4 * This file was part of the Independent JPEG Group's software:
5 * Copyright (C) 1991-1997, Thomas G. Lane.
6 * libjpeg-turbo Modifications:
7 * Copyright (C) 2016, D. R. Commander.
8 * For conditions of distribution and use, see the accompanying README.ijg
11 * This file contains the JPEG system-independent memory management
12 * routines. This code is usable across a wide variety of machines; most
13 * of the system dependencies have been isolated in a separate file.
14 * The major functions provided here are:
15 * * pool-based allocation and freeing of memory;
16 * * policy decisions about how to divide available memory among the
18 * * control logic for swapping virtual arrays between main memory and
20 * The separate system-dependent file provides the actual backing-storage
21 * access code, and it contains the policy decision about how much total
23 * This file is system-dependent in the sense that some of its functions
24 * are unnecessary in some systems. For example, if there is enough virtual
25 * memory so that backing storage will never be used, much of the virtual
26 * array control logic could be removed. (Of course, if you have that much
27 * memory then you shouldn't care about a little bit of unused code...)
30 #define JPEG_INTERNALS
31 #define AM_MEMORY_MANAGER /* we define jvirt_Xarray_control structs */
34 #include "jmemsys.h" /* import the system-dependent declarations */
35 #if !defined(_MSC_VER) || _MSC_VER > 1600
41 #ifndef HAVE_STDLIB_H /* <stdlib.h> should declare getenv() */
42 extern char *getenv(const char *name
);
48 round_up_pow2(size_t a
, size_t b
)
49 /* a rounded up to the next multiple of b, i.e. ceil(a/b)*b */
50 /* Assumes a >= 0, b > 0, and b is a power of 2 */
52 return ((a
+ b
- 1) & (~(b
- 1)));
57 * Some important notes:
58 * The allocation routines provided here must never return NULL.
59 * They should exit to error_exit if unsuccessful.
61 * It's not a good idea to try to merge the sarray and barray routines,
62 * even though they are textually almost the same, because samples are
63 * usually stored as bytes while coefficients are shorts or ints. Thus,
64 * in machines where byte pointers have a different representation from
65 * word pointers, the resulting machine code could not be the same.
70 * Many machines require storage alignment: longs must start on 4-byte
71 * boundaries, doubles on 8-byte boundaries, etc. On such machines, malloc()
72 * always returns pointers that are multiples of the worst-case alignment
73 * requirement, and we had better do so too.
74 * There isn't any really portable way to determine the worst-case alignment
75 * requirement. This module assumes that the alignment requirement is
76 * multiples of ALIGN_SIZE.
77 * By default, we define ALIGN_SIZE as sizeof(double). This is necessary on
78 * some workstations (where doubles really do need 8-byte alignment) and will
79 * work fine on nearly everything. If your machine has lesser alignment needs,
80 * you can save a few bytes by making ALIGN_SIZE smaller.
81 * The only place I know of where this will NOT work is certain Macintosh
82 * 680x0 compilers that define double as a 10-byte IEEE extended float.
83 * Doing 10-byte alignment is counterproductive because longwords won't be
84 * aligned well. Put "#define ALIGN_SIZE 4" in jconfig.h if you have
88 #ifndef ALIGN_SIZE /* so can override from jconfig.h */
90 #define ALIGN_SIZE sizeof(double)
92 #define ALIGN_SIZE 32 /* Most of the SIMD instructions we support require
93 16-byte (128-bit) alignment, but AVX2 requires
99 * We allocate objects from "pools", where each pool is gotten with a single
100 * request to jpeg_get_small() or jpeg_get_large(). There is no per-object
101 * overhead within a pool, except for alignment padding. Each pool has a
102 * header with a link to the next pool of the same class.
103 * Small and large pool headers are identical.
106 typedef struct small_pool_struct
*small_pool_ptr
;
108 typedef struct small_pool_struct
{
109 small_pool_ptr next
; /* next in list of pools */
110 size_t bytes_used
; /* how many bytes already used within pool */
111 size_t bytes_left
; /* bytes still available in this pool */
114 typedef struct large_pool_struct
*large_pool_ptr
;
116 typedef struct large_pool_struct
{
117 large_pool_ptr next
; /* next in list of pools */
118 size_t bytes_used
; /* how many bytes already used within pool */
119 size_t bytes_left
; /* bytes still available in this pool */
123 * Here is the full definition of a memory manager object.
127 struct jpeg_memory_mgr pub
; /* public fields */
129 /* Each pool identifier (lifetime class) names a linked list of pools. */
130 small_pool_ptr small_list
[JPOOL_NUMPOOLS
];
131 large_pool_ptr large_list
[JPOOL_NUMPOOLS
];
133 /* Since we only have one lifetime class of virtual arrays, only one
134 * linked list is necessary (for each datatype). Note that the virtual
135 * array control blocks being linked together are actually stored somewhere
136 * in the small-pool list.
138 jvirt_sarray_ptr virt_sarray_list
;
139 jvirt_barray_ptr virt_barray_list
;
141 /* This counts total space obtained from jpeg_get_small/large */
142 size_t total_space_allocated
;
144 /* alloc_sarray and alloc_barray set this value for use by virtual
147 JDIMENSION last_rowsperchunk
; /* from most recent alloc_sarray/barray */
150 typedef my_memory_mgr
*my_mem_ptr
;
154 * The control blocks for virtual arrays.
155 * Note that these blocks are allocated in the "small" pool area.
156 * System-dependent info for the associated backing store (if any) is hidden
157 * inside the backing_store_info struct.
