1 /*
2 * jmemmgr.c
3 *
4 * Copyright (C) 1991-1997, Thomas G. Lane.
5 * Modified 2011-2012 by Guido Vollbeding.
6 * This file is part of the Independent JPEG Group's software.
7 * For conditions of distribution and use, see the accompanying README file.
8 *
9 * This file contains the JPEG system-independent memory management
10 * routines. This code is usable across a wide variety of machines; most
11 * of the system dependencies have been isolated in a separate file.
12 * The major functions provided here are:
13 * * pool-based allocation and freeing of memory;
14 * * policy decisions about how to divide available memory among the
15 * virtual arrays;
16 * * control logic for swapping virtual arrays between main memory and
17 * backing storage.
18 * The separate system-dependent file provides the actual backing-storage
19 * access code, and it contains the policy decision about how much total
20 * main memory to use.
21 * This file is system-dependent in the sense that some of its functions
22 * are unnecessary in some systems. For example, if there is enough virtual
23 * memory so that backing storage will never be used, much of the virtual
24 * array control logic could be removed. (Of course, if you have that much
25 * memory then you shouldn't care about a little bit of unused code...)
26 */
27
28 #define JPEG_INTERNALS
29 #define AM_MEMORY_MANAGER /* we define jvirt_Xarray_control structs */
30 #include "jinclude.h"
31 #include "jpeglib.h"
32 #include "jmemsys.h" /* import the system-dependent declarations */
33
34 #ifndef NO_GETENV
35 #ifndef HAVE_STDLIB_H /* <stdlib.h> should declare getenv() */
36 extern char * getenv JPP((const char * name));
37 #endif
38 #endif
39
40
41 /*
42 * Some important notes:
43 * The allocation routines provided here must never return NULL.
44 * They should exit to error_exit if unsuccessful.
45 *
46 * It's not a good idea to try to merge the sarray and barray routines,
47 * even though they are textually almost the same, because samples are
48 * usually stored as bytes while coefficients are shorts or ints. Thus,
49 * in machines where byte pointers have a different representation from
50 * word pointers, the resulting machine code could not be the same.
51 */
52
53
54 /*
55 * Many machines require storage alignment: longs must start on 4-byte
56 * boundaries, doubles on 8-byte boundaries, etc. On such machines, malloc()
57 * always returns pointers that are multiples of the worst-case alignment
58 * requirement, and we had better do so too.
59 * There isn't any really portable way to determine the worst-case alignment
60 * requirement. This module assumes that the alignment requirement is
61 * multiples of sizeof(ALIGN_TYPE).
62 * By default, we define ALIGN_TYPE as double. This is necessary on some
63 * workstations (where doubles really do need 8-byte alignment) and will work
64 * fine on nearly everything. If your machine has lesser alignment needs,
65 * you can save a few bytes by making ALIGN_TYPE smaller.
66 * The only place I know of where this will NOT work is certain Macintosh
67 * 680x0 compilers that define double as a 10-byte IEEE extended float.
68 * Doing 10-byte alignment is counterproductive because longwords won't be
69 * aligned well. Put "#define ALIGN_TYPE long" in jconfig.h if you have
70 * such a compiler.
71 */
72
73 #ifndef ALIGN_TYPE /* so can override from jconfig.h */
74 #define ALIGN_TYPE double
75 #endif
76
77
78 /*
79 * We allocate objects from "pools", where each pool is gotten with a single
80 * request to jpeg_get_small() or jpeg_get_large(). There is no per-object
81 * overhead within a pool, except for alignment padding. Each pool has a
82 * header with a link to the next pool of the same class.
83 * Small and large pool headers are identical except that the latter's
84 * link pointer must be FAR on 80x86 machines.
85 * Notice that the "real" header fields are union'ed with a dummy ALIGN_TYPE
86 * field. This forces the compiler to make SIZEOF(small_pool_hdr) a multiple
87 * of the alignment requirement of ALIGN_TYPE.
88 */
89
90 typedef union small_pool_struct * small_pool_ptr;
91
92 typedef union small_pool_struct {
93 struct {
94 small_pool_ptr next; /* next in list of pools */
95 size_t bytes_used; /* how many bytes already used within pool */
96 size_t bytes_left; /* bytes still available in this pool */
97 } hdr;
98 ALIGN_TYPE dummy; /* included in union to ensure alignment */
99 } small_pool_hdr;
100
101 typedef union large_pool_struct FAR * large_pool_ptr;
102
103 typedef union large_pool_struct {
104 struct {
105 large_pool_ptr next; /* next in list of pools */
106 size_t bytes_used; /* how many bytes already used within pool */
107 size_t bytes_left; /* bytes still available in this pool */
108 } hdr;
109 ALIGN_TYPE dummy; /* included in union to ensure alignment */
110 } large_pool_hdr;
111
112
113 /*
114 * Here is the full definition of a memory manager object.
115 */
116
117 typedef struct {
118 struct jpeg_memory_mgr pub; /* public fields */
119
120 /* Each pool identifier (lifetime class) names a linked list of pools. */
121 small_pool_ptr small_list[JPOOL_NUMPOOLS];
122 large_pool_ptr large_list[JPOOL_NUMPOOLS];
123
124 /* Since we only have one lifetime class of virtual arrays, only one
125 * linked list is necessary (for each datatype). Note that the virtual
126 * array control blocks being linked together are actually stored somewhere
127 * in the small-pool list.
128 */
129 jvirt_sarray_ptr virt_sarray_list;
130 jvirt_barray_ptr virt_barray_list;
131
132 /* This counts total space obtained from jpeg_get_small/large */
133 long total_space_allocated;
134
135 /* alloc_sarray and alloc_barray set this value for use by virtual
136 * array routines.
137 */
138 JDIMENSION last_rowsperchunk; /* from most recent alloc_sarray/barray */
139 } my_memory_mgr;
140
141 typedef my_memory_mgr * my_mem_ptr;
142
143
144 /*
145 * The control blocks for virtual arrays.
146 * Note that these blocks are allocated in the "small" pool area.
147 * System-dependent info for the associated backing store (if any) is hidden
148 * inside the backing_store_info struct.
