4 * Copyright (C) 1991-1997, Thomas G. Lane.
5 * Modified 2011-2019 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.
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
16 * * control logic for swapping virtual arrays between main memory and
18 * The separate system-dependent file provides the actual backing-storage
19 * access code, and it contains the policy decision about how much total
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...)
28 #define JPEG_INTERNALS
29 #define AM_MEMORY_MANAGER /* we define jvirt_Xarray_control structs */
32 #include "jmemsys.h" /* import the system-dependent declarations */
35 #ifndef HAVE_STDLIB_H /* <stdlib.h> should declare getenv() */
36 extern char * getenv
JPP((const char * name
));
42 * Some important notes:
43 * The allocation routines provided here must never return NULL.
44 * They should exit to error_exit if unsuccessful.
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.
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
73 #ifndef ALIGN_TYPE /* so can override from jconfig.h */
74 #define ALIGN_TYPE double
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.
90 typedef union small_pool_struct
* small_pool_ptr
;
92 typedef union small_pool_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 */
98 ALIGN_TYPE dummy
; /* included in union to ensure alignment */
101 typedef union large_pool_struct FAR
* large_pool_ptr
;
103 typedef union large_pool_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 */
109 ALIGN_TYPE dummy
; /* included in union to ensure alignment */
114 * Here is the full definition of a memory manager object.
118 struct jpeg_memory_mgr pub
; /* public fields */
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
];
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.
129 jvirt_sarray_ptr virt_sarray_list
;
130 jvirt_barray_ptr virt_barray_list
;
132 /* This counts total space obtained from jpeg_get_small/large */
133 size_t total_space_allocated
;
135 /* alloc_sarray and alloc_barray set this value for use by virtual
138 JDIMENSION last_rowsperchunk
; /* from most recent alloc_sarray/barray */
141 typedef my_memory_mgr
* my_mem_ptr
;
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.
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 */
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 */
184 #ifdef MEM_STATS /* optional extra stuff for statistics */
187 print_mem_stats (j_common_ptr cinfo
, int pool_id
)
189 my_mem_ptr mem
= (my_mem_ptr
) cinfo
->mem
;
190 small_pool_ptr shdr_ptr
;
191 large_pool_ptr lhdr_ptr
;
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.
197 fprintf(stderr
, "Freeing pool %d, total space = %ld\n",
198 pool_id
, (long) mem
->total_space_allocated
);
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
);
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
);
214 #endif /* MEM_STATS */
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 */
223 cinfo
->err
->trace_level
= 2; /* force self_destruct to report stats */
225 ERREXIT1(cinfo
, JERR_OUT_OF_MEMORY
, which
);
230 * Allocation of "small" objects.
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.
242 static const size_t first_pool_slop
[JPOOL_NUMPOOLS
] =
244 1600, /* first PERMANENT pool */
245 16000 /* first IMAGE pool */
248 static const size_t extra_pool_slop
[JPOOL_NUMPOOLS
] =
250 0, /* additional PERMANENT pools */
251 5000 /* additional IMAGE pools */
254 #define MIN_SLOP 50 /* greater than 0 to avoid futile looping */
258 alloc_small (j_common_ptr cinfo
, int pool_id
, size_t sizeofobject
)
259 /* Allocate a "small" object */
261 my_mem_ptr mem
= (my_mem_ptr
) cinfo
->mem
;
262 small_pool_ptr hdr_ptr
, prev_hdr_ptr
;
263 size_t odd_bytes
, min_request
, slop
;
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 */
270 /* Round up the requested size to a multiple of SIZEOF(ALIGN_TYPE) */
271 odd_bytes
= sizeofobject
% SIZEOF(ALIGN_TYPE
);
273 sizeofobject
+= SIZEOF(ALIGN_TYPE
) - odd_bytes
;
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 */
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
;
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
];
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 */
300 hdr_ptr
= (small_pool_ptr
) jpeg_get_small(cinfo
, min_request
+ slop
);
304 if (slop
< MIN_SLOP
) /* give up when it gets real small */
305 out_of_memory(cinfo
, 2); /* jpeg_get_small failed */
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
;
315 prev_hdr_ptr
->hdr
.next
= hdr_ptr
;
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
;
324 return (void *) data_ptr
;
329 * Allocation of "large" objects.
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.
