#ifndef lint
static const char RCSid[] = "$Id: ambient.c,v 2.47 2003/02/22 02:07:28 greg Exp $";
#endif
/*
* ambient.c - routines dealing with ambient (inter-reflected) component.
*
* Declarations of external symbols in ambient.h
*/
/* ====================================================================
* The Radiance Software License, Version 1.0
*
* Copyright (c) 1990 - 2002 The Regents of the University of California,
* through Lawrence Berkeley National Laboratory. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes Radiance software
* (http://radsite.lbl.gov/)
* developed by the Lawrence Berkeley National Laboratory
* (http://www.lbl.gov/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Radiance," "Lawrence Berkeley National Laboratory"
* and "The Regents of the University of California" must
* not be used to endorse or promote products derived from this
* software without prior written permission. For written
* permission, please contact radiance@radsite.lbl.gov.
*
* 5. Products derived from this software may not be called "Radiance",
* nor may "Radiance" appear in their name, without prior written
* permission of Lawrence Berkeley National Laboratory.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL Lawrence Berkeley National Laboratory OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of Lawrence Berkeley National Laboratory. For more
* information on Lawrence Berkeley National Laboratory, please see
* .
*/
#include "ray.h"
#include "otypes.h"
#include "ambient.h"
#include "random.h"
#ifndef OCTSCALE
#define OCTSCALE 1.0 /* ceil((valid rad.)/(cube size)) */
#endif
extern char *shm_boundary; /* memory sharing boundary */
#define MAXASET 511 /* maximum number of elements in ambient set */
OBJECT ambset[MAXASET+1]={0}; /* ambient include/exclude set */
double maxarad; /* maximum ambient radius */
double minarad; /* minimum ambient radius */
static AMBTREE atrunk; /* our ambient trunk node */
static FILE *ambfp = NULL; /* ambient file pointer */
static int nunflshed = 0; /* number of unflushed ambient values */
#ifndef SORT_THRESH
#ifdef BIGMEM
#define SORT_THRESH ((9L<<20)/sizeof(AMBVAL))
#else
#define SORT_THRESH ((3L<<20)/sizeof(AMBVAL))
#endif
#endif
#ifndef SORT_INTVL
#define SORT_INTVL (SORT_THRESH<<1)
#endif
#ifndef MAX_SORT_INTVL
#define MAX_SORT_INTVL (SORT_INTVL<<6)
#endif
static double avsum = 0.; /* computed ambient value sum (log) */
static unsigned int navsum = 0; /* number of values in avsum */
static unsigned int nambvals = 0; /* total number of indirect values */
static unsigned int nambshare = 0; /* number of values from file */
static unsigned long ambclock = 0; /* ambient access clock */
static unsigned long lastsort = 0; /* time of last value sort */
static long sortintvl = SORT_INTVL; /* time until next sort */
static FILE *ambinp = NULL; /* auxiliary file for input */
static long lastpos = -1; /* last flush position */
#define MAXACLOCK (1L<<30) /* clock turnover value */
/*
* Track access times unless we are sharing ambient values
* through memory on a multiprocessor, when we want to avoid
* claiming our own memory (copy on write). Go ahead anyway
* if more than two thirds of our values are unshared.
* Compile with -Dtracktime=0 to turn this code off.