149 */
150
151 struct jvirt_sarray_control {
152 JSAMPARRAY mem_buffer; /* => the in-memory buffer */
153 JDIMENSION rows_in_array; /* total virtual array height */
154 JDIMENSION samplesperrow; /* width of array (and of memory buffer) */
155 JDIMENSION maxaccess; /* max rows accessed by access_virt_sarray */
156 JDIMENSION rows_in_mem; /* height of memory buffer */
157 JDIMENSION rowsperchunk; /* allocation chunk size in mem_buffer */
158 JDIMENSION cur_start_row; /* first logical row # in the buffer */
159 JDIMENSION first_undef_row; /* row # of first uninitialized row */
160 boolean pre_zero; /* pre-zero mode requested? */
161 boolean dirty; /* do current buffer contents need written? */
162 boolean b_s_open; /* is backing-store data valid? */
163 jvirt_sarray_ptr next; /* link to next virtual sarray control block */
164 backing_store_info b_s_info; /* System-dependent control info */
165 };
166
167 struct jvirt_barray_control {
168 JBLOCKARRAY mem_buffer; /* => the in-memory buffer */
169 JDIMENSION rows_in_array; /* total virtual array height */
170 JDIMENSION blocksperrow; /* width of array (and of memory buffer) */
171 JDIMENSION maxaccess; /* max rows accessed by access_virt_barray */
172 JDIMENSION rows_in_mem; /* height of memory buffer */
173 JDIMENSION rowsperchunk; /* allocation chunk size in mem_buffer */
174 JDIMENSION cur_start_row; /* first logical row # in the buffer */
175 JDIMENSION first_undef_row; /* row # of first uninitialized row */
176 boolean pre_zero; /* pre-zero mode requested? */
177 boolean dirty; /* do current buffer contents need written? */
178 boolean b_s_open; /* is backing-store data valid? */
179 jvirt_barray_ptr next; /* link to next virtual barray control block */
180 backing_store_info b_s_info; /* System-dependent control info */
181 };
182
183
184 #ifdef MEM_STATS /* optional extra stuff for statistics */
185
186 LOCAL(void)
187 print_mem_stats (j_common_ptr cinfo, int pool_id)
188 {
189 my_mem_ptr mem = (my_mem_ptr) cinfo->mem;
190 small_pool_ptr shdr_ptr;
191 large_pool_ptr lhdr_ptr;
192
193 /* Since this is only a debugging stub, we can cheat a little by using
194 * fprintf directly rather than going through the trace message code.
195 * This is helpful because message parm array can't handle longs.
196 */
197 fprintf(stderr, "Freeing pool %d, total space = %ld\n",
198 pool_id, mem->total_space_allocated);
199
200 for (lhdr_ptr = mem->large_list[pool_id]; lhdr_ptr != NULL;
201 lhdr_ptr = lhdr_ptr->hdr.next) {
202 fprintf(stderr, " Large chunk used %ld\n",
203 (long) lhdr_ptr->hdr.bytes_used);
204 }
205
206 for (shdr_ptr = mem->small_list[pool_id]; shdr_ptr != NULL;
207 shdr_ptr = shdr_ptr->hdr.next) {
208 fprintf(stderr, " Small chunk used %ld free %ld\n",
209 (long) shdr_ptr->hdr.bytes_used,
210 (long) shdr_ptr->hdr.bytes_left);
211 }
212 }
213
214 #endif /* MEM_STATS */
215
216
217 LOCAL(noreturn_t)
218 out_of_memory (j_common_ptr cinfo, int which)
219 /* Report an out-of-memory error and stop execution */
220 /* If we compiled MEM_STATS support, report alloc requests before dying */
221 {
222 #ifdef MEM_STATS
223 cinfo->err->trace_level = 2; /* force self_destruct to report stats */
224 #endif
225 ERREXIT1(cinfo, JERR_OUT_OF_MEMORY, which);
226 }
227
228
229 /*
230 * Allocation of "small" objects.
231 *
232 * For these, we use pooled storage. When a new pool must be created,
233 * we try to get enough space for the current request plus a "slop" factor,
234 * where the slop will be the amount of leftover space in the new pool.
235 * The speed vs. space tradeoff is largely determined by the slop values.
236 * A different slop value is provided for each pool class (lifetime),
237 * and we also distinguish the first pool of a class from later ones.
238 * NOTE: the values given work fairly well on both 16- and 32-bit-int
239 * machines, but may be too small if longs are 64 bits or more.
240 */
241
242 static const size_t first_pool_slop[JPOOL_NUMPOOLS] =
243 {
244 1600, /* first PERMANENT pool */
245 16000 /* first IMAGE pool */
246 };
247
248 static const size_t extra_pool_slop[JPOOL_NUMPOOLS] =
249 {
250 0, /* additional PERMANENT pools */
251 5000 /* additional IMAGE pools */
252 };
253
254 #define MIN_SLOP 50 /* greater than 0 to avoid futile looping */
255
256
257 METHODDEF(void *)
258 alloc_small (j_common_ptr cinfo, int pool_id, size_t sizeofobject)
259 /* Allocate a "small" object */
260 {
261 my_mem_ptr mem = (my_mem_ptr) cinfo->mem;
262 small_pool_ptr hdr_ptr, prev_hdr_ptr;
263 char * data_ptr;
264 size_t odd_bytes, min_request, slop;
265
266 /* Check for unsatisfiable request (do now to ensure no overflow below) */
267 if (sizeofobject > (size_t) (MAX_ALLOC_CHUNK-SIZEOF(small_pool_hdr)))
268 out_of_memory(cinfo, 1); /* request exceeds malloc's ability */
269
270 /* Round up the requested size to a multiple of SIZEOF(ALIGN_TYPE) */
271 odd_bytes = sizeofobject % SIZEOF(ALIGN_TYPE);
272 if (odd_bytes > 0)
273 sizeofobject += SIZEOF(ALIGN_TYPE) - odd_bytes;
274
275 /* See if space is available in any existing pool */
276 if (pool_id < 0 || pool_id >= JPOOL_NUMPOOLS)
277 ERREXIT1(cinfo, JERR_BAD_POOL_ID, pool_id); /* safety check */
278 prev_hdr_ptr = NULL;
279 hdr_ptr = mem->small_list[pool_id];
280 while (hdr_ptr != NULL) {
281 if (hdr_ptr->hdr.bytes_left >= sizeofobject)
282 break; /* found pool with enough space */
283 prev_hdr_ptr = hdr_ptr;
284 hdr_ptr = hdr_ptr->hdr.next;
285 }
286
287 /* Time to make a new pool? */
288 if (hdr_ptr == NULL) {
289 /* min_request is what we need now, slop is what will be leftover */
