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root/radiance/ray/src/rt/ambient.c
Revision: 2.60
Committed: Sat May 28 22:27:54 2005 UTC (18 years, 11 months ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 2.59: +14 -11 lines
Log Message:
Fixed application of ray weights and coefficients in ambient calculation

File Contents

# Content
1 #ifndef lint
2 static const char RCSid[] = "$Id: ambient.c,v 2.59 2005/05/25 18:06:22 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 aw,
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 < 0.85*aw)
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, aw, 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 awt;
452 FVECT gp, gd;
453 int i;
454
455 amb.weight = AVGREFL; /* compute weight */
456 for (i = al; i-- >= 0; )
457 amb.weight *= AVGREFL;
458 awt = intens(ac)*r->rweight;
459 if (awt < 0.07*amb.weight) /* heuristic override */
460 amb.weight = 1.2*awt;
461 /* compute ambient */
462 amb.rad = doambient(acol, r, ac, amb.weight, gp, gd);
463 if (amb.rad <= FTINY)
464 return(0.0);
465 /* store it */
466 VCOPY(amb.pos, r->rop);
467 VCOPY(amb.dir, r->ron);
468 amb.lvl = al;
469 copycolor(amb.val, acol);
470 VCOPY(amb.gpos, gp);
471 VCOPY(amb.gdir, gd);
472 /* insert into tree */
473 avsave(&amb); /* and save to file */
474 if (rn != r->ron)
475 extambient(acol, &amb, r->rop, rn); /* texture */
476 return(amb.rad);
477 }
478
479
480 extern void
481 extambient( /* extrapolate value at pv, nv */
482 COLOR cr,
483 register AMBVAL *ap,
484 FVECT pv,
485 FVECT nv
486 )
487 {
488 FVECT v1;
489 register int i;
490 double d;
491
492 d = 1.0; /* zeroeth order */
493 /* gradient due to translation */
494 for (i = 0; i < 3; i++)
495 d += ap->gpos[i]*(pv[i]-ap->pos[i]);
496 /* gradient due to rotation */
497 VCROSS(v1, ap->dir, nv);
498 d += DOT(ap->gdir, v1);
499 if (d <= 0.0) {
500 setcolor(cr, 0.0, 0.0, 0.0);
501 return;
502 }
503 copycolor(cr, ap->val);
504 scalecolor(cr, d);
505 }
506
507
508 static void
509 initambfile( /* initialize ambient file */
510 int creat
511 )
512 {
513 extern char *progname, *octname;
514 static char *mybuf = NULL;
515
516 #ifdef F_SETLKW
517 aflock(creat ? F_WRLCK : F_RDLCK);
518 #endif
519 SET_FILE_BINARY(ambfp);
520 if (mybuf == NULL)
521 mybuf = (char *)bmalloc(BUFSIZ+8);
522 setbuf(ambfp, mybuf);
523 if (creat) { /* new file */
524 newheader("RADIANCE", ambfp);
525 fprintf(ambfp, "%s -av %g %g %g -aw %d -ab %d -aa %g ",
526 progname, colval(ambval,RED),
527 colval(ambval,GRN), colval(ambval,BLU),
528 ambvwt, ambounce, ambacc);
529 fprintf(ambfp, "-ad %d -as %d -ar %d ",
530 ambdiv, ambssamp, ambres);
531 if (octname != NULL)
532 printargs(1, &octname, ambfp);
533 else
534 fputc('\n', ambfp);
535 fprintf(ambfp, "SOFTWARE= %s\n", VersionID);
536 fputnow(ambfp);
537 fputformat(AMBFMT, ambfp);
538 putc('\n', ambfp);
539 putambmagic(ambfp);
540 } else if (checkheader(ambfp, AMBFMT, NULL) < 0 || !hasambmagic(ambfp))
541 error(USER, "bad ambient file");
542 }
543
544
545 static void
546 avsave( /* insert and save an ambient value */
547 AMBVAL *av
548 )
549 {
550 avinsert(avstore(av));
551 if (ambfp == NULL)
552 return;
553 if (writambval(av, ambfp) < 0)
554 goto writerr;
555 if (++nunflshed >= AMBFLUSH)
556 if (ambsync() == EOF)
557 goto writerr;
558 return;
559 writerr:
560 error(SYSTEM, "error writing to ambient file");
561 }
562
563
564 static AMBVAL *
565 avstore( /* allocate memory and store aval */
566 register AMBVAL *aval
567 )
568 {
569 register AMBVAL *av;
570 double d;
571
572 if ((av = newambval()) == NULL)
573 error(SYSTEM, "out of memory in avstore");
574 *av = *aval;
575 av->latick = ambclock;
576 av->next = NULL;
577 nambvals++;
