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root/radiance/ray/src/rt/ambient.c
Revision: 2.56
Committed: Tue Mar 30 16:13:00 2004 UTC (20 years ago) by schorsch
Content type: text/plain
Branch: MAIN
CVS Tags: rad3R6, rad3R6P1
Changes since 2.55: +120 -83 lines
Log Message:
Continued ANSIfication. There are only bits and pieces left now.

File Contents

# Content
1 #ifndef lint
2 static const char RCSid[] = "$Id: ambient.c,v 2.55 2003/10/20 16:01:55 greg Exp $";
3 #endif
4 /*
5 * ambient.c - routines dealing with ambient (inter-reflected) component.
6 *
7 * Declarations of external symbols in ambient.h
8 */
9
10 #include "copyright.h"
11
12 #include <string.h>
13
14 #include "platform.h"
15 #include "ray.h"
16 #include "otypes.h"
17 #include "resolu.h"
18 #include "ambient.h"
19 #include "random.h"
20
21 #ifndef OCTSCALE
22 #define OCTSCALE 1.0 /* ceil((valid rad.)/(cube size)) */
23 #endif
24
25 extern char *shm_boundary; /* memory sharing boundary */
26
27 #define MAXASET 511 /* maximum number of elements in ambient set */
28 OBJECT ambset[MAXASET+1]={0}; /* ambient include/exclude set */
29
30 double maxarad; /* maximum ambient radius */
31 double minarad; /* minimum ambient radius */
32
33 static AMBTREE atrunk; /* our ambient trunk node */
34
35 static FILE *ambfp = NULL; /* ambient file pointer */
36 static int nunflshed = 0; /* number of unflushed ambient values */
37
38 #ifndef SORT_THRESH
39 #ifdef SMLMEM
40 #define SORT_THRESH ((3L<<20)/sizeof(AMBVAL))
41 #else
42 #define SORT_THRESH ((9L<<20)/sizeof(AMBVAL))
43 #endif
44 #endif
45 #ifndef SORT_INTVL
46 #define SORT_INTVL (SORT_THRESH<<1)
47 #endif
48 #ifndef MAX_SORT_INTVL
49 #define MAX_SORT_INTVL (SORT_INTVL<<6)
50 #endif
51
52 static double avsum = 0.; /* computed ambient value sum (log) */
53 static unsigned int navsum = 0; /* number of values in avsum */
54 static unsigned int nambvals = 0; /* total number of indirect values */
55 static unsigned int nambshare = 0; /* number of values from file */
56 static unsigned long ambclock = 0; /* ambient access clock */
57 static unsigned long lastsort = 0; /* time of last value sort */
58 static long sortintvl = SORT_INTVL; /* time until next sort */
59 static FILE *ambinp = NULL; /* auxiliary file for input */
60 static long lastpos = -1; /* last flush position */
61
62 #define MAXACLOCK (1L<<30) /* clock turnover value */
63 /*
64 * Track access times unless we are sharing ambient values
65 * through memory on a multiprocessor, when we want to avoid
66 * claiming our own memory (copy on write). Go ahead anyway
67 * if more than two thirds of our values are unshared.
68 * Compile with -Dtracktime=0 to turn this code off.
