4 * Copyright (C) 1991-1997, Thomas G. Lane.
5 * This file is part of the Independent JPEG Group's software.
6 * For conditions of distribution and use, see the accompanying README file.
8 * This file contains the JPEG system-independent memory management
9 * routines. This code is usable across a wide variety of machines; most
10 * of the system dependencies have been isolated in a separate file.
11 * The major functions provided here are:
12 * * pool-based allocation and freeing of memory;
13 * * policy decisions about how to divide available memory among the
15 * * control logic for swapping virtual arrays between main memory and
17 * The separate system-dependent file provides the actual backing-storage
18 * access code, and it contains the policy decision about how much total
20 * This file is system-dependent in the sense that some of its functions
21 * are unnecessary in some systems. For example, if there is enough virtual
22 * memory so that backing storage will never be used, much of the virtual
23 * array control logic could be removed. (Of course, if you have that much
24 * memory then you shouldn't care about a little bit of unused code...)
27 #define JPEG_INTERNALS
28 #define AM_MEMORY_MANAGER /* we define jvirt_Xarray_control structs */
31 #include "jmemsys.h" /* import the system-dependent declarations */
34 #ifndef HAVE_STDLIB_H /* <stdlib.h> should declare getenv() */
35 extern char * getenv
JPP((const char * name
));
41 round_up_pow2 (size_t a
, size_t b
)
42 /* a rounded up to the next multiple of b, i.e. ceil(a/b)*b */
43 /* Assumes a >= 0, b > 0, and b is a power of 2 */
45 return ((a
+ b
- 1) & (~(b
- 1)));
50 * Some important notes:
51 * The allocation routines provided here must never return NULL.
52 * They should exit to error_exit if unsuccessful.
54 * It's not a good idea to try to merge the sarray and barray routines,
55 * even though they are textually almost the same, because samples are
56 * usually stored as bytes while coefficients are shorts or ints. Thus,
57 * in machines where byte pointers have a different representation from
58 * word pointers, the resulting machine code could not be the same.
63 * Many machines require storage alignment: longs must start on 4-byte
64 * boundaries, doubles on 8-byte boundaries, etc. On such machines, malloc()
65 * always returns pointers that are multiples of the worst-case alignment
66 * requirement, and we had better do so too.
67 * There isn't any really portable way to determine the worst-case alignment
68 * requirement. This module assumes that the alignment requirement is
69 * multiples of ALIGN_SIZE.
70 * By default, we define ALIGN_SIZE as sizeof(double). This is necessary on some
71 * workstations (where doubles really do need 8-byte alignment) and will work
72 * fine on nearly everything. If your machine has lesser alignment needs,
73 * you can save a few bytes by making ALIGN_SIZE smaller.
74 * The only place I know of where this will NOT work is certain Macintosh
75 * 680x0 compilers that define double as a 10-byte IEEE extended float.
76 * Doing 10-byte alignment is counterproductive because longwords won't be
77 * aligned well. Put "#define ALIGN_SIZE 4" in jconfig.h if you have
81 #ifndef ALIGN_SIZE /* so can override from jconfig.h */
83 #define ALIGN_SIZE SIZEOF(double)
85 #define ALIGN_SIZE 16 /* Most SIMD implementations require this */
90 * We allocate objects from "pools", where each pool is gotten with a single
91 * request to jpeg_get_small() or jpeg_get_large(). There is no per-object
92 * overhead within a pool, except for alignment padding. Each pool has a
93 * header with a link to the next pool of the same class.
94 * Small and large pool headers are identical except that the latter's
95 * link pointer must be FAR on 80x86 machines.
98 typedef struct small_pool_struct
* small_pool_ptr
;
100 typedef struct small_pool_struct
{
101 small_pool_ptr next
; /* next in list of pools */
102 size_t bytes_used
; /* how many bytes already used within pool */
103 size_t bytes_left
; /* bytes still available in this pool */
106 typedef struct large_pool_struct FAR
* large_pool_ptr
;
108 typedef struct large_pool_struct
{
109 large_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 */
115 * Here is the full definition of a memory manager object.
119 struct jpeg_memory_mgr pub
; /* public fields */
121 /* Each pool identifier (lifetime class) names a linked list of pools. */
122 small_pool_ptr small_list
[JPOOL_NUMPOOLS
];
123 large_pool_ptr large_list
[JPOOL_NUMPOOLS
];
125 /* Since we only have one lifetime class of virtual arrays, only one
126 * linked list is necessary (for each datatype). Note that the virtual
127 * array control blocks being linked together are actually stored somewhere
128 * in the small-pool list.
130 jvirt_sarray_ptr virt_sarray_list
;
131 jvirt_barray_ptr virt_barray_list
;
133 /* This counts total space obtained from jpeg_get_small/large */
134 size_t total_space_allocated
;
136 /* alloc_sarray and alloc_barray set this value for use by virtual
139 JDIMENSION last_rowsperchunk
; /* from most recent alloc_sarray/barray */
142 typedef my_memory_mgr
* my_mem_ptr
;
146 * The control blocks for virtual arrays.
147 * Note that these blocks are allocated in the "small" pool area.
148 * System-dependent info for the associated backing store (if any) is hidden
149 * inside the backing_store_info struct.