342 METHODDEF(void FAR
*)
343 alloc_large (j_common_ptr cinfo
, int pool_id
, size_t sizeofobject
)
344 /* Allocate a "large" object */
346 my_mem_ptr mem
= (my_mem_ptr
) cinfo
->mem
;
347 large_pool_ptr hdr_ptr
;
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 */
354 /* Round up the requested size to a multiple of SIZEOF(ALIGN_TYPE) */
355 odd_bytes
= sizeofobject
% SIZEOF(ALIGN_TYPE
);
357 sizeofobject
+= SIZEOF(ALIGN_TYPE
) - odd_bytes
;
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 */
363 hdr_ptr
= (large_pool_ptr
) jpeg_get_large(cinfo
, sizeofobject
+
364 SIZEOF(large_pool_hdr
));
366 out_of_memory(cinfo
, 4); /* jpeg_get_large failed */
367 mem
->total_space_allocated
+= sizeofobject
+ SIZEOF(large_pool_hdr
);
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.
374 hdr_ptr
->hdr
.bytes_used
= sizeofobject
;
375 hdr_ptr
->hdr
.bytes_left
= 0;
376 mem
->large_list
[pool_id
] = hdr_ptr
;
378 return (void FAR
*) (hdr_ptr
+ 1); /* point to first data byte in pool */
383 * Creation of 2-D sample arrays.
384 * The pointers are in near heap, the samples themselves in FAR heap.
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
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 */
400 my_mem_ptr mem
= (my_mem_ptr
) cinfo
->mem
;
403 JDIMENSION rowsperchunk
, currow
, i
;
406 /* Calculate max # of rows allowed in one allocation chunk */
407 ltemp
= (MAX_ALLOC_CHUNK
- SIZEOF(large_pool_hdr
)) /
408 ((long) samplesperrow
* SIZEOF(JSAMPLE
));
410 ERREXIT(cinfo
, JERR_WIDTH_OVERFLOW
);
411 if (ltemp
< (long) numrows
)
412 rowsperchunk
= (JDIMENSION
) ltemp
;
414 rowsperchunk
= numrows
;
415 mem
->last_rowsperchunk
= rowsperchunk
;
417 /* Get space for row pointers (small object) */
418 result
= (JSAMPARRAY
) alloc_small(cinfo
, pool_id
,
419 (size_t) numrows
* SIZEOF(JSAMPROW
));
421 /* Get the rows themselves (large objects) */
423 while (currow
< numrows
) {
424 rowsperchunk
= MIN(rowsperchunk
, numrows
- currow
);
425 workspace
= (JSAMPROW
) alloc_large(cinfo
, pool_id
,
426 (size_t) rowsperchunk
* (size_t) samplesperrow
* SIZEOF(JSAMPLE
));
427 for (i
= rowsperchunk
; i
> 0; i
--) {
428 result
[currow
++] = workspace
;
429 workspace
+= samplesperrow
;
438 * Creation of 2-D coefficient-block arrays.
439 * This is essentially the same as the code for sample arrays, above.
442 METHODDEF(JBLOCKARRAY
)
443 alloc_barray (j_common_ptr cinfo
, int pool_id
,
444 JDIMENSION blocksperrow
, JDIMENSION numrows
)
445 /* Allocate a 2-D coefficient-block array */
447 my_mem_ptr mem
= (my_mem_ptr
) cinfo
->mem
;
450 JDIMENSION rowsperchunk
, currow
, i
;
453 /* Calculate max # of rows allowed in one allocation chunk */
454 ltemp
= (MAX_ALLOC_CHUNK
- SIZEOF(large_pool_hdr
)) /
455 ((long) blocksperrow
* SIZEOF(JBLOCK
));
457 ERREXIT(cinfo
, JERR_WIDTH_OVERFLOW
);
458 if (ltemp
< (long) numrows
)
459 rowsperchunk
= (JDIMENSION
) ltemp
;
461 rowsperchunk
= numrows
;
462 mem
->last_rowsperchunk
= rowsperchunk
;
464 /* Get space for row pointers (small object) */
465 result
= (JBLOCKARRAY
) alloc_small(cinfo
, pool_id
,
466 (size_t) numrows
* SIZEOF(JBLOCKROW
));
468 /* Get the rows themselves (large objects) */
470 while (currow
< numrows
) {
471 rowsperchunk
= MIN(rowsperchunk
, numrows
- currow
);
472 workspace
= (JBLOCKROW
) alloc_large(cinfo
, pool_id
,
473 (size_t) rowsperchunk
* (size_t) blocksperrow
* SIZEOF(JBLOCK
));
474 for (i
= rowsperchunk
; i
> 0; i
--) {
475 result
[currow
++] = workspace
;
476 workspace
+= blocksperrow
;
485 * About virtual array management:
487 * The above "normal" array routines are only used to allocate strip buffers
488 * (as wide as the image, but just a few rows high). Full-image-sized buffers
489 * are handled as "virtual" arrays. The array is still accessed a strip at a
490 * time, but the memory manager must save the whole array for repeated
491 * accesses. The intended implementation is that there is a strip buffer in
492 * memory (as high as is possible given the desired memory limit), plus a
493 * backing file that holds the rest of the array.