*/
#ifndef tracktime
#define tracktime (shm_boundary == NULL || nambvals > 3*nambshare)
#endif
#define AMBFLUSH (BUFSIZ/AMBVALSIZ)
#define newambval() (AMBVAL *)malloc(sizeof(AMBVAL))
#define freeav(av) free((void *)av);
static void initambfile(), avsave(), avinsert(), sortambvals(), unloadatree();
static int avlmemi();
static AMBVAL *avstore();
#ifdef F_SETLKW
static void aflock();
#endif
void
setambres(ar) /* set ambient resolution */
int ar;
{
ambres = ar < 0 ? 0 : ar; /* may be done already */
/* set min & max radii */
if (ar <= 0) {
minarad = 0;
maxarad = thescene.cusize / 2.0;
} else {
minarad = thescene.cusize / ar;
maxarad = 64 * minarad; /* heuristic */
if (maxarad > thescene.cusize / 2.0)
maxarad = thescene.cusize / 2.0;
}
if (minarad <= FTINY)
minarad = 10*FTINY;
if (maxarad <= minarad)
maxarad = 64 * minarad;
}
void
setambacc(newa) /* set ambient accuracy */
double newa;
{
double ambdiff;
if (newa < 0.0)
newa = 0.0;
ambdiff = fabs(newa - ambacc);
if (ambdiff >= .01 && (ambacc = newa) > FTINY && nambvals > 0)
sortambvals(1); /* rebuild tree */
}
void
setambient() /* initialize calculation */
{
int readonly = 0;
long pos, flen;
AMBVAL amb;
/* make sure we're fresh */
ambdone();
/* init ambient limits */
setambres(ambres);
setambacc(ambacc);
if (ambfile == NULL || !ambfile[0])
return;
if (ambacc <= FTINY) {
sprintf(errmsg, "zero ambient accuracy so \"%s\" not opened",
ambfile);
error(WARNING, errmsg);
return;
}
/* open ambient file */
if ((ambfp = fopen(ambfile, "r+")) == NULL)
readonly = (ambfp = fopen(ambfile, "r")) != NULL;
if (ambfp != NULL) {
initambfile(0); /* file exists */
pos = ftell(ambfp);
while (readambval(&amb, ambfp))
avinsert(avstore(&amb));
nambshare = nambvals; /* share loaded values */
if (readonly) {
sprintf(errmsg,
"loaded %u values from read-only ambient file",
nambvals);
error(WARNING, errmsg);
fclose(ambfp); /* close file so no writes */
ambfp = NULL;
return; /* avoid ambsync() */
}
/* align file pointer */
pos += (long)nambvals*AMBVALSIZ;
flen = lseek(fileno(ambfp), (off_t)0L, 2);
if (flen != pos) {
sprintf(errmsg,
"ignoring last %ld values in ambient file (corrupted)",
(flen - pos)/AMBVALSIZ);
error(WARNING, errmsg);
fseek(ambfp, pos, 0);
ftruncate(fileno(ambfp), (off_t)pos);
}
} else if ((ambfp = fopen(ambfile, "w+")) != NULL) {
initambfile(1); /* else create new file */
} else {
sprintf(errmsg, "cannot open ambient file \"%s\"", ambfile);
error(SYSTEM, errmsg);
}
nunflshed++; /* lie */
ambsync();
}
void
ambdone() /* close ambient file and free memory */
{
if (ambfp != NULL) { /* close ambient file */
ambsync();
fclose(ambfp);
ambfp = NULL;
if (ambinp != NULL) {
fclose(ambinp);
ambinp = NULL;
}
lastpos = -1;
}
/* free ambient tree */
unloadatree(&atrunk, free);
/* reset state variables */
avsum = 0.;
navsum = 0;
nambvals = 0;
nambshare = 0;
ambclock = 0;
lastsort = 0;
sortintvl = SORT_INTVL;
}
void
ambnotify(obj) /* record new modifier */
OBJECT obj;
{
static int hitlimit = 0;
register OBJREC *o;
register char **amblp;
if (obj == OVOID) { /* starting over */
ambset[0] = 0;
hitlimit = 0;
return;
}
o = objptr(obj);
if (hitlimit || !ismodifier(o->otype))
return;
for (amblp = amblist; *amblp != NULL; amblp++)
if (!strcmp(o->oname, *amblp)) {
if (ambset[0] >= MAXASET) {
error(WARNING, "too many modifiers in ambient list");
hitlimit++;
return; /* should this be fatal? */
}
insertelem(ambset, obj);
return;
}
}
void
ambient(acol, r, nrm) /* compute ambient component for ray */
COLOR acol;
register RAY *r;
FVECT nrm;
{
static int rdepth = 0; /* ambient recursion */
double d, l;
if (ambdiv <= 0) /* no ambient calculation */
goto dumbamb;
/* check number of bounces */
if (rdepth >= ambounce)
goto dumbamb;
/* check ambient list */
if (ambincl != -1 && r->ro != NULL &&
ambincl != inset(ambset, r->ro->omod))
goto dumbamb;
if (ambacc <= FTINY) { /* no ambient storage */
rdepth++;
d = doambient(acol, r, r->rweight, NULL, NULL);
rdepth--;
if (d <= FTINY)
goto dumbamb;
return;
}
if (tracktime) /* sort to minimize thrashing */
sortambvals(0);
/* get ambient value */
setcolor(acol, 0.0, 0.0, 0.0);
d = sumambient(acol, r, nrm, rdepth,
&atrunk, thescene.cuorg, thescene.cusize);
if (d > FTINY) {
scalecolor(acol, 1.0/d);
return;
}
rdepth++; /* need to cache new value */
d = makeambient(acol, r, nrm, rdepth-1);
rdepth--;
if (d > FTINY)
return;
dumbamb: /* return global value */
copycolor(acol, ambval);
if (ambvwt <= 0 | navsum == 0)
return;
l = bright(ambval); /* average in computations */
if (l > FTINY) {
d = (log(l)*(double)ambvwt + avsum) /
(double)(ambvwt + navsum);
d = exp(d) / l;
scalecolor(acol, d); /* apply color of ambval */
} else {
d = exp( avsum / (double)navsum );
setcolor(acol, d, d, d); /* neutral color */
}
}
double
sumambient(acol, r, rn, al, at, c0, s) /* get interpolated ambient value */
COLOR acol;
register RAY *r;
FVECT rn;
int al;
AMBTREE *at;
FVECT c0;
double s;
{
double d, e1, e2, wt, wsum;
COLOR ct;
FVECT ck0;
int i;
register int j;
register AMBVAL *av;
wsum = 0.0;
/* do this node */
for (av = at->alist; av != NULL; av = av->next) {
double rn_dot = -2.0;
if (tracktime)
av->latick = ambclock;
/*
* Ambient level test.
