2 * Handling of points and other moveable features.
7 /*========== declarations ==========*/
14 typedef struct KindInfo KindInfo;
16 /* Kind-independent code is responsible for determining
17 * the method, doing a bit of cleanup, and adjusting the flow
18 * slightly. Per-kind code does the actual work and is mostly in
19 * charge - it is also responsible for updating seg->moving and ->motion.
21 /* The following states exist for each MovPosChange
22 * at points when control flow passes between kind and indep:
23 * U Unallocated no memory allocated (MovPosChange does not exist)
24 * A Allocated memory allocation done
25 * R Reserved reservation was successful
26 * C Confirmed motion queued and will occur
27 * D Done motion is complete and callback just needs to be made
28 * E Erroneous indep must call destroy straight away
29 * seg->moving and ->motion is in one of the states UC
32 typedef struct MovPosChange { /* valid in: filled in by and when: */
33 const KindInfo *ki; /* ARCDE indep after allocate() */
34 Segment *move; /* ARCDE indep after allocate() */
35 MovPosComb actual; /* CD see below */
36 MovPosComb intent; /* RCD indep after allocate() */
37 /* kind-specific data follows */ /* varies kind-specific code, varies */
39 /* `actual' contains the kind's public opinion about the physical
40 * state. It is initialised by indep (just before confirm) from
41 * move->motion->actual or move->movposcomb as the case may be. It
42 * should be updated by the kind, since it is used by indep for
43 * calculating the number and identities of the features which may
44 * need to change when a new move request is intended to replace an
45 * existing one - ie, the contents of the motions[] provided to a
46 * subsequent confirm(). So while a change is Confirmed, the
47 * physical state is recorded only in the relevant change, and not
48 * in the segment's movposcomb. Once a change goes to Confirmed,
49 * the indep code never untangles it so the kind can manage the
50 * proper transition. */
54 Change *(*allocate)(int alloc_motions); /* U->A (always succeeds) */
55 ErrorCode (*reserve)(Change*, Segment*, int ms); /* A->R; error: A->E */
56 ErrorCode (*confirm)(Change*, Segment*, int n_motions,
57 const Motion*, int ms); /* [AR]->C; error; [AR]->E */
58 void (*destroy)(Change*); /* [ARCE]->U */
59 /* indep guarantees that
60 * alloc_motions >= move->i->n_motions on reserve
61 * alloc_motions >= n_motions on confirm
62 * and that if on entry to reserve move->motion is non-0,
63 * it move->motion is non-0 and of the same kind
67 static const char *posnpname(Segment *move, MovPosComb poscomb) {
68 return poscomb<0 ? "?" : move->i->poscombs[poscomb].pname;
71 static void ouposn_moving(Change *chg) {
72 Segment *move= chg->move;
73 oprintf(UPO, "movpos %s position %s moving\n",
74 move->i->pname, posnpname(move, chg->actual));
77 static void motion_done(Segment *move, MovPosComb actual) {
80 move->movposcomb= actual;
81 oprintf(UPO, "movpos %s position %s stable\n",
82 move->i->pname, posnpname(move, move->movposcomb));
85 /*========== points ==========*/
88 * We maintain two queues, one for reserved one for actually confirmed
89 * requests where we know what we're doing.
91 * We divide time into discrete slots, numbered with clock arithmetic.
93 * cslot cslot+1 cslot+2
95 * currently next in after
98 * We increment cslot when we issue a POINT command to the PIC.
99 * In a request, the deadline represents the latest allowable value
100 * of cslot just before that increment.
103 typedef unsigned PtSlot;
104 typedef int PtSlotSigned;
106 /* We think there are three states: Allocated, Reserved and Confirmed.
107 * (plus of course Unallocated where we don't have a request at all).
108 * These correspond to the indep code as follows:
110 * indep state pt state queues checked and plan viable
111 * Unallocated n/a yes
112 * Allocated Allocated yes
113 * Reserved Reserved yes
114 * Confirmed Confirmed yes
117 * Erroneous exists only after a failed reserve() or confirm() so it's
118 * not that confusing to have this slightly malleable terminology.
121 typedef struct { /* Allocated Reserved Confirmed */
122 /* in queue? absent reserved confirmed */
124 PtSlot deadline; /* ~0 relative absolute <- */
125 MovPosComb actual; /* undef undef see below */
126 int n_motions; /* alloc'd alloc'd undone */
127 Motion motions[]; /* [0].i: 0 0 non-0 <- */
128 /* [..].i: undef undef non-0 */
129 /* .posn: undef undef defined */
131 /* We can determine the the state by looking at the two
132 * `statedet' fields, marked <- above.