495 * The request_virt_array routines are told the total size of the image and
496 * the maximum number of rows that will be accessed at once. The in-memory
497 * buffer must be at least as large as the maxaccess value.
499 * The request routines create control blocks but not the in-memory buffers.
500 * That is postponed until realize_virt_arrays is called. At that time the
501 * total amount of space needed is known (approximately, anyway), so free
502 * memory can be divided up fairly.
504 * The access_virt_array routines are responsible for making a specific strip
505 * area accessible (after reading or writing the backing file, if necessary).
506 * Note that the access routines are told whether the caller intends to modify
507 * the accessed strip; during a read-only pass this saves having to rewrite
508 * data to disk. The access routines are also responsible for pre-zeroing
509 * any newly accessed rows, if pre-zeroing was requested.
511 * In current usage, the access requests are usually for nonoverlapping
512 * strips; that is, successive access start_row numbers differ by exactly
513 * num_rows = maxaccess. This means we can get good performance with simple
514 * buffer dump/reload logic, by making the in-memory buffer be a multiple
515 * of the access height; then there will never be accesses across bufferload
516 * boundaries. The code will still work with overlapping access requests,
517 * but it doesn't handle bufferload overlaps very efficiently.
521 METHODDEF(jvirt_sarray_ptr
)
522 request_virt_sarray (j_common_ptr cinfo
, int pool_id
, boolean pre_zero
,
523 JDIMENSION samplesperrow
, JDIMENSION numrows
,
524 JDIMENSION maxaccess
)
525 /* Request a virtual 2-D sample array */
527 my_mem_ptr mem
= (my_mem_ptr
) cinfo
->mem
;
528 jvirt_sarray_ptr result
;
530 /* Only IMAGE-lifetime virtual arrays are currently supported */
531 if (pool_id
!= JPOOL_IMAGE
)
532 ERREXIT1(cinfo
, JERR_BAD_POOL_ID
, pool_id
); /* safety check */
534 /* get control block */
535 result
= (jvirt_sarray_ptr
) alloc_small(cinfo
, pool_id
,
536 SIZEOF(struct jvirt_sarray_control
));
538 result
->mem_buffer
= NULL
; /* marks array not yet realized */
539 result
->rows_in_array
= numrows
;
540 result
->samplesperrow
= samplesperrow
;
541 result
->maxaccess
= maxaccess
;
542 result
->pre_zero
= pre_zero
;
543 result
->b_s_open
= FALSE
; /* no associated backing-store object */
544 result
->next
= mem
->virt_sarray_list
; /* add to list of virtual arrays */
545 mem
->virt_sarray_list
= result
;
551 METHODDEF(jvirt_barray_ptr
)
552 request_virt_barray (j_common_ptr cinfo
, int pool_id
, boolean pre_zero
,
553 JDIMENSION blocksperrow
, JDIMENSION numrows
,
554 JDIMENSION maxaccess
)
555 /* Request a virtual 2-D coefficient-block array */
557 my_mem_ptr mem
= (my_mem_ptr
) cinfo
->mem
;
558 jvirt_barray_ptr result
;
560 /* Only IMAGE-lifetime virtual arrays are currently supported */
561 if (pool_id
!= JPOOL_IMAGE
)
562 ERREXIT1(cinfo
, JERR_BAD_POOL_ID
, pool_id
); /* safety check */
564 /* get control block */
565 result
= (jvirt_barray_ptr
) alloc_small(cinfo
, pool_id
,
566 SIZEOF(struct jvirt_barray_control
));
568 result
->mem_buffer
= NULL
; /* marks array not yet realized */
569 result
->rows_in_array
= numrows
;
570 result
->blocksperrow
= blocksperrow
;
571 result
->maxaccess
= maxaccess
;
572 result
->pre_zero
= pre_zero
;
573 result
->b_s_open
= FALSE
; /* no associated backing-store object */
574 result
->next
= mem
->virt_barray_list
; /* add to list of virtual arrays */
575 mem
->virt_barray_list
= result
;
582 realize_virt_arrays (j_common_ptr cinfo
)
583 /* Allocate the in-memory buffers for any unrealized virtual arrays */
585 my_mem_ptr mem
= (my_mem_ptr
) cinfo
->mem
;
586 long bytesperrow
, space_per_minheight
, maximum_space
;
587 long avail_mem
, minheights
, max_minheights
;
588 jvirt_sarray_ptr sptr
;
589 jvirt_barray_ptr bptr
;
591 /* Compute the minimum space needed (maxaccess rows in each buffer)
592 * and the maximum space needed (full image height in each buffer).