152 struct jvirt_sarray_control
{
153 JSAMPARRAY mem_buffer
; /* => the in-memory buffer */
154 JDIMENSION rows_in_array
; /* total virtual array height */
155 JDIMENSION samplesperrow
; /* width of array (and of memory buffer) */
156 JDIMENSION maxaccess
; /* max rows accessed by access_virt_sarray */
157 JDIMENSION rows_in_mem
; /* height of memory buffer */
158 JDIMENSION rowsperchunk
; /* allocation chunk size in mem_buffer */
159 JDIMENSION cur_start_row
; /* first logical row # in the buffer */
160 JDIMENSION first_undef_row
; /* row # of first uninitialized row */
161 boolean pre_zero
; /* pre-zero mode requested? */
162 boolean dirty
; /* do current buffer contents need written? */
163 boolean b_s_open
; /* is backing-store data valid? */
164 jvirt_sarray_ptr next
; /* link to next virtual sarray control block */
165 backing_store_info b_s_info
; /* System-dependent control info */
168 struct jvirt_barray_control
{
169 JBLOCKARRAY mem_buffer
; /* => the in-memory buffer */
170 JDIMENSION rows_in_array
; /* total virtual array height */
171 JDIMENSION blocksperrow
; /* width of array (and of memory buffer) */
172 JDIMENSION maxaccess
; /* max rows accessed by access_virt_barray */
173 JDIMENSION rows_in_mem
; /* height of memory buffer */
174 JDIMENSION rowsperchunk
; /* allocation chunk size in mem_buffer */
175 JDIMENSION cur_start_row
; /* first logical row # in the buffer */
176 JDIMENSION first_undef_row
; /* row # of first uninitialized row */
177 boolean pre_zero
; /* pre-zero mode requested? */
178 boolean dirty
; /* do current buffer contents need written? */
179 boolean b_s_open
; /* is backing-store data valid? */
180 jvirt_barray_ptr next
; /* link to next virtual barray control block */
181 backing_store_info b_s_info
; /* System-dependent control info */
185 #ifdef MEM_STATS /* optional extra stuff for statistics */
188 print_mem_stats (j_common_ptr cinfo
, int pool_id
)
190 my_mem_ptr mem
= (my_mem_ptr
) cinfo
->mem
;
191 small_pool_ptr shdr_ptr
;
192 large_pool_ptr lhdr_ptr
;
194 /* Since this is only a debugging stub, we can cheat a little by using
195 * fprintf directly rather than going through the trace message code.
196 * This is helpful because message parm array can't handle longs.
198 fprintf(stderr
, "Freeing pool %d, total space = %ld\n",
199 pool_id
, mem
->total_space_allocated
);
201 for (lhdr_ptr
= mem
->large_list
[pool_id
]; lhdr_ptr
!= NULL
;
202 lhdr_ptr
= lhdr_ptr
->next
) {
203 fprintf(stderr
, " Large chunk used %ld\n",
204 (long) lhdr_ptr
->bytes_used
);
207 for (shdr_ptr
= mem
->small_list
[pool_id
]; shdr_ptr
!= NULL
;
208 shdr_ptr
= shdr_ptr
->next
) {
209 fprintf(stderr
, " Small chunk used %ld free %ld\n",
210 (long) shdr_ptr
->bytes_used
,
211 (long) shdr_ptr
->bytes_left
);
215 #endif /* MEM_STATS */
219 out_of_memory (j_common_ptr cinfo
, int which
)
220 /* Report an out-of-memory error and stop execution */
221 /* If we compiled MEM_STATS support, report alloc requests before dying */
224 cinfo
->err
->trace_level
= 2; /* force self_destruct to report stats */
226 ERREXIT1(cinfo
, JERR_OUT_OF_MEMORY
, which
);
231 * Allocation of "small" objects.
233 * For these, we use pooled storage. When a new pool must be created,
234 * we try to get enough space for the current request plus a "slop" factor,
235 * where the slop will be the amount of leftover space in the new pool.
236 * The speed vs. space tradeoff is largely determined by the slop values.
237 * A different slop value is provided for each pool class (lifetime),
238 * and we also distinguish the first pool of a class from later ones.
239 * NOTE: the values given work fairly well on both 16- and 32-bit-int
240 * machines, but may be too small if longs are 64 bits or more.
242 * Since we do not know what alignment malloc() gives us, we have to
243 * allocate ALIGN_SIZE-1 extra space per pool to have room for alignment
247 static const size_t first_pool_slop
[JPOOL_NUMPOOLS
] =
249 1600, /* first PERMANENT pool */
250 16000 /* first IMAGE pool */
253 static const size_t extra_pool_slop
[JPOOL_NUMPOOLS
] =
255 0, /* additional PERMANENT pools */
256 5000 /* additional IMAGE pools */
259 #define MIN_SLOP 50 /* greater than 0 to avoid futile looping */
263 alloc_small (j_common_ptr cinfo
, int pool_id
, size_t sizeofobject
)
264 /* Allocate a "small" object */
266 my_mem_ptr mem
= (my_mem_ptr
) cinfo
->mem
;
267 small_pool_ptr hdr_ptr
, prev_hdr_ptr
;
269 size_t min_request
, slop
;
272 * Round up the requested size to a multiple of ALIGN_SIZE in order
273 * to assure alignment for the next object allocated in the same pool
274 * and so that algorithms can straddle outside the proper area up
275 * to the next alignment.
277 sizeofobject
= round_up_pow2(sizeofobject
, ALIGN_SIZE
);
279 /* Check for unsatisfiable request (do now to ensure no overflow below) */
280 if ((SIZEOF(small_pool_hdr
) + sizeofobject
+ ALIGN_SIZE
- 1) > MAX_ALLOC_CHUNK
)
281 out_of_memory(cinfo
, 1); /* request exceeds malloc's ability */
283 /* See if space is available in any existing pool */
284 if (pool_id
< 0 || pool_id
>= JPOOL_NUMPOOLS
)
285 ERREXIT1(cinfo
, JERR_BAD_POOL_ID
, pool_id
); /* safety check */
287 hdr_ptr
= mem
->small_list
[pool_id
];
288 while (hdr_ptr
!= NULL
) {
289 if (hdr_ptr
->bytes_left
>= sizeofobject
)
290 break; /* found pool with enough space */
291 prev_hdr_ptr
= hdr_ptr
;
292 hdr_ptr
= hdr_ptr
->next
;
295 /* Time to make a new pool? */
296 if (hdr_ptr
== NULL
) {
297 /* min_request is what we need now, slop is what will be leftover */
298 min_request
= SIZEOF(small_pool_hdr
) + sizeofobject
+ ALIGN_SIZE
- 1;
299 if (prev_hdr_ptr
== NULL
) /* first pool in class? */
300 slop
= first_pool_slop
[pool_id
];
302 slop
= extra_pool_slop
[pool_id
];
303 /* Don't ask for more than MAX_ALLOC_CHUNK */
304 if (slop
> (size_t) (MAX_ALLOC_CHUNK
-min_request
))
305 slop
= (size_t) (MAX_ALLOC_CHUNK
-min_request
);
306 /* Try to get space, if fail reduce slop and try again */
308 hdr_ptr
= (small_pool_ptr
) jpeg_get_small(cinfo
, min_request
+ slop
);
312 if (slop
< MIN_SLOP
) /* give up when it gets real small */
313 out_of_memory(cinfo
, 2); /* jpeg_get_small failed */
315 mem
->total_space_allocated
+= min_request
+ slop
;
316 /* Success, initialize the new pool header and add to end of list */
317 hdr_ptr
->next
= NULL
;
318 hdr_ptr
->bytes_used
= 0;
319 hdr_ptr
->bytes_left
= sizeofobject
+ slop
;
320 if (prev_hdr_ptr
== NULL
) /* first pool in class? */
321 mem
->small_list
[pool_id
] = hdr_ptr
;
323 prev_hdr_ptr
->next
= hdr_ptr
;
326 /* OK, allocate the object from the current pool */
327 data_ptr
= (char *) hdr_ptr
; /* point to first data byte in pool... */
328 data_ptr
+= SIZEOF(small_pool_hdr
); /* ...by skipping the header... */
329 if ((size_t)data_ptr
% ALIGN_SIZE
) /* ...and adjust for alignment */
330 data_ptr
+= ALIGN_SIZE
- (size_t)data_ptr
% ALIGN_SIZE
;
331 data_ptr
+= hdr_ptr
->bytes_used
; /* point to place for object */
332 hdr_ptr
->bytes_used
+= sizeofobject
;
333 hdr_ptr
->bytes_left
-= sizeofobject
;
335 return (void *) data_ptr
;
340 * Allocation of "large" objects.
