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root/radiance/ray/src/rt/ambient.c
Revision: 2.57
Committed: Fri Nov 5 17:36:55 2004 UTC (19 years, 5 months ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 2.56: +4 -2 lines
Log Message:
Increased defaults and allowed for compiler override related to -a{E,I} options

File Contents

# Content
1 #ifndef lint
2 static const char RCSid[] = "$Id: ambient.c,v 2.56 2004/03/30 16:13:00 schorsch 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 ambient( /* compute ambient component for ray */
258 COLOR acol,
259 register RAY *r,
260 FVECT nrm
261 )
262 {
263 static int rdepth = 0; /* ambient recursion */
264 double d, l;
265
266 if (ambdiv <= 0) /* no ambient calculation */
267 goto dumbamb;
268 /* check number of bounces */
269 if (rdepth >= ambounce)
270 goto dumbamb;
271 /* check ambient list */
272 if (ambincl != -1 && r->ro != NULL &&
273 ambincl != inset(ambset, r->ro->omod))
274 goto dumbamb;
275
276 if (ambacc <= FTINY) { /* no ambient storage */
277 rdepth++;
278 d = doambient(acol, r, r->rweight, NULL, NULL);
279 rdepth--;
280 if (d <= FTINY)
281 goto dumbamb;
282 return;
283 }
284
285 if (tracktime) /* sort to minimize thrashing */
286 sortambvals(0);
287 /* get ambient value */
288 setcolor(acol, 0.0, 0.0, 0.0);
289 d = sumambient(acol, r, nrm, rdepth,
290 &atrunk, thescene.cuorg, thescene.cusize);
291 if (d > FTINY) {
292 scalecolor(acol, 1.0/d);
293 return;
294 }
295 rdepth++; /* need to cache new value */
296 d = makeambient(acol, r, nrm, rdepth-1);
297 rdepth--;
298 if (d > FTINY)
299 return;
300 dumbamb: /* return global value */
301 copycolor(acol, ambval);
302 if ((ambvwt <= 0) | (navsum == 0))
303 return;
304 l = bright(ambval); /* average in computations */
305 if (l > FTINY) {
306 d = (log(l)*(double)ambvwt + avsum) /
307 (double)(ambvwt + navsum);
308 d = exp(d) / l;
309 scalecolor(acol, d); /* apply color of ambval */
310 } else {
311 d = exp( avsum / (double)navsum );
312 setcolor(acol, d, d, d); /* neutral color */
313 }
314 }
315
316
317 extern double
318 sumambient( /* get interpolated ambient value */
319 COLOR acol,
320 register RAY *r,
321 FVECT rn,
322 int al,
323 AMBTREE *at,
324 FVECT c0,
325 double s
326 )
327 {
328 double d, e1, e2, wt, wsum;
329 COLOR ct;
330 FVECT ck0;
331 int i;
332 register int j;
333 register AMBVAL *av;
334
335 wsum = 0.0;
336 /* do this node */
337 for (av = at->alist; av != NULL; av = av->next) {
338 double rn_dot = -2.0;
339 if (tracktime)
340 av->latick = ambclock;
341 /*
342 * Ambient level test.
343 */
344 if (av->lvl > al) /* list sorted, so this works */
345 break;
346 if (av->weight < r->rweight-FTINY)
347 continue;
348 /*
349 * Ambient radius test.
350 */
351 d = av->pos[0] - r->rop[0];
352 e1 = d * d;
353 d = av->pos[1] - r->rop[1];
354 e1 += d * d;
355 d = av->pos[2] - r->rop[2];
356 e1 += d * d;
357 e1 /= av->rad * av->rad;
358 if (e1 > ambacc*ambacc*1.21)
359 continue;
360 /*
361 * Direction test using closest normal.
362 */
363 d = DOT(av->dir, r->ron);
364 if (rn != r->ron) {
365 rn_dot = DOT(av->dir, rn);
366 if (rn_dot > 1.0-FTINY)
367 rn_dot = 1.0-FTINY;
368 if (rn_dot >= d-FTINY) {
369 d = rn_dot;
370 rn_dot = -2.0;
371 }
372 }
373 e2 = (1.0 - d) * r->rweight;
374 if (e2 < 0.0) e2 = 0.0;
375 if (e1 + e2 > ambacc*ambacc*1.21)
376 continue;
377 /*
378 * Ray behind test.
379 */
380 d = 0.0;
381 for (j = 0; j < 3; j++)
382 d += (r->rop[j] - av->pos[j]) *
383 (av->dir[j] + r->ron[j]);
384 if (d*0.5 < -minarad*ambacc-.001)
385 continue;
386 /*
387 * Jittering final test reduces image artifacts.