593 * These may be of use to the system-dependent jpeg_mem_available routine.
595 space_per_minheight
= 0;
597 for (sptr
= mem
->virt_sarray_list
; sptr
!= NULL
; sptr
= sptr
->next
) {
598 if (sptr
->mem_buffer
== NULL
) { /* if not realized yet */
599 bytesperrow
= (long) sptr
->samplesperrow
* SIZEOF(JSAMPLE
);
600 space_per_minheight
+= (long) sptr
->maxaccess
* bytesperrow
;
601 maximum_space
+= (long) sptr
->rows_in_array
* bytesperrow
;
604 for (bptr
= mem
->virt_barray_list
; bptr
!= NULL
; bptr
= bptr
->next
) {
605 if (bptr
->mem_buffer
== NULL
) { /* if not realized yet */
606 bytesperrow
= (long) bptr
->blocksperrow
* SIZEOF(JBLOCK
);
607 space_per_minheight
+= (long) bptr
->maxaccess
* bytesperrow
;
608 maximum_space
+= (long) bptr
->rows_in_array
* bytesperrow
;
612 if (space_per_minheight
<= 0)
613 return; /* no unrealized arrays, no work */
615 /* Determine amount of memory to actually use; this is system-dependent. */
616 avail_mem
= jpeg_mem_available(cinfo
, space_per_minheight
, maximum_space
,
617 (long) mem
->total_space_allocated
);
619 /* If the maximum space needed is available, make all the buffers full
620 * height; otherwise parcel it out with the same number of minheights
623 if (avail_mem
>= maximum_space
)
624 max_minheights
= 1000000000L;
626 max_minheights
= avail_mem
/ space_per_minheight
;
627 /* If there doesn't seem to be enough space, try to get the minimum
628 * anyway. This allows a "stub" implementation of jpeg_mem_available().
630 if (max_minheights
<= 0)
634 /* Allocate the in-memory buffers and initialize backing store as needed. */
636 for (sptr
= mem
->virt_sarray_list
; sptr
!= NULL
; sptr
= sptr
->next
) {
637 if (sptr
->mem_buffer
== NULL
) { /* if not realized yet */
638 minheights
= ((long) sptr
->rows_in_array
- 1L) / sptr
->maxaccess
+ 1L;
639 if (minheights
<= max_minheights
) {
640 /* This buffer fits in memory */
641 sptr
->rows_in_mem
= sptr
->rows_in_array
;
643 /* It doesn't fit in memory, create backing store. */
644 sptr
->rows_in_mem
= (JDIMENSION
) (max_minheights
* sptr
->maxaccess
);
645 jpeg_open_backing_store(cinfo
, & sptr
->b_s_info
,
646 (long) sptr
->rows_in_array
*
647 (long) sptr
->samplesperrow
*
648 (long) SIZEOF(JSAMPLE
));
649 sptr
->b_s_open
= TRUE
;
651 sptr
->mem_buffer
= alloc_sarray(cinfo
, JPOOL_IMAGE
,
652 sptr
->samplesperrow
, sptr
->rows_in_mem
);
653 sptr
->rowsperchunk
= mem
->last_rowsperchunk
;
654 sptr
->cur_start_row
= 0;
655 sptr
->first_undef_row
= 0;
660 for (bptr
= mem
->virt_barray_list
; bptr
!= NULL
; bptr
= bptr
->next
) {
661 if (bptr
->mem_buffer
== NULL
) { /* if not realized yet */
662 minheights
= ((long) bptr
->rows_in_array
- 1L) / bptr
->maxaccess
+ 1L;
663 if (minheights
<= max_minheights
) {
664 /* This buffer fits in memory */
665 bptr
->rows_in_mem
= bptr
->rows_in_array
;
667 /* It doesn't fit in memory, create backing store. */
668 bptr
->rows_in_mem
= (JDIMENSION
) (max_minheights
* bptr
->maxaccess
);
669 jpeg_open_backing_store(cinfo
, & bptr
->b_s_info
,
670 (long) bptr
->rows_in_array
*
671 (long) bptr
->blocksperrow
*
672 (long) SIZEOF(JBLOCK
));
673 bptr
->b_s_open
= TRUE
;
675 bptr
->mem_buffer
= alloc_barray(cinfo
, JPOOL_IMAGE
,
676 bptr
->blocksperrow
, bptr
->rows_in_mem
);
677 bptr
->rowsperchunk
= mem
->last_rowsperchunk
;
678 bptr
->cur_start_row
= 0;
679 bptr
->first_undef_row
= 0;
687 do_sarray_io (j_common_ptr cinfo
, jvirt_sarray_ptr ptr
, boolean writing
)
688 /* Do backing store read or write of a virtual sample array */
690 long bytesperrow
, file_offset
, byte_count
, rows
, thisrow