160 struct jvirt_sarray_control
{
161 JSAMPARRAY mem_buffer
; /* => the in-memory buffer */
162 JDIMENSION rows_in_array
; /* total virtual array height */
163 JDIMENSION samplesperrow
; /* width of array (and of memory buffer) */
164 JDIMENSION maxaccess
; /* max rows accessed by access_virt_sarray */
165 JDIMENSION rows_in_mem
; /* height of memory buffer */
166 JDIMENSION rowsperchunk
; /* allocation chunk size in mem_buffer */
167 JDIMENSION cur_start_row
; /* first logical row # in the buffer */
168 JDIMENSION first_undef_row
; /* row # of first uninitialized row */
169 boolean pre_zero
; /* pre-zero mode requested? */
170 boolean dirty
; /* do current buffer contents need written? */
171 boolean b_s_open
; /* is backing-store data valid? */
172 jvirt_sarray_ptr next
; /* link to next virtual sarray control block */
173 backing_store_info b_s_info
; /* System-dependent control info */
176 struct jvirt_barray_control
{
177 JBLOCKARRAY mem_buffer
; /* => the in-memory buffer */
178 JDIMENSION rows_in_array
; /* total virtual array height */
179 JDIMENSION blocksperrow
; /* width of array (and of memory buffer) */
180 JDIMENSION maxaccess
; /* max rows accessed by access_virt_barray */
181 JDIMENSION rows_in_mem
; /* height of memory buffer */
182 JDIMENSION rowsperchunk
; /* allocation chunk size in mem_buffer */
183 JDIMENSION cur_start_row
; /* first logical row # in the buffer */
184 JDIMENSION first_undef_row
; /* row # of first uninitialized row */
185 boolean pre_zero
; /* pre-zero mode requested? */
186 boolean dirty
; /* do current buffer contents need written? */
187 boolean b_s_open
; /* is backing-store data valid? */
188 jvirt_barray_ptr next
; /* link to next virtual barray control block */
189 backing_store_info b_s_info
; /* System-dependent control info */
193 #ifdef MEM_STATS /* optional extra stuff for statistics */
196 print_mem_stats(j_common_ptr cinfo
, int pool_id
)
198 my_mem_ptr mem
= (my_mem_ptr
)cinfo
->mem
;
199 small_pool_ptr shdr_ptr
;
200 large_pool_ptr lhdr_ptr
;
202 /* Since this is only a debugging stub, we can cheat a little by using
203 * fprintf directly rather than going through the trace message code.
204 * This is helpful because message parm array can't handle longs.
206 fprintf(stderr
, "Freeing pool %d, total space = %ld\n",
207 pool_id
, mem
->total_space_allocated
);
209 for (lhdr_ptr
= mem
->large_list
[pool_id
]; lhdr_ptr
!= NULL
;
210 lhdr_ptr
= lhdr_ptr
->next
) {
211 fprintf(stderr
, " Large chunk used %ld\n", (long)lhdr_ptr
->bytes_used
);
214 for (shdr_ptr
= mem
->small_list
[pool_id
]; shdr_ptr
!= NULL
;
215 shdr_ptr
= shdr_ptr
->next
) {
216 fprintf(stderr
, " Small chunk used %ld free %ld\n",
217 (long)shdr_ptr
->bytes_used
, (long)shdr_ptr
->bytes_left
);
221 #endif /* MEM_STATS */
225 out_of_memory(j_common_ptr cinfo
, int which
)
226 /* Report an out-of-memory error and stop execution */
227 /* If we compiled MEM_STATS support, report alloc requests before dying */
230 cinfo
->err
->trace_level
= 2; /* force self_destruct to report stats */
232 ERREXIT1(cinfo
, JERR_OUT_OF_MEMORY
, which
);
237 * Allocation of "small" objects.
239 * For these, we use pooled storage. When a new pool must be created,
240 * we try to get enough space for the current request plus a "slop" factor,
241 * where the slop will be the amount of leftover space in the new pool.
242 * The speed vs. space tradeoff is largely determined by the slop values.
243 * A different slop value is provided for each pool class (lifetime),
244 * and we also distinguish the first pool of a class from later ones.
245 * NOTE: the values given work fairly well on both 16- and 32-bit-int
246 * machines, but may be too small if longs are 64 bits or more.
248 * Since we do not know what alignment malloc() gives us, we have to
249 * allocate ALIGN_SIZE-1 extra space per pool to have room for alignment
253 static const size_t first_pool_slop
[JPOOL_NUMPOOLS
] = {
254 1600, /* first PERMANENT pool */
255 16000 /* first IMAGE pool */
258 static const size_t extra_pool_slop
[JPOOL_NUMPOOLS
] = {
259 0, /* additional PERMANENT pools */
260 5000 /* additional IMAGE pools */
263 #define MIN_SLOP 50 /* greater than 0 to avoid futile looping */
267 alloc_small(j_common_ptr cinfo
, int pool_id
, size_t sizeofobject
)
268 /* Allocate a "small" object */
270 my_mem_ptr mem
= (my_mem_ptr
)cinfo
->mem
;
271 small_pool_ptr hdr_ptr
, prev_hdr_ptr
;
273 size_t min_request
, slop
;
276 * Round up the requested size to a multiple of ALIGN_SIZE in order
277 * to assure alignment for the next object allocated in the same pool
278 * and so that algorithms can straddle outside the proper area up
279 * to the next alignment.
