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Annotation of coherent/d/kernel/USRSRC/coh/proc.c, revision 1.1

1.1     ! root        1: /* $Header: /newbits/kernel/USRSRC/coh/RCS/proc.c,v 1.4 91/07/24 07:51:40 bin Exp Locker: bin $ */
        !             2: /* (lgl-
        !             3:  *     The information contained herein is a trade secret of Mark Williams
        !             4:  *     Company, and  is confidential information.  It is provided  under a
        !             5:  *     license agreement,  and may be  copied or disclosed  only under the
        !             6:  *     terms of  that agreement.  Any  reproduction or disclosure  of this
        !             7:  *     material without the express written authorization of Mark Williams
        !             8:  *     Company or persuant to the license agreement is unlawful.
        !             9:  *
        !            10:  *     COHERENT Version 2.3.37
        !            11:  *     Copyright (c) 1982, 1983, 1984.
        !            12:  *     An unpublished work by Mark Williams Company, Chicago.
        !            13:  *     All rights reserved.
        !            14:  -lgl) */
        !            15: /*
        !            16:  * Coherent.
        !            17:  * Process handling and scheduling.
        !            18:  *
        !            19:  * $Log:       proc.c,v $
        !            20:  * Revision 1.4  91/07/24  07:51:40  bin
        !            21:  * update prov by hal
        !            22:  * 
        !            23:  * 
        !            24:  * Revision 1.2        88/08/05  15:30:01      src
        !            25:  * pfork() made more rigorous, supports loadable driver forks, etc.
        !            26:  * lock/unlock more efficient, since know wakeup is synchronous.
        !            27:  * 
        !            28:  * Revision 1.1        88/03/24  16:14:16      src
        !            29:  * Initial revision
        !            30:  * 
        !            31:  * 88/03/10    Allan Cornish           /usr/src/sys/coh/proc.c
        !            32:  * Numerous temporary fixes due to AMD 286 chip being buggy in protected mode.
        !            33:  * These partial fixes will be removed once all CPU's are replaced.
        !            34:  *
        !            35:  * 88/01/21    Allan Cornish           /usr/src/sys/coh/proc.c
        !            36:  * Race condition caused by pexit() calling sfree() on the user-area
        !            37:  * when the segmentation gate is locked is now prevented.
        !            38:  * Release of the user area now deferred until relproc() invoked by uwait().
        !            39:  *
        !            40:  * 87/11/13    Allan Cornish           /usr/src/sys/coh/proc.c
        !            41:  * pexit() now sets uasa to 0 before dispatching processor.
        !            42:  *
        !            43:  * 87/11/05    Allan Cornish           /usr/src/sys/coh/proc.c
        !            44:  * New seg struct now used to allow extended addressing.
        !            45:  *
        !            46:  * 87/07/08    Allan Cornish           /usr/src/sys/coh/proc.c
        !            47:  * pexit() now cancels poll/alarm timed functions before terminating.
        !            48:  *
        !            49:  * 87/01/05    Allan Cornish           /usr/src/sys/coh/proc.c
        !            50:  * pexit() now wakes the swapper before terminating.
        !            51:  */
        !            52: #include <sys/coherent.h>
        !            53: #include <acct.h>
        !            54: #include <errno.h>
        !            55: #include <sys/inode.h>
        !            56: #include <sys/proc.h>
        !            57: #include <sys/ptrace.h>
        !            58: #include <sys/sched.h>
        !            59: #include <sys/seg.h>
        !            60: #include <signal.h>
        !            61: #include <sys/stat.h>
        !            62: #include <sys/uproc.h>
        !            63: 
        !            64: /*
        !            65:  * Initialisation.
        !            66:  * Set up the hash table queues.