, i
;
692 bytesperrow
= (long) ptr
->samplesperrow
* SIZEOF(JSAMPLE
);
693 file_offset
= (long) ptr
->cur_start_row
* bytesperrow
;
694 /* Loop to read or write each allocation chunk in mem_buffer */
695 for (i
= 0; i
< (long) ptr
->rows_in_mem
; i
+= ptr
->rowsperchunk
) {
696 /* One chunk, but check for short chunk at end of buffer */
697 rows
= MIN((long) ptr
->rowsperchunk
, (long) ptr
->rows_in_mem
- i
);
698 /* Transfer no more than is currently defined */
699 thisrow
= (long) ptr
->cur_start_row
+ i
;
700 rows
= MIN(rows
, (long) ptr
->first_undef_row
- thisrow
);
701 /* Transfer no more than fits in file */
702 rows
= MIN(rows
, (long) ptr
->rows_in_array
- thisrow
);
703 if (rows
<= 0) /* this chunk might be past end of file! */
705 byte_count
= rows
* bytesperrow
;
707 (*ptr
->b_s_info
.write_backing_store
) (cinfo
, & ptr
->b_s_info
,
708 (void FAR
*) ptr
->mem_buffer
[i
],
709 file_offset
, byte_count
);
711 (*ptr
->b_s_info
.read_backing_store
) (cinfo
, & ptr
->b_s_info
,
712 (void FAR
*) ptr
->mem_buffer
[i
],
713 file_offset
, byte_count
);
714 file_offset
+= byte_count
;
720 do_barray_io (j_common_ptr cinfo
, jvirt_barray_ptr ptr
, boolean writing
)
721 /* Do backing store read or write of a virtual coefficient-block array */
723 long bytesperrow
, file_offset
, byte_count
, rows
, thisrow
, i
;
725 bytesperrow
= (long) ptr
->blocksperrow
* SIZEOF(JBLOCK
);
726 file_offset
= (long) ptr
->cur_start_row
* bytesperrow
;
727 /* Loop to read or write each allocation chunk in mem_buffer */
728 for (i
= 0; i
< (long) ptr
->rows_in_mem
; i
+= ptr
->rowsperchunk
) {
729 /* One chunk, but check for short chunk at end of buffer */
730 rows
= MIN((long) ptr
->rowsperchunk
, (long) ptr
->rows_in_mem
- i
);
731 /* Transfer no more than is currently defined */
732 thisrow
= (long) ptr
->cur_start_row
+ i
;
733 rows
= MIN(rows
, (long) ptr
->first_undef_row
- thisrow
);
734 /* Transfer no more than fits in file */
735 rows
= MIN(rows
, (long) ptr
->rows_in_array
- thisrow
);
736 if (rows
<= 0) /* this chunk might be past end of file! */
738 byte_count
= rows
* bytesperrow
;
740 (*ptr
->b_s_info
.write_backing_store
) (cinfo
, & ptr
->b_s_info
,
741 (void FAR
*) ptr
->mem_buffer
[i
],
742 file_offset
, byte_count
);
744 (*ptr
->b_s_info
.read_backing_store
) (cinfo
, & ptr
->b_s_info
,
745 (void FAR
*) ptr
->mem_buffer
[i
],
746 file_offset
, byte_count
);
747 file_offset
+= byte_count
;
752 METHODDEF(JSAMPARRAY
)
753 access_virt_sarray (j_common_ptr cinfo
, jvirt_sarray_ptr ptr
,
754 JDIMENSION start_row
, JDIMENSION num_rows
,
756 /* Access the part of a virtual sample array starting at start_row */
757 /* and extending for num_rows rows. writable is true if */
758 /* caller intends to modify the accessed area. */
760 JDIMENSION end_row
= start_row
+ num_rows
;
761 JDIMENSION undef_row
;
763 /* debugging check */
764 if (end_row
> ptr
->rows_in_array
|| num_rows
> ptr
->maxaccess
||
765 ptr
->mem_buffer
== NULL
)
766 ERREXIT(cinfo
, JERR_BAD_VIRTUAL_ACCESS
);
768 /* Make the desired part of the virtual array accessible */
769 if (start_row
< ptr
->cur_start_row
||
770 end_row
> ptr
->cur_start_row
+ ptr
->rows_in_mem
) {
772 ERREXIT(cinfo
, JERR_VIRTUAL_BUG
);
773 /* Flush old buffer contents if necessary */
775 do_sarray_io(cinfo
, ptr
, TRUE
);
778 /* Decide what part of virtual array to access.
779 * Algorithm: if target address > current window, assume forward scan,
780 * load starting at target address. If target address < current window,
781 * assume backward scan, load so that target area is top of window.
