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root/radiance/ray/src/hd/holofile.c
Revision: 3.13
Committed: Fri Dec 12 21:29:34 1997 UTC (26 years, 4 months ago) by gregl
Content type: text/plain
Branch: MAIN
Changes since 3.12: +22 -12 lines
Log Message:
made recovery from file write errors more robust

File Contents

# User Rev Content
1 gregl 3.1 /* Copyright (c) 1997 Silicon Graphics, Inc. */
2    
3     #ifndef lint
4     static char SCCSid[] = "$SunId$ SGI";
5     #endif
6    
7     /*
8     * Routines for managing holodeck files
9     *
10     * 9/30/97 GWLarson
11     */
12    
13     #include "holo.h"
14    
15     #ifndef CACHESIZE
16     #define CACHESIZE 16 /* default cache size (Mbytes, 0==inf) */
17     #endif
18     #ifndef FREEBEAMS
19 gregl 3.5 #define FREEBEAMS 512 /* maximum beams to free at a time */
20 gregl 3.1 #endif
21     #ifndef PCTFREE
22 gregl 3.5 #define PCTFREE 20 /* maximum fraction to free (%) */
23 gregl 3.1 #endif
24    
25 gregl 3.7 /* define MAXFRAG if you want to limit fragment tracking memory */
26    
27 gregl 3.6 #ifndef BSD
28     #define write writebuf /* safe i/o routines */
29     #define read readbuf
30     #endif
31 gregl 3.4
32     #define FRAGBLK 64 /* number of fragments to allocate at a time */
33    
34 gregl 3.1 int hdcachesize = CACHESIZE*1024*1024; /* target cache size (bytes) */
35     unsigned long hdclock; /* clock value */
36    
37     HOLO *hdlist[HDMAX+1]; /* holodeck pointers (NULL term.) */
38    
39     static struct fragment {
40     short nlinks; /* number of holodeck sections using us */
41 gregl 3.13 short writerr; /* write error encountered */
42     int nfrags; /* number of known fragments */
43 gregl 3.4 BEAMI *fi; /* fragments, descending file position */
44 gregl 3.1 long flen; /* last known file length */
45 gregl 3.4 } *hdfrag; /* fragment lists, indexed by file descriptor */
46 gregl 3.1
47 gregl 3.4 static int nhdfrags; /* size of hdfrag array */
48 gregl 3.1
49 gregl 3.4
50 gregl 3.1 hdattach(fd) /* start tracking file fragments for some section */
51     register int fd;
52     {
53 gregl 3.4 if (fd >= nhdfrags) {
54     if (nhdfrags)
55     hdfrag = (struct fragment *)realloc((char *)hdfrag,
56     (fd+1)*sizeof(struct fragment));
57     else
58     hdfrag = (struct fragment *)malloc(
59     (fd+1)*sizeof(struct fragment));
60     if (hdfrag == NULL)
61     error(SYSTEM, "out of memory in hdattach");
62     bzero((char *)(hdfrag+nhdfrags),
63     (fd+1-nhdfrags)*sizeof(struct fragment));
64     nhdfrags = fd+1;
65 gregl 3.1 }
66 gregl 3.4 hdfrag[fd].nlinks++;
67     hdfrag[fd].flen = lseek(fd, 0L, 2); /* get file length */
68 gregl 3.1 }
69    
70    
71     /* Do we need a routine to locate file fragments given known occupants? */
72    
73    
74     hdrelease(fd) /* stop tracking file fragments for some section */
75     register int fd;
76     {
77 gregl 3.8 if (fd < 0 | fd >= nhdfrags || !hdfrag[fd].nlinks)
78 gregl 3.1 return;
79 gregl 3.4 if (!--hdfrag[fd].nlinks && hdfrag[fd].nfrags) {