        !            67:  */
        !            68: pcsinit()
        !            69: {
        !            70:        register PROC *pp;
        !            71:        register PLINK *lp;
        !            72: 
        !            73:        pp = &procq;
        !            74:        SELF = pp;
        !            75:        procq.p_nforw = pp;
        !            76:        procq.p_nback = pp;
        !            77:        procq.p_lforw = pp;
        !            78:        procq.p_lback = pp;
        !            79:        for (lp=&linkq[0]; lp<&linkq[NHPLINK]; lp++) {
        !            80:                lp->p_lforw = lp;
        !            81:                lp->p_lback = lp;
        !            82:        }
        !            83: }
        !            84: 
        !            85: /*
        !            86:  * Initiate a process.  `f' is a kernel function that is associated with
        !            87:  * the process.
        !            88:  */
        !            89: PROC *
        !            90: process(f)
        !            91: int (*f)();
        !            92: {
        !            93:        register PROC *pp1;
        !            94:        register PROC *pp;
        !            95:        register SEG *sp;
        !            96:        MCON mcon;
        !            97: 
        !            98:        if ((pp=kalloc(sizeof(PROC))) == NULL)
        !            99:                return (NULL);
        !           100: 
        !           101:        pp->p_flags = PFCORE;
        !           102:        pp->p_state = PSRUN;
        !           103:        pp->p_ttdev = NODEV;
        !           104: 
        !           105:        if (f != NULL) {
        !           106:                pp->p_flags |= PFKERN;
        !           107:                sp = salloc((fsize_t)UPASIZE, SFSYST|SFHIGH|SFNSWP);
        !           108:                if (sp == NULL) {
        !           109:                        kfree(pp);
        !           110:                        return (NULL);
        !           111:                }
        !           112:                pp->p_segp[SIUSERP] = sp;
        !           113:                msetsys( &mcon, f, FP_SEL(sp->s_faddr) );
        !           114:                kfcopy( (char *)&mcon,
        !           115:                        sp->s_faddr + offset(uproc, u_syscon),
        !           116:                        sizeof(mcon) );
        !           117:        }
        !           118:        lock(pnxgate);
        !           119: next:
        !           120:        pp->p_pid = cpid++;
        !           121:        if (cpid >= NPID)
        !           122:                cpid = 2;
        !           123:        pp1 = &procq;
        !           124:        while ((pp1=pp1->p_nforw) != &procq) {
        !           125:                if (pp1->p_pid < pp->p_pid)
        !           126:                        break;
        !           127:                if (pp1->p_pid == pp->p_pid)
        !           128:                        goto next;
        !           129:        }
        !           130:        pp->p_nback = pp1->p_nback;
        !           131:        pp1->p_nback->p_nforw = pp;
        !           132:        pp->p_nforw = pp1;
        !           133:        pp1->p_nback = pp;
        !           134:        unlock(pnxgate);
        !           135:        return (pp);
        !           136: }
        !           137: 
        !           138: /*
        !           139:  * Remove a process from the next queue and release and space.
        !           140:  */
        !           141: relproc(pp)
        !           142: register PROC *pp;
        !           143: {
        !           144:        register SEG * sp;
        !           145: 
        !           146:        /*
        !           147:         * Child process still has a user-area.
        !           148:         */
        !           149:        if ( (sp = pp->p_segp[SIUSERP]) != NULL ) {
        !           150: 
        !           151:                /*
        !           152:                 * Detach user-area from child process.
        !           153:                 */
        !           154:                pp->p_segp[SIUSERP] = NULL;
        !           155: 
        !           156:                /*
        !           157:                 * Child process is swapped out.
        !           158:                 */
        !           159:                if ( pp->p_flags & PFSWAP )
        !           160:                        sp->s_lrefc++;
        !           161: 
        !           162:                /*
        !           163:                 * Release child's user-area.
        !           164:                 */
        !           165:                sfree( sp );
        !           166:        }
        !           167: 
        !           168:        /*
        !           169:         * Remove process from doubly-linked list of all processes.
        !           170:         * Release space allocated for proc structure.