*/
if (av->lvl > al) /* list sorted, so this works */
break;
if (av->weight < r->rweight-FTINY)
continue;
/*
* Ambient radius test.
*/
d = av->pos[0] - r->rop[0];
e1 = d * d;
d = av->pos[1] - r->rop[1];
e1 += d * d;
d = av->pos[2] - r->rop[2];
e1 += d * d;
e1 /= av->rad * av->rad;
if (e1 > ambacc*ambacc*1.21)
continue;
/*
* Direction test using closest normal.
*/
d = DOT(av->dir, r->ron);
if (rn != r->ron) {
rn_dot = DOT(av->dir, rn);
if (rn_dot > 1.0-FTINY)
rn_dot = 1.0-FTINY;
if (rn_dot >= d-FTINY) {
d = rn_dot;
rn_dot = -2.0;
}
}
e2 = (1.0 - d) * r->rweight;
if (e2 < 0.0) e2 = 0.0;
if (e1 + e2 > ambacc*ambacc*1.21)
continue;
/*
* Ray behind test.
*/
d = 0.0;
for (j = 0; j < 3; j++)
d += (r->rop[j] - av->pos[j]) *
(av->dir[j] + r->ron[j]);
if (d*0.5 < -minarad*ambacc-.001)
continue;
/*
* Jittering final test reduces image artifacts.
*/
e1 = sqrt(e1);
e2 = sqrt(e2);
wt = e1 + e2;
if (wt > ambacc*(.9+.2*urand(9015+samplendx)))
continue;
/*
* Recompute directional error using perturbed normal
*/
if (rn_dot > 0.0) {
e2 = sqrt((1.0 - rn_dot)*r->rweight);
wt = e1 + e2;
}
if (wt <= 1e-3)
wt = 1e3;
else
wt = 1.0 / wt;
wsum += wt;
extambient(ct, av, r->rop, rn);
scalecolor(ct, wt);
addcolor(acol, ct);
}
if (at->kid == NULL)
return(wsum);
/* do children */
s *= 0.5;
for (i = 0; i < 8; i++) {
for (j = 0; j < 3; j++) {
ck0[j] = c0[j];
if (1<rop[j] < ck0[j] - OCTSCALE*s)
break;
if (r->rop[j] > ck0[j] + (1.0+OCTSCALE)*s)
break;
}
if (j == 3)
wsum += sumambient(acol, r, rn, al, at->kid+i, ck0, s);
}
return(wsum);
}
double
makeambient(acol, r, rn, al) /* make a new ambient value */
COLOR acol;
register RAY *r;
FVECT rn;
int al;
{
AMBVAL amb;
FVECT gp, gd;
/* compute weight */
amb.weight = pow(AVGREFL, (double)al);
if (r->rweight < 0.1*amb.weight) /* heuristic */
amb.weight = r->rweight;
/* compute ambient */
amb.rad = doambient(acol, r, amb.weight, gp, gd);
if (amb.rad <= FTINY)
return(0.0);
/* store it */
VCOPY(amb.pos, r->rop);
VCOPY(amb.dir, r->ron);
amb.lvl = al;
copycolor(amb.val, acol);
VCOPY(amb.gpos, gp);
VCOPY(amb.gdir, gd);
/* insert into tree */
avsave(&amb); /* and save to file */
if (rn != r->ron)
extambient(acol, &amb, r->rop, rn); /* texture */
return(amb.rad);
}
void
extambient(cr, ap, pv, nv) /* extrapolate value at pv, nv */
COLOR cr;
register AMBVAL *ap;
FVECT pv, nv;
{
FVECT v1;
register int i;
double d;
d = 1.0; /* zeroeth order */
/* gradient due to translation */
for (i = 0; i < 3; i++)
d += ap->gpos[i]*(pv[i]-ap->pos[i]);
/* gradient due to rotation */
VCROSS(v1, ap->dir, nv);
d += DOT(ap->gdir, v1);
if (d <= 0.0) {
setcolor(cr, 0.0, 0.0, 0.0);
return;
}
copycolor(cr, ap->val);
scalecolor(cr, d);
}
static void
initambfile(creat) /* initialize ambient file */
int creat;
{
extern char *progname, *octname;
static char *mybuf = NULL;
#ifdef F_SETLKW
aflock(creat ? F_WRLCK : F_RDLCK);
#endif
#ifdef MSDOS
setmode(fileno(ambfp), O_BINARY);
#endif
if (mybuf == NULL)
mybuf = (char *)bmalloc(BUFSIZ+8);
setbuf(ambfp, mybuf);
if (creat) { /* new file */
newheader("RADIANCE", ambfp);
fprintf(ambfp, "%s -av %g %g %g -aw %d -ab %d -aa %g ",