80     free((char *)hdfrag[fd].fi);
81     hdfrag[fd].fi = NULL;
82     hdfrag[fd].nfrags = 0;
83 gregl 3.1 }
84     }
85    
86    
87 gregl 3.6 markdirty(hp) /* mark holodeck section directory dirty */
88     register HOLO *hp;
89     {
90     static BEAMI smudge = {0, -1};
91    
92     if (hp->dirty) /* already marked? */
93     return;
94     hp->dirty = 1;
95     if (lseek(hp->fd, biglob(hp)->fo+(nbeams(hp)-1)*sizeof(BEAMI), 0) < 0
96     || write(hp->fd, (char *)&smudge,
97     sizeof(BEAMI)) != sizeof(BEAMI))
98     error(SYSTEM, "seek/write error in markdirty");
99     }
100    
101    
102 gregl 3.1 HOLO *
103     hdinit(fd, hproto) /* initialize a holodeck section in a file */
104     int fd; /* corresponding file descriptor */
105     HDGRID *hproto; /* holodeck section grid */
106     {
107     long fpos;
108     register HOLO *hp;
109     register int n;
110     /* prepare for system errors */
111     errno = 0;
112     if ((fpos = lseek(fd, 0L, 1)) < 0)
113     error(SYSTEM, "cannot determine holodeck file position");
114     if (hproto == NULL) { /* assume we're loading it */
115     HDGRID hpr;
116     /* load header */
117     if (read(fd, (char *)&hpr, sizeof(HDGRID)) != sizeof(HDGRID))
118     error(SYSTEM, "cannot load holodeck header");
119     /* allocate grid */
120     if ((hp = hdalloc(&hpr)) == NULL)
121     goto memerr;
122     /* load beam directory */
123     n = nbeams(hp)*sizeof(BEAMI);
124     if (read(fd, (char *)(hp->bi+1), n) != n)
125     error(SYSTEM, "failure loading holodeck directory");
126 gregl 3.6 /* check that it's clean */
127     if (hp->bi[nbeams(hp)].fo < 0)
128     error(USER, "dirty holodeck section");
129 gregl 3.1 } else { /* assume we're creating it */
130     if ((hp = hdalloc(hproto)) == NULL)
131     goto memerr;
132     /* write header and skeleton */
133     n = nbeams(hp)*sizeof(BEAMI);
134     if (write(fd, (char *)hproto, sizeof(HDGRID)) !=
135     sizeof(HDGRID) ||
136     write(fd, (char *)(hp->bi+1), n) != n)
137     error(SYSTEM, "cannot write header to holodeck file");
138     }
139     hp->fd = fd;
140     hp->dirty = 0;
141     biglob(hp)->fo = fpos + sizeof(HDGRID);
142 gregl 3.13 /* start tracking fragments */
143     hdattach(fd);
144     /* check rays on disk */
145     fpos = hdfilen(fd);
146     biglob(hp)->nrd = 0;
147     for (n = hproto == NULL ? nbeams(hp) : 0; n > 0; n--)
148     if (hp->bi[n].nrd)
149     if (hp->bi[n].fo + hp->bi[n].nrd > fpos)
150     hp->bi[n].nrd = 0; /* off end */
151     else
152     biglob(hp)->nrd += hp->bi[n].nrd;
153 gregl 3.1 /* add to holodeck list */
154     for (n = 0; n < HDMAX; n++)
155     if (hdlist[n] == NULL) {
156     hdlist[n] = hp;
157     break;
158     }
159     /* all done */
160     return(hp);
161     memerr:
162     error(SYSTEM, "cannot allocate holodeck grid");
163     }
164    
165    
166     int
167 gregl 3.12 hdsync(hp, all) /* update beams and directory on disk */
168 gregl 3.1 register HOLO *hp;
169 gregl 3.12 int all;
170 gregl 3.1 {
171     register int j, n;