        !           171:         */
        !           172:        lock(pnxgate);
        !           173:        pp->p_nback->p_nforw = pp->p_nforw;
        !           174:        pp->p_nforw->p_nback = pp->p_nback;
        !           175:        unlock(pnxgate);
        !           176:        kfree(pp);
        !           177: }
        !           178: 
        !           179: /*
        !           180:  * Create a clone of ourselves.
        !           181:  *     N.B. - consave(&mcon) returns twice; anything not initialized
        !           182:  *     in automatic storage before the call to segadup() will not be
        !           183:  *     initialized when the second return from consave() commences.
        !           184:  */
        !           185: pfork()
        !           186: {
        !           187:        register PROC *cpp;
        !           188:        register PROC *pp;
        !           189:        register int s;
        !           190:        MCON mcon;
        !           191: 
        !           192:        if ((cpp=process(NULL)) == NULL) {
        !           193:                u.u_error = EAGAIN;
        !           194:                return;
        !           195:        }
        !           196: 
        !           197:        s = sphi();     /* Make usave a null macro if unnecessary */
        !           198:        usave();        /* Put the current copy of uarea into its segment */
        !           199:        spl(s);
        !           200: 
        !           201:        if (segadup(cpp) == 0) {
        !           202:                u.u_error = EAGAIN;
        !           203:                relproc(cpp);
        !           204:                return;
        !           205:        }
        !           206:        if ( u.u_rdir != NULL )
        !           207:                u.u_rdir->i_refc++;
        !           208:        if ( u.u_cdir != NULL )
        !           209:                u.u_cdir->i_refc++;
        !           210:        fdadupl();
        !           211:        pp = SELF;
        !           212:        cpp->p_uid   = pp->p_uid;
        !           213:        cpp->p_ruid  = pp->p_ruid;
        !           214:        cpp->p_rgid  = pp->p_rgid;
        !           215:        cpp->p_ppid  = pp->p_pid;
        !           216:        cpp->p_ttdev = pp->p_ttdev;
        !           217:        cpp->p_group = pp->p_group;
        !           218:        cpp->p_ssig  = pp->p_ssig;
        !           219:        cpp->p_isig  = pp->p_isig;
        !           220:        cpp->p_cval  = CVCHILD;
        !           221:        cpp->p_ival  = IVCHILD;
        !           222:        cpp->p_sval  = SVCHILD;
        !           223:        cpp->p_rval  = RVCHILD;
        !           224: 
        !           225:        s = sphi();
        !           226:        consave(&mcon);
        !           227:        spl( s );
        !           228: 
        !           229:        /*
        !           230:         * Parent process.
        !           231:         */
        !           232:        if ( (pp = SELF) != cpp ) {
        !           233:                segfinm(cpp->p_segp[SIUSERP]);
        !           234:                kfcopy( (char *)&mcon,
        !           235:                        cpp->p_segp[SIUSERP]->s_faddr + offset(uproc,u_syscon),
        !           236:                        sizeof(mcon) );
        !           237:                mfixcon(cpp);
        !           238:                s = sphi();
        !           239:                setrun(cpp);
        !           240:                spl(s);
        !           241:                return( cpp->p_pid );
        !           242:        }
        !           243: 
        !           244:        /*
        !           245:         * Child process.
        !           246:         */
        !           247:        else {
        !           248:                u.u_btime = timer.t_time;
        !           249:                u.u_flag = AFORK;
        !           250:                /* for (i=0; i<NUSEG; i++) done in sproto */
        !           251:                        /* u.u_segl[i].sr_segp = pp->p_segp[i]; ditto */
        !           252:                sproto();
        !           253:                segload();
        !           254:                return( 0 );
        !           255:        }
        !           256: }
        !           257: 
        !           258: /*
        !           259:  * Die.