progname, colval(ambval,RED),
colval(ambval,GRN), colval(ambval,BLU),
ambvwt, ambounce, ambacc);
fprintf(ambfp, "-ad %d -as %d -ar %d ",
ambdiv, ambssamp, ambres);
if (octname != NULL)
printargs(1, &octname, ambfp);
else
fputc('\n', ambfp);
fprintf(ambfp, "SOFTWARE= %s\n", VersionID);
fputnow(ambfp);
fputformat(AMBFMT, ambfp);
putc('\n', ambfp);
putambmagic(ambfp);
} else if (checkheader(ambfp, AMBFMT, NULL) < 0 || !hasambmagic(ambfp))
error(USER, "bad ambient file");
}
static void
avsave(av) /* insert and save an ambient value */
AMBVAL *av;
{
avinsert(avstore(av));
if (ambfp == NULL)
return;
if (writambval(av, ambfp) < 0)
goto writerr;
if (++nunflshed >= AMBFLUSH)
if (ambsync() == EOF)
goto writerr;
return;
writerr:
error(SYSTEM, "error writing to ambient file");
}
static AMBVAL *
avstore(aval) /* allocate memory and store aval */
register AMBVAL *aval;
{
register AMBVAL *av;
double d;
if ((av = newambval()) == NULL)
error(SYSTEM, "out of memory in avstore");
copystruct(av, aval);
av->latick = ambclock;
av->next = NULL;
nambvals++;
d = bright(av->val);
if (d > FTINY) { /* add to log sum for averaging */
avsum += log(d);
navsum++;
}
return(av);
}
#define ATALLOCSZ 512 /* #/8 trees to allocate at once */
static AMBTREE *atfreelist = NULL; /* free ambient tree structures */
static AMBTREE *
newambtree() /* allocate 8 ambient tree structs */
{
register AMBTREE *atp, *upperlim;
if (atfreelist == NULL) { /* get more nodes */
atfreelist = (AMBTREE *)malloc(ATALLOCSZ*8*sizeof(AMBTREE));
if (atfreelist == NULL)
return(NULL);
/* link new free list */
upperlim = atfreelist + 8*(ATALLOCSZ-1);
for (atp = atfreelist; atp < upperlim; atp += 8)
atp->kid = atp + 8;
atp->kid = NULL;
}
atp = atfreelist;
atfreelist = atp->kid;
bzero((char *)atp, 8*sizeof(AMBTREE));
return(atp);
}
static void
freeambtree(atp) /* free 8 ambient tree structs */
AMBTREE *atp;
{
atp->kid = atfreelist;
atfreelist = atp;
}
static void
avinsert(av) /* insert ambient value in our tree */
register AMBVAL *av;
{
register AMBTREE *at;
register AMBVAL *ap;
AMBVAL avh;
FVECT ck0;
double s;
int branch;
register int i;
if (av->rad <= FTINY)
error(CONSISTENCY, "zero ambient radius in avinsert");
at = &atrunk;
VCOPY(ck0, thescene.cuorg);
s = thescene.cusize;
while (s*(OCTSCALE/2) > av->rad*ambacc) {
if (at->kid == NULL)
if ((at->kid = newambtree()) == NULL)
error(SYSTEM, "out of memory in avinsert");
s *= 0.5;
branch = 0;
for (i = 0; i < 3; i++)
if (av->pos[i] > ck0[i] + s) {
ck0[i] += s;
branch |= 1 << i;
}
at = at->kid + branch;
}
avh.next = at->alist; /* order by increasing level */
for (ap = &avh; ap->next != NULL; ap = ap->next)
if (ap->next->lvl >= av->lvl)
break;
av->next = ap->next;
ap->next = av;
at->alist = avh.next;
}
static void
unloadatree(at, f) /* unload an ambient value tree */
register AMBTREE *at;
void (*f)();
{
register AMBVAL *av;
register int i;
/* transfer values at this node */
for (av = at->alist; av != NULL; av = at->alist) {
at->alist = av->next;
(*f)(av);
}
if (at->kid == NULL)
return;
for (i = 0; i < 8; i++) /* transfer and free children */
unloadatree(at->kid+i, f);