172    
173 gregl 3.12 if (hp == NULL) { /* do all holodecks */
174 gregl 3.1 n = 0;
175     for (j = 0; hdlist[j] != NULL; j++)
176 gregl 3.12 n += hdsync(hdlist[j], all);
177 gregl 3.1 return(n);
178     }
179 gregl 3.12 /* sync the beams */
180     for (j = all ? nbeams(hp) : 0; j > 0; j--)
181     if (hp->bl[j] != NULL)
182     hdsyncbeam(hp, j);
183 gregl 3.13 if (!hp->dirty) /* directory clean? */
184 gregl 3.1 return(0);
185 gregl 3.3 errno = 0;
186 gregl 3.1 if (lseek(hp->fd, biglob(hp)->fo, 0) < 0)
187     error(SYSTEM, "cannot seek on holodeck file");
188     n = nbeams(hp)*sizeof(BEAMI);
189     if (write(hp->fd, (char *)(hp->bi+1), n) != n)
190     error(SYSTEM, "cannot update holodeck section directory");
191     hp->dirty = 0;
192     return(1);
193     }
194    
195    
196     long
197     hdmemuse(all) /* return memory usage (in bytes) */
198     int all; /* include overhead (painful) */
199     {
200     long total = 0;
201     register int i, j;
202    
203     for (j = 0; hdlist[j] != NULL; j++) {
204     total += blglob(hdlist[j])->nrm * sizeof(RAYVAL);
205     if (all) {
206     total += sizeof(HOLO) + sizeof(BEAM *) +
207     nbeams(hdlist[j]) *
208     (sizeof(BEAM *)+sizeof(BEAMI));
209     for (i = nbeams(hdlist[j]); i > 0; i--)
210     if (hdlist[j]->bl[i] != NULL)
211     total += sizeof(BEAM);
212     }
213     }
214     if (all)
215 gregl 3.4 for (j = 0; j < nhdfrags; j++) {
216     total += sizeof(struct fragment);
217     if (hdfrag[j].nfrags)
218     total += FRAGBLK*sizeof(BEAMI) *
219     ((hdfrag[j].nfrags-1)/FRAGBLK + 1) ;
220     }
221 gregl 3.1 return(total);
222 gregl 3.8 }
223    
224    
225     long
226     hdfilen(fd) /* return file length for fd */
227     int fd;
228     {
229     long fpos, flen;
230    
231     if (fd < 0)
232     return(-1);
233     if (fd >= nhdfrags || !hdfrag[fd].nlinks) {
234     if ((fpos = lseek(fd, 0L, 1)) < 0)
235     return(-1);
236     flen = lseek(fd, 0L, 2);
237     lseek(fd, fpos, 0);
238     return(flen);
239     }
240     return(hdfrag[fd].flen);
241 gregl 3.1 }
242    
243    
244     long
245     hdfiluse(fd, all) /* compute file usage (in bytes) */
246     int fd; /* open file descriptor to check */
247     int all; /* include overhead and unflushed data */
248     {
249     long total = 0;
250     register int i, j;
251    
252     for (j = 0; hdlist[j] != NULL; j++) {
253     if (hdlist[j]->fd != fd)
254     continue;
255     total += biglob(hdlist[j])->nrd * sizeof(RAYVAL);
256     if (all) {
257     for (i = nbeams(hdlist[j]); i > 0; i--)
258     if (hdlist[j]->bl[i] != NULL)
259     total += sizeof(RAYVAL) *
260     (hdlist[j]->bl[i]->nrm -
261     hdlist[j]->bi[i].nrd);
262     total += sizeof(HDGRID) +
263     nbeams(hdlist[j])*sizeof(BEAMI);
264     }
265     }
266     return(total); /* does not include fragments */
267     }
268    
269    
270     RAYVAL *
271     hdnewrays(hp, i, nr) /* allocate space for add'l rays and return pointer */
272     register HOLO *hp;
273     register int i;
