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root/radiance/ray/src/rt/ambient.c
Revision: 2.59
Committed: Wed May 25 18:06:22 2005 UTC (18 years, 11 months ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 2.58: +6 -4 lines
Log Message:
Fixed bug introduced with ray contribution output in ambient calculation

File Contents

# Content
1 #ifndef lint
2 static const char RCSid[] = "$Id: ambient.c,v 2.58 2005/04/19 01:15:06 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 #ifndef MAXASET
28 #define MAXASET 2047 /* maximum number of elements in ambient set */
29 #endif
30 OBJECT ambset[MAXASET+1]={0}; /* ambient include/exclude set */
31
32 double maxarad; /* maximum ambient radius */
33 double minarad; /* minimum ambient radius */
34
35 static AMBTREE atrunk; /* our ambient trunk node */
36
37 static FILE *ambfp = NULL; /* ambient file pointer */
38 static int nunflshed = 0; /* number of unflushed ambient values */
39
40 #ifndef SORT_THRESH
41 #ifdef SMLMEM
42 #define SORT_THRESH ((3L<<20)/sizeof(AMBVAL))
43 #else
44 #define SORT_THRESH ((9L<<20)/sizeof(AMBVAL))
45 #endif
46 #endif
47 #ifndef SORT_INTVL
48 #define SORT_INTVL (SORT_THRESH<<1)
49 #endif
50 #ifndef MAX_SORT_INTVL
51 #define MAX_SORT_INTVL (SORT_INTVL<<6)
52 #endif
53
54 static double avsum = 0.; /* computed ambient value sum (log) */
55 static unsigned int navsum = 0; /* number of values in avsum */
56 static unsigned int nambvals = 0; /* total number of indirect values */
57 static unsigned int nambshare = 0; /* number of values from file */
58 static unsigned long ambclock = 0; /* ambient access clock */
59 static unsigned long lastsort = 0; /* time of last value sort */
60 static long sortintvl = SORT_INTVL; /* time until next sort */
61 static FILE *ambinp = NULL; /* auxiliary file for input */
62 static long lastpos = -1; /* last flush position */
63
64 #define MAXACLOCK (1L<<30) /* clock turnover value */
65 /*
66 * Track access times unless we are sharing ambient values
67 * through memory on a multiprocessor, when we want to avoid
68 * claiming our own memory (copy on write). Go ahead anyway
69 * if more than two thirds of our values are unshared.
70 * Compile with -Dtracktime=0 to turn this code off.
71 */
72 #ifndef tracktime
73 #define tracktime (shm_boundary == NULL || nambvals > 3*nambshare)
74 #endif
75
76 #define AMBFLUSH (BUFSIZ/AMBVALSIZ)
77
78 #define newambval() (AMBVAL *)malloc(sizeof(AMBVAL))
79 #define freeav(av) free((void *)av);
80
81 static void initambfile(int creat);
82 static void avsave(AMBVAL *av);
83 static AMBVAL *avstore(AMBVAL *aval);
84 static AMBTREE *newambtree(void);
85 static void freeambtree(AMBTREE *atp);
86
87 typedef void unloadtf_t(void *);
88 static unloadtf_t avinsert;
89 static unloadtf_t av2list;
90 static void unloadatree(AMBTREE *at, unloadtf_t *f);
91
92 static int aposcmp(const void *avp1, const void *avp2);
93 static int avlmemi(AMBVAL *avaddr);
94 static void sortambvals(int always);
95
96 #ifdef F_SETLKW
97 static void aflock(int typ);
98 #endif
99
100
101 extern void
102 setambres( /* set ambient resolution */