782 * Note that when switching from forward write to forward read, will have
783 * start_row = 0, so the limiting case applies and we load from 0 anyway.
785 if (start_row
> ptr
->cur_start_row
) {
786 ptr
->cur_start_row
= start_row
;
788 /* use long arithmetic here to avoid overflow & unsigned problems */
791 ltemp
= (long) end_row
- (long) ptr
->rows_in_mem
;
793 ltemp
= 0; /* don't fall off front end of file */
794 ptr
->cur_start_row
= (JDIMENSION
) ltemp
;
796 /* Read in the selected part of the array.
797 * During the initial write pass, we will do no actual read
798 * because the selected part is all undefined.
800 do_sarray_io(cinfo
, ptr
, FALSE
);
802 /* Ensure the accessed part of the array is defined; prezero if needed.
803 * To improve locality of access, we only prezero the part of the array
804 * that the caller is about to access, not the entire in-memory array.
806 if (ptr
->first_undef_row
< end_row
) {
807 if (ptr
->first_undef_row
< start_row
) {
808 if (writable
) /* writer skipped over a section of array */
809 ERREXIT(cinfo
, JERR_BAD_VIRTUAL_ACCESS
);
810 undef_row
= start_row
; /* but reader is allowed to read ahead */
812 undef_row
= ptr
->first_undef_row
;
815 ptr
->first_undef_row
= end_row
;
817 size_t bytesperrow
= (size_t) ptr
->samplesperrow
* SIZEOF(JSAMPLE
);
818 undef_row
-= ptr
->cur_start_row
; /* make indexes relative to buffer */
819 end_row
-= ptr
->cur_start_row
;
820 while (undef_row
< end_row
) {
821 FMEMZERO((void FAR
*) ptr
->mem_buffer
[undef_row
], bytesperrow
);
825 if (! writable
) /* reader looking at undefined data */
826 ERREXIT(cinfo
, JERR_BAD_VIRTUAL_ACCESS
);
829 /* Flag the buffer dirty if caller will write in it */
832 /* Return address of proper part of the buffer */
833 return ptr
->mem_buffer
+ (start_row
- ptr
->cur_start_row
);
837 METHODDEF(JBLOCKARRAY
)
838 access_virt_barray (j_common_ptr cinfo
, jvirt_barray_ptr ptr
,
839 JDIMENSION start_row
, JDIMENSION num_rows
,
841 /* Access the part of a virtual block array starting at start_row */
842 /* and extending for num_rows rows. writable is true if */
843 /* caller intends to modify the accessed area. */
845 JDIMENSION end_row
= start_row
+ num_rows
;
846 JDIMENSION undef_row
;
848 /* debugging check */
849 if (end_row
> ptr
->rows_in_array
|| num_rows
> ptr
->maxaccess
||
850 ptr
->mem_buffer
== NULL
)
851 ERREXIT(cinfo
, JERR_BAD_VIRTUAL_ACCESS
);
853 /* Make the desired part of the virtual array accessible */
854 if (start_row
< ptr
->cur_start_row
||
855 end_row
> ptr
->cur_start_row
+ ptr
->rows_in_mem
) {
857 ERREXIT(cinfo
, JERR_VIRTUAL_BUG
);
858 /* Flush old buffer contents if necessary */
860 do_barray_io(cinfo
, ptr
, TRUE
);
863 /* Decide what part of virtual array to access.
864 * Algorithm: if target address > current window, assume forward scan,
865 * load starting at target address. If target address < current window,
866 * assume backward scan, load so that target area is top of window.
867 * Note that when switching from forward write to forward read, will have
868 * start_row = 0, so the limiting case applies and we load from 0 anyway.
870 if (start_row
> ptr
->cur_start_row
) {
871 ptr
->cur_start_row
= start_row
;
873 /* use long arithmetic here to avoid overflow & unsigned problems */
876 ltemp
= (long) end_row
- (long) ptr
->rows_in_mem
;
878 ltemp
= 0; /* don't fall off front end of file */
879 ptr
->cur_start_row
= (JDIMENSION
) ltemp
;
881 /* Read in the selected part of the array.
882 * During the initial write pass, we will do no actual read
883 * because the selected part is all undefined.
885 do_barray_io(cinfo
, ptr
, FALSE
);
887 /* Ensure the accessed part of the array is defined; prezero if needed.
888 * To improve locality of access, we only prezero the part of the array
889 * that the caller is about to access, not the entire in-memory array.