342 * The external semantics of these are the same as "small" objects,
343 * except that FAR pointers are used on 80x86. However the pool
344 * management heuristics are quite different. We assume that each
345 * request is large enough that it may as well be passed directly to
346 * jpeg_get_large; the pool management just links everything together
347 * so that we can free it all on demand.
348 * Note: the major use of "large" objects is in JSAMPARRAY and JBLOCKARRAY
349 * structures. The routines that create these structures (see below)
350 * deliberately bunch rows together to ensure a large request size.
353 METHODDEF(void FAR
*)
354 alloc_large (j_common_ptr cinfo
, int pool_id
, size_t sizeofobject
)
355 /* Allocate a "large" object */
357 my_mem_ptr mem
= (my_mem_ptr
) cinfo
->mem
;
358 large_pool_ptr hdr_ptr
;
362 * Round up the requested size to a multiple of ALIGN_SIZE so that
363 * algorithms can straddle outside the proper area up to the next
366 sizeofobject
= round_up_pow2(sizeofobject
, ALIGN_SIZE
);
368 /* Check for unsatisfiable request (do now to ensure no overflow below) */
369 if ((SIZEOF(large_pool_hdr
) + sizeofobject
+ ALIGN_SIZE
- 1) > MAX_ALLOC_CHUNK
)
370 out_of_memory(cinfo
, 3); /* request exceeds malloc's ability */
372 /* Always make a new pool */
373 if (pool_id
< 0 || pool_id
>= JPOOL_NUMPOOLS
)
374 ERREXIT1(cinfo
, JERR_BAD_POOL_ID
, pool_id
); /* safety check */
376 hdr_ptr
= (large_pool_ptr
) jpeg_get_large(cinfo
, sizeofobject
+
377 SIZEOF(large_pool_hdr
) +
380 out_of_memory(cinfo
, 4); /* jpeg_get_large failed */
381 mem
->total_space_allocated
+= sizeofobject
+ SIZEOF(large_pool_hdr
) + ALIGN_SIZE
- 1;
383 /* Success, initialize the new pool header and add to list */
384 hdr_ptr
->next
= mem
->large_list
[pool_id
];
385 /* We maintain space counts in each pool header for statistical purposes,
386 * even though they are not needed for allocation.
388 hdr_ptr
->bytes_used
= sizeofobject
;
389 hdr_ptr
->bytes_left
= 0;
390 mem
->large_list
[pool_id
] = hdr_ptr
;
392 data_ptr
= (char *) hdr_ptr
; /* point to first data byte in pool... */
393 data_ptr
+= SIZEOF(small_pool_hdr
); /* ...by skipping the header... */
394 if ((size_t)data_ptr
% ALIGN_SIZE
) /* ...and adjust for alignment */
395 data_ptr
+= ALIGN_SIZE
- (size_t)data_ptr
% ALIGN_SIZE
;
397 return (void FAR
*) data_ptr
;
402 * Creation of 2-D sample arrays.
403 * The pointers are in near heap, the samples themselves in FAR heap.
405 * To minimize allocation overhead and to allow I/O of large contiguous
406 * blocks, we allocate the sample rows in groups of as many rows as possible
407 * without exceeding MAX_ALLOC_CHUNK total bytes per allocation request.
408 * NB: the virtual array control routines, later in this file, know about
409 * this chunking of rows. The rowsperchunk value is left in the mem manager
410 * object so that it can be saved away if this sarray is the workspace for
413 * Since we are often upsampling with a factor 2, we align the size (not
414 * the start) to 2 * ALIGN_SIZE so that the upsampling routines don't have
415 * to be as careful about size.
418 METHODDEF(JSAMPARRAY
)
419 alloc_sarray (j_common_ptr cinfo
, int pool_id
,
420 JDIMENSION samplesperrow
, JDIMENSION numrows
)
421 /* Allocate a 2-D sample array */
423 my_mem_ptr mem
= (my_mem_ptr
) cinfo
->mem
;
426 JDIMENSION rowsperchunk
, currow
, i
;
429 /* Make sure each row is properly aligned */
430 if ((ALIGN_SIZE
% SIZEOF(JSAMPLE
)) != 0)
431 out_of_memory(cinfo
, 5); /* safety check */
432 samplesperrow
= (JDIMENSION
)round_up_pow2(samplesperrow
, (2 * ALIGN_SIZE
) / SIZEOF(JSAMPLE
));
434 /* Calculate max # of rows allowed in one allocation chunk */
435 ltemp
= (MAX_ALLOC_CHUNK
-SIZEOF(large_pool_hdr
)) /
436 ((long) samplesperrow
* SIZEOF(JSAMPLE
));
438 ERREXIT(cinfo
, JERR_WIDTH_OVERFLOW
);
439 if (ltemp
< (long) numrows
)
440 rowsperchunk
= (JDIMENSION
) ltemp
;
442 rowsperchunk
= numrows
;
443 mem
->last_rowsperchunk
= rowsperchunk
;
445 /* Get space for row pointers (small object) */
446 result
= (JSAMPARRAY
) alloc_small(cinfo
, pool_id
,
447 (size_t) (numrows
* SIZEOF(JSAMPROW
)));
449 /* Get the rows themselves (large objects) */
451 while (currow
< numrows
) {
452 rowsperchunk
= MIN(rowsperchunk
, numrows
- currow
);
453 workspace
= (JSAMPROW
) alloc_large(cinfo
, pool_id
,
454 (size_t) ((size_t) rowsperchunk
* (size_t) samplesperrow
456 for (i
= rowsperchunk
; i
> 0; i
--) {
457 result
[currow
++] = workspace
;
458 workspace
+= samplesperrow
;
467 * Creation of 2-D coefficient-block arrays.
