4 * This file was part of the Independent JPEG Group's software:
5 * Copyright (C) 1991-1997, Thomas G. Lane.
6 * It was modified by The libjpeg-turbo Project to include only code and
7 * information relevant to libjpeg-turbo.
8 * For conditions of distribution and use, see the accompanying README file.
10 * This file contains the JPEG system-independent memory management
11 * routines. This code is usable across a wide variety of machines; most
12 * of the system dependencies have been isolated in a separate file.
13 * The major functions provided here are:
14 * * pool-based allocation and freeing of memory;
15 * * policy decisions about how to divide available memory among the
17 * * control logic for swapping virtual arrays between main memory and
19 * The separate system-dependent file provides the actual backing-storage
20 * access code, and it contains the policy decision about how much total
22 * This file is system-dependent in the sense that some of its functions
23 * are unnecessary in some systems. For example, if there is enough virtual
24 * memory so that backing storage will never be used, much of the virtual
25 * array control logic could be removed. (Of course, if you have that much
26 * memory then you shouldn't care about a little bit of unused code...)
29 #define JPEG_INTERNALS
30 #define AM_MEMORY_MANAGER /* we define jvirt_Xarray_control structs */
33 #include "jmemsys.h" /* import the system-dependent declarations */
36 #ifndef HAVE_STDLIB_H /* <stdlib.h> should declare getenv() */
37 extern char * getenv (const char * name);
43 round_up_pow2 (size_t a, size_t b)
44 /* a rounded up to the next multiple of b, i.e. ceil(a/b)*b */
45 /* Assumes a >= 0, b > 0, and b is a power of 2 */
47 return ((a + b - 1) & (~(b - 1)));
52 * Some important notes:
53 * The allocation routines provided here must never return NULL.
54 * They should exit to error_exit if unsuccessful.
56 * It's not a good idea to try to merge the sarray and barray routines,
57 * even though they are textually almost the same, because samples are
58 * usually stored as bytes while coefficients are shorts or ints. Thus,
59 * in machines where byte pointers have a different representation from
60 * word pointers, the resulting machine code could not be the same.
65 * Many machines require storage alignment: longs must start on 4-byte
66 * boundaries, doubles on 8-byte boundaries, etc. On such machines, malloc()
67 * always returns pointers that are multiples of the worst-case alignment
68 * requirement, and we had better do so too.
69 * There isn't any really portable way to determine the worst-case alignment
70 * requirement. This module assumes that the alignment requirement is
71 * multiples of ALIGN_SIZE.
72 * By default, we define ALIGN_SIZE as sizeof(double). This is necessary on some
73 * workstations (where doubles really do need 8-byte alignment) and will work
74 * fine on nearly everything. If your machine has lesser alignment needs,
75 * you can save a few bytes by making ALIGN_SIZE smaller.
76 * The only place I know of where this will NOT work is certain Macintosh
77 * 680x0 compilers that define double as a 10-byte IEEE extended float.
78 * Doing 10-byte alignment is counterproductive because longwords won't be
79 * aligned well. Put "#define ALIGN_SIZE 4" in jconfig.h if you have
83 #ifndef ALIGN_SIZE /* so can override from jconfig.h */
85 #define ALIGN_SIZE sizeof(double)
87 #define ALIGN_SIZE 16 /* Most SIMD implementations require this */
92 * We allocate objects from "pools", where each pool is gotten with a single
93 * request to jpeg_get_small() or jpeg_get_large(). There is no per-object
94 * overhead within a pool, except for alignment padding. Each pool has a
95 * header with a link to the next pool of the same class.
96 * Small and large pool headers are identical.
99 typedef struct small_pool_struct * small_pool_ptr;
101 typedef struct small_pool_struct {
102 small_pool_ptr next; /* next in list of pools */
103 size_t bytes_used; /* how many bytes already used within pool */
104 size_t bytes_left; /* bytes still available in this pool */
107 typedef struct large_pool_struct * large_pool_ptr;
109 typedef struct large_pool_struct {
110 large_pool_ptr next; /* next in list of pools */
111 size_t bytes_used; /* how many bytes already used within pool */
112 size_t bytes_left; /* bytes still available in this pool */
116 * Here is the full definition of a memory manager object.
120 struct jpeg_memory_mgr pub; /* public fields */
122 /* Each pool identifier (lifetime class) names a linked list of pools. */
123 small_pool_ptr small_list[JPOOL_NUMPOOLS];
124 large_pool_ptr large_list[JPOOL_NUMPOOLS];
126 /* Since we only have one lifetime class of virtual arrays, only one
127 * linked list is necessary (for each datatype). Note that the virtual
128 * array control blocks being linked together are actually stored somewhere
129 * in the small-pool list.
131 jvirt_sarray_ptr virt_sarray_list;
132 jvirt_barray_ptr virt_barray_list;
134 /* This counts total space obtained from jpeg_get_small/large */
135 size_t total_space_allocated;
137 /* alloc_sarray and alloc_barray set this value for use by virtual
140 JDIMENSION last_rowsperchunk; /* from most recent alloc_sarray/barray */
143 typedef my_memory_mgr * my_mem_ptr;
147 * The control blocks for virtual arrays.
148 * Note that these blocks are allocated in the "small" pool area.
149 * System-dependent info for the associated backing store (if any) is hidden
150 * inside the backing_store_info struct.