103 int ar
104 )
105 {
106 ambres = ar < 0 ? 0 : ar; /* may be done already */
107 /* set min & max radii */
108 if (ar <= 0) {
109 minarad = 0;
110 maxarad = thescene.cusize / 2.0;
111 } else {
112 minarad = thescene.cusize / ar;
113 maxarad = 64 * minarad; /* heuristic */
114 if (maxarad > thescene.cusize / 2.0)
115 maxarad = thescene.cusize / 2.0;
116 }
117 if (minarad <= FTINY)
118 minarad = 10*FTINY;
119 if (maxarad <= minarad)
120 maxarad = 64 * minarad;
121 }
122
123
124 extern void
125 setambacc( /* set ambient accuracy */
126 double newa
127 )
128 {
129 double ambdiff;
130
131 if (newa < 0.0)
132 newa = 0.0;
133 ambdiff = fabs(newa - ambacc);
134 if (ambdiff >= .01 && (ambacc = newa) > FTINY && nambvals > 0)
135 sortambvals(1); /* rebuild tree */
136 }
137
138
139 extern void
140 setambient(void) /* initialize calculation */
141 {
142 int readonly = 0;
143 long pos, flen;
144 AMBVAL amb;
145 /* make sure we're fresh */
146 ambdone();
147 /* init ambient limits */
148 setambres(ambres);
149 setambacc(ambacc);
150 if (ambfile == NULL || !ambfile[0])
151 return;
152 if (ambacc <= FTINY) {
153 sprintf(errmsg, "zero ambient accuracy so \"%s\" not opened",
154 ambfile);
155 error(WARNING, errmsg);
156 return;
157 }
158 /* open ambient file */
159 if ((ambfp = fopen(ambfile, "r+")) == NULL)
160 readonly = (ambfp = fopen(ambfile, "r")) != NULL;
161 if (ambfp != NULL) {
162 initambfile(0); /* file exists */
163 pos = ftell(ambfp);
164 while (readambval(&amb, ambfp))
165 avinsert(avstore(&amb));
166 nambshare = nambvals; /* share loaded values */
167 if (readonly) {
168 sprintf(errmsg,
169 "loaded %u values from read-only ambient file",
170 nambvals);
171 error(WARNING, errmsg);
172 fclose(ambfp); /* close file so no writes */
173 ambfp = NULL;
174 return; /* avoid ambsync() */
175 }
176 /* align file pointer */
177 pos += (long)nambvals*AMBVALSIZ;
178 flen = lseek(fileno(ambfp), (off_t)0, SEEK_END);
179 if (flen != pos) {
180 sprintf(errmsg,
181 "ignoring last %ld values in ambient file (corrupted)",
182 (flen - pos)/AMBVALSIZ);
183 error(WARNING, errmsg);
184 fseek(ambfp, pos, 0);
185 #ifndef _WIN32 /* XXX we need a replacement for that one */
186 ftruncate(fileno(ambfp), (off_t)pos);
187 #endif
188 }
189 } else if ((ambfp = fopen(ambfile, "w+")) != NULL) {
190 initambfile(1); /* else create new file */
191 } else {
192 sprintf(errmsg, "cannot open ambient file \"%s\"", ambfile);
193 error(SYSTEM, errmsg);
194 }
195 nunflshed++; /* lie */
196 ambsync();
197 }
198
199
200 extern void
201 ambdone(void) /* close ambient file and free memory */
202 {
203 if (ambfp != NULL) { /* close ambient file */
204 ambsync();
205 fclose(ambfp);
206 ambfp = NULL;
207 if (ambinp != NULL) {
208 fclose(ambinp);
209 ambinp = NULL;
210 }
211 lastpos = -1;
212 }
213 /* free ambient tree */
214 unloadatree(&atrunk, free);
215 /* reset state variables */
216 avsum = 0.;
217 navsum = 0;
218 nambvals = 0;
219 nambshare = 0;
220 ambclock = 0;
221 lastsort = 0;
222 sortintvl = SORT_INTVL;
223 }
224
225
226 extern void