281 if (sizeofobject
> MAX_ALLOC_CHUNK
) {
282 /* This prevents overflow/wrap-around in round_up_pow2() if sizeofobject
283 is close to SIZE_MAX. */
284 out_of_memory(cinfo
, 7);
286 sizeofobject
= round_up_pow2(sizeofobject
, ALIGN_SIZE
);
288 /* Check for unsatisfiable request (do now to ensure no overflow below) */
289 if ((sizeof(small_pool_hdr
) + sizeofobject
+ ALIGN_SIZE
- 1) >
291 out_of_memory(cinfo
, 1); /* request exceeds malloc's ability */
293 /* See if space is available in any existing pool */
294 if (pool_id
< 0 || pool_id
>= JPOOL_NUMPOOLS
)
295 ERREXIT1(cinfo
, JERR_BAD_POOL_ID
, pool_id
); /* safety check */
297 hdr_ptr
= mem
->small_list
[pool_id
];
298 while (hdr_ptr
!= NULL
) {
299 if (hdr_ptr
->bytes_left
>= sizeofobject
)
300 break; /* found pool with enough space */
301 prev_hdr_ptr
= hdr_ptr
;
302 hdr_ptr
= hdr_ptr
->next
;
305 /* Time to make a new pool? */
306 if (hdr_ptr
== NULL
) {
307 /* min_request is what we need now, slop is what will be leftover */
308 min_request
= sizeof(small_pool_hdr
) + sizeofobject
+ ALIGN_SIZE
- 1;
309 if (prev_hdr_ptr
== NULL
) /* first pool in class? */
310 slop
= first_pool_slop
[pool_id
];
312 slop
= extra_pool_slop
[pool_id
];
313 /* Don't ask for more than MAX_ALLOC_CHUNK */
314 if (slop
> (size_t)(MAX_ALLOC_CHUNK
- min_request
))
315 slop
= (size_t)(MAX_ALLOC_CHUNK
- min_request
);
316 /* Try to get space, if fail reduce slop and try again */
318 hdr_ptr
= (small_pool_ptr
)jpeg_get_small(cinfo
, min_request
+ slop
);
322 if (slop
< MIN_SLOP
) /* give up when it gets real small */
323 out_of_memory(cinfo
, 2); /* jpeg_get_small failed */
325 mem
->total_space_allocated
+= min_request
+ slop
;
326 /* Success, initialize the new pool header and add to end of list */
327 hdr_ptr
->next
= NULL
;
328 hdr_ptr
->bytes_used
= 0;
329 hdr_ptr
->bytes_left
= sizeofobject
+ slop
;
330 if (prev_hdr_ptr
== NULL
) /* first pool in class? */
331 mem
->small_list
[pool_id
] = hdr_ptr
;
333 prev_hdr_ptr
->next
= hdr_ptr
;
336 /* OK, allocate the object from the current pool */
337 data_ptr
= (char *)hdr_ptr
; /* point to first data byte in pool... */
338 data_ptr
+= sizeof(small_pool_hdr
); /* ...by skipping the header... */
339 if ((size_t)data_ptr
% ALIGN_SIZE
) /* ...and adjust for alignment */
340 data_ptr
+= ALIGN_SIZE
- (size_t)data_ptr
% ALIGN_SIZE
;
341 data_ptr
+= hdr_ptr
->bytes_used
; /* point to place for object */
342 hdr_ptr
->bytes_used
+= sizeofobject
;
343 hdr_ptr
->bytes_left
-= sizeofobject
;
345 return (void *)data_ptr
;
350 * Allocation of "large" objects.
352 * The external semantics of these are the same as "small" objects. However,
353 * the pool management heuristics are quite different. We assume that each
354 * request is large enough that it may as well be passed directly to
355 * jpeg_get_large; the pool management just links everything together
356 * so that we can free it all on demand.
357 * Note: the major use of "large" objects is in JSAMPARRAY and JBLOCKARRAY
358 * structures. The routines that create these structures (see below)
359 * deliberately bunch rows together to ensure a large request size.
363 alloc_large(j_common_ptr cinfo
, int pool_id
, size_t sizeofobject
)
364 /* Allocate a "large" object */
366 my_mem_ptr mem
= (my_mem_ptr
)cinfo
->mem
;
367 large_pool_ptr hdr_ptr
;
371 * Round up the requested size to a multiple of ALIGN_SIZE so that
372 * algorithms can straddle outside the proper area up to the next
375 if (sizeofobject
> MAX_ALLOC_CHUNK
) {
376 /* This prevents overflow/wrap-around in round_up_pow2() if sizeofobject
377 is close to SIZE_MAX. */
378 out_of_memory(cinfo
, 8);
380 sizeofobject
= round_up_pow2(sizeofobject
, ALIGN_SIZE
);
382 /* Check for unsatisfiable request (do now to ensure no overflow below) */
383 if ((sizeof(large_pool_hdr
) + sizeofobject
+ ALIGN_SIZE
- 1) >
385 out_of_memory(cinfo
, 3); /* request exceeds malloc's ability */
387 /* Always make a new pool */
388 if (pool_id
< 0 || pool_id
>= JPOOL_NUMPOOLS
)
389 ERREXIT1(cinfo
, JERR_BAD_POOL_ID
, pool_id
); /* safety check */
391 hdr_ptr
= (large_pool_ptr
)jpeg_get_large(cinfo
, sizeofobject
+
392 sizeof(large_pool_hdr
) +
395 out_of_memory(cinfo
, 4); /* jpeg_get_large failed */
396 mem
->total_space_allocated
+= sizeofobject
+ sizeof(large_pool_hdr
) +
399 /* Success, initialize the new pool header and add to list */
400 hdr_ptr
->next
= mem
->large_list
[pool_id
];
401 /* We maintain space counts in each pool header for statistical purposes,
402 * even though they are not needed for allocation.
404 hdr_ptr
->bytes_used
= sizeofobject
;
405 hdr_ptr
->bytes_left
= 0;
406 mem
->large_list
[pool_id
] = hdr_ptr
;
408 data_ptr
= (char *)hdr_ptr
; /* point to first data byte in pool... */
409 data_ptr
+= sizeof(small_pool_hdr
); /* ...by skipping the header... */
410 if ((size_t)data_ptr
% ALIGN_SIZE
) /* ...and adjust for alignment */
411 data_ptr
+= ALIGN_SIZE
- (size_t)data_ptr
% ALIGN_SIZE
;
413 return (void *)data_ptr
;
418 * Creation of 2-D sample arrays.
420 * To minimize allocation overhead and to allow I/O of large contiguous
421 * blocks, we allocate the sample rows in groups of as many rows as possible
422 * without exceeding MAX_ALLOC_CHUNK total bytes per allocation request.
423 * NB: the virtual array control routines, later in this file, know about
424 * this chunking of rows. The rowsperchunk value is left in the mem manager
425 * object so that it can be saved away if this sarray is the workspace for
428 * Since we are often upsampling with a factor 2, we align the size (not
429 * the start) to 2 * ALIGN_SIZE so that the upsampling routines don't have
430 * to be as careful about size.