153 struct jvirt_sarray_control {
154 JSAMPARRAY mem_buffer; /* => the in-memory buffer */
155 JDIMENSION rows_in_array; /* total virtual array height */
156 JDIMENSION samplesperrow; /* width of array (and of memory buffer) */
157 JDIMENSION maxaccess; /* max rows accessed by access_virt_sarray */
158 JDIMENSION rows_in_mem; /* height of memory buffer */
159 JDIMENSION rowsperchunk; /* allocation chunk size in mem_buffer */
160 JDIMENSION cur_start_row; /* first logical row # in the buffer */
161 JDIMENSION first_undef_row; /* row # of first uninitialized row */
162 boolean pre_zero; /* pre-zero mode requested? */
163 boolean dirty; /* do current buffer contents need written? */
164 boolean b_s_open; /* is backing-store data valid? */
165 jvirt_sarray_ptr next; /* link to next virtual sarray control block */
166 backing_store_info b_s_info; /* System-dependent control info */
169 struct jvirt_barray_control {
170 JBLOCKARRAY mem_buffer; /* => the in-memory buffer */
171 JDIMENSION rows_in_array; /* total virtual array height */
172 JDIMENSION blocksperrow; /* width of array (and of memory buffer) */
173 JDIMENSION maxaccess; /* max rows accessed by access_virt_barray */
174 JDIMENSION rows_in_mem; /* height of memory buffer */
175 JDIMENSION rowsperchunk; /* allocation chunk size in mem_buffer */
176 JDIMENSION cur_start_row; /* first logical row # in the buffer */
177 JDIMENSION first_undef_row; /* row # of first uninitialized row */
178 boolean pre_zero; /* pre-zero mode requested? */
179 boolean dirty; /* do current buffer contents need written? */
180 boolean b_s_open; /* is backing-store data valid? */
181 jvirt_barray_ptr next; /* link to next virtual barray control block */
182 backing_store_info b_s_info; /* System-dependent control info */
186 #ifdef MEM_STATS /* optional extra stuff for statistics */
189 print_mem_stats (j_common_ptr cinfo, int pool_id)
191 my_mem_ptr mem = (my_mem_ptr) cinfo->mem;
192 small_pool_ptr shdr_ptr;
193 large_pool_ptr lhdr_ptr;
195 /* Since this is only a debugging stub, we can cheat a little by using
196 * fprintf directly rather than going through the trace message code.
197 * This is helpful because message parm array can't handle longs.
199 fprintf(stderr, "Freeing pool %d, total space = %ld\n",
200 pool_id, mem->total_space_allocated);
202 for (lhdr_ptr = mem->large_list[pool_id]; lhdr_ptr != NULL;
203 lhdr_ptr = lhdr_ptr->next) {
204 fprintf(stderr, " Large chunk used %ld\n",
205 (long) lhdr_ptr->bytes_used);
208 for (shdr_ptr = mem->small_list[pool_id]; shdr_ptr != NULL;
209 shdr_ptr = shdr_ptr->next) {
210 fprintf(stderr, " Small chunk used %ld free %ld\n",
211 (long) shdr_ptr->bytes_used,
212 (long) shdr_ptr->bytes_left);
216 #endif /* MEM_STATS */
220 out_of_memory (j_common_ptr cinfo, int which)
221 /* Report an out-of-memory error and stop execution */
222 /* If we compiled MEM_STATS support, report alloc requests before dying */
225 cinfo->err->trace_level = 2; /* force self_destruct to report stats */
227 ERREXIT1(cinfo, JERR_OUT_OF_MEMORY, which);
232 * Allocation of "small" objects.
234 * For these, we use pooled storage. When a new pool must be created,
235 * we try to get enough space for the current request plus a "slop" factor,
236 * where the slop will be the amount of leftover space in the new pool.
237 * The speed vs. space tradeoff is largely determined by the slop values.
238 * A different slop value is provided for each pool class (lifetime),
239 * and we also distinguish the first pool of a class from later ones.
240 * NOTE: the values given work fairly well on both 16- and 32-bit-int
241 * machines, but may be too small if longs are 64 bits or more.
243 * Since we do not know what alignment malloc() gives us, we have to
244 * allocate ALIGN_SIZE-1 extra space per pool to have room for alignment
248 static const size_t first_pool_slop[JPOOL_NUMPOOLS] =
250 1600, /* first PERMANENT pool */
251 16000 /* first IMAGE pool */
254 static const size_t extra_pool_slop[JPOOL_NUMPOOLS] =
256 0, /* additional PERMANENT pools */
257 5000 /* additional IMAGE pools */
260 #define MIN_SLOP 50 /* greater than 0 to avoid futile looping */
264 alloc_small (j_common_ptr cinfo, int pool_id, size_t sizeofobject)
265 /* Allocate a "small" object */
267 my_mem_ptr mem = (my_mem_ptr) cinfo->mem;
268 small_pool_ptr hdr_ptr, prev_hdr_ptr;
270 size_t min_request, slop;
273 * Round up the requested size to a multiple of ALIGN_SIZE in order
274 * to assure alignment for the next object allocated in the same pool
275 * and so that algorithms can straddle outside the proper area up
276 * to the next alignment.