468 * This is essentially the same as the code for sample arrays, above.
471 METHODDEF(JBLOCKARRAY
)
472 alloc_barray (j_common_ptr cinfo
, int pool_id
,
473 JDIMENSION blocksperrow
, JDIMENSION numrows
)
474 /* Allocate a 2-D coefficient-block array */
476 my_mem_ptr mem
= (my_mem_ptr
) cinfo
->mem
;
479 JDIMENSION rowsperchunk
, currow
, i
;
482 /* Make sure each row is properly aligned */
483 if ((SIZEOF(JBLOCK
) % ALIGN_SIZE
) != 0)
484 out_of_memory(cinfo
, 6); /* safety check */
486 /* Calculate max # of rows allowed in one allocation chunk */
487 ltemp
= (MAX_ALLOC_CHUNK
-SIZEOF(large_pool_hdr
)) /
488 ((long) blocksperrow
* SIZEOF(JBLOCK
));
490 ERREXIT(cinfo
, JERR_WIDTH_OVERFLOW
);
491 if (ltemp
< (long) numrows
)
492 rowsperchunk
= (JDIMENSION
) ltemp
;
494 rowsperchunk
= numrows
;
495 mem
->last_rowsperchunk
= rowsperchunk
;
497 /* Get space for row pointers (small object) */
498 result
= (JBLOCKARRAY
) alloc_small(cinfo
, pool_id
,
499 (size_t) (numrows
* SIZEOF(JBLOCKROW
)));
501 /* Get the rows themselves (large objects) */
503 while (currow
< numrows
) {
504 rowsperchunk
= MIN(rowsperchunk
, numrows
- currow
);
505 workspace
= (JBLOCKROW
) alloc_large(cinfo
, pool_id
,
506 (size_t) ((size_t) rowsperchunk
* (size_t) blocksperrow
508 for (i
= rowsperchunk
; i
> 0; i
--) {
509 result
[currow
++] = workspace
;
510 workspace
+= blocksperrow
;
519 * About virtual array management:
521 * The above "normal" array routines are only used to allocate strip buffers
522 * (as wide as the image, but just a few rows high). Full-image-sized buffers
523 * are handled as "virtual" arrays. The array is still accessed a strip at a
524 * time, but the memory manager must save the whole array for repeated
525 * accesses. The intended implementation is that there is a strip buffer in
526 * memory (as high as is possible given the desired memory limit), plus a
527 * backing file that holds the rest of the array.
529 * The request_virt_array routines are told the total size of the image and
530 * the maximum number of rows that will be accessed at once. The in-memory
531 * buffer must be at least as large as the maxaccess value.
533 * The request routines create control blocks but not the in-memory buffers.
534 * That is postponed until realize_virt_arrays is called. At that time the
535 * total amount of space needed is known (approximately, anyway), so free
536 * memory can be divided up fairly.
538 * The access_virt_array routines are responsible for making a specific strip
539 * area accessible (after reading or writing the backing file, if necessary).
540 * Note that the access routines are told whether the caller intends to modify
541 * the accessed strip; during a read-only pass this saves having to rewrite
542 * data to disk. The access routines are also responsible for pre-zeroing
543 * any newly accessed rows, if pre-zeroing was requested.
545 * In current usage, the access requests are usually for nonoverlapping
546 * strips; that is, successive access start_row numbers differ by exactly
547 * num_rows = maxaccess. This means we can get good performance with simple
548 * buffer dump/reload logic, by making the in-memory buffer be a multiple
549 * of the access height; then there will never be accesses across bufferload
550 * boundaries. The code will still work with overlapping access requests,
551 * but it doesn't handle bufferload overlaps very efficiently.
