { int b; qlock(&broken);
1992/1208		for(b=0; b < broken.n; b++)
1992/1225		if(broken.p[b] == p) {
1992/1208		broken.n--; memmove(&broken.p[b], &broken.p[b+1], sizeof(Proc*)*(NBROKEN-(b+1))); ready(p); break; }
1992/1206		qunlock(&broken); }
1990/1101		int freebroken(void) {
1991/0109		int i, n;
1990/1101
1992/1206		qlock(&broken);
1990/1101		n = broken.n;
1992/1206		for(i=0; i<n; i++) {
1991/0109		ready(broken.p[i]);
1992/1206		broken.p[i] = 0; }
1991/0109		broken.n = 0;
1992/1206		qunlock(&broken);
1990/1101		return n; } void
1991/0717		pexit(char *exitstr, int freemem)
1990/0227		{
1991/1218		int n;
1992/0205		long utime, stime;
1991/0926		Proc *p, *c;
1992/1206		Segment **s, **es;
1991/0926		Waitq *wq, *f, *next;
1990/0227
1990/03081		c = u->p;
1991/0513		c->alarm = 0;
1991/0517
1991/0712		if(c->fgrp) closefgrp(c->fgrp);
1991/1024		closepgrp(c->pgrp); close(u->dot); if(c->egrp) closeegrp(c->egrp);
1991/0517
1992/0115		/* * if not a kernel process and have a parent, * do some housekeeping. */
1992/0303		if(c->kp == 0) {
1992/1206		p = c->parent; if(p == 0) {
1992/0902		if(exitstr == 0) exitstr = "unknown"; panic("boot process died: %s", exitstr); }
1992/0805		while(waserror()) ;
1992/0620		wq = smalloc(sizeof(Waitq));
1992/0805		poperror();
1992/0309		readnum(0, wq->w.pid, NUMSIZE, c->pid, NUMSIZE);
1992/0205		utime = c->time[TUser] + c->time[TCUser]; stime = c->time[TSys] + c->time[TCSys];
1992/0309		readnum(0, &wq->w.time[TUser*12], NUMSIZE, TK2MS(utime), NUMSIZE); readnum(0, &wq->w.time[TSys*12], NUMSIZE, TK2MS(stime), NUMSIZE); readnum(0, &wq->w.time[TReal*12], NUMSIZE, TK2MS(MACHP(0)->ticks - c->time[TReal]), NUMSIZE);
1991/1218		if(exitstr && exitstr[0]){ n = sprint(wq->w.msg, "%s %d:", c->text, c->pid); strncpy(wq->w.msg+n, exitstr, ERRLEN-n);
1992/1206		} else
1991/1006		wq->w.msg[0] = '\0';
1991/1005		lock(&p->exl);
1992/0309		/* My parent still alive, processes are limited to 128 Zombies to
1992/0620		* prevent a badly written daemon lots of wait records */
1991/1005		if(p->pid == c->parentpid && p->state != Broken && p->nwait < 128) { p->nchild--;
1992/0205		p->time[TCUser] += utime; p->time[TCSys] += stime;
1991/1005		wq->next = p->waitq; p->waitq = wq; p->nwait++; unlock(&p->exl);
1993/0309
1991/1005		wakeup(&p->waitr); } else { unlock(&p->exl);
1992/0620		free(wq);
1991/1005		}
1990/0227		}
1990/03081
1991/0926		if(!freemem) addbroken(c);
1990/03081
1991/0926		es = &c->seg[NSEG]; for(s = c->seg; s < es; s++)
1992/1206		if(*s) putseg(*s);
1991/0926		lock(&c->exl); /* Prevent my children from leaving waits */ c->pid = 0; unlock(&c->exl); for(f = c->waitq; f; f = next) { next = f->next;
1992/0620		free(f);
1991/0926		}
1991/0705		/* * sched() cannot wait on these locks */
1991/1216		qlock(&c->debug);
1991/1110		/* release debuggers */ if(c->pdbg) { wakeup(&c->pdbg->sleep); c->pdbg = 0; } lock(&procalloc);
1991/0705		lock(&palloc);
1990/03081		c->state = Moribund;
1991/0705		sched(); panic("pexit");
1990/0227		}
1991/0926		int haswaitq(void *x) { Proc *p; p = (Proc *)x; return p->waitq != 0; }
1990/0227		ulong pwait(Waitmsg *w) {
1991/0926		Proc *p;
1990/0227		ulong cpid;
1991/0926		Waitq *wq;
1990/0227		p = u->p;
1991/0926
1993/0309		if(!canqlock(&p->qwaitr)) error(Einuse); if(waserror()) { qunlock(&p->qwaitr); nexterror(); }
1991/0926		lock(&p->exl); if(p->nchild == 0 && p->waitq == 0) { unlock(&p->exl); error(Enochild);
1990/0227		}
1991/0926		unlock(&p->exl); sleep(&p->waitr, haswaitq, u->p); lock(&p->exl); wq = p->waitq; p->waitq = wq->next; p->nwait--; unlock(&p->exl);