69 */
70 #ifndef tracktime
71 #define tracktime (shm_boundary == NULL || nambvals > 3*nambshare)
72 #endif
73
74 #define AMBFLUSH (BUFSIZ/AMBVALSIZ)
75
76 #define newambval() (AMBVAL *)malloc(sizeof(AMBVAL))
77 #define freeav(av) free((void *)av);
78
79 static void initambfile(int creat);
80 static void avsave(AMBVAL *av);
81 static AMBVAL *avstore(AMBVAL *aval);
82 static AMBTREE *newambtree(void);
83 static void freeambtree(AMBTREE *atp);
84
85 typedef void unloadtf_t(void *);
86 static unloadtf_t avinsert;
87 static unloadtf_t av2list;
88 static void unloadatree(AMBTREE *at, unloadtf_t *f);
89
90 static int aposcmp(const void *avp1, const void *avp2);
91 static int avlmemi(AMBVAL *avaddr);
92 static void sortambvals(int always);
93
94 #ifdef F_SETLKW
95 static void aflock(int typ);
96 #endif
97
98
99 extern void
100 setambres( /* set ambient resolution */
101 int ar
102 )
103 {
104 ambres = ar < 0 ? 0 : ar; /* may be done already */
105 /* set min & max radii */
106 if (ar <= 0) {
107 minarad = 0;
108 maxarad = thescene.cusize / 2.0;
109 } else {
110 minarad = thescene.cusize / ar;
111 maxarad = 64 * minarad; /* heuristic */
112 if (maxarad > thescene.cusize / 2.0)
113 maxarad = thescene.cusize / 2.0;
114 }
115 if (minarad <= FTINY)
116 minarad = 10*FTINY;
117 if (maxarad <= minarad)
118 maxarad = 64 * minarad;
119 }
120
121
122 extern void
123 setambacc( /* set ambient accuracy */
124 double newa
125 )
126 {
127 double ambdiff;
128
129 if (newa < 0.0)
130 newa = 0.0;
131 ambdiff = fabs(newa - ambacc);
132 if (ambdiff >= .01 && (ambacc = newa) > FTINY && nambvals > 0)
133 sortambvals(1); /* rebuild tree */
134 }
135
136
137 extern void
138 setambient(void) /* initialize calculation */
139 {
140 int readonly = 0;
141 long pos, flen;
142 AMBVAL amb;
143 /* make sure we're fresh */
144 ambdone();
145 /* init ambient limits */
146 setambres(ambres);
147 setambacc(ambacc);
148 if (ambfile == NULL || !ambfile[0])
149 return;
150 if (ambacc <= FTINY) {
151 sprintf(errmsg, "zero ambient accuracy so \"%s\" not opened",
152 ambfile);
153 error(WARNING, errmsg);
154 return;
155 }
156 /* open ambient file */
157 if ((ambfp = fopen(ambfile, "r+")) == NULL)
158 readonly = (ambfp = fopen(ambfile, "r")) != NULL;
159 if (ambfp != NULL) {
160 initambfile(0); /* file exists */
161 pos = ftell(ambfp);
162 while (readambval(&amb, ambfp))
163 avinsert(avstore(&amb));
164 nambshare = nambvals; /* share loaded values */
165 if (readonly) {
166 sprintf(errmsg,
167 "loaded %u values from read-only ambient file",
168 nambvals);
169 error(WARNING, errmsg);
170 fclose(ambfp); /* close file so no writes */
171 ambfp = NULL;
172 return; /* avoid ambsync() */
173 }
174 /* align file pointer */
175 pos += (long)nambvals*AMBVALSIZ;
176 flen = lseek(fileno(ambfp), (off_t)0, SEEK_END);
177 if (flen != pos) {
178 sprintf(errmsg,
179 "ignoring last %ld values in ambient file (corrupted)",
180 (flen - pos)/AMBVALSIZ);
181 error(WARNING, errmsg);
182 fseek(ambfp, pos, 0);
183 #ifndef _WIN32 /* XXX we need a replacement for that one */
184 ftruncate(fileno(ambfp), (off_t)pos);
185 #endif
186 }
187 } else if ((ambfp = fopen(ambfile, "w+")) != NULL) {
188 initambfile(1); /* else create new file */
189 } else {
190 sprintf(errmsg, "cannot open ambient file \"%s\"", ambfile);
191 error(SYSTEM, errmsg);