        !           260:  */
        !           261: pexit(s)
        !           262: {
        !           263:        register PROC *pp1;
        !           264:        register PROC *pp;
        !           265:        register SEG  *sp;
        !           266:        register int n;
        !           267: 
        !           268:        pp = SELF;
        !           269: 
        !           270:        /*
        !           271:         * Cancel alarm and poll timers [if any].
        !           272:         */
        !           273:        timeout( &pp->p_alrmtim, 0, NULL, 0 );
        !           274:        timeout( &pp->p_polltim, 0, NULL, 0 );
        !           275: 
        !           276:        /*
        !           277:         * Write out accounting directory and close all files associated with
        !           278:         * this process.
        !           279:         */
        !           280:        setacct();
        !           281:        if ( u.u_rdir )
        !           282:                ldetach(u.u_rdir);
        !           283:        if ( u.u_cdir )
        !           284:                ldetach(u.u_cdir);
        !           285:        fdaclose();
        !           286: 
        !           287:        /*
        !           288:         * Free all segments in reverse order, except for user-area.
        !           289:         */
        !           290:        for ( n = NUSEG; --n > 0; ) {
        !           291:                if ( (sp = pp->p_segp[n]) != NULL ) {
        !           292:                        pp->p_segp[n] = NULL;
        !           293:                        sfree( sp );
        !           294:                }
        !           295:        }
        !           296: 
        !           297:        /*
        !           298:         * Wakeup our parent.  If we have any children, init will become the
        !           299:         * new parent.  If there are any children we are tracing who are
        !           300:         * waiting for us, we wake them up.
        !           301:         */
        !           302:        pp1 = &procq;
        !           303:        while ((pp1=pp1->p_nforw) != &procq) {
        !           304:                if (pp1->p_pid == pp->p_ppid) {
        !           305:                        if (pp1->p_state==PSSLEEP && pp1->p_event==(char *)pp1)
        !           306:                                wakeup((char *)pp1);
        !           307:                }
        !           308:                if (pp1->p_ppid == pp->p_pid) {
        !           309:                        pp1->p_ppid = 1;
        !           310:                        if (pp1->p_state == PSDEAD)
        !           311:                                wakeup((char *)eprocp);
        !           312:                        if ((pp1->p_flags&PFTRAC) != 0)
        !           313:                                wakeup((char *)&pts.pt_req);
        !           314:                }
        !           315:        }
        !           316: 
        !           317:        /*
        !           318:         * Wake up swapper if swap timer is active.
        !           319:         */
        !           320:        if ( stimer.t_last != 0 )
        !           321:                wakeup( (char *) &stimer );
        !           322: 
        !           323:        /*
        !           324:         * And finally mark us as dead and give up the processor forever.
        !           325:         */
        !           326:        pp->p_exit = s;
        !           327:        pp->p_state = PSDEAD;
        !           328:        uasa = 0;
        !           329:        dispatch();
        !           330: }
        !           331: 
        !           332: /*
        !           333:  * Sleep on the event `e'.  This gives up the processor until someone
        !           334:  * wakes us up.  Since it is possible for many people to sleep on the
        !           335:  * same event, the caller when awakened should make sure that what he
        !           336:  * was waiting for has completed and if not, go to sleep again.  `cl'
        !           337:  * is the cpu value we get to get the cpu as soon as we are woken up.
        !           338:  * `sl' is the swap value we get to keep us in memory for the duration
        !           339:  * of the sleep.  `sr' is the swap value that allows us to get swapped
        !           340:  * in if we have been swapped out.
        !           341:  */
        !           342: sleep(e, cl, sl, sr)
        !           343: char *e;
        !           344: {
        !           345:        register PROC *bp;
        !           346:        register PROC *fp;
        !           347:        register PROC *pp;
        !           348:        register int s;
        !           349: 
        !           350:        pp = SELF;
        !           351: 
        !           352:        /*
        !           353:         * See if we have a signal awaiting.