578 d = bright(av->val);
579 if (d > FTINY) { /* add to log sum for averaging */
580 avsum += log(d);
581 navsum++;
582 }
583 return(av);
584 }
585
586
587 #define ATALLOCSZ 512 /* #/8 trees to allocate at once */
588
589 static AMBTREE *atfreelist = NULL; /* free ambient tree structures */
590
591
592 static AMBTREE *
593 newambtree(void) /* allocate 8 ambient tree structs */
594 {
595 register AMBTREE *atp, *upperlim;
596
597 if (atfreelist == NULL) { /* get more nodes */
598 atfreelist = (AMBTREE *)malloc(ATALLOCSZ*8*sizeof(AMBTREE));
599 if (atfreelist == NULL)
600 return(NULL);
601 /* link new free list */
602 upperlim = atfreelist + 8*(ATALLOCSZ-1);
603 for (atp = atfreelist; atp < upperlim; atp += 8)
604 atp->kid = atp + 8;
605 atp->kid = NULL;
606 }
607 atp = atfreelist;
608 atfreelist = atp->kid;
609 memset((char *)atp, '\0', 8*sizeof(AMBTREE));
610 return(atp);
611 }
612
613
614 static void
615 freeambtree( /* free 8 ambient tree structs */
616 AMBTREE *atp
617 )
618 {
619 atp->kid = atfreelist;
620 atfreelist = atp;
621 }
622
623
624 static void
625 avinsert( /* insert ambient value in our tree */
626 void *av
627 )
628 {
629 register AMBTREE *at;
630 register AMBVAL *ap;
631 AMBVAL avh;
632 FVECT ck0;
633 double s;
634 int branch;
635 register int i;
636
637 if (((AMBVAL*)av)->rad <= FTINY)
638 error(CONSISTENCY, "zero ambient radius in avinsert");
639 at = &atrunk;
640 VCOPY(ck0, thescene.cuorg);
641 s = thescene.cusize;
642 while (s*(OCTSCALE/2) > ((AMBVAL*)av)->rad*ambacc) {
643 if (at->kid == NULL)
644 if ((at->kid = newambtree()) == NULL)
645 error(SYSTEM, "out of memory in avinsert");
646 s *= 0.5;
647 branch = 0;
648 for (i = 0; i < 3; i++)
649 if (((AMBVAL*)av)->pos[i] > ck0[i] + s) {
650 ck0[i] += s;
651 branch |= 1 << i;
652 }
653 at = at->kid + branch;
654 }
655 avh.next = at->alist; /* order by increasing level */
656 for (ap = &avh; ap->next != NULL; ap = ap->next)
657 if (ap->next->lvl >= ((AMBVAL*)av)->lvl)
658 break;
659 ((AMBVAL*)av)->next = ap->next;
660 ap->next = (AMBVAL*)av;
661 at->alist = avh.next;
662 }
663
664
665 static void
666 unloadatree( /* unload an ambient value tree */
667 register AMBTREE *at,
668 unloadtf_t *f
669 )
670 {
671 register AMBVAL *av;
672 register int i;
673 /* transfer values at this node */
674 for (av = at->alist; av != NULL; av = at->alist) {
675 at->alist = av->next;
676 (*f)(av);
677 }
678 if (at->kid == NULL)
679 return;
680 for (i = 0; i < 8; i++) /* transfer and free children */
681 unloadatree(at->kid+i, f);
682 freeambtree(at->kid);
683 at->kid = NULL;
684 }
685
686
687 static struct avl {
688 AMBVAL *p;
689 unsigned long t;
690 } *avlist1; /* ambient value list with ticks */
691 static AMBVAL **avlist2; /* memory positions for sorting */
692 static int i_avlist; /* index for lists */
693
694 static int alatcmp(const void *av1, const void *av2);
695
696 static void
697 av2list(
698 void *av
699 )
700 {
701 #ifdef DEBUG
702 if (i_avlist >= nambvals)
703 error(CONSISTENCY, "too many ambient values in av2list1");
704 #endif
705 avlist1[i_avlist].p = avlist2[i_avlist] = (AMBVAL*)av;
706 avlist1[i_avlist++].t = ((AMBVAL*)av)->latick;
707 }
708
709
710 static int
711 alatcmp( /* compare ambient values for MRA */
712 const void *av1,
713 const void *av2
714 )
715 {
716 register long lc = ((struct avl *)av2)->t - ((struct avl *)av1)->t;
717 return(lc<0 ? -1 : lc>0 ? 1 : 0);
718 }
719
720
721 /* GW NOTE 2002/10/3:
722 * I used to compare AMBVAL pointers, but found that this was the
723 * cause of a serious consistency error with gcc, since the optimizer
724 * uses some dangerous trick in pointer subtraction that
725 * assumes pointers differ by exact struct size increments.