227 ambnotify( /* record new modifier */
228 OBJECT obj
229 )
230 {
231 static int hitlimit = 0;
232 register OBJREC *o;
233 register char **amblp;
234
235 if (obj == OVOID) { /* starting over */
236 ambset[0] = 0;
237 hitlimit = 0;
238 return;
239 }
240 o = objptr(obj);
241 if (hitlimit || !ismodifier(o->otype))
242 return;
243 for (amblp = amblist; *amblp != NULL; amblp++)
244 if (!strcmp(o->oname, *amblp)) {
245 if (ambset[0] >= MAXASET) {
246 error(WARNING, "too many modifiers in ambient list");
247 hitlimit++;
248 return; /* should this be fatal? */
249 }
250 insertelem(ambset, obj);
251 return;
252 }
253 }
254
255
256 extern void
257 multambient( /* compute ambient component & multiply by coef. */
258 COLOR aval,
259 register RAY *r,
260 FVECT nrm
261 )
262 {
263 static int rdepth = 0; /* ambient recursion */
264 COLOR acol;
265 double d, l;
266
267 if (ambdiv <= 0) /* no ambient calculation */
268 goto dumbamb;
269 /* check number of bounces */
270 if (rdepth >= ambounce)
271 goto dumbamb;
272 /* check ambient list */
273 if (ambincl != -1 && r->ro != NULL &&
274 ambincl != inset(ambset, r->ro->omod))
275 goto dumbamb;
276
277 if (ambacc <= FTINY) { /* no ambient storage */
278 rdepth++;
279 d = doambient(acol, r, aval, intens(aval)*r->rweight,
280 NULL, NULL);
281 rdepth--;
282 if (d <= FTINY)
283 goto dumbamb;
284 multcolor(aval, acol);
285 return;
286 }
287
288 if (tracktime) /* sort to minimize thrashing */
289 sortambvals(0);
290 /* get ambient value */
291 setcolor(acol, 0.0, 0.0, 0.0);
292 d = sumambient(acol, r, intens(aval)*r->rweight, nrm, rdepth,
293 &atrunk, thescene.cuorg, thescene.cusize);
294 if (d > FTINY) {
295 scalecolor(acol, 1.0/d);
296 multcolor(aval, acol);
297 return;
298 }
299 rdepth++; /* need to cache new value */
300 d = makeambient(acol, r, aval, nrm, rdepth-1);
301 rdepth--;
302 if (d > FTINY) {
303 multcolor(aval, acol); /* got new value */
304 return;
305 }
306 dumbamb: /* return global value */
307 if ((ambvwt <= 0) | (navsum == 0)) {
308 multcolor(aval, ambval);
309 return;
310 }
311 l = bright(ambval); /* average in computations */
312 if (l > FTINY) {
313 d = (log(l)*(double)ambvwt + avsum) /
314 (double)(ambvwt + navsum);
315 d = exp(d) / l;
316 scalecolor(aval, d);
317 multcolor(aval, ambval); /* apply color of ambval */
318 } else {
319 d = exp( avsum / (double)navsum );
320 scalecolor(aval, d); /* neutral color */
321 }
322 }
323
324
325 extern double
326 sumambient( /* get interpolated ambient value */
327 COLOR acol,
328 register RAY *r,
329 double rw,
330 FVECT rn,
331 int al,
332 AMBTREE *at,
333 FVECT c0,
334 double s
335 )
336 {
337 double d, e1, e2, wt, wsum;
338 COLOR ct;
339 FVECT ck0;
340 int i;
341 register int j;
342 register AMBVAL *av;
343
344 wsum = 0.0;
345 /* do this node */
346 for (av = at->alist; av != NULL; av = av->next) {
347 double rn_dot = -2.0;
348 if (tracktime)
349 av->latick = ambclock;
350 /*
351 * Ambient level test.
352 */
353 if (av->lvl > al) /* list sorted, so this works */
354 break;
355 if (av->weight < 0.9*rw)
356 continue;
357 /*
358 * Ambient radius test.