192 }
193 nunflshed++; /* lie */
194 ambsync();
195 }
196
197
198 extern void
199 ambdone(void) /* close ambient file and free memory */
200 {
201 if (ambfp != NULL) { /* close ambient file */
202 ambsync();
203 fclose(ambfp);
204 ambfp = NULL;
205 if (ambinp != NULL) {
206 fclose(ambinp);
207 ambinp = NULL;
208 }
209 lastpos = -1;
210 }
211 /* free ambient tree */
212 unloadatree(&atrunk, free);
213 /* reset state variables */
214 avsum = 0.;
215 navsum = 0;
216 nambvals = 0;
217 nambshare = 0;
218 ambclock = 0;
219 lastsort = 0;
220 sortintvl = SORT_INTVL;
221 }
222
223
224 extern void
225 ambnotify( /* record new modifier */
226 OBJECT obj
227 )
228 {
229 static int hitlimit = 0;
230 register OBJREC *o;
231 register char **amblp;
232
233 if (obj == OVOID) { /* starting over */
234 ambset[0] = 0;
235 hitlimit = 0;
236 return;
237 }
238 o = objptr(obj);
239 if (hitlimit || !ismodifier(o->otype))
240 return;
241 for (amblp = amblist; *amblp != NULL; amblp++)
242 if (!strcmp(o->oname, *amblp)) {
243 if (ambset[0] >= MAXASET) {
244 error(WARNING, "too many modifiers in ambient list");
245 hitlimit++;
246 return; /* should this be fatal? */
247 }
248 insertelem(ambset, obj);
249 return;
250 }
251 }
252
253
254 extern void
255 ambient( /* compute ambient component for ray */
256 COLOR acol,
257 register RAY *r,
258 FVECT nrm
259 )
260 {
261 static int rdepth = 0; /* ambient recursion */
262 double d, l;
263
264 if (ambdiv <= 0) /* no ambient calculation */
265 goto dumbamb;
266 /* check number of bounces */
267 if (rdepth >= ambounce)
268 goto dumbamb;
269 /* check ambient list */
270 if (ambincl != -1 && r->ro != NULL &&
271 ambincl != inset(ambset, r->ro->omod))
272 goto dumbamb;
273
274 if (ambacc <= FTINY) { /* no ambient storage */
275 rdepth++;
276 d = doambient(acol, r, r->rweight, NULL, NULL);
277 rdepth--;
278 if (d <= FTINY)
279 goto dumbamb;
280 return;
281 }
282
283 if (tracktime) /* sort to minimize thrashing */
284 sortambvals(0);
285 /* get ambient value */
286 setcolor(acol, 0.0, 0.0, 0.0);
287 d = sumambient(acol, r, nrm, rdepth,
288 &atrunk, thescene.cuorg, thescene.cusize);
289 if (d > FTINY) {
290 scalecolor(acol, 1.0/d);
291 return;
292 }
293 rdepth++; /* need to cache new value */
294 d = makeambient(acol, r, nrm, rdepth-1);
295 rdepth--;
296 if (d > FTINY)
297 return;
298 dumbamb: /* return global value */
299 copycolor(acol, ambval);
300 if ((ambvwt <= 0) | (navsum == 0))
301 return;
302 l = bright(ambval); /* average in computations */
303 if (l > FTINY) {
304 d = (log(l)*(double)ambvwt + avsum) /
305 (double)(ambvwt + navsum);
306 d = exp(d) / l;
307 scalecolor(acol, d); /* apply color of ambval */
308 } else {
309 d = exp( avsum / (double)navsum );
310 setcolor(acol, d, d, d); /* neutral color */
311 }
312 }
313
314
315 extern double
316 sumambient( /* get interpolated ambient value */
317 COLOR acol,
318 register RAY *r,
319 FVECT rn,
320 int al,
321 AMBTREE *at,
322 FVECT c0,
323 double s
324 )
325 {
326 double d, e1, e2, wt, wsum;
327 COLOR ct;
328 FVECT ck0;
329 int i;
330 register int j;
331 register AMBVAL *av;
332
333 wsum = 0.0;
334 /* do this node */
335 for (av = at->alist; av != NULL; av = av->next) {
336 double rn_dot = -2.0;
337 if (tracktime)
338 av->latick = ambclock;
339 /*
340 * Ambient level test.