433 METHODDEF(JSAMPARRAY
)
434 alloc_sarray(j_common_ptr cinfo
, int pool_id
, JDIMENSION samplesperrow
,
436 /* Allocate a 2-D sample array */
438 my_mem_ptr mem
= (my_mem_ptr
)cinfo
->mem
;
441 JDIMENSION rowsperchunk
, currow
, i
;
444 /* Make sure each row is properly aligned */
445 if ((ALIGN_SIZE
% sizeof(JSAMPLE
)) != 0)
446 out_of_memory(cinfo
, 5); /* safety check */
448 if (samplesperrow
> MAX_ALLOC_CHUNK
) {
449 /* This prevents overflow/wrap-around in round_up_pow2() if sizeofobject
450 is close to SIZE_MAX. */
451 out_of_memory(cinfo
, 9);
453 samplesperrow
= (JDIMENSION
)round_up_pow2(samplesperrow
, (2 * ALIGN_SIZE
) /
456 /* Calculate max # of rows allowed in one allocation chunk */
457 ltemp
= (MAX_ALLOC_CHUNK
- sizeof(large_pool_hdr
)) /
458 ((long)samplesperrow
* sizeof(JSAMPLE
));
460 ERREXIT(cinfo
, JERR_WIDTH_OVERFLOW
);
461 if (ltemp
< (long)numrows
)
462 rowsperchunk
= (JDIMENSION
)ltemp
;
464 rowsperchunk
= numrows
;
465 mem
->last_rowsperchunk
= rowsperchunk
;
467 /* Get space for row pointers (small object) */
468 result
= (JSAMPARRAY
)alloc_small(cinfo
, pool_id
,
469 (size_t)(numrows
* sizeof(JSAMPROW
)));
471 /* Get the rows themselves (large objects) */
473 while (currow
< numrows
) {
474 rowsperchunk
= MIN(rowsperchunk
, numrows
- currow
);
475 workspace
= (JSAMPROW
)alloc_large(cinfo
, pool_id
,
476 (size_t)((size_t)rowsperchunk
* (size_t)samplesperrow
*
478 for (i
= rowsperchunk
; i
> 0; i
--) {
479 result
[currow
++] = workspace
;
480 workspace
+= samplesperrow
;
489 * Creation of 2-D coefficient-block arrays.
490 * This is essentially the same as the code for sample arrays, above.
493 METHODDEF(JBLOCKARRAY
)
494 alloc_barray(j_common_ptr cinfo
, int pool_id
, JDIMENSION blocksperrow
,
496 /* Allocate a 2-D coefficient-block array */
498 my_mem_ptr mem
= (my_mem_ptr
)cinfo
->mem
;
501 JDIMENSION rowsperchunk
, currow
, i
;
504 /* Make sure each row is properly aligned */
505 if ((sizeof(JBLOCK
) % ALIGN_SIZE
) != 0)
506 out_of_memory(cinfo
, 6); /* safety check */
508 /* Calculate max # of rows allowed in one allocation chunk */
509 ltemp
= (MAX_ALLOC_CHUNK
- sizeof(large_pool_hdr
)) /
510 ((long)blocksperrow
* sizeof(JBLOCK
));
512 ERREXIT(cinfo
, JERR_WIDTH_OVERFLOW
);
513 if (ltemp
< (long)numrows
)
514 rowsperchunk
= (JDIMENSION
)ltemp
;
516 rowsperchunk
= numrows
;
517 mem
->last_rowsperchunk
= rowsperchunk
;
519 /* Get space for row pointers (small object) */
520 result
= (JBLOCKARRAY
)alloc_small(cinfo
, pool_id
,
521 (size_t)(numrows
* sizeof(JBLOCKROW
)));
523 /* Get the rows themselves (large objects) */
525 while (currow
< numrows
) {
526 rowsperchunk
= MIN(rowsperchunk
, numrows
- currow
);
527 workspace
= (JBLOCKROW
)alloc_large(cinfo
, pool_id
,
528 (size_t)((size_t)rowsperchunk
* (size_t)blocksperrow
*
530 for (i
= rowsperchunk
; i
> 0; i
--) {
531 result
[currow
++] = workspace
;
532 workspace
+= blocksperrow
;
541 * About virtual array management:
543 * The above "normal" array routines are only used to allocate strip buffers
544 * (as wide as the image, but just a few rows high). Full-image-sized buffers
545 * are handled as "virtual" arrays. The array is still accessed a strip at a
546 * time, but the memory manager must save the whole array for repeated
547 * accesses. The intended implementation is that there is a strip buffer in
548 * memory (as high as is possible given the desired memory limit), plus a
549 * backing file that holds the rest of the array.
551 * The request_virt_array routines are told the total size of the image and
552 * the maximum number of rows that will be accessed at once. The in-memory
553 * buffer must be at least as large as the maxaccess value.
555 * The request routines create control blocks but not the in-memory buffers.
556 * That is postponed until realize_virt_arrays is called. At that time the
557 * total amount of space needed is known (approximately, anyway), so free
558 * memory can be divided up fairly.
560 * The access_virt_array routines are responsible for making a specific strip
561 * area accessible (after reading or writing the backing file, if necessary).
562 * Note that the access routines are told whether the caller intends to modify
563 * the accessed strip; during a read-only pass this saves having to rewrite
564 * data to disk. The access routines are also responsible for pre-zeroing
565 * any newly accessed rows, if pre-zeroing was requested.
567 * In current usage, the access requests are usually for nonoverlapping
568 * strips; that is, successive access start_row numbers differ by exactly
569 * num_rows = maxaccess. This means we can get good performance with simple
570 * buffer dump/reload logic, by making the in-memory buffer be a multiple
571 * of the access height; then there will never be accesses across bufferload
572 * boundaries. The code will still work with overlapping access requests,
573 * but it doesn't handle bufferload overlaps very efficiently.