274     int nr; /* number of new rays desired */
275     {
276     RAYVAL *p;
277     int n;
278    
279     if (nr <= 0)
280     return(NULL);
281     if (i < 1 | i > nbeams(hp))
282     error(CONSISTENCY, "bad beam index given to hdnewrays");
283     if (hp->bl[i] != NULL)
284     hp->bl[i]->tick = hdclock; /* preempt swap */
285     if (hdcachesize > 0 && hdmemuse(0) >= hdcachesize)
286     hdfreecache(PCTFREE, NULL); /* free some space */
287 gregl 3.3 errno = 0;
288 gregl 3.1 if (hp->bl[i] == NULL) { /* allocate (and load) */
289     n = hp->bi[i].nrd + nr;
290     if ((hp->bl[i] = (BEAM *)malloc(hdbsiz(n))) == NULL)
291     goto memerr;
292     blglob(hp)->nrm += n;
293     if (n = hp->bl[i]->nrm = hp->bi[i].nrd) {
294     if (lseek(hp->fd, hp->bi[i].fo, 0) < 0)
295     error(SYSTEM, "seek error on holodeck file");
296     n *= sizeof(RAYVAL);
297     if (read(hp->fd, (char *)hdbray(hp->bl[i]), n) != n)
298     error(SYSTEM,
299     "error reading beam from holodeck file");
300     }
301     } else { /* just grow in memory */
302     hp->bl[i] = (BEAM *)realloc( (char *)hp->bl[i],
303     hdbsiz(hp->bl[i]->nrm + nr) );
304     if (hp->bl[i] == NULL)
305     goto memerr;
306     blglob(hp)->nrm += nr;
307     }
308     p = hdbray(hp->bl[i]) + hp->bl[i]->nrm;
309     hp->bl[i]->nrm += nr; /* update in-core structure */
310     bzero((char *)p, nr*sizeof(RAYVAL));
311     hp->bl[i]->tick = ++hdclock; /* update LRU clock */
312     blglob(hp)->tick = hdclock;
313     return(p); /* point to new rays */
314     memerr:
315     error(SYSTEM, "out of memory in hdnewrays");
316     }
317    
318    
319     BEAM *
320     hdgetbeam(hp, i) /* get beam (from file if necessary) */
321     register HOLO *hp;
322     register int i;
323     {
324     register int n;
325    
326     if (i < 1 | i > nbeams(hp))
327     error(CONSISTENCY, "bad beam index given to hdgetbeam");
328     if (hp->bl[i] == NULL) { /* load from disk */
329     if (!(n = hp->bi[i].nrd))
330     return(NULL);
331     if (hdcachesize > 0 && hdmemuse(0) >= hdcachesize)
332     hdfreecache(PCTFREE, NULL); /* get free space */
333     errno = 0;
334     if ((hp->bl[i] = (BEAM *)malloc(hdbsiz(n))) == NULL)
335     error(SYSTEM, "cannot allocate memory for beam");
336     blglob(hp)->nrm += hp->bl[i]->nrm = n;
337     if (lseek(hp->fd, hp->bi[i].fo, 0) < 0)
338     error(SYSTEM, "seek error on holodeck file");
339     n *= sizeof(RAYVAL);
340     if (read(hp->fd, (char *)hdbray(hp->bl[i]), n) != n)
341     error(SYSTEM, "error reading beam from holodeck file");
342     }
343     hp->bl[i]->tick = ++hdclock; /* update LRU clock */
344     blglob(hp)->tick = hdclock;
345     return(hp->bl[i]);
346     }
347    
348    
349     int
350 gregl 3.12 hdsyncbeam(hp, i) /* sync beam in memory with beam on disk */
351 gregl 3.1 register HOLO *hp;
352     register int i;
353     {
354 gregl 3.12 unsigned int nrays;
355 gregl 3.11 long nfo;
356     unsigned int n;
357 gregl 3.13 /* check file status */
358     if (hdfrag[hp->fd].writerr)