726 */
727 static int
728 aposcmp( /* compare ambient value positions */
729 const void *avp1,
730 const void *avp2
731 )
732 {
733 register long diff = *(char * const *)avp1 - *(char * const *)avp2;
734 if (diff < 0)
735 return(-1);
736 return(diff > 0);
737 }
738
739 #if 1
740 static int
741 avlmemi( /* find list position from address */
742 AMBVAL *avaddr
743 )
744 {
745 register AMBVAL **avlpp;
746
747 avlpp = (AMBVAL **)bsearch((char *)&avaddr, (char *)avlist2,
748 nambvals, sizeof(AMBVAL *), aposcmp);
749 if (avlpp == NULL)
750 error(CONSISTENCY, "address not found in avlmemi");
751 return(avlpp - avlist2);
752 }
753 #else
754 #define avlmemi(avaddr) ((AMBVAL **)bsearch((char *)&avaddr,(char *)avlist2, \
755 nambvals,sizeof(AMBVAL *),aposcmp) - avlist2)
756 #endif
757
758
759 static void
760 sortambvals( /* resort ambient values */
761 int always
762 )
763 {
764 AMBTREE oldatrunk;
765 AMBVAL tav, *tap, *pnext;
766 register int i, j;
767 /* see if it's time yet */
768 if (!always && (ambclock++ < lastsort+sortintvl ||
769 nambvals < SORT_THRESH))
770 return;
771 /*
772 * The idea here is to minimize memory thrashing
773 * in VM systems by improving reference locality.
774 * We do this by periodically sorting our stored ambient
775 * values in memory in order of most recently to least
776 * recently accessed. This ordering was chosen so that new
777 * ambient values (which tend to be less important) go into
778 * higher memory with the infrequently accessed values.
779 * Since we expect our values to need sorting less
780 * frequently as the process continues, we double our
781 * waiting interval after each call.
782 * This routine is also called by setambacc() with
783 * the "always" parameter set to 1 so that the ambient
784 * tree will be rebuilt with the new accuracy parameter.
785 */
786 if (tracktime) { /* allocate pointer arrays to sort */
787 avlist2 = (AMBVAL **)malloc(nambvals*sizeof(AMBVAL *));
788 avlist1 = (struct avl *)malloc(nambvals*sizeof(struct avl));
789 } else {
790 avlist2 = NULL;
791 avlist1 = NULL;
792 }
793 if (avlist1 == NULL) { /* no time tracking -- rebuild tree? */
794 if (avlist2 != NULL)
795 free((void *)avlist2);
796 if (always) { /* rebuild without sorting */
797 oldatrunk = atrunk;
798 atrunk.alist = NULL;
799 atrunk.kid = NULL;
800 unloadatree(&oldatrunk, avinsert);
801 }
802 } else { /* sort memory by last access time */
803 /*
804 * Sorting memory is tricky because it isn't contiguous.
805 * We have to sort an array of pointers by MRA and also
806 * by memory position. We then copy values in "loops"
807 * to minimize memory hits. Nevertheless, we will visit
808 * everyone at least twice, and this is an expensive process
809 * when we're thrashing, which is when we need to do it.