278 sizeofobject = round_up_pow2(sizeofobject, ALIGN_SIZE);
280 /* Check for unsatisfiable request (do now to ensure no overflow below) */
281 if ((sizeof(small_pool_hdr) + sizeofobject + ALIGN_SIZE - 1) > MAX_ALLOC_CHUNK)
282 out_of_memory(cinfo, 1); /* request exceeds malloc's ability */
284 /* See if space is available in any existing pool */
285 if (pool_id < 0 || pool_id >= JPOOL_NUMPOOLS)
286 ERREXIT1(cinfo, JERR_BAD_POOL_ID, pool_id); /* safety check */
288 hdr_ptr = mem->small_list[pool_id];
289 while (hdr_ptr != NULL) {
290 if (hdr_ptr->bytes_left >= sizeofobject)
291 break; /* found pool with enough space */
292 prev_hdr_ptr = hdr_ptr;
293 hdr_ptr = hdr_ptr->next;
296 /* Time to make a new pool? */
297 if (hdr_ptr == NULL) {
298 /* min_request is what we need now, slop is what will be leftover */
299 min_request = sizeof(small_pool_hdr) + sizeofobject + ALIGN_SIZE - 1;
300 if (prev_hdr_ptr == NULL) /* first pool in class? */
301 slop = first_pool_slop[pool_id];
303 slop = extra_pool_slop[pool_id];
304 /* Don't ask for more than MAX_ALLOC_CHUNK */
305 if (slop > (size_t) (MAX_ALLOC_CHUNK-min_request))
306 slop = (size_t) (MAX_ALLOC_CHUNK-min_request);
307 /* Try to get space, if fail reduce slop and try again */
309 hdr_ptr = (small_pool_ptr) jpeg_get_small(cinfo, min_request + slop);
313 if (slop < MIN_SLOP) /* give up when it gets real small */
314 out_of_memory(cinfo, 2); /* jpeg_get_small failed */
316 mem->total_space_allocated += min_request + slop;
317 /* Success, initialize the new pool header and add to end of list */
318 hdr_ptr->next = NULL;
319 hdr_ptr->bytes_used = 0;
320 hdr_ptr->bytes_left = sizeofobject + slop;
321 if (prev_hdr_ptr == NULL) /* first pool in class? */
322 mem->small_list[pool_id] = hdr_ptr;
324 prev_hdr_ptr->next = hdr_ptr;
327 /* OK, allocate the object from the current pool */
328 data_ptr = (char *) hdr_ptr; /* point to first data byte in pool... */
329 data_ptr += sizeof(small_pool_hdr); /* ...by skipping the header... */
330 if ((size_t)data_ptr % ALIGN_SIZE) /* ...and adjust for alignment */
331 data_ptr += ALIGN_SIZE - (size_t)data_ptr % ALIGN_SIZE;
332 data_ptr += hdr_ptr->bytes_used; /* point to place for object */
333 hdr_ptr->bytes_used += sizeofobject;
334 hdr_ptr->bytes_left -= sizeofobject;
336 return (void *) data_ptr;
341 * Allocation of "large" objects.
343 * The external semantics of these are the same as "small" objects. However,
344 * the pool 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.
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 *) data_ptr;
402 * Creation of 2-D sample arrays.
404 * To minimize allocation overhead and to allow I/O of large contiguous
405 * blocks, we allocate the sample rows in groups of as many rows as possible
406 * without exceeding MAX_ALLOC_CHUNK total bytes per allocation request.
407 * NB: the virtual array control routines, later in this file, know about
408 * this chunking of rows. The rowsperchunk value is left in the mem manager
409 * object so that it can be saved away if this sarray is the workspace for
412 * Since we are often upsampling with a factor 2, we align the size (not
413 * the start) to 2 * ALIGN_SIZE so that the upsampling routines don't have
414 * to be as careful about size.
417 METHODDEF(JSAMPARRAY)
418 alloc_sarray (j_common_ptr cinfo, int pool_id,
419 JDIMENSION samplesperrow, JDIMENSION numrows)
420 /* Allocate a 2-D sample array */
422 my_mem_ptr mem = (my_mem_ptr) cinfo->mem;
425 JDIMENSION rowsperchunk, currow, i;
428 /* Make sure each row is properly aligned */
429 if ((ALIGN_SIZE % sizeof(JSAMPLE)) != 0)
430 out_of_memory(cinfo, 5); /* safety check */
431 samplesperrow = (JDIMENSION)round_up_pow2(samplesperrow, (2 * ALIGN_SIZE) / sizeof(JSAMPLE));
433 /* Calculate max # of rows allowed in one allocation chunk */
434 ltemp = (MAX_ALLOC_CHUNK-sizeof(large_pool_hdr)) /
435 ((long) samplesperrow * sizeof(JSAMPLE));
437 ERREXIT(cinfo, JERR_WIDTH_OVERFLOW);
438 if (ltemp < (long) numrows)
439 rowsperchunk = (JDIMENSION) ltemp;
441 rowsperchunk = numrows;
442 mem->last_rowsperchunk = rowsperchunk;
444 /* Get space for row pointers (small object) */
445 result = (JSAMPARRAY) alloc_small(cinfo, pool_id,
446 (size_t) (numrows * sizeof(JSAMPROW)));
448 /* Get the rows themselves (large objects) */
450 while (currow < numrows) {
451 rowsperchunk = MIN(rowsperchunk, numrows - currow);
452 workspace = (JSAMPROW) alloc_large(cinfo, pool_id,
453 (size_t) ((size_t) rowsperchunk * (size_t) samplesperrow
455 for (i = rowsperchunk; i > 0; i--) {
456 result[currow++] = workspace;
457 workspace += samplesperrow;
466 * Creation of 2-D coefficient-block arrays.
467 * This is essentially the same as the code for sample arrays, above.