359     return(-1);
360 gregl 3.12 #ifdef DEBUG
361     if (i < 1 | i > nbeams(hp))
362     error(CONSISTENCY, "bad beam index in hdsyncbeam");
363     #endif
364 gregl 3.11 /* is current fragment OK? */
365 gregl 3.12 if (hp->bl[i] == NULL || (nrays = hp->bl[i]->nrm) == hp->bi[i].nrd)
366 gregl 3.1 return(0);
367 gregl 3.13 /* locate fragment */
368 gregl 3.4 if (hp->fd >= nhdfrags || !hdfrag[hp->fd].nlinks) /* untracked */
369 gregl 3.1 hp->bi[i].fo = lseek(hp->fd, 0L, 2);
370    
371     else if (hp->bi[i].fo + hp->bi[i].nrd*sizeof(RAYVAL) ==
372 gregl 3.4 hdfrag[hp->fd].flen) /* EOF special case */
373 gregl 3.11 hdfrag[hp->fd].flen = (nfo=hp->bi[i].fo) + nrays*sizeof(RAYVAL);
374 gregl 3.1
375     else { /* general case */
376 gregl 3.4 register struct fragment *f = &hdfrag[hp->fd];
377 gregl 3.1 register int j, k;
378     /* relinquish old fragment */
379 gregl 3.2 if (hp->bi[i].nrd) {
380 gregl 3.5 j = f->nfrags++;
381 gregl 3.4 #ifdef MAXFRAG
382 gregl 3.5 if (j >= MAXFRAG-1)
383 gregl 3.2 f->nfrags--;
384 gregl 3.4 #endif
385 gregl 3.5 if (j % FRAGBLK == 0) { /* more frag. space */
386 gregl 3.4 if (f->fi == NULL)
387     f->fi = (BEAMI *)malloc(
388     FRAGBLK*sizeof(BEAMI));
389     else
390     f->fi = (BEAMI *)realloc((char *)f->fi,
391 gregl 3.5 (j+FRAGBLK)*sizeof(BEAMI));
392 gregl 3.4 if (f->fi == NULL)
393     error(SYSTEM,
394 gregl 3.12 "out of memory in hdsyncbeam");
395 gregl 3.4 }
396 gregl 3.5 for ( ; ; j--) { /* insert in descending list */
397     if (!j || hp->bi[i].fo < f->fi[j-1].fo) {
398 gregl 3.2 f->fi[j].fo = hp->bi[i].fo;
399     f->fi[j].nrd = hp->bi[i].nrd;
400     break;
401     }
402     copystruct(f->fi+j, f->fi+j-1);
403 gregl 3.1 }
404     /* coalesce adjacent fragments */
405 gregl 3.2 for (j = k = 0; k < f->nfrags; j++, k++) {
406 gregl 3.3 if (k > j)
407 gregl 3.2 copystruct(f->fi+j, f->fi+k);
408 gregl 3.3 while (k+1 < f->nfrags && f->fi[k+1].fo +
409     f->fi[k+1].nrd*sizeof(RAYVAL)
410     == f->fi[j].fo) {
411 gregl 3.2 f->fi[j].fo -=
412     f->fi[++k].nrd*sizeof(RAYVAL);
413 gregl 3.3 f->fi[j].nrd += f->fi[k].nrd;
414     }
415 gregl 3.2 }
416     f->nfrags = j;
417 gregl 3.1 }
418     k = -1; /* find closest-sized fragment */
419 gregl 3.11 for (j = nrays ? f->nfrags : 0; j-- > 0; )
420 gregl 3.1 if (f->fi[j].nrd >= nrays &&
421 gregl 3.3 (k < 0 || f->fi[j].nrd < f->fi[k].nrd))
422     if (f->fi[k=j].nrd == nrays)
423     break;
424 gregl 3.1 if (k < 0) { /* no fragment -- extend file */
425 gregl 3.11 nfo = f->flen;
426 gregl 3.1 f->flen += nrays*sizeof(RAYVAL);
427     } else { /* else use fragment */
428 gregl 3.11 nfo = f->fi[k].fo;
429 gregl 3.1 if (f->fi[k].nrd == nrays) { /* delete fragment */
430     f->nfrags--;
431     for (j = k; j < f->nfrags; j++)
432     copystruct(f->fi+j, f->fi+j+1);
433     } else { /* else shrink it */
434     f->fi[k].fo += nrays*sizeof(RAYVAL);
435     f->fi[k].nrd -= nrays;
436     }
437     }
438     }
439 gregl 3.11 if (nrays) { /* write the new fragment */
440     errno = 0;
441     if (lseek(hp->fd, nfo, 0) < 0)