341 */
342 if (av->lvl > al) /* list sorted, so this works */
343 break;
344 if (av->weight < r->rweight-FTINY)
345 continue;
346 /*
347 * Ambient radius test.
348 */
349 d = av->pos[0] - r->rop[0];
350 e1 = d * d;
351 d = av->pos[1] - r->rop[1];
352 e1 += d * d;
353 d = av->pos[2] - r->rop[2];
354 e1 += d * d;
355 e1 /= av->rad * av->rad;
356 if (e1 > ambacc*ambacc*1.21)
357 continue;
358 /*
359 * Direction test using closest normal.
360 */
361 d = DOT(av->dir, r->ron);
362 if (rn != r->ron) {
363 rn_dot = DOT(av->dir, rn);
364 if (rn_dot > 1.0-FTINY)
365 rn_dot = 1.0-FTINY;
366 if (rn_dot >= d-FTINY) {
367 d = rn_dot;
368 rn_dot = -2.0;
369 }
370 }
371 e2 = (1.0 - d) * r->rweight;
372 if (e2 < 0.0) e2 = 0.0;
373 if (e1 + e2 > ambacc*ambacc*1.21)
374 continue;
375 /*
376 * Ray behind test.
377 */
378 d = 0.0;
379 for (j = 0; j < 3; j++)
380 d += (r->rop[j] - av->pos[j]) *
381 (av->dir[j] + r->ron[j]);
382 if (d*0.5 < -minarad*ambacc-.001)
383 continue;
384 /*
385 * Jittering final test reduces image artifacts.
386 */
387 e1 = sqrt(e1);
388 e2 = sqrt(e2);
389 wt = e1 + e2;
390 if (wt > ambacc*(.9+.2*urand(9015+samplendx)))
391 continue;
392 /*
393 * Recompute directional error using perturbed normal
394 */
395 if (rn_dot > 0.0) {
396 e2 = sqrt((1.0 - rn_dot)*r->rweight);
397 wt = e1 + e2;
398 }
399 if (wt <= 1e-3)
400 wt = 1e3;
401 else
402 wt = 1.0 / wt;
403 wsum += wt;
404 extambient(ct, av, r->rop, rn);
405 scalecolor(ct, wt);
406 addcolor(acol, ct);
407 }
408 if (at->kid == NULL)
409 return(wsum);
410 /* do children */
411 s *= 0.5;
412 for (i = 0; i < 8; i++) {
413 for (j = 0; j < 3; j++) {
414 ck0[j] = c0[j];
415 if (1<<j & i)
416 ck0[j] += s;
417 if (r->rop[j] < ck0[j] - OCTSCALE*s)
418 break;
419 if (r->rop[j] > ck0[j] + (1.0+OCTSCALE)*s)
420 break;
421 }
422 if (j == 3)
423 wsum += sumambient(acol, r, rn, al, at->kid+i, ck0, s);
424 }
425 return(wsum);
426 }
427
428
429 extern double
430 makeambient( /* make a new ambient value */
431 COLOR acol,
432 register RAY *r,
433 FVECT rn,
434 int al
435 )
436 {
437 AMBVAL amb;
438 FVECT gp, gd;
439 /* compute weight */
440 amb.weight = pow(AVGREFL, (double)al);
441 if (r->rweight < 0.1*amb.weight) /* heuristic */
442 amb.weight = r->rweight;
443 /* compute ambient */
444 amb.rad = doambient(acol, r, amb.weight, gp, gd);
445 if (amb.rad <= FTINY)
446 return(0.0);
447 /* store it */
448 VCOPY(amb.pos, r->rop);
449 VCOPY(amb.dir, r->ron);
450 amb.lvl = al;
451 copycolor(amb.val, acol);
452 VCOPY(amb.gpos, gp);
453 VCOPY(amb.gdir, gd);
454 /* insert into tree */
455 avsave(&amb); /* and save to file */
456 if (rn != r->ron)
457 extambient(acol, &amb, r->rop, rn); /* texture */
458 return(amb.rad);
459 }
460
461
462 extern void
463 extambient( /* extrapolate value at pv, nv */
464 COLOR cr,
465 register AMBVAL *ap,
466 FVECT pv,
467 FVECT nv
468 )
469 {
470 FVECT v1;
471 register int i;
472 double d;