133 * There are also intermediate states where the req's
134 * statedet fields do not agree with the queue it's on.
135 * We write these as, for example,
136 * AR to mean statedet says Allocated, but queued on pt_reserved
137 * A? to mean statedet says Allocated, but may be queued
138 * etc. They are only allowed while we are in a pt_... method function.
140 /* PointReq.actual is subtly differnet to MovPosChange.actual,
142 * in MovPosChange in PointReq
143 * Position unknown -1 0
144 * Position partly known -1 unknown feats are 0
145 * Position completely known exact exact
147 * The partial knowledge positions can only occur in requests that
148 * are confirmed with as many motions as features, so we know that
149 * if we complete a request we know that we can copy actual out
152 * If we abandon a half-done change to a multi-feat segment
153 * we lose the partial knowledge.
156 #define CDU_RECHARGE 250 /*ms*/
157 #define POINT_MOVEMENT 50 /*ms*/
158 #define PT_MAX_QUEUE 15
162 PointReq *l[PT_MAX_QUEUE];
166 * CDU and point queue states:
169 * ____________ pt_cdu_ conf'd
170 * / points_ \ charged .n
174 * |from INACTIVE -1 0
175 * |any <=Sta_Settling
178 * ___________ |turning
195 static PtSlot pt_cslot;
196 static int pt_cdu_charged;
197 static PointQueue pt_confirmed, pt_reserved;
199 static void pt_check_action(void);
201 static PtSlot pt_maxdelay_reldeadline(int maxdelay_ms) {
202 return (maxdelay_ms - POINT_MOVEMENT + CDU_RECHARGE) / CDU_RECHARGE;
205 static void pt_queue_remove_index(PointQueue *q, int index) {
207 memmove(&q->l[index], &q->l[index+1], sizeof(q->l[0]) * (q->n - index));
210 static int pt_req_compar(const void *av, const void *bv) {
211 PointReq *const *a= av;
212 PointReq *const *b= av;
213 return (PtSlotSigned)((*b)->deadline - (*a)->deadline);
216 static void pt_queue_remove_item(PointQueue *q, PointReq *r) {
218 entry= bsearch(r, q->l, q->n, sizeof(q->l[0]), pt_req_compar);
220 pt_queue_remove_index(q, entry - q->l);
223 static void pt_dequeue(PointReq *r) { /* X->XA */
224 if (r->motions[0].i) {
225 pt_queue_remove_item(&pt_confirmed, r);
226 } else if (~r->deadline) {
227 pt_queue_remove_item(&pt_reserved, r);
231 static void pt_mark_as_allocated(PointReq *r) { /* AX->X */
232 /* Sets statedet fields for Allocated */
233 r->deadline= ~(PtSlot)0;
237 static ErrorCode pt_check_plan(void) {
238 /* Checks whether we can meet the currently queued commitments */
239 int future, conf, resv, usewhen;
241 fixme there is something wrong as
242 INT_MAX maxdelay_ms should not work as it overflows and makes
245 debug movpos/change : A5/P0 maxdelay_ms=2147483647 actual=?
247 debug movpos/change-needed : point:P(2*1) -1<-0 => 1debug movpos/change : confirm point:1...