359 */
360 d = av->pos[0] - r->rop[0];
361 e1 = d * d;
362 d = av->pos[1] - r->rop[1];
363 e1 += d * d;
364 d = av->pos[2] - r->rop[2];
365 e1 += d * d;
366 e1 /= av->rad * av->rad;
367 if (e1 > ambacc*ambacc*1.21)
368 continue;
369 /*
370 * Direction test using closest normal.
371 */
372 d = DOT(av->dir, r->ron);
373 if (rn != r->ron) {
374 rn_dot = DOT(av->dir, rn);
375 if (rn_dot > 1.0-FTINY)
376 rn_dot = 1.0-FTINY;
377 if (rn_dot >= d-FTINY) {
378 d = rn_dot;
379 rn_dot = -2.0;
380 }
381 }
382 e2 = (1.0 - d) * r->rweight;
383 if (e2 < 0.0) e2 = 0.0;
384 if (e1 + e2 > ambacc*ambacc*1.21)
385 continue;
386 /*
387 * Ray behind test.
388 */
389 d = 0.0;
390 for (j = 0; j < 3; j++)
391 d += (r->rop[j] - av->pos[j]) *
392 (av->dir[j] + r->ron[j]);
393 if (d*0.5 < -minarad*ambacc-.001)
394 continue;
395 /*
396 * Jittering final test reduces image artifacts.
397 */
398 e1 = sqrt(e1);
399 e2 = sqrt(e2);
400 wt = e1 + e2;
401 if (wt > ambacc*(.9+.2*urand(9015+samplendx)))
402 continue;
403 /*
404 * Recompute directional error using perturbed normal
405 */
406 if (rn_dot > 0.0) {
407 e2 = sqrt((1.0 - rn_dot)*r->rweight);
408 wt = e1 + e2;
409 }
410 if (wt <= 1e-3)
411 wt = 1e3;
412 else
413 wt = 1.0 / wt;
414 wsum += wt;
415 extambient(ct, av, r->rop, rn);
416 scalecolor(ct, wt);
417 addcolor(acol, ct);
418 }
419 if (at->kid == NULL)
420 return(wsum);
421 /* do children */
422 s *= 0.5;
423 for (i = 0; i < 8; i++) {
424 for (j = 0; j < 3; j++) {
425 ck0[j] = c0[j];
426 if (1<<j & i)
427 ck0[j] += s;
428 if (r->rop[j] < ck0[j] - OCTSCALE*s)
429 break;
430 if (r->rop[j] > ck0[j] + (1.0+OCTSCALE)*s)
431 break;
432 }
433 if (j == 3)
434 wsum += sumambient(acol, r, rw, rn, al,
435 at->kid+i, ck0, s);
436 }
437 return(wsum);
438 }
439
440
441 extern double
442 makeambient( /* make a new ambient value */
443 COLOR acol,
444 RAY *r,
445 COLOR ac,
446 FVECT rn,
447 int al
448 )
449 {
450 AMBVAL amb;
451 double coef;
452 FVECT gp, gd;
453 /* compute weight */
454 amb.weight = pow(AVGREFL, (double)al);
455 coef = intens(ac)*r->rweight;
456 if (coef < 0.1*amb.weight) /* heuristic */
457 amb.weight = coef;
458 /* compute ambient */
459 amb.rad = doambient(acol, r, ac, amb.weight, gp, gd);
460 if (amb.rad <= FTINY)
461 return(0.0);
462 /* store it */
463 VCOPY(amb.pos, r->rop);
464 VCOPY(amb.dir, r->ron);
465 amb.lvl = al;
466 copycolor(amb.val, acol);
467 VCOPY(amb.gpos, gp);
468 VCOPY(amb.gdir, gd);
469 /* insert into tree */
470 avsave(&amb); /* and save to file */
471 if (rn != r->ron)
472 extambient(acol, &amb, r->rop, rn); /* texture */
473 return(amb.rad);
474 }
475
476
477 extern void
478 extambient( /* extrapolate value at pv, nv */
479 COLOR cr,
480 register AMBVAL *ap,
481 FVECT pv,
482 FVECT nv
483 )
484 {
485 FVECT v1;
486 register int i;
487 double d;
488
489 d = 1.0; /* zeroeth order */
490 /* gradient due to translation */