470 METHODDEF(JBLOCKARRAY)
471 alloc_barray (j_common_ptr cinfo, int pool_id,
472 JDIMENSION blocksperrow, JDIMENSION numrows)
473 /* Allocate a 2-D coefficient-block array */
475 my_mem_ptr mem = (my_mem_ptr) cinfo->mem;
478 JDIMENSION rowsperchunk, currow, i;
481 /* Make sure each row is properly aligned */
482 if ((sizeof(JBLOCK) % ALIGN_SIZE) != 0)
483 out_of_memory(cinfo, 6); /* safety check */
485 /* Calculate max # of rows allowed in one allocation chunk */
486 ltemp = (MAX_ALLOC_CHUNK-sizeof(large_pool_hdr)) /
487 ((long) blocksperrow * sizeof(JBLOCK));
489 ERREXIT(cinfo, JERR_WIDTH_OVERFLOW);
490 if (ltemp < (long) numrows)
491 rowsperchunk = (JDIMENSION) ltemp;
493 rowsperchunk = numrows;
494 mem->last_rowsperchunk = rowsperchunk;
496 /* Get space for row pointers (small object) */
497 result = (JBLOCKARRAY) alloc_small(cinfo, pool_id,
498 (size_t) (numrows * sizeof(JBLOCKROW)));
500 /* Get the rows themselves (large objects) */
502 while (currow < numrows) {
503 rowsperchunk = MIN(rowsperchunk, numrows - currow);
504 workspace = (JBLOCKROW) alloc_large(cinfo, pool_id,
505 (size_t) ((size_t) rowsperchunk * (size_t) blocksperrow
507 for (i = rowsperchunk; i > 0; i--) {
508 result[currow++] = workspace;
509 workspace += blocksperrow;
518 * About virtual array management:
520 * The above "normal" array routines are only used to allocate strip buffers
521 * (as wide as the image, but just a few rows high). Full-image-sized buffers
522 * are handled as "virtual" arrays. The array is still accessed a strip at a
523 * time, but the memory manager must save the whole array for repeated
524 * accesses. The intended implementation is that there is a strip buffer in
525 * memory (as high as is possible given the desired memory limit), plus a
526 * backing file that holds the rest of the array.
528 * The request_virt_array routines are told the total size of the image and
529 * the maximum number of rows that will be accessed at once. The in-memory
530 * buffer must be at least as large as the maxaccess value.
532 * The request routines create control blocks but not the in-memory buffers.
533 * That is postponed until realize_virt_arrays is called. At that time the
534 * total amount of space needed is known (approximately, anyway), so free
535 * memory can be divided up fairly.
537 * The access_virt_array routines are responsible for making a specific strip
538 * area accessible (after reading or writing the backing file, if necessary).
539 * Note that the access routines are told whether the caller intends to modify
540 * the accessed strip; during a read-only pass this saves having to rewrite
541 * data to disk. The access routines are also responsible for pre-zeroing
542 * any newly accessed rows, if pre-zeroing was requested.
544 * In current usage, the access requests are usually for nonoverlapping
545 * strips; that is, successive access start_row numbers differ by exactly
546 * num_rows = maxaccess. This means we can get good performance with simple
547 * buffer dump/reload logic, by making the in-memory buffer be a multiple
548 * of the access height; then there will never be accesses across bufferload
549 * boundaries. The code will still work with overlapping access requests,
550 * but it doesn't handle bufferload overlaps very efficiently.
554 METHODDEF(jvirt_sarray_ptr)
555 request_virt_sarray (j_common_ptr cinfo, int pool_id, boolean pre_zero,
556 JDIMENSION samplesperrow, JDIMENSION numrows,
557 JDIMENSION maxaccess)
558 /* Request a virtual 2-D sample array */
560 my_mem_ptr mem = (my_mem_ptr) cinfo->mem;
561 jvirt_sarray_ptr result;
563 /* Only IMAGE-lifetime virtual arrays are currently supported */
564 if (pool_id != JPOOL_IMAGE)
565 ERREXIT1(cinfo, JERR_BAD_POOL_ID, pool_id); /* safety check */
567 /* get control block */
568 result = (jvirt_sarray_ptr) alloc_small(cinfo, pool_id,
569 sizeof(struct jvirt_sarray_control));
571 result->mem_buffer = NULL; /* marks array not yet realized */
572 result->rows_in_array = numrows;
573 result->samplesperrow = samplesperrow;
574 result->maxaccess = maxaccess;
575 result->pre_zero = pre_zero;
576 result->b_s_open = FALSE; /* no associated backing-store object */
577 result->next = mem->virt_sarray_list; /* add to list of virtual arrays */
578 mem->virt_sarray_list = result;
584 METHODDEF(jvirt_barray_ptr)
585 request_virt_barray (j_common_ptr cinfo, int pool_id, boolean pre_zero,
586 JDIMENSION blocksperrow, JDIMENSION numrows,
587 JDIMENSION maxaccess)
588 /* Request a virtual 2-D coefficient-block array */
590 my_mem_ptr mem = (my_mem_ptr) cinfo->mem;
591 jvirt_barray_ptr result;
593 /* Only IMAGE-lifetime virtual arrays are currently supported */
594 if (pool_id != JPOOL_IMAGE)
595 ERREXIT1(cinfo, JERR_BAD_POOL_ID, pool_id); /* safety check */
597 /* get control block */
598 result = (jvirt_barray_ptr) alloc_small(cinfo, pool_id,
599 sizeof(struct jvirt_barray_control));
601 result->mem_buffer = NULL; /* marks array not yet realized */
602 result->rows_in_array = numrows;
603 result->blocksperrow = blocksperrow;
604 result->maxaccess = maxaccess;
605 result->pre_zero = pre_zero;
606 result->b_s_open = FALSE; /* no associated backing-store object */
607 result->next = mem->virt_barray_list; /* add to list of virtual arrays */
608 mem->virt_barray_list = result;
615 realize_virt_arrays (j_common_ptr cinfo)
616 /* Allocate the in-memory buffers for any unrealized virtual arrays */
618 my_mem_ptr mem = (my_mem_ptr) cinfo->mem;
619 size_t space_per_minheight, maximum_space, avail_mem;
620 size_t minheights, max_minheights;
621 jvirt_sarray_ptr sptr;
622 jvirt_barray_ptr bptr;
624 /* Compute the minimum space needed (maxaccess rows in each buffer)
625 * and the maximum space needed (full image height in each buffer).