        !           354:         */
        !           355:        if (cl<CVNOSIG && pp->p_ssig && nondsig()) {
        !           356:                sphi();
        !           357:                envrest(&u.u_sigenv);
        !           358:        }
        !           359: 
        !           360:        /*
        !           361:         * Get ready to go to sleep and do so.
        !           362:         */
        !           363:        s = sphi();
        !           364:        pp->p_state = PSSLEEP;
        !           365:        pp->p_event = e;
        !           366:        pp->p_lctim = utimer;
        !           367:        addu(pp->p_cval, cl);
        !           368:        pp->p_ival = sl;
        !           369:        pp->p_rval = sr;
        !           370:        fp = &linkq[hash(e)];
        !           371:        bp = fp->p_lback;
        !           372:        pp->p_lforw = fp;
        !           373:        fp->p_lback = pp;
        !           374:        pp->p_lback = bp;
        !           375:        bp->p_lforw = pp;
        !           376:        spl(s);
        !           377:        dispatch();
        !           378: 
        !           379:        /*
        !           380:         * We have just woken up.  Get ready to return.
        !           381:         */
        !           382:        subu(pp->p_cval, cl);
        !           383:        pp->p_ival = 0;
        !           384:        pp->p_rval = 0;
        !           385: 
        !           386:        /*
        !           387:         * Check for an interrupted system call.
        !           388:         */
        !           389:        if (cl<CVNOSIG && pp->p_ssig && nondsig()) {
        !           390:                sphi();
        !           391:                envrest(&u.u_sigenv);
        !           392:        }
        !           393: }
        !           394: 
        !           395: /*
        !           396:  * Defer function to wake up all processes sleeping on the event `e'.
        !           397:  */
        !           398: wakeup(e)
        !           399: char *e;
        !           400: {
        !           401:        extern void dwakeup();
        !           402: 
        !           403:        defer( dwakeup, e );
        !           404: }
        !           405: 
        !           406: /*
        !           407:  * Wake up all processes sleeping on the event `e'.
        !           408:  */
        !           409: static void
        !           410: dwakeup( e )
        !           411: char *e;
        !           412: {
        !           413:        register PROC *pp;
        !           414:        register PROC *pp1;
        !           415:        register int s;
        !           416: 
        !           417:        /*
        !           418:         * Identify event queue to check.
        !           419:         * Disable interrupts.
        !           420:         */
        !           421:        pp1 = &linkq[hash(e)];
        !           422:        pp = pp1;
        !           423:        s = sphi();
        !           424: 
        !           425:        /*
        !           426:         * Traverse doubly-linked circular event-queue.
        !           427:         */
        !           428:        while ( (pp = pp->p_lforw) != pp1 ) {
        !           429: 
        !           430:                /*
        !           431:                 * Process is waiting on event 'e'.
        !           432:                 */
        !           433:                if ( pp->p_event == e ) {
        !           434:                        /*
        !           435:                         * Remove process from event queue.
        !           436:                         * Update process priority.
        !           437:                         * Insert process into run queue.
        !           438:                         */
        !           439:                        pp->p_lback->p_lforw = pp->p_lforw;
        !           440:                        pp->p_lforw->p_lback = pp->p_lback;
        !           441:                        addu( pp->p_cval, (utimer-pp->p_lctim)*CVCLOCK );
        !           442:                        setrun( pp );
        !           443: 
        !           444:                        /*
        !           445:                         * Enable interrupts.
        !           446:                         * Restart search at start of event queue.
        !           447:                         * Disable interrupts.
        !           448:                         */
        !           449:                        spl( s );
        !           450:                        pp = pp1;
        !           451:                        s = sphi();
        !           452:                }
        !           453:        }
        !           454:        spl(s);
        !           455: }
        !           456: 
        !           457: /*
        !           458:  * Reschedule the processor.