442     error(SYSTEM, "cannot seek on holodeck file");
443     n = hp->bl[i]->nrm * sizeof(RAYVAL);
444     if (write(hp->fd, (char *)hdbray(hp->bl[i]), n) != n) {
445 gregl 3.13 hdfrag[hp->fd].writerr++;
446     hdsync(hp, 0); /* sync directory */
447 gregl 3.12 error(SYSTEM, "write error in hdsyncbeam");
448 gregl 3.11 }
449     }
450 gregl 3.1 biglob(hp)->nrd += nrays - hp->bi[i].nrd;
451     hp->bi[i].nrd = nrays;
452 gregl 3.11 hp->bi[i].fo = nfo;
453 gregl 3.6 markdirty(hp); /* section directory now out of date */
454 gregl 3.1 return(1);
455     }
456    
457    
458     int
459     hdfreebeam(hp, i) /* free beam, writing if dirty */
460     register HOLO *hp;
461     register int i;
462     {
463 gregl 3.11 int nchanged;
464 gregl 3.1
465     if (hp == NULL) { /* clear all holodecks */
466     nchanged = 0;
467     for (i = 0; hdlist[i] != NULL; i++)
468     nchanged += hdfreebeam(hdlist[i], 0);
469     return(nchanged);
470     }
471 gregl 3.13 if (hdfrag[hp->fd].writerr) /* check for file error */
472     return(0);
473 gregl 3.1 if (i == 0) { /* clear entire holodeck */
474     nchanged = 0;
475 gregl 3.10 for (i = nbeams(hp); i > 0; i--)
476     if (hp->bl[i] != NULL)
477     nchanged += hdfreebeam(hp, i);
478 gregl 3.1 return(nchanged);
479     }
480 gregl 3.12 #ifdef DEBUG
481 gregl 3.1 if (i < 1 | i > nbeams(hp))
482     error(CONSISTENCY, "bad beam index to hdfreebeam");
483 gregl 3.12 #endif
484 gregl 3.1 if (hp->bl[i] == NULL)
485     return(0);
486     /* check for additions */
487     nchanged = hp->bl[i]->nrm - hp->bi[i].nrd;
488 gregl 3.11 if (nchanged)
489 gregl 3.12 hdsyncbeam(hp, i); /* write new fragment */
490 gregl 3.1 blglob(hp)->nrm -= hp->bl[i]->nrm;
491     free((char *)hp->bl[i]); /* free memory */
492     hp->bl[i] = NULL;
493     return(nchanged);
494     }
495    
496    
497 gregl 3.10 int
498     hdkillbeam(hp, i) /* delete beam from holodeck */
499     register HOLO *hp;
500     register int i;
501     {
502     static BEAM emptybeam;
503 gregl 3.11 int nchanged;
504 gregl 3.10
505     if (hp == NULL) { /* clobber all holodecks */
506     nchanged = 0;
507     for (i = 0; hdlist[i] != NULL; i++)
508     nchanged += hdkillbeam(hdlist[i], 0);
509     return(nchanged);
510     }
511     if (i == 0) { /* clobber entire holodeck */
512     nchanged = 0;
513     for (i = nbeams(hp); i > 0; i--)
514     if (hp->bi[i].nrd > 0 || hp->bl[i] != NULL)
515     nchanged += hdkillbeam(hp, i);
516     #ifdef DEBUG
517     if (biglob(hp)->nrd != 0 | blglob(hp)->nrm != 0)
518     error(CONSISTENCY, "bad beam count in hdkillbeam");
519     #endif
520     return(nchanged);
521     }
522 gregl 3.12 #ifdef DEBUG
523 gregl 3.10 if (i < 1 | i > nbeams(hp))
524     error(CONSISTENCY, "bad beam index to hdkillbeam");
525 gregl 3.12 #endif
526 gregl 3.10 if (hp->bl[i] != NULL) { /* free memory */
527     blglob(hp)->nrm -= nchanged = hp->bl[i]->nrm;
528     free((char *)hp->bl[i]);
529     } else
530     nchanged = hp->bi[i].nrd;