290 min_request = sizeofobject + SIZEOF(small_pool_hdr);
291 if (prev_hdr_ptr == NULL) /* first pool in class? */
292 slop = first_pool_slop[pool_id];
293 else
294 slop = extra_pool_slop[pool_id];
295 /* Don't ask for more than MAX_ALLOC_CHUNK */
296 if (slop > (size_t) (MAX_ALLOC_CHUNK-min_request))
297 slop = (size_t) (MAX_ALLOC_CHUNK-min_request);
298 /* Try to get space, if fail reduce slop and try again */
299 for (;;) {
300 hdr_ptr = (small_pool_ptr) jpeg_get_small(cinfo, min_request + slop);
301 if (hdr_ptr != NULL)
302 break;
303 slop /= 2;
304 if (slop < MIN_SLOP) /* give up when it gets real small */
305 out_of_memory(cinfo, 2); /* jpeg_get_small failed */
306 }
307 mem->total_space_allocated += min_request + slop;
308 /* Success, initialize the new pool header and add to end of list */
309 hdr_ptr->hdr.next = NULL;
310 hdr_ptr->hdr.bytes_used = 0;
311 hdr_ptr->hdr.bytes_left = sizeofobject + slop;
312 if (prev_hdr_ptr == NULL) /* first pool in class? */
313 mem->small_list[pool_id] = hdr_ptr;
314 else
315 prev_hdr_ptr->hdr.next = hdr_ptr;
316 }
317
318 /* OK, allocate the object from the current pool */
319 data_ptr = (char *) (hdr_ptr + 1); /* point to first data byte in pool */
320 data_ptr += hdr_ptr->hdr.bytes_used; /* point to place for object */
321 hdr_ptr->hdr.bytes_used += sizeofobject;
322 hdr_ptr->hdr.bytes_left -= sizeofobject;
323
324 return (void *) data_ptr;
325 }
326
327
328 /*
329 * Allocation of "large" objects.
330 *
331 * The external semantics of these are the same as "small" objects,
332 * except that FAR pointers are used on 80x86. However the pool
333 * management heuristics are quite different. We assume that each
334 * request is large enough that it may as well be passed directly to
335 * jpeg_get_large; the pool management just links everything together
336 * so that we can free it all on demand.
337 * Note: the major use of "large" objects is in JSAMPARRAY and JBLOCKARRAY
338 * structures. The routines that create these structures (see below)
339 * deliberately bunch rows together to ensure a large request size.
340 */
341
342 METHODDEF(void FAR *)
343 alloc_large (j_common_ptr cinfo, int pool_id, size_t sizeofobject)
344 /* Allocate a "large" object */
345 {
346 my_mem_ptr mem = (my_mem_ptr) cinfo->mem;
347 large_pool_ptr hdr_ptr;
348 size_t odd_bytes;
349
350 /* Check for unsatisfiable request (do now to ensure no overflow below) */
351 if (sizeofobject > (size_t) (MAX_ALLOC_CHUNK-SIZEOF(large_pool_hdr)))
352 out_of_memory(cinfo, 3); /* request exceeds malloc's ability */
353
354 /* Round up the requested size to a multiple of SIZEOF(ALIGN_TYPE) */
355 odd_bytes = sizeofobject % SIZEOF(ALIGN_TYPE);
356 if (odd_bytes > 0)
357 sizeofobject += SIZEOF(ALIGN_TYPE) - odd_bytes;
358
359 /* Always make a new pool */
360 if (pool_id < 0 || pool_id >= JPOOL_NUMPOOLS)
361 ERREXIT1(cinfo, JERR_BAD_POOL_ID, pool_id); /* safety check */
362
363 hdr_ptr = (large_pool_ptr) jpeg_get_large(cinfo, sizeofobject +
364 SIZEOF(large_pool_hdr));
365 if (hdr_ptr == NULL)
366 out_of_memory(cinfo, 4); /* jpeg_get_large failed */
367 mem->total_space_allocated += sizeofobject + SIZEOF(large_pool_hdr);
368
369 /* Success, initialize the new pool header and add to list */
370 hdr_ptr->hdr.next = mem->large_list[pool_id];
371 /* We maintain space counts in each pool header for statistical purposes,
372 * even though they are not needed for allocation.
373 */
374 hdr_ptr->hdr.bytes_used = sizeofobject;
375 hdr_ptr->hdr.bytes_left = 0;
376 mem->large_list[pool_id] = hdr_ptr;
377
378 return (void FAR *) (hdr_ptr + 1); /* point to first data byte in pool */
379 }
380
381
382 /*
383 * Creation of 2-D sample arrays.
384 * The pointers are in near heap, the samples themselves in FAR heap.
385 *
386 * To minimize allocation overhead and to allow I/O of large contiguous
387 * blocks, we allocate the sample rows in groups of as many rows as possible
388 * without exceeding MAX_ALLOC_CHUNK total bytes per allocation request.
389 * NB: the virtual array control routines, later in this file, know about
390 * this chunking of rows. The rowsperchunk value is left in the mem manager
391 * object so that it can be saved away if this sarray is the workspace for
392 * a virtual array.
393 */
394
395 METHODDEF(JSAMPARRAY)
396 alloc_sarray (j_common_ptr cinfo, int pool_id,
397 JDIMENSION samplesperrow, JDIMENSION numrows)
398 /* Allocate a 2-D sample array */
399 {
400 my_mem_ptr mem = (my_mem_ptr) cinfo->mem;
401 JSAMPARRAY result;
402 JSAMPROW workspace;
403 JDIMENSION rowsperchunk, currow, i;
404 long ltemp;
405
406 /* Calculate max # of rows allowed in one allocation chunk */
407 ltemp = (MAX_ALLOC_CHUNK-SIZEOF(large_pool_hdr)) /
408 ((long) samplesperrow * SIZEOF(JSAMPLE));
409 if (ltemp <= 0)
410 ERREXIT(cinfo, JERR_WIDTH_OVERFLOW);
411 if (ltemp < (long) numrows)
412 rowsperchunk = (JDIMENSION) ltemp;
413 else
414 rowsperchunk = numrows;
415 mem->last_rowsperchunk = rowsperchunk;
416
417 /* Get space for row pointers (small object) */
418 result = (JSAMPARRAY) alloc_small(cinfo, pool_id,
419 (size_t) (numrows * SIZEOF(JSAMPROW)));
420
421 /* Get the rows themselves (large objects) */
422 currow = 0;
423 while (currow < numrows) {
424 rowsperchunk = MIN(rowsperchunk, numrows - currow);
425 workspace = (JSAMPROW) alloc_large(cinfo, pool_id,
426 (size_t) ((size_t) rowsperchunk * (size_t) samplesperrow
427 * SIZEOF(JSAMPLE)));
428 for (i = rowsperchunk; i > 0; i--) {
429 result[currow++] = workspace;
430 workspace += samplesperrow;
431 }
432 }
433
434 return result;
435 }
436
437
438 /*
439 * Creation of 2-D coefficient-block arrays.