473
474 d = 1.0; /* zeroeth order */
475 /* gradient due to translation */
476 for (i = 0; i < 3; i++)
477 d += ap->gpos[i]*(pv[i]-ap->pos[i]);
478 /* gradient due to rotation */
479 VCROSS(v1, ap->dir, nv);
480 d += DOT(ap->gdir, v1);
481 if (d <= 0.0) {
482 setcolor(cr, 0.0, 0.0, 0.0);
483 return;
484 }
485 copycolor(cr, ap->val);
486 scalecolor(cr, d);
487 }
488
489
490 static void
491 initambfile( /* initialize ambient file */
492 int creat
493 )
494 {
495 extern char *progname, *octname;
496 static char *mybuf = NULL;
497
498 #ifdef F_SETLKW
499 aflock(creat ? F_WRLCK : F_RDLCK);
500 #endif
501 SET_FILE_BINARY(ambfp);
502 if (mybuf == NULL)
503 mybuf = (char *)bmalloc(BUFSIZ+8);
504 setbuf(ambfp, mybuf);
505 if (creat) { /* new file */
506 newheader("RADIANCE", ambfp);
507 fprintf(ambfp, "%s -av %g %g %g -aw %d -ab %d -aa %g ",
508 progname, colval(ambval,RED),
509 colval(ambval,GRN), colval(ambval,BLU),
510 ambvwt, ambounce, ambacc);
511 fprintf(ambfp, "-ad %d -as %d -ar %d ",
512 ambdiv, ambssamp, ambres);
513 if (octname != NULL)
514 printargs(1, &octname, ambfp);
515 else
516 fputc('\n', ambfp);
517 fprintf(ambfp, "SOFTWARE= %s\n", VersionID);
518 fputnow(ambfp);
519 fputformat(AMBFMT, ambfp);
520 putc('\n', ambfp);
521 putambmagic(ambfp);
522 } else if (checkheader(ambfp, AMBFMT, NULL) < 0 || !hasambmagic(ambfp))
523 error(USER, "bad ambient file");
524 }
525
526
527 static void
528 avsave( /* insert and save an ambient value */
529 AMBVAL *av
530 )
531 {
532 avinsert(avstore(av));
533 if (ambfp == NULL)
534 return;
535 if (writambval(av, ambfp) < 0)
536 goto writerr;
537 if (++nunflshed >= AMBFLUSH)
538 if (ambsync() == EOF)
539 goto writerr;
540 return;
541 writerr:
542 error(SYSTEM, "error writing to ambient file");
543 }
544
545
546 static AMBVAL *
547 avstore( /* allocate memory and store aval */
548 register AMBVAL *aval
549 )
550 {
551 register AMBVAL *av;
552 double d;
553
554 if ((av = newambval()) == NULL)
555 error(SYSTEM, "out of memory in avstore");
556 *av = *aval;
557 av->latick = ambclock;
558 av->next = NULL;
559 nambvals++;
560 d = bright(av->val);
561 if (d > FTINY) { /* add to log sum for averaging */
562 avsum += log(d);
563 navsum++;
564 }
565 return(av);
566 }
567
568
569 #define ATALLOCSZ 512 /* #/8 trees to allocate at once */
570
571 static AMBTREE *atfreelist = NULL; /* free ambient tree structures */
572
573
574 static AMBTREE *
575 newambtree(void) /* allocate 8 ambient tree structs */
576 {
577 register AMBTREE *atp, *upperlim;
578
579 if (atfreelist == NULL) { /* get more nodes */
580 atfreelist = (AMBTREE *)malloc(ATALLOCSZ*8*sizeof(AMBTREE));
581 if (atfreelist == NULL)
582 return(NULL);
583 /* link new free list */
584 upperlim = atfreelist + 8*(ATALLOCSZ-1);
585 for (atp = atfreelist; atp < upperlim; atp += 8)
586 atp->kid = atp + 8;
587 atp->kid = NULL;
588 }
589 atp = atfreelist;
590 atfreelist = atp->kid;