491 for (i = 0; i < 3; i++)
492 d += ap->gpos[i]*(pv[i]-ap->pos[i]);
493 /* gradient due to rotation */
494 VCROSS(v1, ap->dir, nv);
495 d += DOT(ap->gdir, v1);
496 if (d <= 0.0) {
497 setcolor(cr, 0.0, 0.0, 0.0);
498 return;
499 }
500 copycolor(cr, ap->val);
501 scalecolor(cr, d);
502 }
503
504
505 static void
506 initambfile( /* initialize ambient file */
507 int creat
508 )
509 {
510 extern char *progname, *octname;
511 static char *mybuf = NULL;
512
513 #ifdef F_SETLKW
514 aflock(creat ? F_WRLCK : F_RDLCK);
515 #endif
516 SET_FILE_BINARY(ambfp);
517 if (mybuf == NULL)
518 mybuf = (char *)bmalloc(BUFSIZ+8);
519 setbuf(ambfp, mybuf);
520 if (creat) { /* new file */
521 newheader("RADIANCE", ambfp);
522 fprintf(ambfp, "%s -av %g %g %g -aw %d -ab %d -aa %g ",
523 progname, colval(ambval,RED),
524 colval(ambval,GRN), colval(ambval,BLU),
525 ambvwt, ambounce, ambacc);
526 fprintf(ambfp, "-ad %d -as %d -ar %d ",
527 ambdiv, ambssamp, ambres);
528 if (octname != NULL)
529 printargs(1, &octname, ambfp);
530 else
531 fputc('\n', ambfp);
532 fprintf(ambfp, "SOFTWARE= %s\n", VersionID);
533 fputnow(ambfp);
534 fputformat(AMBFMT, ambfp);
535 putc('\n', ambfp);
536 putambmagic(ambfp);
537 } else if (checkheader(ambfp, AMBFMT, NULL) < 0 || !hasambmagic(ambfp))
538 error(USER, "bad ambient file");
539 }
540
541
542 static void
543 avsave( /* insert and save an ambient value */
544 AMBVAL *av
545 )
546 {
547 avinsert(avstore(av));
548 if (ambfp == NULL)
549 return;
550 if (writambval(av, ambfp) < 0)
551 goto writerr;
552 if (++nunflshed >= AMBFLUSH)
553 if (ambsync() == EOF)
554 goto writerr;
555 return;
556 writerr:
557 error(SYSTEM, "error writing to ambient file");
558 }
559
560
561 static AMBVAL *
562 avstore( /* allocate memory and store aval */
563 register AMBVAL *aval
564 )
565 {
566 register AMBVAL *av;
567 double d;
568
569 if ((av = newambval()) == NULL)
570 error(SYSTEM, "out of memory in avstore");
571 *av = *aval;
572 av->latick = ambclock;
573 av->next = NULL;
574 nambvals++;
575 d = bright(av->val);
576 if (d > FTINY) { /* add to log sum for averaging */
577 avsum += log(d);
578 navsum++;
579 }
580 return(av);
581 }
582
583
584 #define ATALLOCSZ 512 /* #/8 trees to allocate at once */
585
586 static AMBTREE *atfreelist = NULL; /* free ambient tree structures */
587
588
589 static AMBTREE *
590 newambtree(void) /* allocate 8 ambient tree structs */
591 {
592 register AMBTREE *atp, *upperlim;
593
594 if (atfreelist == NULL) { /* get more nodes */
595 atfreelist = (AMBTREE *)malloc(ATALLOCSZ*8*sizeof(AMBTREE));
596 if (atfreelist == NULL)
597 return(NULL);
598 /* link new free list */
599 upperlim = atfreelist + 8*(ATALLOCSZ-1);
600 for (atp = atfreelist; atp < upperlim; atp += 8)
601 atp->kid = atp + 8;
602 atp->kid = NULL;
603 }
604 atp = atfreelist;
605 atfreelist = atp->kid;