626 * These may be of use to the system-dependent jpeg_mem_available routine.
628 space_per_minheight = 0;
630 for (sptr = mem->virt_sarray_list; sptr != NULL; sptr = sptr->next) {
631 if (sptr->mem_buffer == NULL) { /* if not realized yet */
632 space_per_minheight += (long) sptr->maxaccess *
633 (long) sptr->samplesperrow * sizeof(JSAMPLE);
634 maximum_space += (long) sptr->rows_in_array *
635 (long) sptr->samplesperrow * sizeof(JSAMPLE);
638 for (bptr = mem->virt_barray_list; bptr != NULL; bptr = bptr->next) {
639 if (bptr->mem_buffer == NULL) { /* if not realized yet */
640 space_per_minheight += (long) bptr->maxaccess *
641 (long) bptr->blocksperrow * sizeof(JBLOCK);
642 maximum_space += (long) bptr->rows_in_array *
643 (long) bptr->blocksperrow * sizeof(JBLOCK);
647 if (space_per_minheight <= 0)
648 return; /* no unrealized arrays, no work */
650 /* Determine amount of memory to actually use; this is system-dependent. */
651 avail_mem = jpeg_mem_available(cinfo, space_per_minheight, maximum_space,
652 mem->total_space_allocated);
654 /* If the maximum space needed is available, make all the buffers full
655 * height; otherwise parcel it out with the same number of minheights
658 if (avail_mem >= maximum_space)
659 max_minheights = 1000000000L;
661 max_minheights = avail_mem / space_per_minheight;
662 /* If there doesn't seem to be enough space, try to get the minimum
663 * anyway. This allows a "stub" implementation of jpeg_mem_available().
665 if (max_minheights <= 0)
669 /* Allocate the in-memory buffers and initialize backing store as needed. */
671 for (sptr = mem->virt_sarray_list; sptr != NULL; sptr = sptr->next) {
672 if (sptr->mem_buffer == NULL) { /* if not realized yet */
673 minheights = ((long) sptr->rows_in_array - 1L) / sptr->maxaccess + 1L;
674 if (minheights <= max_minheights) {
675 /* This buffer fits in memory */
676 sptr->rows_in_mem = sptr->rows_in_array;
678 /* It doesn't fit in memory, create backing store. */
679 sptr->rows_in_mem = (JDIMENSION) (max_minheights * sptr->maxaccess);
680 jpeg_open_backing_store(cinfo, & sptr->b_s_info,
681 (long) sptr->rows_in_array *
682 (long) sptr->samplesperrow *
683 (long) sizeof(JSAMPLE));
684 sptr->b_s_open = TRUE;
686 sptr->mem_buffer = alloc_sarray(cinfo, JPOOL_IMAGE,
687 sptr->samplesperrow, sptr->rows_in_mem);
688 sptr->rowsperchunk = mem->last_rowsperchunk;
689 sptr->cur_start_row = 0;
690 sptr->first_undef_row = 0;
695 for (bptr = mem->virt_barray_list; bptr != NULL; bptr = bptr->next) {
696 if (bptr->mem_buffer == NULL) { /* if not realized yet */
697 minheights = ((long) bptr->rows_in_array - 1L) / bptr->maxaccess + 1L;
698 if (minheights <= max_minheights) {
699 /* This buffer fits in memory */
700 bptr->rows_in_mem = bptr->rows_in_array;
702 /* It doesn't fit in memory, create backing store. */
703 bptr->rows_in_mem = (JDIMENSION) (max_minheights * bptr->maxaccess);
704 jpeg_open_backing_store(cinfo, & bptr->b_s_info,
705 (long) bptr->rows_in_array *
706 (long) bptr->blocksperrow *
707 (long) sizeof(JBLOCK));
708 bptr->b_s_open = TRUE;
710 bptr->mem_buffer = alloc_barray(cinfo, JPOOL_IMAGE,
711 bptr->blocksperrow, bptr->rows_in_mem);
712 bptr->rowsperchunk = mem->last_rowsperchunk;
713 bptr->cur_start_row = 0;
714 bptr->first_undef_row = 0;
722 do_sarray_io (j_common_ptr cinfo, jvirt_sarray_ptr ptr, boolean writing)
723 /* Do backing store read or write of a virtual sample array */
725 long bytesperrow, file_offset, byte_count, rows, thisrow, i;
727 bytesperrow = (long) ptr->samplesperrow * sizeof(JSAMPLE);
728 file_offset = ptr->cur_start_row * bytesperrow;
729 /* Loop to read or write each allocation chunk in mem_buffer */
730 for (i = 0; i < (long) ptr->rows_in_mem; i += ptr->rowsperchunk) {
731 /* One chunk, but check for short chunk at end of buffer */
732 rows = MIN((long) ptr->rowsperchunk, (long) ptr->rows_in_mem - i);
733 /* Transfer no more than is currently defined */