555 METHODDEF(jvirt_sarray_ptr
)
556 request_virt_sarray (j_common_ptr cinfo
, int pool_id
, boolean pre_zero
,
557 JDIMENSION samplesperrow
, JDIMENSION numrows
,
558 JDIMENSION maxaccess
)
559 /* Request a virtual 2-D sample array */
561 my_mem_ptr mem
= (my_mem_ptr
) cinfo
->mem
;
562 jvirt_sarray_ptr result
;
564 /* Only IMAGE-lifetime virtual arrays are currently supported */
565 if (pool_id
!= JPOOL_IMAGE
)
566 ERREXIT1(cinfo
, JERR_BAD_POOL_ID
, pool_id
); /* safety check */
568 /* get control block */
569 result
= (jvirt_sarray_ptr
) alloc_small(cinfo
, pool_id
,
570 SIZEOF(struct jvirt_sarray_control
));
572 result
->mem_buffer
= NULL
; /* marks array not yet realized */
573 result
->rows_in_array
= numrows
;
574 result
->samplesperrow
= samplesperrow
;
575 result
->maxaccess
= maxaccess
;
576 result
->pre_zero
= pre_zero
;
577 result
->b_s_open
= FALSE
; /* no associated backing-store object */
578 result
->next
= mem
->virt_sarray_list
; /* add to list of virtual arrays */
579 mem
->virt_sarray_list
= result
;
585 METHODDEF(jvirt_barray_ptr
)
586 request_virt_barray (j_common_ptr cinfo
, int pool_id
, boolean pre_zero
,
587 JDIMENSION blocksperrow
, JDIMENSION numrows
,
588 JDIMENSION maxaccess
)
589 /* Request a virtual 2-D coefficient-block array */
591 my_mem_ptr mem
= (my_mem_ptr
) cinfo
->mem
;
592 jvirt_barray_ptr result
;
594 /* Only IMAGE-lifetime virtual arrays are currently supported */
595 if (pool_id
!= JPOOL_IMAGE
)
596 ERREXIT1(cinfo
, JERR_BAD_POOL_ID
, pool_id
); /* safety check */
598 /* get control block */
599 result
= (jvirt_barray_ptr
) alloc_small(cinfo
, pool_id
,
600 SIZEOF(struct jvirt_barray_control
));
602 result
->mem_buffer
= NULL
; /* marks array not yet realized */
603 result
->rows_in_array
= numrows
;
604 result
->blocksperrow
= blocksperrow
;
605 result
->maxaccess
= maxaccess
;
606 result
->pre_zero
= pre_zero
;
607 result
->b_s_open
= FALSE
; /* no associated backing-store object */
608 result
->next
= mem
->virt_barray_list
; /* add to list of virtual arrays */
609 mem
->virt_barray_list
= result
;
616 realize_virt_arrays (j_common_ptr cinfo
)
617 /* Allocate the in-memory buffers for any unrealized virtual arrays */
619 my_mem_ptr mem
= (my_mem_ptr
) cinfo
->mem
;
620 size_t space_per_minheight
, maximum_space
, avail_mem
;
621 size_t minheights
, max_minheights
;
622 jvirt_sarray_ptr sptr
;
623 jvirt_barray_ptr bptr
;
625 /* Compute the minimum space needed (maxaccess rows in each buffer)
626 * and the maximum space needed (full image height in each buffer).
627 * These may be of use to the system-dependent jpeg_mem_available routine.
629 space_per_minheight
= 0;
631 for (sptr
= mem
->virt_sarray_list
; sptr
!= NULL
; sptr
= sptr
->next
) {
632 if (sptr
->mem_buffer
== NULL
) { /* if not realized yet */
633 space_per_minheight
+= (long) sptr
->maxaccess
*
634 (long) sptr
->samplesperrow
* SIZEOF(JSAMPLE
);
635 maximum_space
+= (long) sptr
->rows_in_array
*
636 (long) sptr
->samplesperrow
* SIZEOF(JSAMPLE
);
639 for (bptr
= mem
->virt_barray_list
; bptr
!= NULL
; bptr
= bptr
->next
) {
640 if (bptr
->mem_buffer
== NULL
) { /* if not realized yet */
641 space_per_minheight
+= (long) bptr
->maxaccess
*
642 (long) bptr
->blocksperrow
* SIZEOF(JBLOCK
);
643 maximum_space
+= (long) bptr
->rows_in_array
*
644 (long) bptr
->blocksperrow
* SIZEOF(JBLOCK
);
648 if (space_per_minheight
<= 0)
649 return; /* no unrealized arrays, no work */
651 /* Determine amount of memory to actually use; this is system-dependent. */
652 avail_mem
= jpeg_mem_available(cinfo
, space_per_minheight
, maximum_space
,
653 mem
->total_space_allocated
);
655 /* If the maximum space needed is available, make all the buffers full
656 * height; otherwise parcel it out with the same number of minheights
659 if (avail_mem
>= maximum_space
)
660 max_minheights
= 1000000000L;
662 max_minheights
= avail_mem
/ space_per_minheight
;
663 /* If there doesn't seem to be enough space, try to get the minimum
664 * anyway. This allows a "stub" implementation of jpeg_mem_available().
666 if (max_minheights
<= 0)
670 /* Allocate the in-memory buffers and initialize backing store as needed. */
672 for (sptr
= mem
->virt_sarray_list
; sptr
!= NULL
; sptr
= sptr
->next
) {
673 if (sptr
->mem_buffer
== NULL
) { /* if not realized yet */
674 minheights
= ((long) sptr
->rows_in_array
- 1L) / sptr
->maxaccess
+ 1L;
675 if (minheights
<= max_minheights
) {
676 /* This buffer fits in memory */
677 sptr
->rows_in_mem
= sptr
->rows_in_array
;
679 /* It doesn't fit in memory, create backing store. */
680 sptr
->rows_in_mem
= (JDIMENSION
) (max_minheights
* sptr
->maxaccess
);
681 jpeg_open_backing_store(cinfo
, & sptr
->b_s_info
,
682 (long) sptr
->rows_in_array
*
683 (long) sptr
->samplesperrow
*
684 (long) SIZEOF(JSAMPLE
));
685 sptr
->b_s_open
= TRUE
;
687 sptr
->mem_buffer
= alloc_sarray(cinfo
, JPOOL_IMAGE
,
688 sptr
->samplesperrow
, sptr
->rows_in_mem
);
689 sptr
->rowsperchunk
= mem
->last_rowsperchunk
;
690 sptr
->cur_start_row
= 0;
691 sptr
->first_undef_row
= 0;
696 for (bptr
= mem
->virt_barray_list
; bptr
!= NULL
; bptr
= bptr
->next
) {
697 if (bptr
->mem_buffer
== NULL
) { /* if not realized yet */
698 minheights
= ((long) bptr
->rows_in_array
- 1L) / bptr
->maxaccess
+ 1L;
699 if (minheights
<= max_minheights