388 */
389 e1 = sqrt(e1);
390 e2 = sqrt(e2);
391 wt = e1 + e2;
392 if (wt > ambacc*(.9+.2*urand(9015+samplendx)))
393 continue;
394 /*
395 * Recompute directional error using perturbed normal
396 */
397 if (rn_dot > 0.0) {
398 e2 = sqrt((1.0 - rn_dot)*r->rweight);
399 wt = e1 + e2;
400 }
401 if (wt <= 1e-3)
402 wt = 1e3;
403 else
404 wt = 1.0 / wt;
405 wsum += wt;
406 extambient(ct, av, r->rop, rn);
407 scalecolor(ct, wt);
408 addcolor(acol, ct);
409 }
410 if (at->kid == NULL)
411 return(wsum);
412 /* do children */
413 s *= 0.5;
414 for (i = 0; i < 8; i++) {
415 for (j = 0; j < 3; j++) {
416 ck0[j] = c0[j];
417 if (1<<j & i)
418 ck0[j] += s;
419 if (r->rop[j] < ck0[j] - OCTSCALE*s)
420 break;
421 if (r->rop[j] > ck0[j] + (1.0+OCTSCALE)*s)
422 break;
423 }
424 if (j == 3)
425 wsum += sumambient(acol, r, rn, al, at->kid+i, ck0, s);
426 }
427 return(wsum);
428 }
429
430
431 extern double
432 makeambient( /* make a new ambient value */
433 COLOR acol,
434 register RAY *r,
435 FVECT rn,
436 int al
437 )
438 {
439 AMBVAL amb;
440 FVECT gp, gd;
441 /* compute weight */
442 amb.weight = pow(AVGREFL, (double)al);
443 if (r->rweight < 0.1*amb.weight) /* heuristic */
444 amb.weight = r->rweight;
445 /* compute ambient */
446 amb.rad = doambient(acol, r, amb.weight, gp, gd);
447 if (amb.rad <= FTINY)
448 return(0.0);
449 /* store it */
450 VCOPY(amb.pos, r->rop);
451 VCOPY(amb.dir, r->ron);
452 amb.lvl = al;
453 copycolor(amb.val, acol);
454 VCOPY(amb.gpos, gp);
455 VCOPY(amb.gdir, gd);
456 /* insert into tree */
457 avsave(&amb); /* and save to file */
458 if (rn != r->ron)
459 extambient(acol, &amb, r->rop, rn); /* texture */
460 return(amb.rad);
461 }
462
463
464 extern void
465 extambient( /* extrapolate value at pv, nv */
466 COLOR cr,
467 register AMBVAL *ap,
468 FVECT pv,
469 FVECT nv
470 )
471 {
472 FVECT v1;
473 register int i;
474 double d;
475
476 d = 1.0; /* zeroeth order */
477 /* gradient due to translation */
478 for (i = 0; i < 3; i++)
479 d += ap->gpos[i]*(pv[i]-ap->pos[i]);
480 /* gradient due to rotation */
481 VCROSS(v1, ap->dir, nv);
482 d += DOT(ap->gdir, v1);
483 if (d <= 0.0) {
484 setcolor(cr, 0.0, 0.0, 0.0);
485 return;
486 }
487 copycolor(cr, ap->val);
488 scalecolor(cr, d);
489 }
490
491
492 static void
493 initambfile( /* initialize ambient file */
494 int creat
495 )
496 {
497 extern char *progname, *octname;
498 static char *mybuf = NULL;
499
500 #ifdef F_SETLKW
501 aflock(creat ? F_WRLCK : F_RDLCK);
502 #endif
503 SET_FILE_BINARY(ambfp);
504 if (mybuf == NULL)
505 mybuf = (char *)bmalloc(BUFSIZ+8);
506 setbuf(ambfp, mybuf);
507 if (creat) { /* new file */
508 newheader("RADIANCE", ambfp);
509 fprintf(ambfp, "%s -av %g %g %g -aw %d -ab %d -aa %g ",
510 progname, colval(ambval,RED),
511 colval(ambval,GRN), colval(ambval,BLU),
512 ambvwt, ambounce, ambacc);
513 fprintf(ambfp, "-ad %d -as %d -ar %d ",
514 ambdiv, ambssamp, ambres);
515 if (octname != NULL)
516 printargs(1, &octname, ambfp);
517 else
518 fputc('\n', ambfp);
519 fprintf(ambfp, "SOFTWARE= %s\n", VersionID);
520 fputnow(ambfp);
521 fputformat(AMBFMT, ambfp);
522 putc('\n', ambfp);
523 putambmagic(ambfp);
524 } else if (checkheader(ambfp, AMBFMT, NULL) < 0 || !hasambmagic(ambfp))
525 error(USER, "bad ambient file");
526 }
527
528
529 static void
530 avsave( /* insert and save an ambient value */
531 AMBVAL *av
532 )
533 {
534 avinsert(avstore(av));
535 if (ambfp == NULL)
536 return;
537 if (writambval(av, ambfp) < 0)
538 goto writerr;
539 if (++nunflshed >= AMBFLUSH)
540 if (ambsync() == EOF)
541 goto writerr;
542 return;
543 writerr:
544 error(SYSTEM, "error writing to ambient file");
545 }
546
547
548 static AMBVAL *
549 avstore( /* allocate memory and store aval */
550 register AMBVAL *aval
551 )
552 {
553 register AMBVAL *av;
554 double d;
555
556 if ((av = newambval()) == NULL)