freeambtree(at->kid);
at->kid = NULL;
}
static struct avl {
AMBVAL *p;
unsigned long t;
} *avlist1; /* ambient value list with ticks */
static AMBVAL **avlist2; /* memory positions for sorting */
static int i_avlist; /* index for lists */
static int
av2list(av)
register AMBVAL *av;
{
#ifdef DEBUG
if (i_avlist >= nambvals)
error(CONSISTENCY, "too many ambient values in av2list1");
#endif
avlist1[i_avlist].p = avlist2[i_avlist] = av;
avlist1[i_avlist++].t = av->latick;
}
static int
alatcmp(av1, av2) /* compare ambient values for MRA */
struct avl *av1, *av2;
{
register long lc = av2->t - av1->t;
return(lc<0 ? -1 : lc>0 ? 1 : 0);
}
/* GW NOTE 2002/10/3:
* I used to compare AMBVAL pointers, but found that this was the
* cause of a serious consistency error with gcc, since the optimizer
* uses some dangerous trick in pointer subtraction that
* assumes pointers differ by exact struct size increments.
*/
static int
aposcmp(avp1, avp2) /* compare ambient value positions */
const void *avp1, *avp2;
{
register long diff = *(char * const *)avp1 - *(char * const *)avp2;
if (diff < 0)
return(-1);
return(diff > 0);
}
#if 1
static int
avlmemi(avaddr) /* find list position from address */
AMBVAL *avaddr;
{
register AMBVAL **avlpp;
avlpp = (AMBVAL **)bsearch((char *)&avaddr, (char *)avlist2,
nambvals, sizeof(AMBVAL *), aposcmp);
if (avlpp == NULL)
error(CONSISTENCY, "address not found in avlmemi");
return(avlpp - avlist2);
}
#else
#define avlmemi(avaddr) ((AMBVAL **)bsearch((char *)&avaddr,(char *)avlist2, \
nambvals,sizeof(AMBVAL *),aposcmp) - avlist2)
#endif
static void
sortambvals(always) /* resort ambient values */
int always;
{
AMBTREE oldatrunk;
AMBVAL tav, *tap, *pnext;
register int i, j;
/* see if it's time yet */
if (!always && (ambclock++ < lastsort+sortintvl ||
nambvals < SORT_THRESH))
return;
/*
* The idea here is to minimize memory thrashing
* in VM systems by improving reference locality.
* We do this by periodically sorting our stored ambient
* values in memory in order of most recently to least
* recently accessed. This ordering was chosen so that new
* ambient values (which tend to be less important) go into
* higher memory with the infrequently accessed values.
* Since we expect our values to need sorting less
* frequently as the process continues, we double our
* waiting interval after each call.
* This routine is also called by setambacc() with
* the "always" parameter set to 1 so that the ambient
* tree will be rebuilt with the new accuracy parameter.
*/
if (tracktime) { /* allocate pointer arrays to sort */
avlist2 = (AMBVAL **)malloc(nambvals*sizeof(AMBVAL *));
avlist1 = (struct avl *)malloc(nambvals*sizeof(struct avl));
} else {
avlist2 = NULL;
avlist1 = NULL;
}
if (avlist1 == NULL) { /* no time tracking -- rebuild tree? */
if (avlist2 != NULL)
free((void *)avlist2);
if (always) { /* rebuild without sorting */
copystruct(&oldatrunk, &atrunk);
atrunk.alist = NULL;
atrunk.kid = NULL;
unloadatree(&oldatrunk, avinsert);
}
} else { /* sort memory by last access time */
/*
* Sorting memory is tricky because it isn't contiguous.