606 memset((char *)atp, '\0', 8*sizeof(AMBTREE));
607 return(atp);
608 }
609
610
611 static void
612 freeambtree( /* free 8 ambient tree structs */
613 AMBTREE *atp
614 )
615 {
616 atp->kid = atfreelist;
617 atfreelist = atp;
618 }
619
620
621 static void
622 avinsert( /* insert ambient value in our tree */
623 void *av
624 )
625 {
626 register AMBTREE *at;
627 register AMBVAL *ap;
628 AMBVAL avh;
629 FVECT ck0;
630 double s;
631 int branch;
632 register int i;
633
634 if (((AMBVAL*)av)->rad <= FTINY)
635 error(CONSISTENCY, "zero ambient radius in avinsert");
636 at = &atrunk;
637 VCOPY(ck0, thescene.cuorg);
638 s = thescene.cusize;
639 while (s*(OCTSCALE/2) > ((AMBVAL*)av)->rad*ambacc) {
640 if (at->kid == NULL)
641 if ((at->kid = newambtree()) == NULL)
642 error(SYSTEM, "out of memory in avinsert");
643 s *= 0.5;
644 branch = 0;
645 for (i = 0; i < 3; i++)
646 if (((AMBVAL*)av)->pos[i] > ck0[i] + s) {
647 ck0[i] += s;
648 branch |= 1 << i;
649 }
650 at = at->kid + branch;
651 }
652 avh.next = at->alist; /* order by increasing level */
653 for (ap = &avh; ap->next != NULL; ap = ap->next)
654 if (ap->next->lvl >= ((AMBVAL*)av)->lvl)
655 break;
656 ((AMBVAL*)av)->next = ap->next;
657 ap->next = (AMBVAL*)av;
658 at->alist = avh.next;
659 }
660
661
662 static void
663 unloadatree( /* unload an ambient value tree */
664 register AMBTREE *at,
665 unloadtf_t *f
666 )
667 {
668 register AMBVAL *av;
669 register int i;
670 /* transfer values at this node */
671 for (av = at->alist; av != NULL; av = at->alist) {
672 at->alist = av->next;
673 (*f)(av);
674 }
675 if (at->kid == NULL)
676 return;
677 for (i = 0; i < 8; i++) /* transfer and free children */
678 unloadatree(at->kid+i, f);
679 freeambtree(at->kid);
680 at->kid = NULL;
681 }
682
683
684 static struct avl {
685 AMBVAL *p;
686 unsigned long t;
687 } *avlist1; /* ambient value list with ticks */
688 static AMBVAL **avlist2; /* memory positions for sorting */
689 static int i_avlist; /* index for lists */
690
691 static int alatcmp(const void *av1, const void *av2);
692
693 static void
694 av2list(
695 void *av
696 )
697 {
698 #ifdef DEBUG
699 if (i_avlist >= nambvals)
700 error(CONSISTENCY, "too many ambient values in av2list1");
701 #endif
702 avlist1[i_avlist].p = avlist2[i_avlist] = (AMBVAL*)av;
703 avlist1[i_avlist++].t = ((AMBVAL*)av)->latick;
704 }
705
706
707 static int
708 alatcmp( /* compare ambient values for MRA */
709 const void *av1,
710 const void *av2
711 )
712 {
713 register long lc = ((struct avl *)av2)->t - ((struct avl *)av1)->t;
714 return(lc<0 ? -1 : lc>0 ? 1 : 0);
715 }
716
717
718 /* GW NOTE 2002/10/3:
719 * I used to compare AMBVAL pointers, but found that this was the
720 * cause of a serious consistency error with gcc, since the optimizer
721 * uses some dangerous trick in pointer subtraction that
722 * assumes pointers differ by exact struct size increments.