591 memset((char *)atp, '\0', 8*sizeof(AMBTREE));
592 return(atp);
593 }
594
595
596 static void
597 freeambtree( /* free 8 ambient tree structs */
598 AMBTREE *atp
599 )
600 {
601 atp->kid = atfreelist;
602 atfreelist = atp;
603 }
604
605
606 static void
607 avinsert( /* insert ambient value in our tree */
608 void *av
609 )
610 {
611 register AMBTREE *at;
612 register AMBVAL *ap;
613 AMBVAL avh;
614 FVECT ck0;
615 double s;
616 int branch;
617 register int i;
618
619 if (((AMBVAL*)av)->rad <= FTINY)
620 error(CONSISTENCY, "zero ambient radius in avinsert");
621 at = &atrunk;
622 VCOPY(ck0, thescene.cuorg);
623 s = thescene.cusize;
624 while (s*(OCTSCALE/2) > ((AMBVAL*)av)->rad*ambacc) {
625 if (at->kid == NULL)
626 if ((at->kid = newambtree()) == NULL)
627 error(SYSTEM, "out of memory in avinsert");
628 s *= 0.5;
629 branch = 0;
630 for (i = 0; i < 3; i++)
631 if (((AMBVAL*)av)->pos[i] > ck0[i] + s) {
632 ck0[i] += s;
633 branch |= 1 << i;
634 }
635 at = at->kid + branch;
636 }
637 avh.next = at->alist; /* order by increasing level */
638 for (ap = &avh; ap->next != NULL; ap = ap->next)
639 if (ap->next->lvl >= ((AMBVAL*)av)->lvl)
640 break;
641 ((AMBVAL*)av)->next = ap->next;
642 ap->next = (AMBVAL*)av;
643 at->alist = avh.next;
644 }
645
646
647 static void
648 unloadatree( /* unload an ambient value tree */
649 register AMBTREE *at,
650 unloadtf_t *f
651 )
652 {
653 register AMBVAL *av;
654 register int i;
655 /* transfer values at this node */
656 for (av = at->alist; av != NULL; av = at->alist) {
657 at->alist = av->next;
658 (*f)(av);
659 }
660 if (at->kid == NULL)
661 return;
662 for (i = 0; i < 8; i++) /* transfer and free children */
663 unloadatree(at->kid+i, f);
664 freeambtree(at->kid);
665 at->kid = NULL;
666 }
667
668
669 static struct avl {
670 AMBVAL *p;
671 unsigned long t;
672 } *avlist1; /* ambient value list with ticks */
673 static AMBVAL **avlist2; /* memory positions for sorting */
674 static int i_avlist; /* index for lists */
675
676 static int alatcmp(const void *av1, const void *av2);
677
678 static void
679 av2list(
680 void *av
681 )
682 {
683 #ifdef DEBUG
684 if (i_avlist >= nambvals)
685 error(CONSISTENCY, "too many ambient values in av2list1");
686 #endif
687 avlist1[i_avlist].p = avlist2[i_avlist] = (AMBVAL*)av;
688 avlist1[i_avlist++].t = ((AMBVAL*)av)->latick;
689 }
690
691
692 static int
693 alatcmp( /* compare ambient values for MRA */
694 const void *av1,
695 const void *av2
696 )
697 {
698 register long lc = ((struct avl *)av2)->t - ((struct avl *)av1)->t;
699 return(lc<0 ? -1 : lc>0 ? 1 : 0);
700 }
701
702
703 /* GW NOTE 2002/10/3:
704 * I used to compare AMBVAL pointers, but found that this was the
705 * cause of a serious consistency error with gcc, since the optimizer
706 * uses some dangerous trick in pointer subtraction that
707 * assumes pointers differ by exact struct size increments.