440 * This is essentially the same as the code for sample arrays, above.
441 */
442
443 METHODDEF(JBLOCKARRAY)
444 alloc_barray (j_common_ptr cinfo, int pool_id,
445 JDIMENSION blocksperrow, JDIMENSION numrows)
446 /* Allocate a 2-D coefficient-block array */
447 {
448 my_mem_ptr mem = (my_mem_ptr) cinfo->mem;
449 JBLOCKARRAY result;
450 JBLOCKROW workspace;
451 JDIMENSION rowsperchunk, currow, i;
452 long ltemp;
453
454 /* Calculate max # of rows allowed in one allocation chunk */
455 ltemp = (MAX_ALLOC_CHUNK-SIZEOF(large_pool_hdr)) /
456 ((long) blocksperrow * SIZEOF(JBLOCK));
457 if (ltemp <= 0)
458 ERREXIT(cinfo, JERR_WIDTH_OVERFLOW);
459 if (ltemp < (long) numrows)
460 rowsperchunk = (JDIMENSION) ltemp;
461 else
462 rowsperchunk = numrows;
463 mem->last_rowsperchunk = rowsperchunk;
464
465 /* Get space for row pointers (small object) */
466 result = (JBLOCKARRAY) alloc_small(cinfo, pool_id,
467 (size_t) (numrows * SIZEOF(JBLOCKROW)));
468
469 /* Get the rows themselves (large objects) */
470 currow = 0;
471 while (currow < numrows) {
472 rowsperchunk = MIN(rowsperchunk, numrows - currow);
473 workspace = (JBLOCKROW) alloc_large(cinfo, pool_id,
474 (size_t) ((size_t) rowsperchunk * (size_t) blocksperrow
475 * SIZEOF(JBLOCK)));
476 for (i = rowsperchunk; i > 0; i--) {
477 result[currow++] = workspace;
478 workspace += blocksperrow;
479 }
480 }
481
482 return result;
483 }
484
485
486 /*
487 * About virtual array management:
488 *
489 * The above "normal" array routines are only used to allocate strip buffers
490 * (as wide as the image, but just a few rows high). Full-image-sized buffers
491 * are handled as "virtual" arrays. The array is still accessed a strip at a
492 * time, but the memory manager must save the whole array for repeated
493 * accesses. The intended implementation is that there is a strip buffer in
494 * memory (as high as is possible given the desired memory limit), plus a
495 * backing file that holds the rest of the array.
496 *
497 * The request_virt_array routines are told the total size of the image and
498 * the maximum number of rows that will be accessed at once. The in-memory
499 * buffer must be at least as large as the maxaccess value.
500 *
501 * The request routines create control blocks but not the in-memory buffers.
502 * That is postponed until realize_virt_arrays is called. At that time the
503 * total amount of space needed is known (approximately, anyway), so free
504 * memory can be divided up fairly.
505 *
506 * The access_virt_array routines are responsible for making a specific strip
507 * area accessible (after reading or writing the backing file, if necessary).
508 * Note that the access routines are told whether the caller intends to modify
509 * the accessed strip; during a read-only pass this saves having to rewrite
510 * data to disk. The access routines are also responsible for pre-zeroing
511 * any newly accessed rows, if pre-zeroing was requested.
512 *
513 * In current usage, the access requests are usually for nonoverlapping
514 * strips; that is, successive access start_row numbers differ by exactly
515 * num_rows = maxaccess. This means we can get good performance with simple
516 * buffer dump/reload logic, by making the in-memory buffer be a multiple
517 * of the access height; then there will never be accesses across bufferload
518 * boundaries. The code will still work with overlapping access requests,
519 * but it doesn't handle bufferload overlaps very efficiently.
520 */
521
522
523 METHODDEF(jvirt_sarray_ptr)
524 request_virt_sarray (j_common_ptr cinfo, int pool_id, boolean pre_zero,
525 JDIMENSION samplesperrow, JDIMENSION numrows,
526 JDIMENSION maxaccess)
527 /* Request a virtual 2-D sample array */
528 {
529 my_mem_ptr mem = (my_mem_ptr) cinfo->mem;
530 jvirt_sarray_ptr result;
531
532 /* Only IMAGE-lifetime virtual arrays are currently supported */
533 if (pool_id != JPOOL_IMAGE)
534 ERREXIT1(cinfo, JERR_BAD_POOL_ID, pool_id); /* safety check */
535
536 /* get control block */
537 result = (jvirt_sarray_ptr) alloc_small(cinfo, pool_id,
538 SIZEOF(struct jvirt_sarray_control));
539
540 result->mem_buffer = NULL; /* marks array not yet realized */
541 result->rows_in_array = numrows;
542 result->samplesperrow = samplesperrow;
543 result->maxaccess = maxaccess;
544 result->pre_zero = pre_zero;
545 result->b_s_open = FALSE; /* no associated backing-store object */
546 result->next = mem->virt_sarray_list; /* add to list of virtual arrays */
547 mem->virt_sarray_list = result;
548
549 return result;
550 }
551
552
553 METHODDEF(jvirt_barray_ptr)
554 request_virt_barray (j_common_ptr cinfo, int pool_id, boolean pre_zero,
555 JDIMENSION blocksperrow, JDIMENSION numrows,
556 JDIMENSION maxaccess)
557 /* Request a virtual 2-D coefficient-block array */
558 {
559 my_mem_ptr mem = (my_mem_ptr) cinfo->mem;
560 jvirt_barray_ptr result;
561
562 /* Only IMAGE-lifetime virtual arrays are currently supported */
563 if (pool_id != JPOOL_IMAGE)
564 ERREXIT1(cinfo, JERR_BAD_POOL_ID, pool_id); /* safety check */
565
566 /* get control block */
567 result = (jvirt_barray_ptr) alloc_small(cinfo, pool_id,
568 SIZEOF(struct jvirt_barray_control));
569
570 result->mem_buffer = NULL; /* marks array not yet realized */
571 result->rows_in_array = numrows;
572 result->blocksperrow = blocksperrow;
573 result->maxaccess = maxaccess;
574 result->pre_zero = pre_zero;
575 result->b_s_open = FALSE; /* no associated backing-store object */
576 result->next = mem->virt_barray_list; /* add to list of virtual arrays */
577 mem->virt_barray_list = result;
578
579 return result;
580 }
581
582
583 METHODDEF(void)
584 realize_virt_arrays (j_common_ptr cinfo)
585 /* Allocate the in-memory buffers for any unrealized virtual arrays */
586 {
587 my_mem_ptr mem = (my_mem_ptr) cinfo->mem;
588 long space_per_minheight, maximum_space, avail_mem;
589 long minheights, max_minheights;
590 jvirt_sarray_ptr sptr;
591 jvirt_barray_ptr bptr;
592
593 /* Compute the minimum space needed (maxaccess rows in each buffer)
594 * and the maximum space needed (full image height in each buffer).