577 METHODDEF(jvirt_sarray_ptr
)
578 request_virt_sarray(j_common_ptr cinfo
, int pool_id
, boolean pre_zero
,
579 JDIMENSION samplesperrow
, JDIMENSION numrows
,
580 JDIMENSION maxaccess
)
581 /* Request a virtual 2-D sample array */
583 my_mem_ptr mem
= (my_mem_ptr
)cinfo
->mem
;
584 jvirt_sarray_ptr result
;
586 /* Only IMAGE-lifetime virtual arrays are currently supported */
587 if (pool_id
!= JPOOL_IMAGE
)
588 ERREXIT1(cinfo
, JERR_BAD_POOL_ID
, pool_id
); /* safety check */
590 /* get control block */
591 result
= (jvirt_sarray_ptr
)alloc_small(cinfo
, pool_id
,
592 sizeof(struct jvirt_sarray_control
));
594 result
->mem_buffer
= NULL
; /* marks array not yet realized */
595 result
->rows_in_array
= numrows
;
596 result
->samplesperrow
= samplesperrow
;
597 result
->maxaccess
= maxaccess
;
598 result
->pre_zero
= pre_zero
;
599 result
->b_s_open
= FALSE
; /* no associated backing-store object */
600 result
->next
= mem
->virt_sarray_list
; /* add to list of virtual arrays */
601 mem
->virt_sarray_list
= result
;
607 METHODDEF(jvirt_barray_ptr
)
608 request_virt_barray(j_common_ptr cinfo
, int pool_id
, boolean pre_zero
,
609 JDIMENSION blocksperrow
, JDIMENSION numrows
,
610 JDIMENSION maxaccess
)
611 /* Request a virtual 2-D coefficient-block array */
613 my_mem_ptr mem
= (my_mem_ptr
)cinfo
->mem
;
614 jvirt_barray_ptr result
;
616 /* Only IMAGE-lifetime virtual arrays are currently supported */
617 if (pool_id
!= JPOOL_IMAGE
)
618 ERREXIT1(cinfo
, JERR_BAD_POOL_ID
, pool_id
); /* safety check */
620 /* get control block */
621 result
= (jvirt_barray_ptr
)alloc_small(cinfo
, pool_id
,
622 sizeof(struct jvirt_barray_control
));
624 result
->mem_buffer
= NULL
; /* marks array not yet realized */
625 result
->rows_in_array
= numrows
;
626 result
->blocksperrow
= blocksperrow
;
627 result
->maxaccess
= maxaccess
;
628 result
->pre_zero
= pre_zero
;
629 result
->b_s_open
= FALSE
; /* no associated backing-store object */
630 result
->next
= mem
->virt_barray_list
; /* add to list of virtual arrays */
631 mem
->virt_barray_list
= result
;
638 realize_virt_arrays(j_common_ptr cinfo
)
639 /* Allocate the in-memory buffers for any unrealized virtual arrays */
641 my_mem_ptr mem
= (my_mem_ptr
)cinfo
->mem
;
642 size_t space_per_minheight
, maximum_space
, avail_mem
;
643 size_t minheights
, max_minheights
;
644 jvirt_sarray_ptr sptr
;
645 jvirt_barray_ptr bptr
;
647 /* Compute the minimum space needed (maxaccess rows in each buffer)
648 * and the maximum space needed (full image height in each buffer).
649 * These may be of use to the system-dependent jpeg_mem_available routine.
651 space_per_minheight
= 0;
653 for (sptr
= mem
->virt_sarray_list
; sptr
!= NULL
; sptr
= sptr
->next
) {
654 if (sptr
->mem_buffer
== NULL
) { /* if not realized yet */
655 size_t new_space
= (long)sptr
->rows_in_array
*
656 (long)sptr
->samplesperrow
* sizeof(JSAMPLE
);
658 space_per_minheight
+= (long)sptr
->maxaccess
*
659 (long)sptr
->samplesperrow
* sizeof(JSAMPLE
);
660 if (SIZE_MAX
- maximum_space
< new_space
)
661 out_of_memory(cinfo
, 10);
662 maximum_space
+= new_space
;
665 for (bptr
= mem
->virt_barray_list
; bptr
!= NULL
; bptr
= bptr
->next
) {
666 if (bptr
->mem_buffer
== NULL
) { /* if not realized yet */
667 size_t new_space
= (long)bptr
->rows_in_array
*
668 (long)bptr
->blocksperrow
* sizeof(JBLOCK
);
670 space_per_minheight
+= (long)bptr
->maxaccess
*
671 (long)bptr
->blocksperrow
* sizeof(JBLOCK
);
672 if (SIZE_MAX
- maximum_space
< new_space
)
673 out_of_memory(cinfo
, 11);
674 maximum_space
+= new_space
;
678 if (space_per_minheight
<= 0)
679 return; /* no unrealized arrays, no work */
681 /* Determine amount of memory to actually use; this is system-dependent. */
682 avail_mem
= jpeg_mem_available(cinfo
, space_per_minheight
, maximum_space
,
683 mem
->total_space_allocated
);
685 /* If the maximum space needed is available, make all the buffers full
686 * height; otherwise parcel it out with the same number of minheights
689 if (avail_mem
>= maximum_space
)
690 max_minheights
= 1000000000L;
692 max_minheights
= avail_mem
/ space_per_minheight
;
693 /* If there doesn't seem to be enough space, try to get the minimum
694 * anyway. This allows a "stub" implementation of jpeg_mem_available().
696 if (max_minheights
<= 0)
700 /* Allocate the in-memory buffers and initialize backing store as needed. */
702 for (sptr
= mem
->virt_sarray_list
; sptr
!= NULL
; sptr
= sptr
->next
) {
703 if (sptr
->mem_buffer
== NULL
) { /* if not realized yet */
704 minheights
= ((long)sptr
->rows_in_array
- 1L) / sptr
->maxaccess
+ 1L;
705 if (minheights
<= max_minheights
) {
706 /* This buffer fits in memory */
707 sptr
->rows_in_mem
= sptr
->rows_in_array
;
709 /* It doesn't fit in memory, create backing store. */
710 sptr
->rows_in_mem
= (JDIMENSION
)(max_minheights
* sptr
->maxaccess
);
711 jpeg_open_backing_store(cinfo
, &sptr
->b_s_info
,
712 (long)sptr
->rows_in_array
*
713 (long)sptr
->samplesperrow
*
714 (long)sizeof(JSAMPLE
));
715 sptr
->b_s_open
= TRUE
;
717 sptr
->mem_buffer
= alloc_sarray(cinfo
, JPOOL_IMAGE
,
718 sptr
->samplesperrow
, sptr
->rows_in_mem
);
719 sptr
->rowsperchunk
= mem
->last_rowsperchunk
;
720 sptr
->cur_start_row
= 0;
721 sptr
->first_undef_row
= 0;
726 for (bptr
= mem
->virt_barray_list
; bptr
!= NULL
; bptr
= bptr
->next
) {
727 if (bptr
->mem_buffer
== NULL
) { /* if not realized yet */