708 */
709 static int
710 aposcmp( /* compare ambient value positions */
711 const void *avp1,
712 const void *avp2
713 )
714 {
715 register long diff = *(char * const *)avp1 - *(char * const *)avp2;
716 if (diff < 0)
717 return(-1);
718 return(diff > 0);
719 }
720
721 #if 1
722 static int
723 avlmemi( /* find list position from address */
724 AMBVAL *avaddr
725 )
726 {
727 register AMBVAL **avlpp;
728
729 avlpp = (AMBVAL **)bsearch((char *)&avaddr, (char *)avlist2,
730 nambvals, sizeof(AMBVAL *), aposcmp);
731 if (avlpp == NULL)
732 error(CONSISTENCY, "address not found in avlmemi");
733 return(avlpp - avlist2);
734 }
735 #else
736 #define avlmemi(avaddr) ((AMBVAL **)bsearch((char *)&avaddr,(char *)avlist2, \
737 nambvals,sizeof(AMBVAL *),aposcmp) - avlist2)
738 #endif
739
740
741 static void
742 sortambvals( /* resort ambient values */
743 int always
744 )
745 {
746 AMBTREE oldatrunk;
747 AMBVAL tav, *tap, *pnext;
748 register int i, j;
749 /* see if it's time yet */
750 if (!always && (ambclock++ < lastsort+sortintvl ||
751 nambvals < SORT_THRESH))
752 return;
753 /*
754 * The idea here is to minimize memory thrashing
755 * in VM systems by improving reference locality.
756 * We do this by periodically sorting our stored ambient
757 * values in memory in order of most recently to least
758 * recently accessed. This ordering was chosen so that new
759 * ambient values (which tend to be less important) go into
760 * higher memory with the infrequently accessed values.
761 * Since we expect our values to need sorting less
762 * frequently as the process continues, we double our
763 * waiting interval after each call.
764 * This routine is also called by setambacc() with
765 * the "always" parameter set to 1 so that the ambient
766 * tree will be rebuilt with the new accuracy parameter.
767 */
768 if (tracktime) { /* allocate pointer arrays to sort */
769 avlist2 = (AMBVAL **)malloc(nambvals*sizeof(AMBVAL *));
770 avlist1 = (struct avl *)malloc(nambvals*sizeof(struct avl));
771 } else {
772 avlist2 = NULL;
773 avlist1 = NULL;
774 }
775 if (avlist1 == NULL) { /* no time tracking -- rebuild tree? */
776 if (avlist2 != NULL)
777 free((void *)avlist2);
778 if (always) { /* rebuild without sorting */
779 oldatrunk = atrunk;
780 atrunk.alist = NULL;
781 atrunk.kid = NULL;
782 unloadatree(&oldatrunk, avinsert);
783 }
784 } else { /* sort memory by last access time */
785 /*
786 * Sorting memory is tricky because it isn't contiguous.
787 * We have to sort an array of pointers by MRA and also
788 * by memory position. We then copy values in "loops"
789 * to minimize memory hits. Nevertheless, we will visit
790 * everyone at least twice, and this is an expensive process
791 * when we're thrashing, which is when we need to do it.