723 */
724 static int
725 aposcmp( /* compare ambient value positions */
726 const void *avp1,
727 const void *avp2
728 )
729 {
730 register long diff = *(char * const *)avp1 - *(char * const *)avp2;
731 if (diff < 0)
732 return(-1);
733 return(diff > 0);
734 }
735
736 #if 1
737 static int
738 avlmemi( /* find list position from address */
739 AMBVAL *avaddr
740 )
741 {
742 register AMBVAL **avlpp;
743
744 avlpp = (AMBVAL **)bsearch((char *)&avaddr, (char *)avlist2,
745 nambvals, sizeof(AMBVAL *), aposcmp);
746 if (avlpp == NULL)
747 error(CONSISTENCY, "address not found in avlmemi");
748 return(avlpp - avlist2);
749 }
750 #else
751 #define avlmemi(avaddr) ((AMBVAL **)bsearch((char *)&avaddr,(char *)avlist2, \
752 nambvals,sizeof(AMBVAL *),aposcmp) - avlist2)
753 #endif
754
755
756 static void
757 sortambvals( /* resort ambient values */
758 int always
759 )
760 {
761 AMBTREE oldatrunk;
762 AMBVAL tav, *tap, *pnext;
763 register int i, j;
764 /* see if it's time yet */
765 if (!always && (ambclock++ < lastsort+sortintvl ||
766 nambvals < SORT_THRESH))
767 return;
768 /*
769 * The idea here is to minimize memory thrashing
770 * in VM systems by improving reference locality.
771 * We do this by periodically sorting our stored ambient
772 * values in memory in order of most recently to least
773 * recently accessed. This ordering was chosen so that new
774 * ambient values (which tend to be less important) go into
775 * higher memory with the infrequently accessed values.
776 * Since we expect our values to need sorting less
777 * frequently as the process continues, we double our
778 * waiting interval after each call.
779 * This routine is also called by setambacc() with
780 * the "always" parameter set to 1 so that the ambient
781 * tree will be rebuilt with the new accuracy parameter.
782 */
783 if (tracktime) { /* allocate pointer arrays to sort */
784 avlist2 = (AMBVAL **)malloc(nambvals*sizeof(AMBVAL *));
785 avlist1 = (struct avl *)malloc(nambvals*sizeof(struct avl));
786 } else {
787 avlist2 = NULL;
788 avlist1 = NULL;
789 }
790 if (avlist1 == NULL) { /* no time tracking -- rebuild tree? */
791 if (avlist2 != NULL)
792 free((void *)avlist2);
793 if (always) { /* rebuild without sorting */
794 oldatrunk = atrunk;
795 atrunk.alist = NULL;
796 atrunk.kid = NULL;
797 unloadatree(&oldatrunk, avinsert);
798 }
799 } else { /* sort memory by last access time */
800 /*
801 * Sorting memory is tricky because it isn't contiguous.
802 * We have to sort an array of pointers by MRA and also
803 * by memory position. We then copy values in "loops"
804 * to minimize memory hits. Nevertheless, we will visit
805 * everyone at least twice, and this is an expensive process
806 * when we're thrashing, which is when we need to do it.