728 minheights
= ((long)bptr
->rows_in_array
- 1L) / bptr
->maxaccess
+ 1L;
729 if (minheights
<= max_minheights
) {
730 /* This buffer fits in memory */
731 bptr
->rows_in_mem
= bptr
->rows_in_array
;
733 /* It doesn't fit in memory, create backing store. */
734 bptr
->rows_in_mem
= (JDIMENSION
)(max_minheights
* bptr
->maxaccess
);
735 jpeg_open_backing_store(cinfo
, &bptr
->b_s_info
,
736 (long)bptr
->rows_in_array
*
737 (long)bptr
->blocksperrow
*
738 (long)sizeof(JBLOCK
));
739 bptr
->b_s_open
= TRUE
;
741 bptr
->mem_buffer
= alloc_barray(cinfo
, JPOOL_IMAGE
,
742 bptr
->blocksperrow
, bptr
->rows_in_mem
);
743 bptr
->rowsperchunk
= mem
->last_rowsperchunk
;
744 bptr
->cur_start_row
= 0;
745 bptr
->first_undef_row
= 0;
753 do_sarray_io(j_common_ptr cinfo
, jvirt_sarray_ptr ptr
, boolean writing
)
754 /* Do backing store read or write of a virtual sample array */
756 long bytesperrow
, file_offset
, byte_count
, rows
, thisrow
, i
;
758 bytesperrow
= (long)ptr
->samplesperrow
* sizeof(JSAMPLE
);
759 file_offset
= ptr
->cur_start_row
* bytesperrow
;
760 /* Loop to read or write each allocation chunk in mem_buffer */
761 for (i
= 0; i
< (long)ptr
->rows_in_mem
; i
+= ptr
->rowsperchunk
) {
762 /* One chunk, but check for short chunk at end of buffer */
763 rows
= MIN((long)ptr
->rowsperchunk
, (long)ptr
->rows_in_mem
- i
);
764 /* Transfer no more than is currently defined */
765 thisrow
= (long)ptr
->cur_start_row
+ i
;
766 rows
= MIN(rows
, (long)ptr
->first_undef_row
- thisrow
);
767 /* Transfer no more than fits in file */
768 rows
= MIN(rows
, (long)ptr
->rows_in_array
- thisrow
);
769 if (rows
<= 0) /* this chunk might be past end of file! */
771 byte_count
= rows
* bytesperrow
;
773 (*ptr
->b_s_info
.write_backing_store
) (cinfo
, &ptr
->b_s_info
,
774 (void *)ptr
->mem_buffer
[i
],
775 file_offset
, byte_count
);
777 (*ptr
->b_s_info
.read_backing_store
) (cinfo
, &ptr
->b_s_info
,
778 (void *)ptr
->mem_buffer
[i
],
779 file_offset
, byte_count
);
780 file_offset
+= byte_count
;
786 do_barray_io(j_common_ptr cinfo
, jvirt_barray_ptr ptr
, boolean writing
)
787 /* Do backing store read or write of a virtual coefficient-block array */
789 long bytesperrow
, file_offset
, byte_count
, rows
, thisrow
, i
;
791 bytesperrow
= (long)ptr
->blocksperrow
* sizeof(JBLOCK
);
792 file_offset
= ptr
->cur_start_row
* bytesperrow
;
793 /* Loop to read or write each allocation chunk in mem_buffer */
794 for (i
= 0; i
< (long)ptr
->rows_in_mem
; i
+= ptr
->rowsperchunk
) {
795 /* One chunk, but check for short chunk at end of buffer */
796 rows
= MIN((long)ptr
->rowsperchunk
, (long)ptr
->rows_in_mem
- i
);
797 /* Transfer no more than is currently defined */
798 thisrow
= (long)ptr
->cur_start_row
+ i
;
799 rows
= MIN(rows
, (long)ptr
->first_undef_row
- thisrow
);
800 /* Transfer no more than fits in file */
801 rows
= MIN(rows
, (long)ptr
->rows_in_array
- thisrow
);
802 if (rows
<= 0) /* this chunk might be past end of file! */
804 byte_count
= rows
* bytesperrow
;
806 (*ptr
->b_s_info
.write_backing_store
) (cinfo
, &ptr
->b_s_info
,
807 (void *)ptr
->mem_buffer
[i
],
808 file_offset
, byte_count
);
810 (*ptr
->b_s_info
.read_backing_store
) (cinfo
, &ptr
->b_s_info
,
811 (void *)ptr
->mem_buffer
[i
],
812 file_offset
, byte_count
);
813 file_offset
+= byte_count
;
818 METHODDEF(JSAMPARRAY
)
819 access_virt_sarray(j_common_ptr cinfo
, jvirt_sarray_ptr ptr
,
820 JDIMENSION start_row
, JDIMENSION num_rows
, boolean writable
)
821 /* Access the part of a virtual sample array starting at start_row */
822 /* and extending for num_rows rows. writable is true if */
823 /* caller intends to modify the accessed area. */
825 JDIMENSION end_row
= start_row
+ num_rows
;
826 JDIMENSION undef_row
;
828 /* debugging check */
829 if (end_row
> ptr
->rows_in_array
|| num_rows
> ptr
->maxaccess
||
830 ptr
->mem_buffer
== NULL
)
831 ERREXIT(cinfo
, JERR_BAD_VIRTUAL_ACCESS
);
833 /* Make the desired part of the virtual array accessible */
834 if (start_row
< ptr
->cur_start_row
||
835 end_row
> ptr
->cur_start_row
+ ptr
->rows_in_mem
) {
837 ERREXIT(cinfo
, JERR_VIRTUAL_BUG
);
838 /* Flush old buffer contents if necessary */
840 do_sarray_io(cinfo
, ptr
, TRUE
);
843 /* Decide what part of virtual array to access.
844 * Algorithm: if target address > current window, assume forward scan,
845 * load starting at target address. If target address < current window,
846 * assume backward scan, load so that target area is top of window.
847 * Note that when switching from forward write to forward read, will have
848 * start_row = 0, so the limiting case applies and we load from 0 anyway.
850 if (start_row
> ptr
->cur_start_row
) {
851 ptr
->cur_start_row
= start_row
;
853 /* use long arithmetic here to avoid overflow & unsigned problems */
856 ltemp
= (long)end_row
- (long)ptr
->rows_in_mem
;
858 ltemp
= 0; /* don't fall off front end of file */
859 ptr
->cur_start_row
= (JDIMENSION
)ltemp
;
861 /* Read in the selected part of the array.
862 * During the initial write pass, we will do no actual read
863 * because the selected part is all undefined.
865 do_sarray_io(cinfo
, ptr
, FALSE
);
867 /* Ensure the accessed part of the array is defined; prezero if needed.
868 * To improve locality of access, we only prezero the part of the array
869 * that the caller is about to access, not the entire in-memory array.