        !           459:  */
        !           460: dispatch()
        !           461: {
        !           462:        register PROC *pp1;
        !           463:        register PROC *pp2;
        !           464:        register unsigned v;
        !           465:        register int s;
        !           466: 
        !           467:        s = sphi();
        !           468:        pp1 = iprocp;
        !           469:        pp2 = &procq;
        !           470:        v = 0;
        !           471:        while ((pp2=pp2->p_lforw) != &procq) {
        !           472:                v -= pp2->p_cval;
        !           473:                if ((pp2->p_flags&PFCORE) == 0)
        !           474:                        continue;
        !           475:                pp1 = pp2->p_lforw;
        !           476:                pp1->p_cval += pp2->p_cval;
        !           477:                pp2->p_cval = v;
        !           478:                pp1->p_lback = pp2->p_lback;
        !           479:                pp1->p_lback->p_lforw = pp1;
        !           480:                pp1 = pp2;
        !           481:                break;
        !           482:        }
        !           483:        spl(s);
        !           484: 
        !           485:        quantum = NCRTICK;
        !           486:        disflag = 0;
        !           487:        if ( pp1 != SELF ) {
        !           488:                /*
        !           489:                 * Consave() returns twice.
        !           490:                 * 1st time is after our context is saved in u.u_syscon,
        !           491:                 *      whereupon we should restore other proc's context.
        !           492:                 * 2nd time is after our context is restored by another proc.
        !           493:                 * Conrest() forces a context switch to a new process.
        !           494:                 */
        !           495:                s = sphi();
        !           496:                SELF = pp1;
        !           497:                if (consave(&u.u_syscon) == 0)
        !           498:                        conrest( FP_SEL(pp1->p_u->s_faddr),
        !           499:                                 offset(uproc,u_syscon) );
        !           500:                if ( SELF->p_pid != 0 )
        !           501:                        segload();
        !           502:                spl(s);
        !           503:        }
        !           504: }
        !           505: 
        !           506: /*
        !           507:  * Add a process to the run queue.
        !           508:  * This routine must be called at high priority.
        !           509:  */
        !           510: setrun(pp1)
        !           511: register PROC *pp1;
        !           512: {
        !           513:        register PROC *pp2;
        !           514:        register unsigned v;
        !           515: 
        !           516:        v = 0;
        !           517:        pp2 = &procq;
        !           518:        for (;;) {
        !           519:                pp2 = pp2->p_lback;
        !           520:                if ((v+=pp2->p_lforw->p_cval) >= pp1->p_cval)
        !           521:                        break;
        !           522:                if (pp2 == &procq)
        !           523:                        break;
        !           524:        }
        !           525:        pp2->p_lforw->p_lback = pp1;
        !           526:        pp1->p_lforw = pp2->p_lforw;
        !           527:        pp2->p_lforw = pp1;
        !           528:        pp1->p_lback = pp2;
        !           529:        v -= pp1->p_cval;
        !           530:        pp1->p_cval = v;
        !           531:        pp1->p_lforw->p_cval -= v;
        !           532:        pp1->p_state = PSRUN;
        !           533: }
        !           534: 
        !           535: /*
        !           536:  * Wait for the gate `g' to unlock, and then lock it.
        !           537:  */
        !           538: lock(g)
        !           539: register GATE g;
        !           540: {
        !           541:        register int s;
        !           542: 
        !           543:        s = sphi();
        !           544:        while (g[0]) {
        !           545:                g[1] = 1;
        !           546:                sleep((char *)g, CVGATE, IVGATE, SVGATE);
        !           547:        }
        !           548:        g[0] = 1;
        !           549:        spl(s);
        !           550: }
        !           551: 
        !           552: /*
        !           553:  * Unlock the gate `g'.
        !           554:  */
        !           555: unlock(g)
        !           556: register GATE g;
        !           557: {
        !           558:        g[0] = 0;
        !           559:        if (g[1]) {
        !           560:                g[1] = 0;
        !           561:                disflag = 1;
        !           562:                wakeup((char *)g);
        !           563:        }
        !           564: }

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