557 error(SYSTEM, "out of memory in avstore");
558 *av = *aval;
559 av->latick = ambclock;
560 av->next = NULL;
561 nambvals++;
562 d = bright(av->val);
563 if (d > FTINY) { /* add to log sum for averaging */
564 avsum += log(d);
565 navsum++;
566 }
567 return(av);
568 }
569
570
571 #define ATALLOCSZ 512 /* #/8 trees to allocate at once */
572
573 static AMBTREE *atfreelist = NULL; /* free ambient tree structures */
574
575
576 static AMBTREE *
577 newambtree(void) /* allocate 8 ambient tree structs */
578 {
579 register AMBTREE *atp, *upperlim;
580
581 if (atfreelist == NULL) { /* get more nodes */
582 atfreelist = (AMBTREE *)malloc(ATALLOCSZ*8*sizeof(AMBTREE));
583 if (atfreelist == NULL)
584 return(NULL);
585 /* link new free list */
586 upperlim = atfreelist + 8*(ATALLOCSZ-1);
587 for (atp = atfreelist; atp < upperlim; atp += 8)
588 atp->kid = atp + 8;
589 atp->kid = NULL;
590 }
591 atp = atfreelist;
592 atfreelist = atp->kid;
593 memset((char *)atp, '\0', 8*sizeof(AMBTREE));
594 return(atp);
595 }
596
597
598 static void
599 freeambtree( /* free 8 ambient tree structs */
600 AMBTREE *atp
601 )
602 {
603 atp->kid = atfreelist;
604 atfreelist = atp;
605 }
606
607
608 static void
609 avinsert( /* insert ambient value in our tree */
610 void *av
611 )
612 {
613 register AMBTREE *at;
614 register AMBVAL *ap;
615 AMBVAL avh;
616 FVECT ck0;
617 double s;
618 int branch;
619 register int i;
620
621 if (((AMBVAL*)av)->rad <= FTINY)
622 error(CONSISTENCY, "zero ambient radius in avinsert");
623 at = &atrunk;
624 VCOPY(ck0, thescene.cuorg);
625 s = thescene.cusize;
626 while (s*(OCTSCALE/2) > ((AMBVAL*)av)->rad*ambacc) {
627 if (at->kid == NULL)
628 if ((at->kid = newambtree()) == NULL)
629 error(SYSTEM, "out of memory in avinsert");
630 s *= 0.5;
631 branch = 0;
632 for (i = 0; i < 3; i++)
633 if (((AMBVAL*)av)->pos[i] > ck0[i] + s) {
634 ck0[i] += s;
635 branch |= 1 << i;
636 }
637 at = at->kid + branch;
638 }
639 avh.next = at->alist; /* order by increasing level */
640 for (ap = &avh; ap->next != NULL; ap = ap->next)
641 if (ap->next->lvl >= ((AMBVAL*)av)->lvl)
642 break;
643 ((AMBVAL*)av)->next = ap->next;
644 ap->next = (AMBVAL*)av;
645 at->alist = avh.next;
646 }
647
648
649 static void
650 unloadatree( /* unload an ambient value tree */
651 register AMBTREE *at,
652 unloadtf_t *f
653 )
654 {
655 register AMBVAL *av;
656 register int i;
657 /* transfer values at this node */
658 for (av = at->alist; av != NULL; av = at->alist) {
659 at->alist = av->next;
660 (*f)(av);
661 }
662 if (at->kid == NULL)
663 return;
664 for (i = 0; i < 8; i++) /* transfer and free children */
665 unloadatree(at->kid+i, f);
666 freeambtree(at->kid);
667 at->kid = NULL;
668 }
669
670
671 static struct avl {
672 AMBVAL *p;
673 unsigned long t;
674 } *avlist1; /* ambient value list with ticks */
675 static AMBVAL **avlist2; /* memory positions for sorting */
676 static int i_avlist; /* index for lists */
677
678 static int alatcmp(const void *av1, const void *av2);
679
680 static void
681 av2list(
682 void *av
683 )
684 {
685 #ifdef DEBUG
686 if (i_avlist >= nambvals)
687 error(CONSISTENCY, "too many ambient values in av2list1");
688 #endif
689 avlist1[i_avlist].p = avlist2[i_avlist] = (AMBVAL*)av;
690 avlist1[i_avlist++].t = ((AMBVAL*)av)->latick;
691 }
692
693
694 static int
695 alatcmp( /* compare ambient values for MRA */
696 const void *av1,
697 const void *av2
698 )
699 {
700 register long lc = ((struct avl *)av2)->t - ((struct avl *)av1)->t;
701 return(lc<0 ? -1 : lc>0 ? 1 : 0);
702 }
703
704
705 /* GW NOTE 2002/10/3:
706 * I used to compare AMBVAL pointers, but found that this was the
707 * cause of a serious consistency error with gcc, since the optimizer
708 * uses some dangerous trick in pointer subtraction that
709 * assumes pointers differ by exact struct size increments.