595 * These may be of use to the system-dependent jpeg_mem_available routine.
596 */
597 space_per_minheight = 0;
598 maximum_space = 0;
599 for (sptr = mem->virt_sarray_list; sptr != NULL; sptr = sptr->next) {
600 if (sptr->mem_buffer == NULL) { /* if not realized yet */
601 space_per_minheight += (long) sptr->maxaccess *
602 (long) sptr->samplesperrow * SIZEOF(JSAMPLE);
603 maximum_space += (long) sptr->rows_in_array *
604 (long) sptr->samplesperrow * SIZEOF(JSAMPLE);
605 }
606 }
607 for (bptr = mem->virt_barray_list; bptr != NULL; bptr = bptr->next) {
608 if (bptr->mem_buffer == NULL) { /* if not realized yet */
609 space_per_minheight += (long) bptr->maxaccess *
610 (long) bptr->blocksperrow * SIZEOF(JBLOCK);
611 maximum_space += (long) bptr->rows_in_array *
612 (long) bptr->blocksperrow * SIZEOF(JBLOCK);
613 }
614 }
615
616 if (space_per_minheight <= 0)
617 return; /* no unrealized arrays, no work */
618
619 /* Determine amount of memory to actually use; this is system-dependent. */
620 avail_mem = jpeg_mem_available(cinfo, space_per_minheight, maximum_space,
621 mem->total_space_allocated);
622
623 /* If the maximum space needed is available, make all the buffers full
624 * height; otherwise parcel it out with the same number of minheights
625 * in each buffer.
626 */
627 if (avail_mem >= maximum_space)
628 max_minheights = 1000000000L;
629 else {
630 max_minheights = avail_mem / space_per_minheight;
631 /* If there doesn't seem to be enough space, try to get the minimum
632 * anyway. This allows a "stub" implementation of jpeg_mem_available().
633 */
634 if (max_minheights <= 0)
635 max_minheights = 1;
636 }
637
638 /* Allocate the in-memory buffers and initialize backing store as needed. */
639
640 for (sptr = mem->virt_sarray_list; sptr != NULL; sptr = sptr->next) {
641 if (sptr->mem_buffer == NULL) { /* if not realized yet */
642 minheights = ((long) sptr->rows_in_array - 1L) / sptr->maxaccess + 1L;
643 if (minheights <= max_minheights) {
644 /* This buffer fits in memory */
645 sptr->rows_in_mem = sptr->rows_in_array;
646 } else {
647 /* It doesn't fit in memory, create backing store. */
648 sptr->rows_in_mem = (JDIMENSION) (max_minheights * sptr->maxaccess);
649 jpeg_open_backing_store(cinfo, & sptr->b_s_info,
650 (long) sptr->rows_in_array *
651 (long) sptr->samplesperrow *
652 (long) SIZEOF(JSAMPLE));
653 sptr->b_s_open = TRUE;
654 }
655 sptr->mem_buffer = alloc_sarray(cinfo, JPOOL_IMAGE,
656 sptr->samplesperrow, sptr->rows_in_mem);
657 sptr->rowsperchunk = mem->last_rowsperchunk;
658 sptr->cur_start_row = 0;
659 sptr->first_undef_row = 0;
660 sptr->dirty = FALSE;
661 }
662 }
663
664 for (bptr = mem->virt_barray_list; bptr != NULL; bptr = bptr->next) {
665 if (bptr->mem_buffer == NULL) { /* if not realized yet */
666 minheights = ((long) bptr->rows_in_array - 1L) / bptr->maxaccess + 1L;
667 if (minheights <= max_minheights) {
668 /* This buffer fits in memory */
669 bptr->rows_in_mem = bptr->rows_in_array;
670 } else {
671 /* It doesn't fit in memory, create backing store. */
672 bptr->rows_in_mem = (JDIMENSION) (max_minheights * bptr->maxaccess);
673 jpeg_open_backing_store(cinfo, & bptr->b_s_info,
674 (long) bptr->rows_in_array *
675 (long) bptr->blocksperrow *
676 (long) SIZEOF(JBLOCK));
677 bptr->b_s_open = TRUE;
678 }
679 bptr->mem_buffer = alloc_barray(cinfo, JPOOL_IMAGE,
680 bptr->blocksperrow, bptr->rows_in_mem);
681 bptr->rowsperchunk = mem->last_rowsperchunk;
682 bptr->cur_start_row = 0;
683 bptr->first_undef_row = 0;
684 bptr->dirty = FALSE;
685 }
686 }
687 }
688
689
690 LOCAL(void)
691 do_sarray_io (j_common_ptr cinfo, jvirt_sarray_ptr ptr, boolean writing)
692 /* Do backing store read or write of a virtual sample array */
693 {
694 long bytesperrow, file_offset, byte_count, rows, thisrow, i;
695
696 bytesperrow = (long) ptr->samplesperrow * SIZEOF(JSAMPLE);
697 file_offset = ptr->cur_start_row * bytesperrow;
698 /* Loop to read or write each allocation chunk in mem_buffer */
699 for (i = 0; i < (long) ptr->rows_in_mem; i += ptr->rowsperchunk) {
700 /* One chunk, but check for short chunk at end of buffer */
701 rows = MIN((long) ptr->rowsperchunk, (long) ptr->rows_in_mem - i);
702 /* Transfer no more than is currently defined */