531     if (hp->bi[i].nrd) { /* free file fragment */
532     hp->bl[i] = &emptybeam;
533 gregl 3.12 hdsyncbeam(hp, i);
534 gregl 3.10 }
535     hp->bl[i] = NULL;
536     return(nchanged);
537     }
538    
539    
540 gregl 3.1 hdlrulist(ha, ba, n, hp) /* add beams from holodeck to LRU list */
541     register HOLO *ha[]; /* section list (NULL terminated) */
542     register int ba[]; /* beam index to go with section */
543     int n; /* length of arrays minus 1 */
544     register HOLO *hp; /* section we're adding from */
545     {
546     register int i, j;
547     int nents;
548     /* find last entry in LRU list */
549     for (j = 0; ha[j] != NULL; j++)
550     ;
551     nents = j;
552     /* insert each beam from hp */
553 gregl 3.10 for (i = nbeams(hp); i > 0; i--) {
554 gregl 3.1 if (hp->bl[i] == NULL) /* check if loaded */
555     continue;
556     if ((j = ++nents) > n) /* grow list if we can */
557     nents--;
558     for ( ; ; ) { /* bubble into place */
559     if (!--j || hp->bl[i]->tick >=
560     ha[j-1]->bl[ba[j-1]]->tick) {
561     ha[j] = hp;
562     ba[j] = i;
563     break;
564     }
565     ha[j] = ha[j-1];
566     ba[j] = ba[j-1];
567     }
568     }
569     ha[nents] = NULL; /* all done */
570     ba[nents] = 0;
571     }
572    
573    
574     hdfreecache(pct, honly) /* free up cache space, writing changes */
575     int pct; /* maximum percentage to free */
576     register HOLO *honly; /* NULL means check all */
577     {
578     HOLO *hp[FREEBEAMS+1];
579     int bn[FREEBEAMS+1];
580     int freetarget;
581     register int i;
582     /* compute free target */
583     freetarget = (honly != NULL) ? blglob(honly)->nrm :
584     hdmemuse(0)/sizeof(RAYVAL) ;
585     freetarget = freetarget*pct/100;
586     /* find least recently used */
587     hp[0] = NULL;
588     bn[0] = 0;
589     if (honly != NULL)
590     hdlrulist(hp, bn, FREEBEAMS, honly);
591     else
592     for (i = 0; hdlist[i] != NULL; i++)
593     hdlrulist(hp, bn, FREEBEAMS, hdlist[i]);
594     /* free LRU beams */
595     for (i = 0; hp[i] != NULL; i++) {
596     hdfreebeam(hp[i], bn[i]);
597     if ((freetarget -= hp[i]->bi[bn[i]].nrd) <= 0)
598     break;
599     }
600 gregl 3.12 hdsync(honly, 0); /* synchronize directories as necessary */
601 gregl 3.1 }
602    
603    
604     hddone(hp) /* clean up holodeck section and free */
605     register HOLO *hp; /* NULL means clean up all */
606     {
607     register int i;
608    
609     if (hp == NULL) { /* NULL means clean up everything */
610     while (hdlist[0] != NULL)
611     hddone(hdlist[0]);
612     return;
613     }
614     /* flush all data and free memory */
615     hdflush(hp);
616     /* release fragment resources */
617     hdrelease(hp->fd);
618     /* remove hp from active list */
619     for (i = 0; hdlist[i] != NULL; i++)
620     if (hdlist[i] == hp) {
621     while ((hdlist[i] = hdlist[i+1]) != NULL)
622     i++;
623     break;
624     }
625     free((char *)hp->bl); /* free beam list */
626     free((char *)hp); /* free holodeck struct */
627     }