710 */
711 static int
712 aposcmp( /* compare ambient value positions */
713 const void *avp1,
714 const void *avp2
715 )
716 {
717 register long diff = *(char * const *)avp1 - *(char * const *)avp2;
718 if (diff < 0)
719 return(-1);
720 return(diff > 0);
721 }
722
723 #if 1
724 static int
725 avlmemi( /* find list position from address */
726 AMBVAL *avaddr
727 )
728 {
729 register AMBVAL **avlpp;
730
731 avlpp = (AMBVAL **)bsearch((char *)&avaddr, (char *)avlist2,
732 nambvals, sizeof(AMBVAL *), aposcmp);
733 if (avlpp == NULL)
734 error(CONSISTENCY, "address not found in avlmemi");
735 return(avlpp - avlist2);
736 }
737 #else
738 #define avlmemi(avaddr) ((AMBVAL **)bsearch((char *)&avaddr,(char *)avlist2, \
739 nambvals,sizeof(AMBVAL *),aposcmp) - avlist2)
740 #endif
741
742
743 static void
744 sortambvals( /* resort ambient values */
745 int always
746 )
747 {
748 AMBTREE oldatrunk;
749 AMBVAL tav, *tap, *pnext;
750 register int i, j;
751 /* see if it's time yet */
752 if (!always && (ambclock++ < lastsort+sortintvl ||
753 nambvals < SORT_THRESH))
754 return;
755 /*
756 * The idea here is to minimize memory thrashing
757 * in VM systems by improving reference locality.
758 * We do this by periodically sorting our stored ambient
759 * values in memory in order of most recently to least
760 * recently accessed. This ordering was chosen so that new
761 * ambient values (which tend to be less important) go into
762 * higher memory with the infrequently accessed values.
763 * Since we expect our values to need sorting less
764 * frequently as the process continues, we double our
765 * waiting interval after each call.
766 * This routine is also called by setambacc() with
767 * the "always" parameter set to 1 so that the ambient
768 * tree will be rebuilt with the new accuracy parameter.
769 */
770 if (tracktime) { /* allocate pointer arrays to sort */
771 avlist2 = (AMBVAL **)malloc(nambvals*sizeof(AMBVAL *));
772 avlist1 = (struct avl *)malloc(nambvals*sizeof(struct avl));
773 } else {
774 avlist2 = NULL;
775 avlist1 = NULL;
776 }
777 if (avlist1 == NULL) { /* no time tracking -- rebuild tree? */
778 if (avlist2 != NULL)
779 free((void *)avlist2);
780 if (always) { /* rebuild without sorting */
781 oldatrunk = atrunk;
782 atrunk.alist = NULL;
783 atrunk.kid = NULL;
784 unloadatree(&oldatrunk, avinsert);
785 }
786 } else { /* sort memory by last access time */
787 /*
788 * Sorting memory is tricky because it isn't contiguous.
789 * We have to sort an array of pointers by MRA and also
790 * by memory position. We then copy values in "loops"
791 * to minimize memory hits. Nevertheless, we will visit
792 * everyone at least twice, and this is an expensive process
793 * when we're thrashing, which is when we need to do it.