) {
700 /* This buffer fits in memory */
701 bptr
->rows_in_mem
= bptr
->rows_in_array
;
703 /* It doesn't fit in memory, create backing store. */
704 bptr
->rows_in_mem
= (JDIMENSION
) (max_minheights
* bptr
->maxaccess
);
705 jpeg_open_backing_store(cinfo
, & bptr
->b_s_info
,
706 (long) bptr
->rows_in_array
*
707 (long) bptr
->blocksperrow
*
708 (long) SIZEOF(JBLOCK
));
709 bptr
->b_s_open
= TRUE
;
711 bptr
->mem_buffer
= alloc_barray(cinfo
, JPOOL_IMAGE
,
712 bptr
->blocksperrow
, bptr
->rows_in_mem
);
713 bptr
->rowsperchunk
= mem
->last_rowsperchunk
;
714 bptr
->cur_start_row
= 0;
715 bptr
->first_undef_row
= 0;
723 do_sarray_io (j_common_ptr cinfo
, jvirt_sarray_ptr ptr
, boolean writing
)
724 /* Do backing store read or write of a virtual sample array */
726 long bytesperrow
, file_offset
, byte_count
, rows
, thisrow
, i
;
728 bytesperrow
= (long) ptr
->samplesperrow
* SIZEOF(JSAMPLE
);
729 file_offset
= ptr
->cur_start_row
* bytesperrow
;
730 /* Loop to read or write each allocation chunk in mem_buffer */
731 for (i
= 0; i
< (long) ptr
->rows_in_mem
; i
+= ptr
->rowsperchunk
) {
732 /* One chunk, but check for short chunk at end of buffer */
733 rows
= MIN((long) ptr
->rowsperchunk
, (long) ptr
->rows_in_mem
- i
);
734 /* Transfer no more than is currently defined */
735 thisrow
= (long) ptr
->cur_start_row
+ i
;
736 rows
= MIN(rows
, (long) ptr
->first_undef_row
- thisrow
);
737 /* Transfer no more than fits in file */
738 rows
= MIN(rows
, (long) ptr
->rows_in_array
- thisrow
);
739 if (rows
<= 0) /* this chunk might be past end of file! */
741 byte_count
= rows
* bytesperrow
;
743 (*ptr
->b_s_info
.write_backing_store
) (cinfo
, & ptr
->b_s_info
,
744 (void FAR
*) ptr
->mem_buffer
[i
],
745 file_offset
, byte_count
);
747 (*ptr
->b_s_info
.read_backing_store
) (cinfo
, & ptr
->b_s_info
,
748 (void FAR
*) ptr
->mem_buffer
[i
],
749 file_offset
, byte_count
);
750 file_offset
+= byte_count
;
756 do_barray_io (j_common_ptr cinfo
, jvirt_barray_ptr ptr
, boolean writing
)
757 /* Do backing store read or write of a virtual coefficient-block array */
759 long bytesperrow
, file_offset
, byte_count
, rows
, thisrow
, i
;
761 bytesperrow
= (long) ptr
->blocksperrow
* SIZEOF(JBLOCK
);
762 file_offset
= ptr
->cur_start_row
* bytesperrow
;
763 /* Loop to read or write each allocation chunk in mem_buffer */
764 for (i
= 0; i
< (long) ptr
->rows_in_mem
; i
+= ptr
->rowsperchunk
) {
765 /* One chunk, but check for short chunk at end of buffer */
766 rows
= MIN((long) ptr
->rowsperchunk
, (long) ptr
->rows_in_mem
- i
);
767 /* Transfer no more than is currently defined */
768 thisrow
= (long) ptr
->cur_start_row
+ i
;
769 rows
= MIN(rows
, (long) ptr
->first_undef_row
- thisrow
);
770 /* Transfer no more than fits in file */
771 rows
= MIN(rows
, (long) ptr
->rows_in_array
- thisrow
);
772 if (rows
<= 0) /* this chunk might be past end of file! */
774 byte_count
= rows
* bytesperrow
;
776 (*ptr
->b_s_info
.write_backing_store
) (cinfo
, & ptr
->b_s_info
,
777 (void FAR
*) ptr
->mem_buffer
[i
],
778 file_offset
, byte_count
);
780 (*ptr
->b_s_info
.read_backing_store
) (cinfo
, & ptr
->b_s_info
,
781 (void FAR
*) ptr
->mem_buffer
[i
],
782 file_offset
, byte_count
);
783 file_offset
+= byte_count
;
788 METHODDEF(JSAMPARRAY
)
789 access_virt_sarray (j_common_ptr cinfo
, jvirt_sarray_ptr ptr
,
790 JDIMENSION start_row
, JDIMENSION num_rows
,
792 /* Access the part of a virtual sample array starting at start_row */
793 /* and extending for num_rows rows. writable is true if */
794 /* caller intends to modify the accessed area. */
796 JDIMENSION end_row
= start_row
+ num_rows
;
797 JDIMENSION undef_row
;
799 /* debugging check */
800 if (end_row
> ptr
->rows_in_array
|| num_rows
> ptr
->maxaccess
||
801 ptr
->mem_buffer
== NULL
)
802 ERREXIT(cinfo
, JERR_BAD_VIRTUAL_ACCESS
);
804 /* Make the desired part of the virtual array accessible */
805 if (start_row
< ptr
->cur_start_row
||
806 end_row
> ptr
->cur_start_row
+ptr
->rows_in_mem
) {
808 ERREXIT(cinfo
, JERR_VIRTUAL_BUG
);
809 /* Flush old buffer contents if necessary */
811 do_sarray_io(cinfo
, ptr
, TRUE
);
814 /* Decide what part of virtual array to access.
815 * Algorithm: if target address > current window, assume forward scan,
816 * load starting at target address. If target address < current window,
817 * assume backward scan, load so that target area is top of window.
818 * Note that when switching from forward write to forward read, will have
819 * start_row = 0, so the limiting case applies and we load from 0 anyway.
821 if (start_row
> ptr
->cur_start_row
) {
822 ptr
->cur_start_row
= start_row
;
824 /* use long arithmetic here to avoid overflow & unsigned problems */
827 ltemp
= (long) end_row
- (long) ptr
->rows_in_mem
;
829 ltemp
= 0; /* don't fall off front end of file */
830 ptr
->cur_start_row
= (JDIMENSION
) ltemp
;
832 /* Read in the selected part of the array.
833 * During the initial write pass, we will do no actual read
834 * because the selected part is all undefined.
836 do_sarray_io(cinfo
, ptr
, FALSE
);
838 /* Ensure the accessed part of the array is defined; prezero if needed.
839 * To improve locality of access, we only prezero the part of the array
840 * that the caller is about to access, not the entire in-memory array.