248 debug movpos/point : confirm A5 n=1 maxdelay=2147483647 (res: n=1 deadline=[t+]-1)
249 debug movpos/point : newdeadline=t+-8589933 allow_failure=1
251 debug movpos/point : pt_enqueue=OK
252 movpos A5 position ? moving
253 debug movpos/change : confirm => OK
257 /* If CDU is charged we can do one thing right away */
258 while (conf < pt_confirmed.n &&
259 pt_confirmed.l[0]->deadline==pt_cslot) {
260 if (!pt_cdu_charged) return EC_MovFeatTooLate;
261 if (conf) return EC_MovFeatTooLate;
267 PointReq *confr= conf < pt_confirmed.n ? pt_confirmed.l[conf] : 0;
268 PointReq *resvr= resv < pt_reserved .n ? pt_reserved .l[conf] : 0;
269 if (!confr && !resvr) break;
270 int confwhen= confr ? confr->deadline - pt_cslot : INT_MAX;
271 int resvwhen= resvr ? resvr->deadline : INT_MAX;
272 if (resvwhen < confwhen) {
279 if (usewhen > future) return EC_MovFeatTooLate;
285 static ErrorCode pt_enqueue(PointQueue *q, PointReq *r) { /* XA -> X */
286 int insat; /* ... where X is R or C and corresponds to q */
287 /* or on error, XA -> A */
289 if (q->n == PT_MAX_QUEUE) {
290 return EC_BufferFull;
293 fprintf(stderr," pt_enqueue\n");
295 insat>0 && (PtSlotSigned)(r->deadline - q->l[insat-1]->deadline) < 0;
297 q->l[insat]= q->l[insat-1];
301 return pt_check_plan();
302 /* if this fails, indep machinery calls pt_destroy which dequeues */
305 /*---------- kind method entrypoints ----------*/
307 static Change *point_allocate(int alloc_motions) {
310 fprintf(stderr," point allocate %d\n",alloc_motions);
311 assert(pt_cdu_charged>=0);
313 /* we need at least one motion in the table so we can tell
314 * the difference between the states by looking at motions[0].i */
317 r= mmalloc(sizeof(*r) + alloc_motions * sizeof(r->motions[0]));
318 r->deadline= ~(PtSlot)0;
319 r->n_motions= alloc_motions;
324 static ErrorCode point_reserve(Change *chg, Segment *move,
326 PointReq *r= (PointReq*)chg;
327 r->deadline= pt_maxdelay_reldeadline(maxdelay_ms);
328 if (!r->deadline) { pt_mark_as_allocated(r); return EC_MovFeatTooLate; }
329 return pt_enqueue(&pt_reserved, r);
332 static ErrorCode point_confirm(Change *chg, Segment *move,
333 int n_motions, const Motion *motions,
335 PointReq *r= (PointReq*)chg;
340 oprintf(DUPO("movpos/point") "confirm %s n=%d maxdelay=%d"
341 " (res: n=%d deadline=[t+]%d)\n",
342 move->i->pname, n_motions, maxdelay_ms,
343 r->n_motions, r->deadline);
345 /* If the segment is moving, these motions are already based on the
346 * actual physical position which is stored in the existing request.
347 * So we try removing the existing request from the queue and put
348 * it back if it doesn't work.
351 if (n_motions > r->n_motions)
352 return EC_MovFeatReservationInapplicable;
353 assert(n_motions <= r->n_motions);
354 if (maxdelay_ms == -1) {
355 newdeadline= r->deadline;
357 newdeadline= pt_maxdelay_reldeadline(maxdelay_ms);
359 allow_failure= newdeadline < r->deadline;
360 oprintf(DUPO("movpos/point") " newdeadline=t+%d allow_failure=%d\n",
361 newdeadline, allow_failure);
362 newdeadline += pt_cslot;
366 /* states of existing: */
368 move->moving ? (PointReq*)move->motion : 0; /* U or C */
370 oprintf(DUPO("movpos/point")
371 " existing %s n=%d deadline=t+%d\n",
372 existing->h.move->i->pname,
374 existing->deadline - pt_cslot);
375 pt_dequeue(existing); /* U or CA */
379 memcpy(r->motions, motions, sizeof(r->motions[0])*n_motions);
380 if (!n_motions) r->motions[0].i= move->i->movfeats;
381 assert(r->motions[0].i);
382 r->n_motions= n_motions;
383 r->deadline= newdeadline + pt_cslot;
385 if (n_motions == move->i->n_movfeats)
388 r->actual= chg->actual;
389 assert(r->actual >= 0);
392 ec= pt_enqueue(&pt_confirmed, r);
393 oprintf(DUPO("movpos/point") " pt_enqueue=%s\n", ec2str(ec));
394 assert(allow_failure || !ec);
396 if (existing) { /* CA */
397 if (ec) { /* state C but bad */
398 pt_dequeue(r); /* state CA */
399 pt_mark_as_allocated(r); /* state A */