794 */
795 #ifdef DEBUG
796 sprintf(errmsg, "sorting %u ambient values at ambclock=%lu...",
797 nambvals, ambclock);
798 eputs(errmsg);
799 #endif
800 i_avlist = 0;
801 unloadatree(&atrunk, av2list); /* empty current tree */
802 #ifdef DEBUG
803 if (i_avlist < nambvals)
804 error(CONSISTENCY, "missing ambient values in sortambvals");
805 #endif
806 qsort((char *)avlist1, nambvals, sizeof(struct avl), alatcmp);
807 qsort((char *)avlist2, nambvals, sizeof(AMBVAL *), aposcmp);
808 for (i = 0; i < nambvals; i++) {
809 if (avlist1[i].p == NULL)
810 continue;
811 tap = avlist2[i];
812 tav = *tap;
813 for (j = i; (pnext = avlist1[j].p) != tap;
814 j = avlmemi(pnext)) {
815 *(avlist2[j]) = *pnext;
816 avinsert(avlist2[j]);
817 avlist1[j].p = NULL;
818 }
819 *(avlist2[j]) = tav;
820 avinsert(avlist2[j]);
821 avlist1[j].p = NULL;
822 }
823 free((void *)avlist1);
824 free((void *)avlist2);
825 /* compute new sort interval */
826 sortintvl = ambclock - lastsort;
827 if (sortintvl >= MAX_SORT_INTVL/2)
828 sortintvl = MAX_SORT_INTVL;
829 else
830 sortintvl <<= 1; /* wait twice as long next */
831 #ifdef DEBUG
832 eputs("done\n");
833 #endif
834 }
835 if (ambclock >= MAXACLOCK)
836 ambclock = MAXACLOCK/2;
837 lastsort = ambclock;
838 }
839
840
841 #ifdef F_SETLKW
842
843 static void
844 aflock( /* lock/unlock ambient file */
845 int typ
846 )
847 {
848 static struct flock fls; /* static so initialized to zeroes */
849
850 fls.l_type = typ;
851 if (fcntl(fileno(ambfp), F_SETLKW, &fls) < 0)
852 error(SYSTEM, "cannot (un)lock ambient file");
853 }
854
855
856 extern int
857 ambsync(void) /* synchronize ambient file */
858 {
859 long flen;
860 AMBVAL avs;
861 register int n;
862
863 if (nunflshed == 0)
864 return(0);
865 if (lastpos < 0) /* initializing (locked in initambfile) */
866 goto syncend;
867 /* gain exclusive access */
868 aflock(F_WRLCK);
869 /* see if file has grown */
870 if ((flen = lseek(fileno(ambfp), (off_t)0, SEEK_END)) < 0)
871 goto seekerr;
872 if ( (n = flen - lastpos) ) { /* file has grown */
873 if (ambinp == NULL) { /* use duplicate filedes */
874 ambinp = fdopen(dup(fileno(ambfp)), "r");
875 if (ambinp == NULL)
876 error(SYSTEM, "fdopen failed in ambsync");
877 }
878 if (fseek(ambinp, lastpos, 0) < 0)
879 goto seekerr;
880 while (n >= AMBVALSIZ) { /* load contributed values */
881 if (!readambval(&avs, ambinp)) {
882 sprintf(errmsg,
883 "ambient file \"%s\" corrupted near character %ld",
884 ambfile, flen - n);
885 error(WARNING, errmsg);
886 break;
887 }
888 avinsert(avstore(&avs));
889 n -= AMBVALSIZ;
890 }
891 /*** seek always as safety measure
892 if (n) ***/ /* alignment */
893 if (lseek(fileno(ambfp), (off_t)(flen-n), SEEK_SET) < 0)
894 goto seekerr;
895 }
896 #ifdef DEBUG
897 if (ambfp->_ptr - ambfp->_base != nunflshed*AMBVALSIZ) {
898 sprintf(errmsg, "ambient file buffer at %d rather than %d",
899 ambfp->_ptr - ambfp->_base,
900 nunflshed*AMBVALSIZ);
901 error(CONSISTENCY, errmsg);
902 }
903 #endif
904 syncend:
905 n = fflush(ambfp); /* calls write() at last */
906 if ((lastpos = lseek(fileno(ambfp), (off_t)0, SEEK_CUR)) < 0)
907 goto seekerr;
908 aflock(F_UNLCK); /* release file */
909 nunflshed = 0;
910 return(n);
911 seekerr:
912 error(SYSTEM, "seek failed in ambsync");
913 return -1; /* pro forma return */
914 }
915
916 #else
917
918 extern int
919 ambsync(void) /* flush ambient file */
920 {
921 if (nunflshed == 0)
922 return(0);
923 nunflshed = 0;
924 return(fflush(ambfp));
925 }
926
927 #endif