703 thisrow = (long) ptr->cur_start_row + i;
704 rows = MIN(rows, (long) ptr->first_undef_row - thisrow);
705 /* Transfer no more than fits in file */
706 rows = MIN(rows, (long) ptr->rows_in_array - thisrow);
707 if (rows <= 0) /* this chunk might be past end of file! */
708 break;
709 byte_count = rows * bytesperrow;
710 if (writing)
711 (*ptr->b_s_info.write_backing_store) (cinfo, & ptr->b_s_info,
712 (void FAR *) ptr->mem_buffer[i],
713 file_offset, byte_count);
714 else
715 (*ptr->b_s_info.read_backing_store) (cinfo, & ptr->b_s_info,
716 (void FAR *) ptr->mem_buffer[i],
717 file_offset, byte_count);
718 file_offset += byte_count;
719 }
720 }
721
722
723 LOCAL(void)
724 do_barray_io (j_common_ptr cinfo, jvirt_barray_ptr ptr, boolean writing)
725 /* Do backing store read or write of a virtual coefficient-block array */
726 {
727 long bytesperrow, file_offset, byte_count, rows, thisrow, i;
728
729 bytesperrow = (long) ptr->blocksperrow * SIZEOF(JBLOCK);
730 file_offset = ptr->cur_start_row * bytesperrow;
731 /* Loop to read or write each allocation chunk in mem_buffer */
732 for (i = 0; i < (long) ptr->rows_in_mem; i += ptr->rowsperchunk) {
733 /* One chunk, but check for short chunk at end of buffer */
734 rows = MIN((long) ptr->rowsperchunk, (long) ptr->rows_in_mem - i);
735 /* Transfer no more than is currently defined */
736 thisrow = (long) ptr->cur_start_row + i;
737 rows = MIN(rows, (long) ptr->first_undef_row - thisrow);
738 /* Transfer no more than fits in file */
739 rows = MIN(rows, (long) ptr->rows_in_array - thisrow);
740 if (rows <= 0) /* this chunk might be past end of file! */
741 break;
742 byte_count = rows * bytesperrow;
743 if (writing)
744 (*ptr->b_s_info.write_backing_store) (cinfo, & ptr->b_s_info,
745 (void FAR *) ptr->mem_buffer[i],
746 file_offset, byte_count);
747 else
748 (*ptr->b_s_info.read_backing_store) (cinfo, & ptr->b_s_info,
749 (void FAR *) ptr->mem_buffer[i],
750 file_offset, byte_count);
751 file_offset += byte_count;
752 }
753 }
754
755
756 METHODDEF(JSAMPARRAY)
757 access_virt_sarray (j_common_ptr cinfo, jvirt_sarray_ptr ptr,
758 JDIMENSION start_row, JDIMENSION num_rows,
759 boolean writable)
760 /* Access the part of a virtual sample array starting at start_row */
761 /* and extending for num_rows rows. writable is true if */
762 /* caller intends to modify the accessed area. */
763 {
764 JDIMENSION end_row = start_row + num_rows;
765 JDIMENSION undef_row;
766
767 /* debugging check */
768 if (end_row > ptr->rows_in_array || num_rows > ptr->maxaccess ||
769 ptr->mem_buffer == NULL)
770 ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS);
771
772 /* Make the desired part of the virtual array accessible */
773 if (start_row < ptr->cur_start_row ||
774 end_row > ptr->cur_start_row+ptr->rows_in_mem) {
775 if (! ptr->b_s_open)
776 ERREXIT(cinfo, JERR_VIRTUAL_BUG);
777 /* Flush old buffer contents if necessary */
778 if (ptr->dirty) {
779 do_sarray_io(cinfo, ptr, TRUE);
780 ptr->dirty = FALSE;
781 }
782 /* Decide what part of virtual array to access.
783 * Algorithm: if target address > current window, assume forward scan,
784 * load starting at target address. If target address < current window,
785 * assume backward scan, load so that target area is top of window.
786 * Note that when switching from forward write to forward read, will have
787 * start_row = 0, so the limiting case applies and we load from 0 anyway.
788 */
789 if (start_row > ptr->cur_start_row) {
790 ptr->cur_start_row = start_row;
791 } else {
792 /* use long arithmetic here to avoid overflow & unsigned problems */
793 long ltemp;
794
795 ltemp = (long) end_row - (long) ptr->rows_in_mem;
796 if (ltemp < 0)
797 ltemp = 0; /* don't fall off front end of file */
798 ptr->cur_start_row = (JDIMENSION) ltemp;
799 }
800 /* Read in the selected part of the array.
801 * During the initial write pass, we will do no actual read
802 * because the selected part is all undefined.
803 */
804 do_sarray_io(cinfo, ptr, FALSE);
805 }
806 /* Ensure the accessed part of the array is defined; prezero if needed.
807 * To improve locality of access, we only prezero the part of the array
808 * that the caller is about to access, not the entire in-memory array.
