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;
243 /* If CDU is charged we can do one thing right away */
244 while (conf < pt_confirmed.n &&
245 pt_confirmed.l[0]->deadline==pt_cslot) {
246 if (!pt_cdu_charged) return EC_MovFeatTooLate;
247 if (conf) return EC_MovFeatTooLate;
253 PointReq *confr= conf < pt_confirmed.n ? pt_confirmed.l[conf] : 0;
254 PointReq *resvr= resv < pt_reserved .n ? pt_reserved .l[conf] : 0;
255 if (!confr && !resvr) break;
256 int confwhen= confr ? confr->deadline - pt_cslot : INT_MAX;
257 int resvwhen= resvr ? resvr->deadline : INT_MAX;
258 if (resvwhen < confwhen) {
265 if (usewhen > future) return EC_MovFeatTooLate;
271 static ErrorCode pt_enqueue(PointQueue *q, PointReq *r) { /* XA -> X */
272 int insat; /* ... where X is R or C and corresponds to q */
273 /* or on error, XA -> A */
275 if (q->n == PT_MAX_QUEUE) {
276 return EC_BufferFull;
279 fprintf(stderr," pt_enqueue\n");
281 insat>0 && (PtSlotSigned)(r->deadline - q->l[insat-1]->deadline) < 0;
283 q->l[insat]= q->l[insat-1];
287 return pt_check_plan();
288 /* if this fails, indep machinery calls pt_destroy which dequeues */
291 /*---------- kind method entrypoints ----------*/
293 static Change *point_allocate(int alloc_motions) {
296 fprintf(stderr," point allocate %d\n",alloc_motions);
297 assert(pt_cdu_charged>=0);
299 /* we need at least one motion in the table so we can tell
300 * the difference between the states by looking at motions[0].i */
303 r= mmalloc(sizeof(*r) + alloc_motions * sizeof(r->motions[0]));
304 r->deadline= ~(PtSlot)0;
305 r->n_motions= alloc_motions;
310 static ErrorCode point_reserve(Change *chg, Segment *move,
312 PointReq *r= (PointReq*)chg;
313 r->deadline= pt_maxdelay_reldeadline(maxdelay_ms);
314 if (!r->deadline) { pt_mark_as_allocated(r); return EC_MovFeatTooLate; }
315 return pt_enqueue(&pt_reserved, r);
318 static ErrorCode point_confirm(Change *chg, Segment *move,
319 int n_motions, const Motion *motions,
321 PointReq *r= (PointReq*)chg;
326 oprintf(DUPO("movpos/point") "confirm %s n=%d maxdelay=%d"
327 " (res: n=%d deadline=[t+]%d)\n",
328 move->i->pname, n_motions, maxdelay_ms,
329 r->n_motions, r->deadline);
331 /* If the segment is moving, these motions are already based on the
332 * actual physical position which is stored in the existing request.
333 * So we try removing the existing request from the queue and put
334 * it back if it doesn't work.
337 if (n_motions >= r->n_motions)
338 return EC_MovFeatReservationInapplicable;
339 assert(n_motions <= r->n_motions);
340 if (maxdelay_ms == -1) {
341 newdeadline= r->deadline;
343 newdeadline= pt_maxdelay_reldeadline(maxdelay_ms);
345 allow_failure= newdeadline < r->deadline;
346 oprintf(DUPO("movpos/point") " newdeadline=t+%d allow_failure=%d\n",
347 newdeadline, allow_failure);
348 newdeadline += pt_cslot;
352 /* states of existing: */
354 move->moving ? (PointReq*)move->motion : 0; /* U or C */
356 oprintf(DUPO("movpos/point")
357 " existing %s n=%d deadline=t+%d\n",
358 existing->h.move->i->pname,
360 existing->deadline - pt_cslot);
361 pt_dequeue(existing); /* U or CA */
365 memcpy(r->motions, motions, sizeof(r->motions[0])*n_motions);
366 if (!n_motions) r->motions[0].i= move->i->movfeats;
367 assert(r->motions[0].i);
368 r->n_motions= n_motions;
369 r->deadline= newdeadline + pt_cslot;
371 if (n_motions == move->i->n_movfeats)
374 r->actual= chg->actual;
375 assert(r->actual >= 0);
378 ec= pt_enqueue(&pt_confirmed, r);
379 oprintf(DUPO("movpos/point") " pt_enqueue=%s\n", ec2str(ec));
380 assert(allow_failure || !ec);
382 if (existing) { /* CA */
383 if (ec) { /* state C but bad */
384 pt_dequeue(r); /* state CA */
385 pt_mark_as_allocated(r); /* state A */
386 ErrorCode ec_putback= pt_enqueue(&pt_confirmed, existing);
387 assert(!ec_putback); /* C */
388 } else { /* state C and good */
389 free(existing); /* U */