734 thisrow = (long) ptr->cur_start_row + i;
735 rows = MIN(rows, (long) ptr->first_undef_row - thisrow);
736 /* Transfer no more than fits in file */
737 rows = MIN(rows, (long) ptr->rows_in_array - thisrow);
738 if (rows <= 0) /* this chunk might be past end of file! */
740 byte_count = rows * bytesperrow;
742 (*ptr->b_s_info.write_backing_store) (cinfo, & ptr->b_s_info,
743 (void *) ptr->mem_buffer[i],
744 file_offset, byte_count);
746 (*ptr->b_s_info.read_backing_store) (cinfo, & ptr->b_s_info,
747 (void *) ptr->mem_buffer[i],
748 file_offset, byte_count);
749 file_offset += byte_count;
755 do_barray_io (j_common_ptr cinfo, jvirt_barray_ptr ptr, boolean writing)
756 /* Do backing store read or write of a virtual coefficient-block array */
758 long bytesperrow, file_offset, byte_count, rows, thisrow, i;
760 bytesperrow = (long) ptr->blocksperrow * sizeof(JBLOCK);
761 file_offset = ptr->cur_start_row * bytesperrow;
762 /* Loop to read or write each allocation chunk in mem_buffer */
763 for (i = 0; i < (long) ptr->rows_in_mem; i += ptr->rowsperchunk) {
764 /* One chunk, but check for short chunk at end of buffer */
765 rows = MIN((long) ptr->rowsperchunk, (long) ptr->rows_in_mem - i);
766 /* Transfer no more than is currently defined */
767 thisrow = (long) ptr->cur_start_row + i;
768 rows = MIN(rows, (long) ptr->first_undef_row - thisrow);
769 /* Transfer no more than fits in file */
770 rows = MIN(rows, (long) ptr->rows_in_array - thisrow);
771 if (rows <= 0) /* this chunk might be past end of file! */
773 byte_count = rows * bytesperrow;
775 (*ptr->b_s_info.write_backing_store) (cinfo, & ptr->b_s_info,
776 (void *) ptr->mem_buffer[i],
777 file_offset, byte_count);
779 (*ptr->b_s_info.read_backing_store) (cinfo, & ptr->b_s_info,
780 (void *) ptr->mem_buffer[i],
781 file_offset, byte_count);
782 file_offset += byte_count;
787 METHODDEF(JSAMPARRAY)
788 access_virt_sarray (j_common_ptr cinfo, jvirt_sarray_ptr ptr,
789 JDIMENSION start_row, JDIMENSION num_rows,
791 /* Access the part of a virtual sample array starting at start_row */
792 /* and extending for num_rows rows. writable is true if */
793 /* caller intends to modify the accessed area. */
795 JDIMENSION end_row = start_row + num_rows;
796 JDIMENSION undef_row;
798 /* debugging check */
799 if (end_row > ptr->rows_in_array || num_rows > ptr->maxaccess ||
800 ptr->mem_buffer == NULL)
801 ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS);
803 /* Make the desired part of the virtual array accessible */
804 if (start_row < ptr->cur_start_row ||
805 end_row > ptr->cur_start_row+ptr->rows_in_mem) {
807 ERREXIT(cinfo, JERR_VIRTUAL_BUG);
808 /* Flush old buffer contents if necessary */
810 do_sarray_io(cinfo, ptr, TRUE);
813 /* Decide what part of virtual array to access.
814 * Algorithm: if target address > current window, assume forward scan,
815 * load starting at target address. If target address < current window,
816 * assume backward scan, load so that target area is top of window.
817 * Note that when switching from forward write to forward read, will have
818 * start_row = 0, so the limiting case applies and we load from 0 anyway.
820 if (start_row > ptr->cur_start_row) {
821 ptr->cur_start_row = start_row;
823 /* use long arithmetic here to avoid overflow & unsigned problems */
826 ltemp = (long) end_row - (long) ptr->rows_in_mem;
828 ltemp = 0; /* don't fall off front end of file */
829 ptr->cur_start_row = (JDIMENSION) ltemp;
831 /* Read in the selected part of the array.
832 * During the initial write pass, we will do no actual read
833 * because the selected part is all undefined.
835 do_sarray_io(cinfo, ptr, FALSE);
837 /* Ensure the accessed part of the array is defined; prezero if needed.
838 * To improve locality of access, we only prezero the part of the array
839 * that the caller is about to access, not the entire in-memory array.