810 */
811 #ifdef DEBUG
812 sprintf(errmsg, "sorting %u ambient values at ambclock=%lu...",
813 nambvals, ambclock);
814 eputs(errmsg);
815 #endif
816 i_avlist = 0;
817 unloadatree(&atrunk, av2list); /* empty current tree */
818 #ifdef DEBUG
819 if (i_avlist < nambvals)
820 error(CONSISTENCY, "missing ambient values in sortambvals");
821 #endif
822 qsort((char *)avlist1, nambvals, sizeof(struct avl), alatcmp);
823 qsort((char *)avlist2, nambvals, sizeof(AMBVAL *), aposcmp);
824 for (i = 0; i < nambvals; i++) {
825 if (avlist1[i].p == NULL)
826 continue;
827 tap = avlist2[i];
828 tav = *tap;
829 for (j = i; (pnext = avlist1[j].p) != tap;
830 j = avlmemi(pnext)) {
831 *(avlist2[j]) = *pnext;
832 avinsert(avlist2[j]);
833 avlist1[j].p = NULL;
834 }
835 *(avlist2[j]) = tav;
836 avinsert(avlist2[j]);
837 avlist1[j].p = NULL;
838 }
839 free((void *)avlist1);
840 free((void *)avlist2);
841 /* compute new sort interval */
842 sortintvl = ambclock - lastsort;
843 if (sortintvl >= MAX_SORT_INTVL/2)
844 sortintvl = MAX_SORT_INTVL;
845 else
846 sortintvl <<= 1; /* wait twice as long next */
847 #ifdef DEBUG
848 eputs("done\n");
849 #endif
850 }
851 if (ambclock >= MAXACLOCK)
852 ambclock = MAXACLOCK/2;
853 lastsort = ambclock;
854 }
855
856
857 #ifdef F_SETLKW
858
859 static void
860 aflock( /* lock/unlock ambient file */
861 int typ
862 )
863 {
864 static struct flock fls; /* static so initialized to zeroes */
865
866 fls.l_type = typ;
867 if (fcntl(fileno(ambfp), F_SETLKW, &fls) < 0)
868 error(SYSTEM, "cannot (un)lock ambient file");
869 }
870
871
872 extern int
873 ambsync(void) /* synchronize ambient file */
874 {
875 long flen;
876 AMBVAL avs;
877 register int n;
878
879 if (nunflshed == 0)
880 return(0);
881 if (lastpos < 0) /* initializing (locked in initambfile) */
882 goto syncend;
883 /* gain exclusive access */
884 aflock(F_WRLCK);
885 /* see if file has grown */
886 if ((flen = lseek(fileno(ambfp), (off_t)0, SEEK_END)) < 0)
887 goto seekerr;
888 if ( (n = flen - lastpos) ) { /* file has grown */
889 if (ambinp == NULL) { /* use duplicate filedes */
890 ambinp = fdopen(dup(fileno(ambfp)), "r");
891 if (ambinp == NULL)
892 error(SYSTEM, "fdopen failed in ambsync");
893 }
894 if (fseek(ambinp, lastpos, 0) < 0)
895 goto seekerr;
896 while (n >= AMBVALSIZ) { /* load contributed values */
897 if (!readambval(&avs, ambinp)) {
898 sprintf(errmsg,
899 "ambient file \"%s\" corrupted near character %ld",
900 ambfile, flen - n);
901 error(WARNING, errmsg);
902 break;
903 }
904 avinsert(avstore(&avs));
905 n -= AMBVALSIZ;
906 }
907 /*** seek always as safety measure
908 if (n) ***/ /* alignment */
909 if (lseek(fileno(ambfp), (off_t)(flen-n), SEEK_SET) < 0)
910 goto seekerr;
911 }
912 #ifdef DEBUG
913 if (ambfp->_ptr - ambfp->_base != nunflshed*AMBVALSIZ) {
914 sprintf(errmsg, "ambient file buffer at %d rather than %d",
915 ambfp->_ptr - ambfp->_base,
916 nunflshed*AMBVALSIZ);
917 error(CONSISTENCY, errmsg);
918 }
919 #endif
920 syncend:
921 n = fflush(ambfp); /* calls write() at last */
922 if ((lastpos = lseek(fileno(ambfp), (off_t)0, SEEK_CUR)) < 0)
923 goto seekerr;
924 aflock(F_UNLCK); /* release file */
925 nunflshed = 0;
926 return(n);
927 seekerr:
928 error(SYSTEM, "seek failed in ambsync");
929 return -1; /* pro forma return */
930 }
931
932 #else
933
934 extern int
935 ambsync(void) /* flush ambient file */
936 {
937 if (nunflshed == 0)
938 return(0);
939 nunflshed = 0;
940 return(fflush(ambfp));
941 }
942
943 #endif