871 if (ptr
->first_undef_row
< end_row
) {
872 if (ptr
->first_undef_row
< start_row
) {
873 if (writable
) /* writer skipped over a section of array */
874 ERREXIT(cinfo
, JERR_BAD_VIRTUAL_ACCESS
);
875 undef_row
= start_row
; /* but reader is allowed to read ahead */
877 undef_row
= ptr
->first_undef_row
;
880 ptr
->first_undef_row
= end_row
;
882 size_t bytesperrow
= (size_t)ptr
->samplesperrow
* sizeof(JSAMPLE
);
883 undef_row
-= ptr
->cur_start_row
; /* make indexes relative to buffer */
884 end_row
-= ptr
->cur_start_row
;
885 while (undef_row
< end_row
) {
886 jzero_far((void *)ptr
->mem_buffer
[undef_row
], bytesperrow
);
890 if (!writable
) /* reader looking at undefined data */
891 ERREXIT(cinfo
, JERR_BAD_VIRTUAL_ACCESS
);
894 /* Flag the buffer dirty if caller will write in it */
897 /* Return address of proper part of the buffer */
898 return ptr
->mem_buffer
+ (start_row
- ptr
->cur_start_row
);
902 METHODDEF(JBLOCKARRAY
)
903 access_virt_barray(j_common_ptr cinfo
, jvirt_barray_ptr ptr
,
904 JDIMENSION start_row
, JDIMENSION num_rows
, boolean writable
)
905 /* Access the part of a virtual block array starting at start_row */
906 /* and extending for num_rows rows. writable is true if */
907 /* caller intends to modify the accessed area. */
909 JDIMENSION end_row
= start_row
+ num_rows
;
910 JDIMENSION undef_row
;
912 /* debugging check */
913 if (end_row
> ptr
->rows_in_array
|| num_rows
> ptr
->maxaccess
||
914 ptr
->mem_buffer
== NULL
)
915 ERREXIT(cinfo
, JERR_BAD_VIRTUAL_ACCESS
);
917 /* Make the desired part of the virtual array accessible */
918 if (start_row
< ptr
->cur_start_row
||
919 end_row
> ptr
->cur_start_row
+ ptr
->rows_in_mem
) {
921 ERREXIT(cinfo
, JERR_VIRTUAL_BUG
);
922 /* Flush old buffer contents if necessary */
924 do_barray_io(cinfo
, ptr
, TRUE
);
927 /* Decide what part of virtual array to access.
928 * Algorithm: if target address > current window, assume forward scan,
929 * load starting at target address. If target address < current window,
930 * assume backward scan, load so that target area is top of window.
931 * Note that when switching from forward write to forward read, will have
932 * start_row = 0, so the limiting case applies and we load from 0 anyway.
934 if (start_row
> ptr
->cur_start_row
) {
935 ptr
->cur_start_row
= start_row
;
937 /* use long arithmetic here to avoid overflow & unsigned problems */
940 ltemp
= (long)end_row
- (long)ptr
->rows_in_mem
;
942 ltemp
= 0; /* don't fall off front end of file */
943 ptr
->cur_start_row
= (JDIMENSION
)ltemp
;
945 /* Read in the selected part of the array.
946 * During the initial write pass, we will do no actual read
947 * because the selected part is all undefined.
949 do_barray_io(cinfo
, ptr
, FALSE
);
951 /* Ensure the accessed part of the array is defined; prezero if needed.
952 * To improve locality of access, we only prezero the part of the array
953 * that the caller is about to access, not the entire in-memory array.
955 if (ptr
->first_undef_row
< end_row
) {
956 if (ptr
->first_undef_row
< start_row
) {
957 if (writable
) /* writer skipped over a section of array */
958 ERREXIT(cinfo
, JERR_BAD_VIRTUAL_ACCESS
);
959 undef_row
= start_row
; /* but reader is allowed to read ahead */
961 undef_row
= ptr
->first_undef_row
;
964 ptr
->first_undef_row
= end_row
;
966 size_t bytesperrow
= (size_t)ptr
->blocksperrow
* sizeof(JBLOCK
);
967 undef_row
-= ptr
->cur_start_row
; /* make indexes relative to buffer */
968 end_row
-= ptr
->cur_start_row
;
969 while (undef_row
< end_row
) {
970 jzero_far((void *)ptr
->mem_buffer
[undef_row
], bytesperrow
);
974 if (!writable
) /* reader looking at undefined data */
975 ERREXIT(cinfo
, JERR_BAD_VIRTUAL_ACCESS
);
978 /* Flag the buffer dirty if caller will write in it */
981 /* Return address of proper part of the buffer */
982 return ptr
->mem_buffer
+ (start_row
- ptr
->cur_start_row
);
987 * Release all objects belonging to a specified pool.
991 free_pool(j_common_ptr cinfo
, int pool_id
)
993 my_mem_ptr mem
= (my_mem_ptr
)cinfo
->mem
;
994 small_pool_ptr shdr_ptr
;
995 large_pool_ptr lhdr_ptr
;
998 if (pool_id
< 0 || pool_id
>= JPOOL_NUMPOOLS
)
999 ERREXIT1(cinfo
, JERR_BAD_POOL_ID
, pool_id
); /* safety check */
1002 if (cinfo
->err
->trace_level
> 1)
1003 print_mem_stats(cinfo
, pool_id
); /* print pool's memory usage statistics */
1006 /* If freeing IMAGE pool, close any virtual arrays first */
1007 if (pool_id
== JPOOL_IMAGE
) {
1008 jvirt_sarray_ptr sptr
;
1009 jvirt_barray_ptr bptr
;
1011 for (sptr
= mem
->virt_sarray_list
; sptr
!= NULL
; sptr
= sptr
->next
) {
1012 if (sptr
->b_s_open
) { /* there may be no backing store */
1013 sptr
->b_s_open
= FALSE
; /* prevent recursive close if error */
1014 (*sptr
->b_s_info
.close_backing_store
) (cinfo
, &sptr
->b_s_info
);
1017 mem
->virt_sarray_list
= NULL
;
1018 for (bptr
= mem
->virt_barray_list
; bptr
!= NULL
; bptr
= bptr
->next
) {
1019 if (bptr
->b_s_open
) { /* there may be no backing store */
1020 bptr
->b_s_open
= FALSE
; /* prevent recursive close if error */
1021 (*bptr
->b_s_info
.close_backing_store
) (cinfo
, &bptr
->b_s_info
);
1024 mem
->virt_barray_list
= NULL
;
1027 /* Release large objects */
1028 lhdr_ptr
= mem
->large_list
[pool_id
];
1029 mem
->large_list
[pool_id
] = NULL
;
1031 while (lhdr_ptr
!= NULL
) {
1032 large_pool_ptr next_lhdr_ptr
= lhdr_ptr
->next
;
1033 space_freed
= lhdr_ptr
->bytes_used
+
1034 lhdr_ptr
->bytes_left
+
1035 sizeof(large_pool_hdr
);
1036 jpeg_free_large(cinfo
, (void *)lhdr_ptr
, space_freed
);
1037 mem
->total_space_allocated
-= space_freed
;
1038 lhdr_ptr
= next_lhdr_ptr
;
1041 /* Release small objects */
1042 shdr_ptr
= mem
->small_list
[pool_id
];
1043 mem
->small_list
[pool_id
] = NULL
;
1045 while (shdr_ptr
!= NULL
) {
1046 small_pool_ptr next_shdr_ptr
= shdr_ptr
->next
;
1047 space_freed
= shdr_ptr
->bytes_used
+ shdr_ptr
->bytes_left
+
1048 sizeof(small_pool_hdr
);
1049 jpeg_free_small(cinfo
, (void *)shdr_ptr
, space_freed
);
1050 mem
->total_space_allocated
-= space_freed
;
1051 shdr_ptr
= next_shdr_ptr
;
1057 * Close up shop entirely.