400 ErrorCode ec_putback= pt_enqueue(&pt_confirmed, existing);
401 assert(!ec_putback); /* C */
402 } else { /* state C and good */
403 free(existing); /* U */
406 /* either ec=0 state C U
408 * or ec!=0 state C but bad C
415 move->movposcomb= -1;
421 static void point_destroy(Change *chg) { /* X->XA and then free it */
422 PointReq *r= (PointReq*)chg;
427 /*---------- actually firing points, yay! ----------*/
429 static void pt_check_action(void) {
432 if (!pt_confirmed.n) {
433 if (sta_state == Sta_Finalising) resolve_motioncheck();
437 PointReq *r= pt_confirmed.l[0];
439 if (r->n_motions && pt_cdu_charged) {
440 /* look for something to fire */
441 Motion *m= &r->motions[--r->n_motions];
442 assert(m->posn < m->i->posns);
443 enco_pic_point(&piob, m->i->boob[m->posn]);
444 serial_transmit(&piob);
445 oprintf(UPO, "movpos %s point %s%d\n", r->h.move->i->pname,
446 m->i->pname, m->posn);
449 MovPosComb above_weight= m->i->weight * m->i->posns;
450 MovPosComb above= r->actual / above_weight;
451 MovPosComb below= r->actual % m->i->weight;
452 r->actual= above*above_weight + m->posn*m->i->weight + below;
453 if (r->h.actual >= 0 || !r->n_motions)
454 r->h.actual= r->actual;
455 ouposn_moving(&r->h);
459 /* look for something to report
460 * we can get things here other than from the above
461 * eg if we are asked to move the
463 Segment *move= r->h.move;
464 assert(move->moving && move->motion == (Change*)r);
465 pt_queue_remove_index(&pt_confirmed,0);
466 pt_mark_as_allocated(r); /* now state A aka Done */
467 motion_done(move,r->h.actual);
473 /*---------- entrypoints from rest of program ----------*/
475 void points_all_abandon(void) {
478 assert(!pt_reserved.n);
480 for (i=0; i<pt_confirmed.n; i++) {
481 PointReq *r= pt_confirmed.l[i];
482 Segment *move= r->h.move;
483 assert(move->motion == (Change*)r);
484 motion_done(move,r->h.actual);
491 void points_turning_on(void) {
495 void on_pic_charged(const PicInsnInfo *pii, const PicInsn *pi, int objnum) {
496 if (pt_cdu_charged<0) return;
501 /*========== dummy `nomove' kind ==========*/
503 static Change *nomove_allocate(int alloc_motions) {
504 oprintf(DUPO("movfeatkind-momove") "allocate %d\n",alloc_motions);
505 return mmalloc(sizeof(Change));
507 static void nomove_destroy(Change *chg) {
511 static ErrorCode nomove_reserve(Change *chg, Segment *move, int ms) {
512 oprintf(DUPO("movfeatkind-nomove") "reserve\n");
515 static ErrorCode nomove_confirm(Change *chg, Segment *move, int n_motions,
516 const Motion *motions, int ms) {
517 oprintf(DUPO("movfeatkind-nomove") "confirm\n");
522 /*========== method-independent machinery ==========*/
524 static const KindInfo methodinfos[]= {
525 { "nomove", nomove_allocate, nomove_reserve, nomove_confirm, nomove_destroy },
526 { "point", point_allocate, point_reserve, point_confirm, point_destroy },
530 static Change *mp_allocate(const KindInfo *ki, Segment *move,
531 int alloc_motions, MovPosComb target) {
532 assert(sta_state >= Sta_Resolving);
533 Change *chg= ki->allocate(alloc_motions);
540 static int change_needed(const MovFeatInfo *feati, MovPosComb target,
541 MovPosComb startpoint) {
544 (target - startpoint) / feati->weight % feati->posns;
545 oprintf(DUPO("movpos/change-needed") "%s:%s(%d*%d) %d<-%d => %d",
546 methodinfos[feati->kind].pname, feati->pname,
547 feati->posns, feati->weight,
548 target, startpoint, r);
552 static int evaluate_target(Segment *move, MovPosComb target,
553 MovPosComb startpoint, MovFeatKind *kind_r) {
554 /* returns number of features which have to change to reach target,
555 * or -1 for mixed kinds. kind_r may be 0. */
556 const SegmentInfo *movei= move->i;
558 const MovFeatInfo *feati;
561 oprintf(DUPO("movpos/eval") "%s/%s <-%s\n",
562 move->i->pname, posnpname(move,target), posnpname(move,startpoint));
565 startpoint= movpos_poscomb_actual(move);
566 oprintf(DUPO("movpos/eval") " actual <-%s\n",
567 posnpname(move,startpoint));