* We have to sort an array of pointers by MRA and also
* by memory position. We then copy values in "loops"
* to minimize memory hits. Nevertheless, we will visit
* everyone at least twice, and this is an expensive process
* when we're thrashing, which is when we need to do it.
*/
#ifdef DEBUG
sprintf(errmsg, "sorting %u ambient values at ambclock=%lu...",
nambvals, ambclock);
eputs(errmsg);
#endif
i_avlist = 0;
unloadatree(&atrunk, av2list); /* empty current tree */
#ifdef DEBUG
if (i_avlist < nambvals)
error(CONSISTENCY, "missing ambient values in sortambvals");
#endif
qsort((char *)avlist1, nambvals, sizeof(struct avl), alatcmp);
qsort((char *)avlist2, nambvals, sizeof(AMBVAL *), aposcmp);
for (i = 0; i < nambvals; i++) {
if (avlist1[i].p == NULL)
continue;
tap = avlist2[i];
copystruct(&tav, tap);
for (j = i; (pnext = avlist1[j].p) != tap;
j = avlmemi(pnext)) {
copystruct(avlist2[j], pnext);
avinsert(avlist2[j]);
avlist1[j].p = NULL;
}
copystruct(avlist2[j], &tav);
avinsert(avlist2[j]);
avlist1[j].p = NULL;
}
free((void *)avlist1);
free((void *)avlist2);
/* compute new sort interval */
sortintvl = ambclock - lastsort;
if (sortintvl >= MAX_SORT_INTVL/2)
sortintvl = MAX_SORT_INTVL;
else
sortintvl <<= 1; /* wait twice as long next */
#ifdef DEBUG
eputs("done\n");
#endif
}
if (ambclock >= MAXACLOCK)
ambclock = MAXACLOCK/2;
lastsort = ambclock;
}
#ifdef F_SETLKW
static void
aflock(typ) /* lock/unlock ambient file */
int typ;
{
static struct flock fls; /* static so initialized to zeroes */
fls.l_type = typ;
if (fcntl(fileno(ambfp), F_SETLKW, &fls) < 0)
error(SYSTEM, "cannot (un)lock ambient file");
}
int
ambsync() /* synchronize ambient file */
{
long flen;
AMBVAL avs;
register int n;
if (nunflshed == 0)
return(0);
if (lastpos < 0) /* initializing (locked in initambfile) */
goto syncend;
/* gain exclusive access */
aflock(F_WRLCK);
/* see if file has grown */
if ((flen = lseek(fileno(ambfp), (off_t)0L, 2)) < 0)
goto seekerr;
if (n = flen - lastpos) { /* file has grown */
if (ambinp == NULL) { /* use duplicate filedes */
ambinp = fdopen(dup(fileno(ambfp)), "r");
if (ambinp == NULL)
error(SYSTEM, "fdopen failed in ambsync");
}
if (fseek(ambinp, lastpos, 0) < 0)
goto seekerr;
while (n >= AMBVALSIZ) { /* load contributed values */
if (!readambval(&avs, ambinp)) {
sprintf(errmsg,
"ambient file \"%s\" corrupted near character %ld",
ambfile, flen - n);
error(WARNING, errmsg);
break;
}
avinsert(avstore(&avs));
n -= AMBVALSIZ;
}
/*** seek always as safety measure
if (n) ***/ /* alignment */
if (lseek(fileno(ambfp), (off_t)(flen-n), 0) < 0)
goto seekerr;
}
#ifdef DEBUG
if (ambfp->_ptr - ambfp->_base != nunflshed*AMBVALSIZ) {
sprintf(errmsg, "ambient file buffer at %d rather than %d",
ambfp->_ptr - ambfp->_base,
nunflshed*AMBVALSIZ);
error(CONSISTENCY, errmsg);
}
#endif
syncend:
n = fflush(ambfp); /* calls write() at last */
if ((lastpos = lseek(fileno(ambfp), (off_t)0L, 1)) < 0)
goto seekerr;
aflock(F_UNLCK); /* release file */
nunflshed = 0;
return(n);
seekerr:
error(SYSTEM, "seek failed in ambsync");
}
#else
int
ambsync() /* flush ambient file */
{
if (nunflshed == 0)
return(0);
nunflshed = 0;
return(fflush(ambfp));
}
#endif