792 */
793 #ifdef DEBUG
794 sprintf(errmsg, "sorting %u ambient values at ambclock=%lu...",
795 nambvals, ambclock);
796 eputs(errmsg);
797 #endif
798 i_avlist = 0;
799 unloadatree(&atrunk, av2list); /* empty current tree */
800 #ifdef DEBUG
801 if (i_avlist < nambvals)
802 error(CONSISTENCY, "missing ambient values in sortambvals");
803 #endif
804 qsort((char *)avlist1, nambvals, sizeof(struct avl), alatcmp);
805 qsort((char *)avlist2, nambvals, sizeof(AMBVAL *), aposcmp);
806 for (i = 0; i < nambvals; i++) {
807 if (avlist1[i].p == NULL)
808 continue;
809 tap = avlist2[i];
810 tav = *tap;
811 for (j = i; (pnext = avlist1[j].p) != tap;
812 j = avlmemi(pnext)) {
813 *(avlist2[j]) = *pnext;
814 avinsert(avlist2[j]);
815 avlist1[j].p = NULL;
816 }
817 *(avlist2[j]) = tav;
818 avinsert(avlist2[j]);
819 avlist1[j].p = NULL;
820 }
821 free((void *)avlist1);
822 free((void *)avlist2);
823 /* compute new sort interval */
824 sortintvl = ambclock - lastsort;
825 if (sortintvl >= MAX_SORT_INTVL/2)
826 sortintvl = MAX_SORT_INTVL;
827 else
828 sortintvl <<= 1; /* wait twice as long next */
829 #ifdef DEBUG
830 eputs("done\n");
831 #endif
832 }
833 if (ambclock >= MAXACLOCK)
834 ambclock = MAXACLOCK/2;
835 lastsort = ambclock;
836 }
837
838
839 #ifdef F_SETLKW
840
841 static void
842 aflock( /* lock/unlock ambient file */
843 int typ
844 )
845 {
846 static struct flock fls; /* static so initialized to zeroes */
847
848 fls.l_type = typ;
849 if (fcntl(fileno(ambfp), F_SETLKW, &fls) < 0)
850 error(SYSTEM, "cannot (un)lock ambient file");
851 }
852
853
854 extern int
855 ambsync(void) /* synchronize ambient file */
856 {
857 long flen;
858 AMBVAL avs;
859 register int n;
860
861 if (nunflshed == 0)
862 return(0);
863 if (lastpos < 0) /* initializing (locked in initambfile) */
864 goto syncend;
865 /* gain exclusive access */
866 aflock(F_WRLCK);
867 /* see if file has grown */
868 if ((flen = lseek(fileno(ambfp), (off_t)0, SEEK_END)) < 0)
869 goto seekerr;
870 if ( (n = flen - lastpos) ) { /* file has grown */
871 if (ambinp == NULL) { /* use duplicate filedes */
872 ambinp = fdopen(dup(fileno(ambfp)), "r");
873 if (ambinp == NULL)
874 error(SYSTEM, "fdopen failed in ambsync");
875 }
876 if (fseek(ambinp, lastpos, 0) < 0)
877 goto seekerr;
878 while (n >= AMBVALSIZ) { /* load contributed values */
879 if (!readambval(&avs, ambinp)) {
880 sprintf(errmsg,
881 "ambient file \"%s\" corrupted near character %ld",
882 ambfile, flen - n);
883 error(WARNING, errmsg);
884 break;
885 }
886 avinsert(avstore(&avs));
887 n -= AMBVALSIZ;
888 }
889 /*** seek always as safety measure
890 if (n) ***/ /* alignment */
891 if (lseek(fileno(ambfp), (off_t)(flen-n), SEEK_SET) < 0)
892 goto seekerr;
893 }
894 #ifdef DEBUG
895 if (ambfp->_ptr - ambfp->_base != nunflshed*AMBVALSIZ) {
896 sprintf(errmsg, "ambient file buffer at %d rather than %d",
897 ambfp->_ptr - ambfp->_base,
898 nunflshed*AMBVALSIZ);
899 error(CONSISTENCY, errmsg);
900 }
901 #endif
902 syncend:
903 n = fflush(ambfp); /* calls write() at last */
904 if ((lastpos = lseek(fileno(ambfp), (off_t)0, SEEK_CUR)) < 0)
905 goto seekerr;
906 aflock(F_UNLCK); /* release file */
907 nunflshed = 0;
908 return(n);
909 seekerr:
910 error(SYSTEM, "seek failed in ambsync");
911 return -1; /* pro forma return */
912 }
913
914 #else
915
916 extern int
917 ambsync(void) /* flush ambient file */
918 {
919 if (nunflshed == 0)
920 return(0);
921 nunflshed = 0;
922 return(fflush(ambfp));
923 }
924
925 #endif