809 */
810 if (ptr->first_undef_row < end_row) {
811 if (ptr->first_undef_row < start_row) {
812 if (writable) /* writer skipped over a section of array */
813 ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS);
814 undef_row = start_row; /* but reader is allowed to read ahead */
815 } else {
816 undef_row = ptr->first_undef_row;
817 }
818 if (writable)
819 ptr->first_undef_row = end_row;
820 if (ptr->pre_zero) {
821 size_t bytesperrow = (size_t) ptr->samplesperrow * SIZEOF(JSAMPLE);
822 undef_row -= ptr->cur_start_row; /* make indexes relative to buffer */
823 end_row -= ptr->cur_start_row;
824 while (undef_row < end_row) {
825 FMEMZERO((void FAR *) ptr->mem_buffer[undef_row], bytesperrow);
826 undef_row++;
827 }
828 } else {
829 if (! writable) /* reader looking at undefined data */
830 ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS);
831 }
832 }
833 /* Flag the buffer dirty if caller will write in it */
834 if (writable)
835 ptr->dirty = TRUE;
836 /* Return address of proper part of the buffer */
837 return ptr->mem_buffer + (start_row - ptr->cur_start_row);
838 }
839
840
841 METHODDEF(JBLOCKARRAY)
842 access_virt_barray (j_common_ptr cinfo, jvirt_barray_ptr ptr,
843 JDIMENSION start_row, JDIMENSION num_rows,
844 boolean writable)
845 /* Access the part of a virtual block array starting at start_row */
846 /* and extending for num_rows rows. writable is true if */
847 /* caller intends to modify the accessed area. */
848 {
849 JDIMENSION end_row = start_row + num_rows;
850 JDIMENSION undef_row;
851
852 /* debugging check */
853 if (end_row > ptr->rows_in_array || num_rows > ptr->maxaccess ||
854 ptr->mem_buffer == NULL)
855 ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS);
856
857 /* Make the desired part of the virtual array accessible */
858 if (start_row < ptr->cur_start_row ||
859 end_row > ptr->cur_start_row+ptr->rows_in_mem) {
860 if (! ptr->b_s_open)
861 ERREXIT(cinfo, JERR_VIRTUAL_BUG);
862 /* Flush old buffer contents if necessary */
863 if (ptr->dirty) {
864 do_barray_io(cinfo, ptr, TRUE);
865 ptr->dirty = FALSE;
866 }
867 /* Decide what part of virtual array to access.
868 * Algorithm: if target address > current window, assume forward scan,
869 * load starting at target address. If target address < current window,
870 * assume backward scan, load so that target area is top of window.
871 * Note that when switching from forward write to forward read, will have
872 * start_row = 0, so the limiting case applies and we load from 0 anyway.
873 */
874 if (start_row > ptr->cur_start_row) {
875 ptr->cur_start_row = start_row;
876 } else {
877 /* use long arithmetic here to avoid overflow & unsigned problems */
878 long ltemp;
879
880 ltemp = (long) end_row - (long) ptr->rows_in_mem;
881 if (ltemp < 0)
882 ltemp = 0; /* don't fall off front end of file */
883 ptr->cur_start_row = (JDIMENSION) ltemp;
884 }
885 /* Read in the selected part of the array.
886 * During the initial write pass, we will do no actual read
887 * because the selected part is all undefined.
888 */
889 do_barray_io(cinfo, ptr, FALSE);
890 }
891 /* Ensure the accessed part of the array is defined; prezero if needed.
892 * To improve locality of access, we only prezero the part of the array
893 * that the caller is about to access, not the entire in-memory array.
894 */
895 if (ptr->first_undef_row < end_row) {
896 if (ptr->first_undef_row < start_row) {
897 if (writable) /* writer skipped over a section of array */
898 ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS);
899 undef_row = start_row; /* but reader is allowed to read ahead */
900 } else {
901 undef_row = ptr->first_undef_row;
902 }
903 if (writable)
904 ptr->first_undef_row = end_row;
905 if (ptr->pre_zero) {
906 size_t bytesperrow = (size_t) ptr->blocksperrow * SIZEOF(JBLOCK);
907 undef_row -= ptr->cur_start_row; /* make indexes relative to buffer */
908 end_row -= ptr->cur_start_row;
909 while (undef_row < end_row) {
910 FMEMZERO((void FAR *) ptr->mem_buffer[undef_row], bytesperrow);
911 undef_row++;
912 }
913 } else {
914 if (! writable) /* reader looking at undefined data */
915 ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS);
916 }
917 }
918 /* Flag the buffer dirty if caller will write in it */
919 if (writable)
920 ptr->dirty = TRUE;
921 /* Return address of proper part of the buffer */
922 return ptr->mem_buffer + (start_row - ptr->cur_start_row);
923 }
924
925
926 /*
927 * Release all objects belonging to a specified pool.
928 */
929
930 METHODDEF(void)
931 free_pool (j_common_ptr cinfo, int pool_id)
932 {
933 my_mem_ptr mem = (my_mem_ptr) cinfo->mem;
934 small_pool_ptr shdr_ptr;
935 large_pool_ptr lhdr_ptr;
936 size_t space_freed;
937
938 if (pool_id < 0 || pool_id >= JPOOL_NUMPOOLS)
939 ERREXIT1(cinfo, JERR_BAD_POOL_ID, pool_id); /* safety check */
940
941 #ifdef MEM_STATS
942 if (cinfo->err->trace_level > 1)
943 print_mem_stats(cinfo, pool_id); /* print pool's memory usage statistics */
944 #endif
945
946 /* If freeing IMAGE pool, close any virtual arrays first */
947 if (pool_id == JPOOL_IMAGE) {
948 jvirt_sarray_ptr sptr;
949 jvirt_barray_ptr bptr;
950
951 for (sptr = mem->virt_sarray_list; sptr != NULL; sptr = sptr->next) {
952 if (sptr->b_s_open) { /* there may be no backing store */
953 sptr->b_s_open = FALSE; /* prevent recursive close if error */
954 (*sptr->b_s_info.close_backing_store) (cinfo, & sptr->b_s_info);
955 }
956 }
957 mem->virt_sarray_list = NULL;
958 for (bptr = mem->virt_barray_list; bptr != NULL; bptr = bptr->next) {
959 if (bptr->b_s_open) { /* there may be no backing store */
960 bptr->b_s_open = FALSE; /* prevent recursive close if error */
961 (*bptr->b_s_info.close_backing_store) (cinfo, & bptr->b_s_info);
962 }
963 }
964 mem->virt_barray_list = NULL;
965 }
966
967 /* Release large objects */
968 lhdr_ptr = mem->large_list[pool_id];
969 mem->large_list[pool_id] = NULL;
970
971 while (lhdr_ptr != NULL) {
972 large_pool_ptr next_lhdr_ptr = lhdr_ptr->hdr.next;
973 space_freed = lhdr_ptr->hdr.bytes_used +
974 lhdr_ptr->hdr.bytes_left +
975 SIZEOF(large_pool_hdr);
976 jpeg_free_large(cinfo, (void FAR *) lhdr_ptr, space_freed);
977 mem->total_space_allocated -= space_freed;
978 lhdr_ptr = next_lhdr_ptr;
979 }
980
981 /* Release small objects */
982 shdr_ptr = mem->small_list[pool_id];
983 mem->small_list[pool_id] = NULL;
984
985 while (shdr_ptr != NULL) {
986 small_pool_ptr next_shdr_ptr = shdr_ptr->hdr.next;
987 space_freed = shdr_ptr->hdr.bytes_used +
988 shdr_ptr->hdr.bytes_left +
989 SIZEOF(small_pool_hdr);
990 jpeg_free_small(cinfo, (void *) shdr_ptr, space_freed);
991 mem->total_space_allocated -= space_freed;
992 shdr_ptr = next_shdr_ptr;
993 }
994 }
995
996
997 /*
998 * Close up shop entirely.
