| 46 |
|
|
| 47 |
|
extern long ftell(), lseek(); |
| 48 |
|
static int initambfile(), avsave(), avinsert(); |
| 49 |
+ |
#ifdef F_SETLKW |
| 50 |
+ |
static aflock(); |
| 51 |
+ |
#endif |
| 52 |
|
|
| 53 |
|
|
| 54 |
|
setambres(ar) /* set ambient resolution */ |
| 76 |
|
AMBVAL amb; |
| 77 |
|
/* init ambient limits */ |
| 78 |
|
setambres(ambres); |
| 79 |
+ |
if (afile == NULL) |
| 80 |
+ |
return; |
| 81 |
|
/* open ambient file */ |
| 82 |
< |
if (afile != NULL) { |
| 83 |
< |
if ((ambfp = fopen(afile, "r+")) != NULL) { |
| 84 |
< |
initambfile(0); |
| 85 |
< |
headlen = ftell(ambfp); |
| 86 |
< |
while (readambval(&amb, ambfp)) |
| 87 |
< |
avinsert(&amb, &atrunk, thescene.cuorg, |
| 88 |
< |
thescene.cusize); |
| 89 |
< |
/* align */ |
| 90 |
< |
fseek(ambfp, -((ftell(ambfp)-headlen)%AMBVALSIZ), 1); |
| 91 |
< |
} else if ((ambfp = fopen(afile, "w+")) != NULL) |
| 92 |
< |
initambfile(1); |
| 93 |
< |
else { |
| 94 |
< |
sprintf(errmsg, "cannot open ambient file \"%s\"", |
| 90 |
< |
afile); |
| 91 |
< |
error(SYSTEM, errmsg); |
| 92 |
< |
} |
| 93 |
< |
nunflshed++; /* lie */ |
| 94 |
< |
ambsync(); |
| 82 |
> |
if ((ambfp = fopen(afile, "r+")) != NULL) { |
| 83 |
> |
initambfile(0); |
| 84 |
> |
headlen = ftell(ambfp); |
| 85 |
> |
while (readambval(&amb, ambfp)) |
| 86 |
> |
avinsert(&amb, &atrunk, thescene.cuorg, |
| 87 |
> |
thescene.cusize); |
| 88 |
> |
/* align */ |
| 89 |
> |
fseek(ambfp, -((ftell(ambfp)-headlen)%AMBVALSIZ), 1); |
| 90 |
> |
} else if ((ambfp = fopen(afile, "w+")) != NULL) |
| 91 |
> |
initambfile(1); |
| 92 |
> |
else { |
| 93 |
> |
sprintf(errmsg, "cannot open ambient file \"%s\"", afile); |
| 94 |
> |
error(SYSTEM, errmsg); |
| 95 |
|
} |
| 96 |
+ |
nunflshed++; /* lie */ |
| 97 |
+ |
ambsync(); |
| 98 |
|
} |
| 99 |
|
|
| 100 |
|
|
| 310 |
|
{ |
| 311 |
|
extern char *progname, *octname, VersionID[]; |
| 312 |
|
|
| 313 |
+ |
#ifdef F_SETLKW |
| 314 |
+ |
aflock(creat ? F_WRLCK : F_RDLCK); |
| 315 |
+ |
#endif |
| 316 |
|
#ifdef MSDOS |
| 317 |
|
setmode(fileno(ambfp), O_BINARY); |
| 318 |
|
#endif |
| 391 |
|
|
| 392 |
|
#ifdef F_SETLKW |
| 393 |
|
|
| 394 |
+ |
static |
| 395 |
+ |
aflock(typ) /* lock/unlock ambient file */ |
| 396 |
+ |
int typ; |
| 397 |
+ |
{ |
| 398 |
+ |
static struct flock fls; /* static so initialized to zeroes */ |
| 399 |
+ |
|
| 400 |
+ |
fls.l_type = typ; |
| 401 |
+ |
if (fcntl(fileno(ambfp), F_SETLKW, &fls) < 0) |
| 402 |
+ |
error(SYSTEM, "cannot (un)lock ambient file"); |
| 403 |
+ |
} |
| 404 |
+ |
|
| 405 |
+ |
|
| 406 |
|
int |
| 407 |
|
ambsync() /* synchronize ambient file */ |
| 408 |
|
{ |
| 409 |
|
static FILE *ambinp = NULL; |
| 410 |
|
static long lastpos = -1; |
| 394 |
– |
struct flock fls; |
| 411 |
|
long flen; |
| 412 |
|
AMBVAL avs; |
| 413 |
|
register int n; |
| 414 |
|
|
| 415 |
|
if (nunflshed == 0) |
| 416 |
|
return(0); |
| 417 |
< |
/* gain exclusive access */ |
| 402 |
< |
fls.l_type = F_WRLCK; |
| 403 |
< |
fls.l_whence = 0; |
| 404 |
< |
fls.l_start = 0L; |
| 405 |
< |
fls.l_len = 0L; |
| 406 |
< |
if (fcntl(fileno(ambfp), F_SETLKW, &fls) < 0) |
| 407 |
< |
error(SYSTEM, "cannot lock ambient file"); |
| 408 |
< |
if (lastpos < 0) /* initializing */ |
| 417 |
> |
if (lastpos < 0) /* initializing (locked in initambfile) */ |
| 418 |
|
goto syncend; |
| 419 |
+ |
/* gain exclusive access */ |
| 420 |
+ |
aflock(F_WRLCK); |
| 421 |
|
/* see if file has grown */ |
| 422 |
|
if ((flen = lseek(fileno(ambfp), 0L, 2)) < 0) |
| 423 |
|
error(SYSTEM, "cannot seek on ambient file"); |
| 440 |
|
syncend: |
| 441 |
|
n = fflush(ambfp); /* calls write() at last */ |
| 442 |
|
lastpos = lseek(fileno(ambfp), 0L, 1); |
| 443 |
< |
fls.l_type = F_UNLCK; /* release file */ |
| 433 |
< |
fcntl(fileno(ambfp), F_SETLKW, &fls); |
| 443 |
> |
aflock(F_UNLCK); /* release file */ |
| 444 |
|
nunflshed = 0; |
| 445 |
|
return(n); |
| 446 |
|
} |