891 if (ptr
->first_undef_row
< end_row
) {
892 if (ptr
->first_undef_row
< start_row
) {
893 if (writable
) /* writer skipped over a section of array */
894 ERREXIT(cinfo
, JERR_BAD_VIRTUAL_ACCESS
);
895 undef_row
= start_row
; /* but reader is allowed to read ahead */
897 undef_row
= ptr
->first_undef_row
;
900 ptr
->first_undef_row
= end_row
;
902 size_t bytesperrow
= (size_t) ptr
->blocksperrow
* SIZEOF(JBLOCK
);
903 undef_row
-= ptr
->cur_start_row
; /* make indexes relative to buffer */
904 end_row
-= ptr
->cur_start_row
;
905 while (undef_row
< end_row
) {
906 FMEMZERO((void FAR
*) ptr
->mem_buffer
[undef_row
], bytesperrow
);
910 if (! writable
) /* reader looking at undefined data */
911 ERREXIT(cinfo
, JERR_BAD_VIRTUAL_ACCESS
);
914 /* Flag the buffer dirty if caller will write in it */
917 /* Return address of proper part of the buffer */
918 return ptr
->mem_buffer
+ (start_row
- ptr
->cur_start_row
);
923 * Release all objects belonging to a specified pool.
927 free_pool (j_common_ptr cinfo
, int pool_id
)
929 my_mem_ptr mem
= (my_mem_ptr
) cinfo
->mem
;
930 small_pool_ptr shdr_ptr
;
931 large_pool_ptr lhdr_ptr
;
934 if (pool_id
< 0 || pool_id
>= JPOOL_NUMPOOLS
)
935 ERREXIT1(cinfo
, JERR_BAD_POOL_ID
, pool_id
); /* safety check */
938 if (cinfo
->err
->trace_level
> 1)
939 print_mem_stats(cinfo
, pool_id
); /* print pool's memory usage statistics */
942 /* If freeing IMAGE pool, close any virtual arrays first */
943 if (pool_id
== JPOOL_IMAGE
) {
944 jvirt_sarray_ptr sptr
;
945 jvirt_barray_ptr bptr
;
947 for (sptr
= mem
->virt_sarray_list
; sptr
!= NULL
; sptr
= sptr
->next
) {
948 if (sptr
->b_s_open
) { /* there may be no backing store */
949 sptr
->b_s_open
= FALSE
; /* prevent recursive close if error */
950 (*sptr
->b_s_info
.close_backing_store
) (cinfo
, & sptr
->b_s_info
);
953 mem
->virt_sarray_list
= NULL
;
954 for (bptr
= mem
->virt_barray_list
; bptr
!= NULL
; bptr
= bptr
->next
) {
955 if (bptr
->b_s_open
) { /* there may be no backing store */
956 bptr
->b_s_open
= FALSE
; /* prevent recursive close if error */
957 (*bptr
->b_s_info
.close_backing_store
) (cinfo
, & bptr
->b_s_info
);
960 mem
->virt_barray_list
= NULL
;
963 /* Release large objects */
964 lhdr_ptr
= mem
->large_list
[pool_id
];
965 mem
->large_list
[pool_id
] = NULL
;
967 while (lhdr_ptr
!= NULL
) {
968 large_pool_ptr next_lhdr_ptr
= lhdr_ptr
->hdr
.next
;
969 space_freed
= lhdr_ptr
->hdr
.bytes_used
+
970 lhdr_ptr
->hdr
.bytes_left
+
971 SIZEOF(large_pool_hdr
);
972 jpeg_free_large(cinfo
, (void FAR
*) lhdr_ptr
, space_freed
);
973 mem
->total_space_allocated
-= space_freed
;
974 lhdr_ptr
= next_lhdr_ptr
;
977 /* Release small objects */
978 shdr_ptr
= mem
->small_list
[pool_id
];
979 mem
->small_list
[pool_id
] = NULL
;
981 while (shdr_ptr
!= NULL
) {
982 small_pool_ptr next_shdr_ptr
= shdr_ptr
->hdr
.next
;
983 space_freed
= shdr_ptr
->hdr
.bytes_used
+
984 shdr_ptr
->hdr
.bytes_left
+
985 SIZEOF(small_pool_hdr
);
986 jpeg_free_small(cinfo
, (void *) shdr_ptr
, space_freed
);
987 mem
->total_space_allocated
-= space_freed
;
988 shdr_ptr
= next_shdr_ptr
;
994 * Close up shop entirely.
995 * Note that this cannot be called unless cinfo->mem is non-NULL.
999 self_destruct (j_common_ptr cinfo
)
1003 /* Close all backing store, release all memory.
1004 * Releasing pools in reverse order might help avoid fragmentation
1005 * with some (brain-damaged) malloc libraries.