392 /* either ec=0 state C U
394 * or ec!=0 state C but bad C
401 move->movposcomb= -1;
407 static void point_destroy(Change *chg) { /* X->XA and then free it */
408 PointReq *r= (PointReq*)chg;
413 /*---------- actually firing points, yay! ----------*/
415 static void pt_check_action(void) {
418 if (!pt_confirmed.n) {
419 if (sta_state == Sta_Finalising) resolve_motioncheck();
423 PointReq *r= pt_confirmed.l[0];
425 if (r->n_motions && pt_cdu_charged) {
426 /* look for something to fire */
427 Motion *m= &r->motions[--r->n_motions];
428 assert(m->posn < m->i->posns);
429 enco_pic_point(&piob, m->i->boob[m->posn]);
430 serial_transmit(&piob);
431 oprintf(UPO, "movpos %s point %s%d\n", r->h.move->i->pname,
432 m->i->pname, m->posn);
435 MovPosComb above_weight= m->i->weight * m->i->posns;
436 MovPosComb above= r->actual / above_weight;
437 MovPosComb below= r->actual % m->i->weight;
438 r->actual= above*above_weight + m->posn*m->i->weight + below;
439 if (r->h.actual >= 0 || !r->n_motions)
440 r->h.actual= r->actual;
441 ouposn_moving(&r->h);
445 /* look for something to report
446 * we can get things here other than from the above
447 * eg if we are asked to move the
449 Segment *move= r->h.move;
450 assert(move->moving && move->motion == (Change*)r);
451 pt_queue_remove_index(&pt_confirmed,0);
452 pt_mark_as_allocated(r); /* now state A aka Done */
453 motion_done(move,r->h.actual);
459 /*---------- entrypoints from rest of program ----------*/
461 void points_all_abandon(void) {
464 assert(!pt_reserved.n);
466 for (i=0; i<pt_confirmed.n; i++) {
467 PointReq *r= pt_confirmed.l[i];
468 Segment *move= r->h.move;
469 assert(move->motion == (Change*)r);
470 motion_done(move,r->h.actual);
477 void points_turning_on(void) {
481 void on_pic_charged(const PicInsnInfo *pii, const PicInsn *pi, int objnum) {
482 if (pt_cdu_charged<0) return;
487 /*========== dummy `nomove' kind ==========*/
489 static Change *nomove_allocate(int alloc_motions) {
490 oprintf(DUPO("movfeatkind-momove") "allocate %d\n",alloc_motions);
491 return mmalloc(sizeof(Change));
493 static void nomove_destroy(Change *chg) {
497 static ErrorCode nomove_reserve(Change *chg, Segment *move, int ms) {
498 oprintf(DUPO("movfeatkind-nomove") "reserve\n");
501 static ErrorCode nomove_confirm(Change *chg, Segment *move, int n_motions,
502 const Motion *motions, int ms) {
503 oprintf(DUPO("movfeatkind-nomove") "confirm\n");
508 /*========== method-independent machinery ==========*/
510 static const KindInfo methodinfos[]= {
511 { "nomove", nomove_allocate, nomove_reserve, nomove_confirm, nomove_destroy },
512 { "point", point_allocate, point_reserve, point_confirm, point_destroy },
516 static Change *mp_allocate(const KindInfo *ki, Segment *move,
517 int alloc_motions, MovPosComb target) {
518 assert(sta_state >= Sta_Resolving);
519 Change *chg= ki->allocate(alloc_motions);
526 static int change_needed(const MovFeatInfo *feati, MovPosComb target,
527 MovPosComb startpoint) {
530 (target - startpoint) / feati->weight % feati->posns;
531 oprintf(DUPO("movpos/change-needed") "%s:%s(%d*%d) %d<-%d => %d",
532 methodinfos[feati->kind].pname, feati->pname,
533 feati->posns, feati->weight,
534 target, startpoint, r);
538 static int evaluate_target(Segment *move, MovPosComb target,
539 MovPosComb startpoint, MovFeatKind *kind_r) {
540 /* returns number of features which have to change to reach target,
541 * or -1 for mixed kinds. kind_r may be 0. */
542 const SegmentInfo *movei= move->i;
544 const MovFeatInfo *feati;
547 oprintf(DUPO("movpos/eval") "%s/%s <-%s\n",
548 move->i->pname, posnpname(move,target), posnpname(move,startpoint));
551 startpoint= movpos_poscomb_actual(move);
552 oprintf(DUPO("movpos/eval") " actual <-%s\n",
553 posnpname(move,startpoint));
556 for (feat=0, feati=movei->movfeats, tchanges=0, kind= mfk_none;