841 if (ptr->first_undef_row < end_row) {
842 if (ptr->first_undef_row < start_row) {
843 if (writable) /* writer skipped over a section of array */
844 ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS);
845 undef_row = start_row; /* but reader is allowed to read ahead */
847 undef_row = ptr->first_undef_row;
850 ptr->first_undef_row = end_row;
852 size_t bytesperrow = (size_t) ptr->samplesperrow * sizeof(JSAMPLE);
853 undef_row -= ptr->cur_start_row; /* make indexes relative to buffer */
854 end_row -= ptr->cur_start_row;
855 while (undef_row < end_row) {
856 jzero_far((void *) ptr->mem_buffer[undef_row], bytesperrow);
860 if (! writable) /* reader looking at undefined data */
861 ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS);
864 /* Flag the buffer dirty if caller will write in it */
867 /* Return address of proper part of the buffer */
868 return ptr->mem_buffer + (start_row - ptr->cur_start_row);
872 METHODDEF(JBLOCKARRAY)
873 access_virt_barray (j_common_ptr cinfo, jvirt_barray_ptr ptr,
874 JDIMENSION start_row, JDIMENSION num_rows,
876 /* Access the part of a virtual block array starting at start_row */
877 /* and extending for num_rows rows. writable is true if */
878 /* caller intends to modify the accessed area. */
880 JDIMENSION end_row = start_row + num_rows;
881 JDIMENSION undef_row;
883 /* debugging check */
884 if (end_row > ptr->rows_in_array || num_rows > ptr->maxaccess ||
885 ptr->mem_buffer == NULL)
886 ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS);
888 /* Make the desired part of the virtual array accessible */
889 if (start_row < ptr->cur_start_row ||
890 end_row > ptr->cur_start_row+ptr->rows_in_mem) {
892 ERREXIT(cinfo, JERR_VIRTUAL_BUG);
893 /* Flush old buffer contents if necessary */
895 do_barray_io(cinfo, ptr, TRUE);
898 /* Decide what part of virtual array to access.
899 * Algorithm: if target address > current window, assume forward scan,
900 * load starting at target address. If target address < current window,
901 * assume backward scan, load so that target area is top of window.
902 * Note that when switching from forward write to forward read, will have
903 * start_row = 0, so the limiting case applies and we load from 0 anyway.
905 if (start_row > ptr->cur_start_row) {
906 ptr->cur_start_row = start_row;
908 /* use long arithmetic here to avoid overflow & unsigned problems */
911 ltemp = (long) end_row - (long) ptr->rows_in_mem;
913 ltemp = 0; /* don't fall off front end of file */
914 ptr->cur_start_row = (JDIMENSION) ltemp;
916 /* Read in the selected part of the array.
917 * During the initial write pass, we will do no actual read
918 * because the selected part is all undefined.
920 do_barray_io(cinfo, ptr, FALSE);
922 /* Ensure the accessed part of the array is defined; prezero if needed.
923 * To improve locality of access, we only prezero the part of the array
924 * that the caller is about to access, not the entire in-memory array.
926 if (ptr->first_undef_row < end_row) {
927 if (ptr->first_undef_row < start_row) {
928 if (writable) /* writer skipped over a section of array */
929 ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS);
930 undef_row = start_row; /* but reader is allowed to read ahead */
932 undef_row = ptr->first_undef_row;
935 ptr->first_undef_row = end_row;
937 size_t bytesperrow = (size_t) ptr->blocksperrow * sizeof(JBLOCK);
938 undef_row -= ptr->cur_start_row; /* make indexes relative to buffer */
939 end_row -= ptr->cur_start_row;
940 while (undef_row < end_row) {
941 jzero_far((void *) ptr->mem_buffer[undef_row], bytesperrow);
945 if (! writable) /* reader looking at undefined data */
946 ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS);
949 /* Flag the buffer dirty if caller will write in it */
952 /* Return address of proper part of the buffer */
953 return ptr->mem_buffer + (start_row - ptr->cur_start_row);
958 * Release all objects belonging to a specified pool.
962 free_pool (j_common_ptr cinfo, int pool_id)
964 my_mem_ptr mem = (my_mem_ptr) cinfo->mem;
965 small_pool_ptr shdr_ptr;
966 large_pool_ptr lhdr_ptr;
969 if (pool_id < 0 || pool_id >= JPOOL_NUMPOOLS)
970 ERREXIT1(cinfo, JERR_BAD_POOL_ID, pool_id); /* safety check */
973 if (cinfo->err->trace_level > 1)
974 print_mem_stats(cinfo, pool_id); /* print pool's memory usage statistics */
977 /* If freeing IMAGE pool, close any virtual arrays first */
978 if (pool_id == JPOOL_IMAGE) {
979 jvirt_sarray_ptr sptr;
980 jvirt_barray_ptr bptr;
982 for (sptr = mem->virt_sarray_list; sptr != NULL; sptr = sptr->next) {
983 if (sptr->b_s_open) { /* there may be no backing store */
984 sptr->b_s_open = FALSE; /* prevent recursive close if error */
985 (*sptr->b_s_info.close_backing_store) (cinfo, & sptr->b_s_info);
988 mem->virt_sarray_list = NULL;
989 for (bptr = mem->virt_barray_list; bptr != NULL; bptr = bptr->next) {
990 if (bptr->b_s_open) { /* there may be no backing store */
991 bptr->b_s_open = FALSE; /* prevent recursive close if error */
992 (*bptr->b_s_info.close_backing_store) (cinfo, & bptr->b_s_info);
995 mem->virt_barray_list = NULL;
998 /* Release large objects */
999 lhdr_ptr = mem->large_list[pool_id];
1000 mem->large_list[pool_id] = NULL;
1002 while (lhdr_ptr != NULL) {
1003 large_pool_ptr next_lhdr_ptr = lhdr_ptr->next;
1004 space_freed = lhdr_ptr->bytes_used +
1005 lhdr_ptr->bytes_left +
1006 sizeof(large_pool_hdr);
1007 jpeg_free_large(cinfo, (void *) lhdr_ptr, space_freed);
1008 mem->total_space_allocated -= space_freed;
1009 lhdr_ptr = next_lhdr_ptr;
1012 /* Release small objects */
1013 shdr_ptr = mem->small_list[pool_id];
1014 mem->small_list[pool_id] = NULL;
1016 while (shdr_ptr != NULL) {
1017 small_pool_ptr next_shdr_ptr = shdr_ptr->next;
1018 space_freed = shdr_ptr->bytes_used +
1019 shdr_ptr->bytes_left +
1020 sizeof(small_pool_hdr);
1021 jpeg_free_small(cinfo, (void *) shdr_ptr, space_freed);
1022 mem->total_space_allocated -= space_freed;
1023 shdr_ptr = next_shdr_ptr;
1029 * Close up shop entirely.