1007 for (pool
= JPOOL_NUMPOOLS
-1; pool
>= JPOOL_PERMANENT
; pool
--) {
1008 free_pool(cinfo
, pool
);
1011 /* Release the memory manager control block too. */
1012 jpeg_free_small(cinfo
, (void *) cinfo
->mem
, SIZEOF(my_memory_mgr
));
1013 cinfo
->mem
= NULL
; /* ensures I will be called only once */
1015 jpeg_mem_term(cinfo
); /* system-dependent cleanup */
1020 * Memory manager initialization.
1021 * When this is called, only the error manager pointer is valid in cinfo!
1025 jinit_memory_mgr (j_common_ptr cinfo
)
1032 cinfo
->mem
= NULL
; /* for safety if init fails */
1034 /* Check for configuration errors.
1035 * SIZEOF(ALIGN_TYPE) should be a power of 2; otherwise, it probably
1036 * doesn't reflect any real hardware alignment requirement.
1037 * The test is a little tricky: for X>0, X and X-1 have no one-bits
1038 * in common if and only if X is a power of 2, ie has only one one-bit.
1039 * Some compilers may give an "unreachable code" warning here; ignore it.
1041 if ((SIZEOF(ALIGN_TYPE
) & (SIZEOF(ALIGN_TYPE
)-1)) != 0)
1042 ERREXIT(cinfo
, JERR_BAD_ALIGN_TYPE
);
1043 /* MAX_ALLOC_CHUNK must be representable as type size_t, and must be
1044 * a multiple of SIZEOF(ALIGN_TYPE).
1045 * Again, an "unreachable code" warning may be ignored here.
1046 * But a "constant too large" warning means you need to fix MAX_ALLOC_CHUNK.
1048 test_mac
= (size_t) MAX_ALLOC_CHUNK
;
1049 if ((long) test_mac
!= MAX_ALLOC_CHUNK
||
1050 (MAX_ALLOC_CHUNK
% SIZEOF(ALIGN_TYPE
)) != 0)
1051 ERREXIT(cinfo
, JERR_BAD_ALLOC_CHUNK
);
1053 max_to_use
= jpeg_mem_init(cinfo
); /* system-dependent initialization */
1055 /* Attempt to allocate memory manager's control block */
1056 mem
= (my_mem_ptr
) jpeg_get_small(cinfo
, SIZEOF(my_memory_mgr
));
1059 jpeg_mem_term(cinfo
); /* system-dependent cleanup */
1060 ERREXIT1(cinfo
, JERR_OUT_OF_MEMORY
, 0);
1063 /* OK, fill in the method pointers */
1064 mem
->pub
.alloc_small
= alloc_small
;
1065 mem
->pub
.alloc_large
= alloc_large
;
1066 mem
->pub
.alloc_sarray
= alloc_sarray
;
1067 mem
->pub
.alloc_barray
= alloc_barray
;
1068 mem
->pub
.request_virt_sarray
= request_virt_sarray
;
1069 mem
->pub
.request_virt_barray
= request_virt_barray
;
1070 mem
->pub
.realize_virt_arrays
= realize_virt_arrays
;
1071 mem
->pub
.access_virt_sarray
= access_virt_sarray
;
1072 mem
->pub
.access_virt_barray
= access_virt_barray
;
1073 mem
->pub
.free_pool
= free_pool
;
1074 mem
->pub
.self_destruct
= self_destruct
;
1076 /* Make MAX_ALLOC_CHUNK accessible to other modules */
1077 mem
->pub
.max_alloc_chunk
= MAX_ALLOC_CHUNK
;
1079 /* Initialize working state */
1080 mem
->pub
.max_memory_to_use
= max_to_use
;
1082 for (pool
= JPOOL_NUMPOOLS
-1; pool
>= JPOOL_PERMANENT
; pool
--) {
1083 mem
->small_list
[pool
] = NULL
;
1084 mem
->large_list
[pool
] = NULL
;
1086 mem
->virt_sarray_list
= NULL
;
1087 mem
->virt_barray_list
= NULL
;
1089 mem
->total_space_allocated
= SIZEOF(my_memory_mgr
);
1091 /* Declare ourselves open for business */
1092 cinfo
->mem
= &mem
->pub
;
1094 /* Check for an environment variable JPEGMEM; if found, override the
1095 * default max_memory setting from jpeg_mem_init. Note that the
1096 * surrounding application may again override this value.
1097 * If your system doesn't support getenv(), define NO_GETENV to disable
1103 if ((memenv
= getenv("JPEGMEM")) != NULL
) {
1106 if (sscanf(memenv
, "%ld%c", &max_to_use
, &ch
) > 0) {
1107 if (ch
== 'm' || ch
== 'M')
1108 max_to_use
*= 1000L;
1109 mem
->pub
.max_memory_to_use
= max_to_use
* 1000L;