999 * Note that this cannot be called unless cinfo->mem is non-NULL.
1000 */
1001
1002 METHODDEF(void)
1003 self_destruct (j_common_ptr cinfo)
1004 {
1005 int pool;
1006
1007 /* Close all backing store, release all memory.
1008 * Releasing pools in reverse order might help avoid fragmentation
1009 * with some (brain-damaged) malloc libraries.
1010 */
1011 for (pool = JPOOL_NUMPOOLS-1; pool >= JPOOL_PERMANENT; pool--) {
1012 free_pool(cinfo, pool);
1013 }
1014
1015 /* Release the memory manager control block too. */
1016 jpeg_free_small(cinfo, (void *) cinfo->mem, SIZEOF(my_memory_mgr));
1017 cinfo->mem = NULL; /* ensures I will be called only once */
1018
1019 jpeg_mem_term(cinfo); /* system-dependent cleanup */
1020 }
1021
1022
1023 /*
1024 * Memory manager initialization.
1025 * When this is called, only the error manager pointer is valid in cinfo!
1026 */
1027
1028 GLOBAL(void)
1029 jinit_memory_mgr (j_common_ptr cinfo)
1030 {
1031 my_mem_ptr mem;
1032 long max_to_use;
1033 int pool;
1034 size_t test_mac;
1035
1036 cinfo->mem = NULL; /* for safety if init fails */
1037
1038 /* Check for configuration errors.
1039 * SIZEOF(ALIGN_TYPE) should be a power of 2; otherwise, it probably
1040 * doesn't reflect any real hardware alignment requirement.
1041 * The test is a little tricky: for X>0, X and X-1 have no one-bits
1042 * in common if and only if X is a power of 2, ie has only one one-bit.
1043 * Some compilers may give an "unreachable code" warning here; ignore it.
1044 */
1045 if ((SIZEOF(ALIGN_TYPE) & (SIZEOF(ALIGN_TYPE)-1)) != 0)
1046 ERREXIT(cinfo, JERR_BAD_ALIGN_TYPE);
1047 /* MAX_ALLOC_CHUNK must be representable as type size_t, and must be
1048 * a multiple of SIZEOF(ALIGN_TYPE).
1049 * Again, an "unreachable code" warning may be ignored here.
1050 * But a "constant too large" warning means you need to fix MAX_ALLOC_CHUNK.
1051 */
1052 test_mac = (size_t) MAX_ALLOC_CHUNK;
1053 if ((long) test_mac != MAX_ALLOC_CHUNK ||
1054 (MAX_ALLOC_CHUNK % SIZEOF(ALIGN_TYPE)) != 0)
1055 ERREXIT(cinfo, JERR_BAD_ALLOC_CHUNK);
1056
1057 max_to_use = jpeg_mem_init(cinfo); /* system-dependent initialization */
1058
1059 /* Attempt to allocate memory manager's control block */
1060 mem = (my_mem_ptr) jpeg_get_small(cinfo, SIZEOF(my_memory_mgr));
1061
1062 if (mem == NULL) {
1063 jpeg_mem_term(cinfo); /* system-dependent cleanup */
1064 ERREXIT1(cinfo, JERR_OUT_OF_MEMORY, 0);
1065 }
1066
1067 /* OK, fill in the method pointers */
1068 mem->pub.alloc_small = alloc_small;
1069 mem->pub.alloc_large = alloc_large;
1070 mem->pub.alloc_sarray = alloc_sarray;
1071 mem->pub.alloc_barray = alloc_barray;
1072 mem->pub.request_virt_sarray = request_virt_sarray;
1073 mem->pub.request_virt_barray = request_virt_barray;
1074 mem->pub.realize_virt_arrays = realize_virt_arrays;
1075 mem->pub.access_virt_sarray = access_virt_sarray;
1076 mem->pub.access_virt_barray = access_virt_barray;
1077 mem->pub.free_pool = free_pool;
1078 mem->pub.self_destruct = self_destruct;
1079
1080 /* Make MAX_ALLOC_CHUNK accessible to other modules */
1081 mem->pub.max_alloc_chunk = MAX_ALLOC_CHUNK;
1082
1083 /* Initialize working state */
1084 mem->pub.max_memory_to_use = max_to_use;
1085
1086 for (pool = JPOOL_NUMPOOLS-1; pool >= JPOOL_PERMANENT; pool--) {
1087 mem->small_list[pool] = NULL;
1088 mem->large_list[pool] = NULL;
1089 }
1090 mem->virt_sarray_list = NULL;
1091 mem->virt_barray_list = NULL;
1092
1093 mem->total_space_allocated = SIZEOF(my_memory_mgr);
1094
1095 /* Declare ourselves open for business */
1096 cinfo->mem = & mem->pub;
1097
1098 /* Check for an environment variable JPEGMEM; if found, override the
1099 * default max_memory setting from jpeg_mem_init. Note that the
1100 * surrounding application may again override this value.
1101 * If your system doesn't support getenv(), define NO_GETENV to disable
1102 * this feature.
1103 */
1104 #ifndef NO_GETENV
1105 { char * memenv;
1106
1107 if ((memenv = getenv("JPEGMEM")) != NULL) {
1108 char ch = 'x';
1109
1110 if (sscanf(memenv, "%ld%c", &max_to_use, &ch) > 0) {
1111 if (ch == 'm' || ch == 'M')
1112 max_to_use *= 1000L;
1113 mem->pub.max_memory_to_use = max_to_use * 1000L;
1114 }
1115 }
1116 }
1117 #endif
1118
1119 }