1058 * Note that this cannot be called unless cinfo->mem is non-NULL.
1062 self_destruct(j_common_ptr cinfo
)
1066 /* Close all backing store, release all memory.
1067 * Releasing pools in reverse order might help avoid fragmentation
1068 * with some (brain-damaged) malloc libraries.
1070 for (pool
= JPOOL_NUMPOOLS
- 1; pool
>= JPOOL_PERMANENT
; pool
--) {
1071 free_pool(cinfo
, pool
);
1074 /* Release the memory manager control block too. */
1075 jpeg_free_small(cinfo
, (void *)cinfo
->mem
, sizeof(my_memory_mgr
));
1076 cinfo
->mem
= NULL
; /* ensures I will be called only once */
1078 jpeg_mem_term(cinfo
); /* system-dependent cleanup */
1083 * Memory manager initialization.
1084 * When this is called, only the error manager pointer is valid in cinfo!
1088 jinit_memory_mgr(j_common_ptr cinfo
)
1095 cinfo
->mem
= NULL
; /* for safety if init fails */
1097 /* Check for configuration errors.
1098 * sizeof(ALIGN_TYPE) should be a power of 2; otherwise, it probably
1099 * doesn't reflect any real hardware alignment requirement.
1100 * The test is a little tricky: for X>0, X and X-1 have no one-bits
1101 * in common if and only if X is a power of 2, ie has only one one-bit.
1102 * Some compilers may give an "unreachable code" warning here; ignore it.
1104 if ((ALIGN_SIZE
& (ALIGN_SIZE
- 1)) != 0)
1105 ERREXIT(cinfo
, JERR_BAD_ALIGN_TYPE
);
1106 /* MAX_ALLOC_CHUNK must be representable as type size_t, and must be
1107 * a multiple of ALIGN_SIZE.
1108 * Again, an "unreachable code" warning may be ignored here.
1109 * But a "constant too large" warning means you need to fix MAX_ALLOC_CHUNK.
1111 test_mac
= (size_t)MAX_ALLOC_CHUNK
;
1112 if ((long)test_mac
!= MAX_ALLOC_CHUNK
||
1113 (MAX_ALLOC_CHUNK
% ALIGN_SIZE
) != 0)
1114 ERREXIT(cinfo
, JERR_BAD_ALLOC_CHUNK
);
1116 max_to_use
= jpeg_mem_init(cinfo
); /* system-dependent initialization */
1118 /* Attempt to allocate memory manager's control block */
1119 mem
= (my_mem_ptr
)jpeg_get_small(cinfo
, sizeof(my_memory_mgr
));
1122 jpeg_mem_term(cinfo
); /* system-dependent cleanup */
1123 ERREXIT1(cinfo
, JERR_OUT_OF_MEMORY
, 0);
1126 /* OK, fill in the method pointers */
1127 mem
->pub
.alloc_small
= alloc_small
;
1128 mem
->pub
.alloc_large
= alloc_large
;
1129 mem
->pub
.alloc_sarray
= alloc_sarray
;
1130 mem
->pub
.alloc_barray
= alloc_barray
;
1131 mem
->pub
.request_virt_sarray
= request_virt_sarray
;
1132 mem
->pub
.request_virt_barray
= request_virt_barray
;
1133 mem
->pub
.realize_virt_arrays
= realize_virt_arrays
;
1134 mem
->pub
.access_virt_sarray
= access_virt_sarray
;
1135 mem
->pub
.access_virt_barray
= access_virt_barray
;
1136 mem
->pub
.free_pool
= free_pool
;
1137 mem
->pub
.self_destruct
= self_destruct
;
1139 /* Make MAX_ALLOC_CHUNK accessible to other modules */
1140 mem
->pub
.max_alloc_chunk
= MAX_ALLOC_CHUNK
;
1142 /* Initialize working state */
1143 mem
->pub
.max_memory_to_use
= max_to_use
;
1145 for (pool
= JPOOL_NUMPOOLS
- 1; pool
>= JPOOL_PERMANENT
; pool
--) {
1146 mem
->small_list
[pool
] = NULL
;
1147 mem
->large_list
[pool
] = NULL
;
1149 mem
->virt_sarray_list
= NULL
;
1150 mem
->virt_barray_list
= NULL
;
1152 mem
->total_space_allocated
= sizeof(my_memory_mgr
);
1154 /* Declare ourselves open for business */
1155 cinfo
->mem
= &mem
->pub
;
1157 /* Check for an environment variable JPEGMEM; if found, override the
1158 * default max_memory setting from jpeg_mem_init. Note that the
1159 * surrounding application may again override this value.
1160 * If your system doesn't support getenv(), define NO_GETENV to disable
1167 if ((memenv
= getenv("JPEGMEM")) != NULL
) {
1170 if (sscanf(memenv
, "%ld%c", &max_to_use
, &ch
) > 0) {
1171 if (ch
== 'm' || ch
== 'M')
1172 max_to_use
*= 1000L;
1173 mem
->pub
.max_memory_to_use
= max_to_use
* 1000L;