842 if (ptr
->first_undef_row
< end_row
) {
843 if (ptr
->first_undef_row
< start_row
) {
844 if (writable
) /* writer skipped over a section of array */
845 ERREXIT(cinfo
, JERR_BAD_VIRTUAL_ACCESS
);
846 undef_row
= start_row
; /* but reader is allowed to read ahead */
848 undef_row
= ptr
->first_undef_row
;
851 ptr
->first_undef_row
= end_row
;
853 size_t bytesperrow
= (size_t) ptr
->samplesperrow
* SIZEOF(JSAMPLE
);
854 undef_row
-= ptr
->cur_start_row
; /* make indexes relative to buffer */
855 end_row
-= ptr
->cur_start_row
;
856 while (undef_row
< end_row
) {
857 jzero_far((void FAR
*) ptr
->mem_buffer
[undef_row
], bytesperrow
);
861 if (! writable
) /* reader looking at undefined data */
862 ERREXIT(cinfo
, JERR_BAD_VIRTUAL_ACCESS
);
865 /* Flag the buffer dirty if caller will write in it */
868 /* Return address of proper part of the buffer */
869 return ptr
->mem_buffer
+ (start_row
- ptr
->cur_start_row
);
873 METHODDEF(JBLOCKARRAY
)
874 access_virt_barray (j_common_ptr cinfo
, jvirt_barray_ptr ptr
,
875 JDIMENSION start_row
, JDIMENSION num_rows
,
877 /* Access the part of a virtual block array starting at start_row */
878 /* and extending for num_rows rows. writable is true if */
879 /* caller intends to modify the accessed area. */
881 JDIMENSION end_row
= start_row
+ num_rows
;
882 JDIMENSION undef_row
;
884 /* debugging check */
885 if (end_row
> ptr
->rows_in_array
|| num_rows
> ptr
->maxaccess
||
886 ptr
->mem_buffer
== NULL
)
887 ERREXIT(cinfo
, JERR_BAD_VIRTUAL_ACCESS
);
889 /* Make the desired part of the virtual array accessible */
890 if (start_row
< ptr
->cur_start_row
||
891 end_row
> ptr
->cur_start_row
+ptr
->rows_in_mem
) {
893 ERREXIT(cinfo
, JERR_VIRTUAL_BUG
);
894 /* Flush old buffer contents if necessary */
896 do_barray_io(cinfo
, ptr
, TRUE
);
899 /* Decide what part of virtual array to access.
900 * Algorithm: if target address > current window, assume forward scan,
901 * load starting at target address. If target address < current window,
902 * assume backward scan, load so that target area is top of window.
903 * Note that when switching from forward write to forward read, will have
904 * start_row = 0, so the limiting case applies and we load from 0 anyway.
906 if (start_row
> ptr
->cur_start_row
) {
907 ptr
->cur_start_row
= start_row
;
909 /* use long arithmetic here to avoid overflow & unsigned problems */
912 ltemp
= (long) end_row
- (long) ptr
->rows_in_mem
;
914 ltemp
= 0; /* don't fall off front end of file */
915 ptr
->cur_start_row
= (JDIMENSION
) ltemp
;
917 /* Read in the selected part of the array.
918 * During the initial write pass, we will do no actual read
919 * because the selected part is all undefined.
921 do_barray_io(cinfo
, ptr
, FALSE
);
923 /* Ensure the accessed part of the array is defined; prezero if needed.
924 * To improve locality of access, we only prezero the part of the array
925 * that the caller is about to access, not the entire in-memory array.
927 if (ptr
->first_undef_row
< end_row
) {
928 if (ptr
->first_undef_row
< start_row
) {
929 if (writable
) /* writer skipped over a section of array */
930 ERREXIT(cinfo
, JERR_BAD_VIRTUAL_ACCESS
);
931 undef_row
= start_row
; /* but reader is allowed to read ahead */
933 undef_row
= ptr
->first_undef_row
;
936 ptr
->first_undef_row
= end_row
;
938 size_t bytesperrow
= (size_t) ptr
->blocksperrow
* SIZEOF(JBLOCK
);
939 undef_row
-= ptr
->cur_start_row
; /* make indexes relative to buffer */
940 end_row
-= ptr
->cur_start_row
;
941 while (undef_row
< end_row
) {
942 jzero_far((void FAR
*) ptr
->mem_buffer
[undef_row
], bytesperrow
);
946 if (! writable
) /* reader looking at undefined data */
947 ERREXIT(cinfo
, JERR_BAD_VIRTUAL_ACCESS
);
950 /* Flag the buffer dirty if caller will write in it */
953 /* Return address of proper part of the buffer */
954 return ptr
->mem_buffer
+ (start_row
- ptr
->cur_start_row
);
959 * Release all objects belonging to a specified pool.
963 free_pool (j_common_ptr cinfo
, int pool_id
)
965 my_mem_ptr mem
= (my_mem_ptr
) cinfo
->mem
;
966 small_pool_ptr shdr_ptr
;
967 large_pool_ptr lhdr_ptr
;
970 if (pool_id
< 0 || pool_id
>= JPOOL_NUMPOOLS
)
971 ERREXIT1(cinfo
, JERR_BAD_POOL_ID
, pool_id
); /* safety check */
974 if (cinfo
->err
->trace_level
> 1)
975 print_mem_stats(cinfo
, pool_id
); /* print pool's memory usage statistics */
978 /* If freeing IMAGE pool, close any virtual arrays first */
979 if (pool_id
== JPOOL_IMAGE
) {
980 jvirt_sarray_ptr sptr
;
981 jvirt_barray_ptr bptr
;
983 for (sptr
= mem
->virt_sarray_list
; sptr
!= NULL
; sptr
= sptr
->next
) {
984 if (sptr
->b_s_open
) { /* there may be no backing store */
985 sptr
->b_s_open
= FALSE
; /* prevent recursive close if error */
986 (*sptr
->b_s_info
.close_backing_store
) (cinfo
, & sptr
->b_s_info
);
989 mem
->virt_sarray_list
= NULL
;
990 for (bptr
= mem
->virt_barray_list
; bptr
!= NULL
; bptr
= bptr
->next
) {
991 if (bptr
->b_s_open
) { /* there may be no backing store */
992 bptr
->b_s_open
= FALSE
; /* prevent recursive close if error */
993 (*bptr
->b_s_info
.close_backing_store
) (cinfo
, & bptr
->b_s_info
);
996 mem
->virt_barray_list
= NULL
;
999 /* Release large objects */
1000 lhdr_ptr
= mem
->large_list
[pool_id
];
1001 mem
->large_list
[pool_id
] = NULL
;
1003 while (lhdr_ptr
!= NULL
) {
1004 large_pool_ptr next_lhdr_ptr
= lhdr_ptr
->next
;
1005 space_freed
= lhdr_ptr
->bytes_used
+
1006 lhdr_ptr
->bytes_left
+
1007 SIZEOF(large_pool_hdr
);
1008 jpeg_free_large(cinfo
, (void FAR
*) lhdr_ptr
, space_freed
);
1009 mem
->total_space_allocated
-= space_freed
;
1010 lhdr_ptr
= next_lhdr_ptr
;
1013 /* Release small objects */
1014 shdr_ptr
= mem
->small_list
[pool_id
];
1015 mem
->small_list
[pool_id
] = NULL
;
1017 while (shdr_ptr
!= NULL
) {
1018 small_pool_ptr next_shdr_ptr
= shdr_ptr
->next
;
1019 space_freed
= shdr_ptr
->bytes_used
+
1020 shdr_ptr
->bytes_left
+
1021 SIZEOF(small_pool_hdr
);
1022 jpeg_free_small(cinfo
, (void *) shdr_ptr
, space_freed
);
1023 mem
->total_space_allocated
-= space_freed
;
1024 shdr_ptr
= next_shdr_ptr
;
1030 * Close up shop entirely.