807 */
808 #ifdef DEBUG
809 sprintf(errmsg, "sorting %u ambient values at ambclock=%lu...",
810 nambvals, ambclock);
811 eputs(errmsg);
812 #endif
813 i_avlist = 0;
814 unloadatree(&atrunk, av2list); /* empty current tree */
815 #ifdef DEBUG
816 if (i_avlist < nambvals)
817 error(CONSISTENCY, "missing ambient values in sortambvals");
818 #endif
819 qsort((char *)avlist1, nambvals, sizeof(struct avl), alatcmp);
820 qsort((char *)avlist2, nambvals, sizeof(AMBVAL *), aposcmp);
821 for (i = 0; i < nambvals; i++) {
822 if (avlist1[i].p == NULL)
823 continue;
824 tap = avlist2[i];
825 tav = *tap;
826 for (j = i; (pnext = avlist1[j].p) != tap;
827 j = avlmemi(pnext)) {
828 *(avlist2[j]) = *pnext;
829 avinsert(avlist2[j]);
830 avlist1[j].p = NULL;
831 }
832 *(avlist2[j]) = tav;
833 avinsert(avlist2[j]);
834 avlist1[j].p = NULL;
835 }
836 free((void *)avlist1);
837 free((void *)avlist2);
838 /* compute new sort interval */
839 sortintvl = ambclock - lastsort;
840 if (sortintvl >= MAX_SORT_INTVL/2)
841 sortintvl = MAX_SORT_INTVL;
842 else
843 sortintvl <<= 1; /* wait twice as long next */
844 #ifdef DEBUG
845 eputs("done\n");
846 #endif
847 }
848 if (ambclock >= MAXACLOCK)
849 ambclock = MAXACLOCK/2;
850 lastsort = ambclock;
851 }
852
853
854 #ifdef F_SETLKW
855
856 static void
857 aflock( /* lock/unlock ambient file */
858 int typ
859 )
860 {
861 static struct flock fls; /* static so initialized to zeroes */
862
863 fls.l_type = typ;
864 if (fcntl(fileno(ambfp), F_SETLKW, &fls) < 0)
865 error(SYSTEM, "cannot (un)lock ambient file");
866 }
867
868
869 extern int
870 ambsync(void) /* synchronize ambient file */
871 {
872 long flen;
873 AMBVAL avs;
874 register int n;
875
876 if (nunflshed == 0)
877 return(0);
878 if (lastpos < 0) /* initializing (locked in initambfile) */
879 goto syncend;
880 /* gain exclusive access */
881 aflock(F_WRLCK);
882 /* see if file has grown */
883 if ((flen = lseek(fileno(ambfp), (off_t)0, SEEK_END)) < 0)
884 goto seekerr;
885 if ( (n = flen - lastpos) ) { /* file has grown */
886 if (ambinp == NULL) { /* use duplicate filedes */
887 ambinp = fdopen(dup(fileno(ambfp)), "r");
888 if (ambinp == NULL)
889 error(SYSTEM, "fdopen failed in ambsync");
890 }
891 if (fseek(ambinp, lastpos, 0) < 0)
892 goto seekerr;
893 while (n >= AMBVALSIZ) { /* load contributed values */
894 if (!readambval(&avs, ambinp)) {
895 sprintf(errmsg,
896 "ambient file \"%s\" corrupted near character %ld",
897 ambfile, flen - n);
898 error(WARNING, errmsg);
899 break;
900 }
901 avinsert(avstore(&avs));
902 n -= AMBVALSIZ;
903 }
904 /*** seek always as safety measure
905 if (n) ***/ /* alignment */
906 if (lseek(fileno(ambfp), (off_t)(flen-n), SEEK_SET) < 0)
907 goto seekerr;
908 }
909 #ifdef DEBUG
910 if (ambfp->_ptr - ambfp->_base != nunflshed*AMBVALSIZ) {
911 sprintf(errmsg, "ambient file buffer at %d rather than %d",
912 ambfp->_ptr - ambfp->_base,
913 nunflshed*AMBVALSIZ);
914 error(CONSISTENCY, errmsg);
915 }
916 #endif
917 syncend:
918 n = fflush(ambfp); /* calls write() at last */
919 if ((lastpos = lseek(fileno(ambfp), (off_t)0, SEEK_CUR)) < 0)
920 goto seekerr;
921 aflock(F_UNLCK); /* release file */
922 nunflshed = 0;
923 return(n);
924 seekerr:
925 error(SYSTEM, "seek failed in ambsync");
926 return -1; /* pro forma return */
927 }
928
929 #else
930
931 extern int
932 ambsync(void) /* flush ambient file */
933 {
934 if (nunflshed == 0)
935 return(0);
936 nunflshed = 0;
937 return(fflush(ambfp));
938 }
939
940 #endif