1030 * Note that this cannot be called unless cinfo->mem is non-NULL.
1034 self_destruct (j_common_ptr cinfo)
1038 /* Close all backing store, release all memory.
1039 * Releasing pools in reverse order might help avoid fragmentation
1040 * with some (brain-damaged) malloc libraries.
1042 for (pool = JPOOL_NUMPOOLS-1; pool >= JPOOL_PERMANENT; pool--) {
1043 free_pool(cinfo, pool);
1046 /* Release the memory manager control block too. */
1047 jpeg_free_small(cinfo, (void *) cinfo->mem, sizeof(my_memory_mgr));
1048 cinfo->mem = NULL; /* ensures I will be called only once */
1050 jpeg_mem_term(cinfo); /* system-dependent cleanup */
1055 * Memory manager initialization.
1056 * When this is called, only the error manager pointer is valid in cinfo!
1060 jinit_memory_mgr (j_common_ptr cinfo)
1067 cinfo->mem = NULL; /* for safety if init fails */
1069 /* Check for configuration errors.
1070 * sizeof(ALIGN_TYPE) should be a power of 2; otherwise, it probably
1071 * doesn't reflect any real hardware alignment requirement.
1072 * The test is a little tricky: for X>0, X and X-1 have no one-bits
1073 * in common if and only if X is a power of 2, ie has only one one-bit.
1074 * Some compilers may give an "unreachable code" warning here; ignore it.
1076 if ((ALIGN_SIZE & (ALIGN_SIZE-1)) != 0)
1077 ERREXIT(cinfo, JERR_BAD_ALIGN_TYPE);
1078 /* MAX_ALLOC_CHUNK must be representable as type size_t, and must be
1079 * a multiple of ALIGN_SIZE.
1080 * Again, an "unreachable code" warning may be ignored here.
1081 * But a "constant too large" warning means you need to fix MAX_ALLOC_CHUNK.
1083 test_mac = (size_t) MAX_ALLOC_CHUNK;
1084 if ((long) test_mac != MAX_ALLOC_CHUNK ||
1085 (MAX_ALLOC_CHUNK % ALIGN_SIZE) != 0)
1086 ERREXIT(cinfo, JERR_BAD_ALLOC_CHUNK);
1088 max_to_use = jpeg_mem_init(cinfo); /* system-dependent initialization */
1090 /* Attempt to allocate memory manager's control block */
1091 mem = (my_mem_ptr) jpeg_get_small(cinfo, sizeof(my_memory_mgr));
1094 jpeg_mem_term(cinfo); /* system-dependent cleanup */
1095 ERREXIT1(cinfo, JERR_OUT_OF_MEMORY, 0);
1098 /* OK, fill in the method pointers */
1099 mem->pub.alloc_small = alloc_small;
1100 mem->pub.alloc_large = alloc_large;
1101 mem->pub.alloc_sarray = alloc_sarray;
1102 mem->pub.alloc_barray = alloc_barray;
1103 mem->pub.request_virt_sarray = request_virt_sarray;
1104 mem->pub.request_virt_barray = request_virt_barray;
1105 mem->pub.realize_virt_arrays = realize_virt_arrays;
1106 mem->pub.access_virt_sarray = access_virt_sarray;
1107 mem->pub.access_virt_barray = access_virt_barray;
1108 mem->pub.free_pool = free_pool;
1109 mem->pub.self_destruct = self_destruct;
1111 /* Make MAX_ALLOC_CHUNK accessible to other modules */
1112 mem->pub.max_alloc_chunk = MAX_ALLOC_CHUNK;
1114 /* Initialize working state */
1115 mem->pub.max_memory_to_use = max_to_use;
1117 for (pool = JPOOL_NUMPOOLS-1; pool >= JPOOL_PERMANENT; pool--) {
1118 mem->small_list[pool] = NULL;
1119 mem->large_list[pool] = NULL;
1121 mem->virt_sarray_list = NULL;
1122 mem->virt_barray_list = NULL;
1124 mem->total_space_allocated = sizeof(my_memory_mgr);
1126 /* Declare ourselves open for business */
1127 cinfo->mem = & mem->pub;
1129 /* Check for an environment variable JPEGMEM; if found, override the
1130 * default max_memory setting from jpeg_mem_init. Note that the
1131 * surrounding application may again override this value.
1132 * If your system doesn't support getenv(), define NO_GETENV to disable
1138 if ((memenv = getenv("JPEGMEM")) != NULL) {
1141 if (sscanf(memenv, "%ld%c", &max_to_use, &ch) > 0) {
1142 if (ch == 'm' || ch == 'M')
1143 max_to_use *= 1000L;
1144 mem->pub.max_memory_to_use = max_to_use * 1000L;