1993/0309		qunlock(&p->qwaitr); poperror();
1991/0926
1990/0227		if(w)
1991/0926		memmove(w, &wq->w, sizeof(Waitmsg));
1992/0309		cpid = atoi(wq->w.pid);
1992/0620		free(wq);
1990/0227		return cpid; } Proc* proctab(int i) { return &procalloc.arena[i]; }
1990/1220		void
1991/0608		procdump(void)
1990/0227		{
1990/0330		int i;
1992/0805		char *s;
1990/0227		Proc *p;
1992/0805		ulong bss;
1990/0227		for(i=0; i<conf.nproc; i++){ p = procalloc.arena+i;
1990/0312		if(p->state != Dead){
1992/0805		bss = 0; if(p->seg[BSEG]) bss = p->seg[BSEG]->top; s = p->psstate; if(s == 0) s = "kproc"; print("%3d:%10s %10s pc %8lux %8s (%s) ut %ld st %ld r %lux qpc %lux bss %lux\n",
1991/1105		p->pid, p->text, p->user, p->pc,
1992/0805		s, statename[p->state], p->time[0], p->time[1], p->r, p->qlockpc, bss);
1990/0312		}
1990/0227		} } void kproc(char *name, void (*func)(void *), void *arg) { Proc *p; int n; ulong upa;
1990/0617		User *up; KMap *k;
1990/0722		static Pgrp *kpgrp;
1991/0705		char *user;
1992/0703		int lastvar; /* used to compute stack address */
1990/0227		/* * Kernel stack */ p = newproc();
1991/0926		p->psstate = 0;
1991/1112		p->procmode = 0644;
1990/1212		p->kp = 1;
1990/0227		p->upage = newpage(1, 0, USERADDR|(p->pid&0xFFFF));
1990/0617		k = kmap(p->upage); upa = VA(k); up = (User*)upa;
1990/0227		/* * Save time: only copy u-> data and useful stack */
1991/0318		memmove(up, u, sizeof(User));
1990/0227		n = USERADDR+BY2PG - (ulong)&lastvar; n = (n+32) & ~(BY2WD-1); /* be safe & word align */
1991/0318		memmove((void*)(upa+BY2PG-n), (void*)(USERADDR+BY2PG-n), n);
1991/0820		up->p = p;
1990/0227		/* * Refs */ incref(up->dot);
1990/0617		kunmap(k);
1990/0227		/* * Sched */ if(setlabel(&p->sched)){ p->state = Running; p->mach = m; m->proc = p; spllo(); (*func)(arg); pexit(0, 1); }
1991/0705
1991/1109		user = eve;
1991/1105		strcpy(p->user, user);
1990/0722		if(kpgrp == 0){ kpgrp = newpgrp(); } p->pgrp = kpgrp; incref(kpgrp);
1991/0705
1992/0703		strcpy(p->text, name);
1991/0705
1990/0227		p->nchild = 0; p->parent = 0; memset(p->time, 0, sizeof(p->time)); p->time[TReal] = MACHP(0)->ticks;
1991/0926		ready(p);
1991/0529		/* * since the bss/data segments are now shareable, * any mmu info about this process is now stale * and has to be discarded. */
1990/0227		flushmmu();
1991/0705		}
1992/0609		/* * called splhi() by notify(). See comment in notify for the * reasoning. */
1991/0705		void procctl(Proc *p) {
1991/1108		char *state;
1991/0705		switch(p->procctl) { case Proc_exitme:
1992/0609		spllo(); /* pexit has locks in it */
1991/0705		pexit("Killed", 1);
1992/0620
1991/1110		case Proc_traceme: if(u->nnote == 0) return; /* No break */
1992/0620
1991/0705		case Proc_stopme: p->procctl = 0;
1991/1108		state = p->psstate; p->psstate = "Stopped";
1991/1110		/* free a waiting debugger */
1991/1216		qlock(&p->debug);
1991/1110		if(p->pdbg) { wakeup(&p->pdbg->sleep); p->pdbg = 0; }
1991/1216		qunlock(&p->debug);
1991/0705		p->state = Stopped;
1992/0609		sched(); /* sched returns spllo() */ splhi();
1991/1108		p->psstate = state;
1991/0705		return; }
1990/0227		}
1991/0710		#include "errstr.h" void
1992/0604		error(char *err)
1991/0710		{
1992/0111		strncpy(u->error, err, ERRLEN);
1991/0710		nexterror(); } void
1992/0114		nexterror(void)
1991/0710		{
1992/0114		gotolabel(&u->errlab[--u->nerrlab]);
1991/0710		} void
1992/0114		exhausted(char *resource)
1991/0710		{
1992/0114		char buf[ERRLEN]; sprint(buf, "no free %s", resource); error(buf);
1991/0926		}