1031 * Note that this cannot be called unless cinfo->mem is non-NULL.
1035 self_destruct (j_common_ptr cinfo
)
1039 /* Close all backing store, release all memory.
1040 * Releasing pools in reverse order might help avoid fragmentation
1041 * with some (brain-damaged) malloc libraries.
1043 for (pool
= JPOOL_NUMPOOLS
-1; pool
>= JPOOL_PERMANENT
; pool
--) {
1044 free_pool(cinfo
, pool
);
1047 /* Release the memory manager control block too. */
1048 jpeg_free_small(cinfo
, (void *) cinfo
->mem
, SIZEOF(my_memory_mgr
));
1049 cinfo
->mem
= NULL
; /* ensures I will be called only once */
1051 jpeg_mem_term(cinfo
); /* system-dependent cleanup */
1056 * Memory manager initialization.
1057 * When this is called, only the error manager pointer is valid in cinfo!
1061 jinit_memory_mgr (j_common_ptr cinfo
)
1068 cinfo
->mem
= NULL
; /* for safety if init fails */
1070 /* Check for configuration errors.
1071 * SIZEOF(ALIGN_TYPE) should be a power of 2; otherwise, it probably
1072 * doesn't reflect any real hardware alignment requirement.
1073 * The test is a little tricky: for X>0, X and X-1 have no one-bits
1074 * in common if and only if X is a power of 2, ie has only one one-bit.
1075 * Some compilers may give an "unreachable code" warning here; ignore it.
1077 if ((ALIGN_SIZE
& (ALIGN_SIZE
-1)) != 0)
1078 ERREXIT(cinfo
, JERR_BAD_ALIGN_TYPE
);
1079 /* MAX_ALLOC_CHUNK must be representable as type size_t, and must be
1080 * a multiple of ALIGN_SIZE.
1081 * Again, an "unreachable code" warning may be ignored here.
1082 * But a "constant too large" warning means you need to fix MAX_ALLOC_CHUNK.
1084 test_mac
= (size_t) MAX_ALLOC_CHUNK
;
1085 if ((long) test_mac
!= MAX_ALLOC_CHUNK
||
1086 (MAX_ALLOC_CHUNK
% ALIGN_SIZE
) != 0)
1087 ERREXIT(cinfo
, JERR_BAD_ALLOC_CHUNK
);
1089 max_to_use
= jpeg_mem_init(cinfo
); /* system-dependent initialization */
1091 /* Attempt to allocate memory manager's control block */
1092 mem
= (my_mem_ptr
) jpeg_get_small(cinfo
, SIZEOF(my_memory_mgr
));
1095 jpeg_mem_term(cinfo
); /* system-dependent cleanup */
1096 ERREXIT1(cinfo
, JERR_OUT_OF_MEMORY
, 0);
1099 /* OK, fill in the method pointers */
1100 mem
->pub
.alloc_small
= alloc_small
;
1101 mem
->pub
.alloc_large
= alloc_large
;
1102 mem
->pub
.alloc_sarray
= alloc_sarray
;
1103 mem
->pub
.alloc_barray
= alloc_barray
;
1104 mem
->pub
.request_virt_sarray
= request_virt_sarray
;
1105 mem
->pub
.request_virt_barray
= request_virt_barray
;
1106 mem
->pub
.realize_virt_arrays
= realize_virt_arrays
;
1107 mem
->pub
.access_virt_sarray
= access_virt_sarray
;
1108 mem
->pub
.access_virt_barray
= access_virt_barray
;
1109 mem
->pub
.free_pool
= free_pool
;
1110 mem
->pub
.self_destruct
= self_destruct
;
1112 /* Make MAX_ALLOC_CHUNK accessible to other modules */
1113 mem
->pub
.max_alloc_chunk
= MAX_ALLOC_CHUNK
;
1115 /* Initialize working state */
1116 mem
->pub
.max_memory_to_use
= max_to_use
;
1118 for (pool
= JPOOL_NUMPOOLS
-1; pool
>= JPOOL_PERMANENT
; pool
--) {
1119 mem
->small_list
[pool
] = NULL
;
1120 mem
->large_list
[pool
] = NULL
;
1122 mem
->virt_sarray_list
= NULL
;
1123 mem
->virt_barray_list
= NULL
;
1125 mem
->total_space_allocated
= SIZEOF(my_memory_mgr
);
1127 /* Declare ourselves open for business */
1128 cinfo
->mem
= & mem
->pub
;
1130 /* Check for an environment variable JPEGMEM; if found, override the
1131 * default max_memory setting from jpeg_mem_init. Note that the
1132 * surrounding application may again override this value.
1133 * If your system doesn't support getenv(), define NO_GETENV to disable
1139 if ((memenv
= getenv("JPEGMEM")) != NULL
) {
1142 if (sscanf(memenv
, "%ld%c", &max_to_use
, &ch
) > 0) {
1143 if (ch
== 'm' || ch
== 'M')
1144 max_to_use
*= 1000L;
1145 mem
->pub
.max_memory_to_use
= max_to_use
* 1000L;