570 for (feat=0, feati=movei->movfeats, tchanges=0, kind= mfk_none;
571 feat<movei->n_movfeats;
573 if (!change_needed(feati,target,startpoint)) continue;
575 if (kind && feati->kind != kind) return -1;
579 if (kind_r) *kind_r= kind;
580 oprintf(DUPO("movpos/eval") "changes=%d kind=%s\n",
581 tchanges, methodinfos[kind].pname);
585 ErrorCode movpos_findcomb_bysegs(Segment *back, Segment *move, Segment *fwd,
586 MovPosComb startpoint, MovPosComb *chosen_r) {
587 const SegmentInfo *movei= move->i;
588 MovPosComb tcomb, bestcomb=-1;
589 int tchanges, bestchanges=INT_MAX;
590 const SegPosCombInfo *pci;
592 for (tcomb=0, pci=movei->poscombs;
593 tcomb<movei->n_poscombs;
595 Segment *tback= &segments[pci->link[1].next];
596 Segment *tfwd= &segments[pci->link[0].next];
597 if (back && !(back==tback || back==tfwd)) continue;
598 if (fwd && !(fwd ==tback || fwd ==tfwd)) continue;
600 if (movei->n_movfeats>1) {
601 /* we have to search for the one which is least effort, then */
602 tchanges= evaluate_target(move,tcomb,startpoint,0);
603 if (tchanges >= bestchanges) /* prefer low-numbered movposcombs */
607 /* fall through and update */
613 bestchanges= tchanges;
615 if (*chosen_r) *chosen_r= bestcomb;
617 bestchanges==INT_MAX ? EC_MovFeatRouteNotFound :
618 bestchanges==INT_MAX-1 ? EC_MovFeatKindsCombination :
622 ErrorCode movpos_change(Segment *move, MovPosComb target,
623 int maxdelay_ms, MovPosChange *chg) {
624 const SegmentInfo *movei= move->i;
625 const MovFeatInfo *feati;
629 MovFeatKind kind= mfk_none;
632 actual= move->movposcomb;
633 assert(!move->motion);
635 kind= move->motion->ki - methodinfos;
636 actual= move->motion->actual;
639 oprintf(DUPO("movpos/change") "%s/%s maxdelay_ms=%d actual=%s\n",
640 move->i->pname, posnpname(move,target),
641 maxdelay_ms, posnpname(move, actual));
642 if (chg) oprintf(DUPO("movpos/change") " chg=%s:%s/%s\n",
643 chg->ki->pname, chg->move->i->pname,
644 posnpname(chg->move, chg->intent));
646 { /* provide horizon for visibility of motions[] */
648 Motion motions[movei->n_movfeats];
650 for (feat=0, feati=movei->movfeats;
651 feat<movei->n_movfeats;
653 if (!change_needed(feati,actual,target))
655 MovPosComb posn= target / feati->weight % feati->posns;
657 if (feati->kind != kind) { ec= EC_MovFeatKindsCombination; goto x; }
661 motions[n_motions].i= feati;
662 motions[n_motions].posn= posn;
666 const KindInfo *ki= &methodinfos[kind];
671 chg->intent != target)
672 return EC_MovFeatReservationInapplicable;
674 chg= mp_allocate(ki,move,n_motions,target);
678 oprintf(DUPO("movpos/change") "confirm %s:%d...\n", ki->pname, n_motions);
679 ec= ki->confirm(chg, move, n_motions, motions, maxdelay_ms);
680 oprintf(DUPO("movpos/change") "confirm => %s\n",errorcodelist[ec]);
686 movpos_unreserve(chg);
691 movpos_reserve(Segment *move, int maxdelay_ms, MovPosChange **res_r,
692 MovPosComb target, MovPosComb startpoint /*as for findcomb*/) {
693 MovFeatKind kind= mfk_none;
697 oprintf(DUPO("movpos/reserve") "%s/%s maxdelay_ms=%d startpoint=%s\n",
698 move->i->pname, posnpname(move,target),
699 maxdelay_ms, posnpname(move,startpoint));
701 nchanges= evaluate_target(move,target,startpoint,&kind);
702 if (nchanges==-1) return EC_MovFeatKindsCombination;
704 const KindInfo *ki= &methodinfos[kind];
705 oprintf(DUPO("movpos/reserve") "allocate %s:%d...\n", ki->pname, nchanges);
706 Change *chg= mp_allocate(ki, move, nchanges, target);
707 ec= ki->reserve(chg, move, maxdelay_ms);
708 oprintf(DUPO("movpos/reserve") "reserve => %s\n",errorcodelist[ec]);
715 movpos_unreserve(chg);
719 void movpos_unreserve(MovPosChange *res) {
721 oprintf(DUPO("movpos/unreserve") "%s:%s/%s\n",
722 res->ki->pname, res->move->i->pname,
723 posnpname(res->move, res->intent));
724 res->ki->destroy(res);
727 MovPosComb movpos_poscomb_actual(Segment *seg) {
728 return seg->moving ? seg->motion->actual : seg->movposcomb;
731 MovPosComb movpos_change_intent(MovPosChange *chg) {