557 feat<movei->n_movfeats;
559 if (!change_needed(feati,target,startpoint)) continue;
561 if (kind && feati->kind != kind) return -1;
565 if (kind_r) *kind_r= kind;
566 oprintf(DUPO("movpos/eval") "changes=%d kind=%s\n",
567 tchanges, methodinfos[kind].pname);
571 ErrorCode movpos_findcomb_bysegs(Segment *back, Segment *move, Segment *fwd,
572 MovPosComb startpoint, MovPosComb *chosen_r) {
573 const SegmentInfo *movei= move->i;
574 MovPosComb tcomb, bestcomb=-1;
575 int tchanges, bestchanges=INT_MAX;
576 const SegPosCombInfo *pci;
578 for (tcomb=0, pci=movei->poscombs;
579 tcomb<movei->n_poscombs;
581 Segment *tback= &segments[pci->link[1].next];
582 Segment *tfwd= &segments[pci->link[0].next];
583 if (back && !(back==tback || back==tfwd)) continue;
584 if (fwd && !(fwd ==tback || fwd ==tfwd)) continue;
586 if (movei->n_movfeats>1) {
587 /* we have to search for the one which is least effort, then */
588 tchanges= evaluate_target(move,tcomb,startpoint,0);
589 if (tchanges >= bestchanges) /* prefer low-numbered movposcombs */
593 /* fall through and update */
599 bestchanges= tchanges;
601 if (*chosen_r) *chosen_r= bestcomb;
603 bestchanges==INT_MAX ? EC_MovFeatRouteNotFound :
604 bestchanges==INT_MAX-1 ? EC_MovFeatKindsCombination :
608 ErrorCode movpos_change(Segment *move, MovPosComb target,
609 int maxdelay_ms, MovPosChange *chg) {
610 const SegmentInfo *movei= move->i;
611 const MovFeatInfo *feati;
615 MovFeatKind kind= mfk_none;
618 actual= move->movposcomb;
619 assert(!move->motion);
621 kind= move->motion->ki - methodinfos;
622 actual= move->motion->actual;
625 oprintf(DUPO("movpos/change") "%s/%s maxdelay_ms=%d actual=%s\n",
626 move->i->pname, posnpname(move,target),
627 maxdelay_ms, posnpname(move, actual));
628 if (chg) oprintf(DUPO("movpos/change") " chg=%s:%s/%s\n",
629 chg->ki->pname, chg->move->i->pname,
630 posnpname(chg->move, chg->intent));
632 { /* provide horizon for visibility of motions[] */
634 Motion motions[movei->n_movfeats];
636 for (feat=0, feati=movei->movfeats;
637 feat<movei->n_movfeats;
639 if (!change_needed(feati,actual,target))
641 MovPosComb posn= target / feati->weight % feati->posns;
643 if (feati->kind != kind) { ec= EC_MovFeatKindsCombination; goto x; }
647 motions[n_motions].i= feati;
648 motions[n_motions].posn= posn;
652 const KindInfo *ki= &methodinfos[kind];
657 chg->intent != target)
658 return EC_MovFeatReservationInapplicable;
660 chg= mp_allocate(ki,move,n_motions,target);
664 oprintf(DUPO("movpos/change") "confirm %s:%d...\n", ki->pname, n_motions);
665 ec= ki->confirm(chg, move, n_motions, motions, maxdelay_ms);
666 oprintf(DUPO("movpos/change") "confirm => %s\n",errorcodelist[ec]);
672 movpos_unreserve(chg);
677 movpos_reserve(Segment *move, int maxdelay_ms, MovPosChange **res_r,
678 MovPosComb target, MovPosComb startpoint /*as for findcomb*/) {
679 MovFeatKind kind= mfk_none;
683 oprintf(DUPO("movpos/reserve") "%s/%s maxdelay_ms=%d startpoint=%s\n",
684 move->i->pname, posnpname(move,target),
685 maxdelay_ms, posnpname(move,startpoint));
687 nchanges= evaluate_target(move,target,startpoint,&kind);
688 if (nchanges==-1) return EC_MovFeatKindsCombination;
690 const KindInfo *ki= &methodinfos[kind];
691 oprintf(DUPO("movpos/reserve") "allocate %s:%d...\n", ki->pname, nchanges);
692 Change *chg= mp_allocate(ki, move, nchanges, target);
693 ec= ki->reserve(chg, move, maxdelay_ms);
694 oprintf(DUPO("movpos/reserve") "reserve => %s\n",errorcodelist[ec]);
701 movpos_unreserve(chg);
705 void movpos_unreserve(MovPosChange *res) {
707 oprintf(DUPO("movpos/unreserve") "%s:%s/%s\n",
708 res->ki->pname, res->move->i->pname,
709 posnpname(res->move, res->intent));
710 res->ki->destroy(res);
713 MovPosComb movpos_poscomb_actual(Segment *seg) {
714 return seg->moving ? seg->motion->actual : seg->movposcomb;
717 MovPosComb movpos_change_intent(MovPosChange *chg) {