1 /* 2 * jmemmgr.c 3 * 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. 7 * 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 14 * virtual arrays; 15 * * control logic for swapping virtual arrays between main memory and 16 * backing storage. 17 * The separate system-dependent file provides the actual backing-storage 18 * access code, and it contains the policy decision about how much total 19 * main memory to use. 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...) 25 */ 26 27 #define JPEG_INTERNALS 28 #define AM_MEMORY_MANAGER /* we define jvirt_Xarray_control structs */ 29 #include "jinclude.h" 30 #include "jpeglib.h" 31 #include "jmemsys.h" /* import the system-dependent declarations */ 32 33 #define NO_GETENV /* XYQ: 2007-5-22 Don't use it */ 34 35 #ifndef NO_GETENV 36 #ifndef HAVE_STDLIB_H /* <stdlib.h> should declare getenv() */ 37 extern char * getenv JPP((const char * name)); 38 #endif 39 #endif 40 41 42 /* 43 * Some important notes: 44 * The allocation routines provided here must never return NULL. 45 * They should exit to error_exit if unsuccessful. 46 * 47 * It's not a good idea to try to merge the sarray and barray routines, 48 * even though they are textually almost the same, because samples are 49 * usually stored as bytes while coefficients are shorts or ints. Thus, 50 * in machines where byte pointers have a different representation from 51 * word pointers, the resulting machine code could not be the same. 52 */ 53 54 55 /* 56 * Many machines require storage alignment: longs must start on 4-byte 57 * boundaries, doubles on 8-byte boundaries, etc. On such machines, malloc() 58 * always returns pointers that are multiples of the worst-case alignment 59 * requirement, and we had better do so too. 60 * There isn't any really portable way to determine the worst-case alignment 61 * requirement. This module assumes that the alignment requirement is 62 * multiples of sizeof(ALIGN_TYPE). 63 * By default, we define ALIGN_TYPE as double. This is necessary on some 64 * workstations (where doubles really do need 8-byte alignment) and will work 65 * fine on nearly everything. If your machine has lesser alignment needs, 66 * you can save a few bytes by making ALIGN_TYPE smaller. 67 * The only place I know of where this will NOT work is certain Macintosh 68 * 680x0 compilers that define double as a 10-byte IEEE extended float. 69 * Doing 10-byte alignment is counterproductive because longwords won't be 70 * aligned well. Put "#define ALIGN_TYPE long" in jconfig.h if you have 71 * such a compiler. 72 */ 73 74 #ifndef ALIGN_TYPE /* so can override from jconfig.h */ 75 #define ALIGN_TYPE double 76 #endif 77 78 79 /* 80 * We allocate objects from "pools", where each pool is gotten with a single 81 * request to jpeg_get_small() or jpeg_get_large(). There is no per-object 82 * overhead within a pool, except for alignment padding. Each pool has a 83 * header with a link to the next pool of the same class. 84 * Small and large pool headers are identical except that the latter's 85 * link pointer must be FAR on 80x86 machines. 86 * Notice that the "real" header fields are union'ed with a dummy ALIGN_TYPE 87 * field. This forces the compiler to make SIZEOF(small_pool_hdr) a multiple 88 * of the alignment requirement of ALIGN_TYPE. 89 */ 90 91 typedef union small_pool_struct * small_pool_ptr; 92 93 typedef union small_pool_struct { 94 struct { 95 small_pool_ptr next; /* next in list of pools */ 96 size_t bytes_used; /* how many bytes already used within pool */ 97 size_t bytes_left; /* bytes still available in this pool */ 98 } hdr; 99 ALIGN_TYPE dummy; /* included in union to ensure alignment */ 100 } small_pool_hdr; 101 102 typedef union large_pool_struct FAR * large_pool_ptr; 103 104 typedef union large_pool_struct { 105 struct { 106 large_pool_ptr next; /* next in list of pools */ 107 size_t bytes_used; /* how many bytes already used within pool */ 108 size_t bytes_left; /* bytes still available in this pool */ 109 } hdr; 110 ALIGN_TYPE dummy; /* included in union to ensure alignment */ 111 } large_pool_hdr; 112 113 114 /* 115 * Here is the full definition of a memory manager object. 116 */ 117 118 typedef struct { 119 struct jpeg_memory_mgr pub; /* public fields */ 120 121 /* 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]; 124 125 /* 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. 129 */ 130 jvirt_sarray_ptr virt_sarray_list; 131 jvirt_barray_ptr virt_barray_list; 132 133 /* This counts total space obtained from jpeg_get_small/large */ 134 long total_space_allocated; 135 136 /* alloc_sarray and alloc_barray set this value for use by virtual 137 * array routines. 138 */ 139 JDIMENSION last_rowsperchunk; /* from most recent alloc_sarray/barray */ 140 } my_memory_mgr; 141 142 typedef my_memory_mgr * my_mem_ptr; 143 144 145 /* 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. 150 */ 151 152 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 */ 166 }; 167 168 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 */ 182 }; 183 184 185 #ifdef MEM_STATS /* optional extra stuff for statistics */ 186 187 LOCAL(void) 188 print_mem_stats (j_common_ptr cinfo, int pool_id) 189 { 190 my_mem_ptr mem = (my_mem_ptr) cinfo->mem; 191 small_pool_ptr shdr_ptr; 192 large_pool_ptr lhdr_ptr; 193 194 /* 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. 197 */ 198 FXSYS_fprintf(stderr, "Freeing pool %d, total space = %ld\n", 199 pool_id, mem->total_space_allocated); 200 201 for (lhdr_ptr = mem->large_list[pool_id]; lhdr_ptr != NULL; 202 lhdr_ptr = lhdr_ptr->hdr.next) { 203 FXSYS_fprintf(stderr, " Large chunk used %ld\n", 204 (long) lhdr_ptr->hdr.bytes_used); 205 } 206 207 for (shdr_ptr = mem->small_list[pool_id]; shdr_ptr != NULL; 208 shdr_ptr = shdr_ptr->hdr.next) { 209 FXSYS_fprintf(stderr, " Small chunk used %ld free %ld\n", 210 (long) shdr_ptr->hdr.bytes_used, 211 (long) shdr_ptr->hdr.bytes_left); 212 } 213 } 214 215 #endif /* MEM_STATS */ 216 217 218 LOCAL(void) 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 */ 222 { 223 #ifdef MEM_STATS 224 cinfo->err->trace_level = 2; /* force self_destruct to report stats */ 225 #endif 226 ERREXIT1(cinfo, JERR_OUT_OF_MEMORY, which); 227 } 228 229 230 /* 231 * Allocation of "small" objects. 232 * 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. 241 */ 242 243 static const size_t first_pool_slop[JPOOL_NUMPOOLS] = 244 { 245 1600, /* first PERMANENT pool */ 246 16000 /* first IMAGE pool */ 247 }; 248 249 static const size_t extra_pool_slop[JPOOL_NUMPOOLS] = 250 { 251 0, /* additional PERMANENT pools */ 252 5000 /* additional IMAGE pools */ 253 }; 254 255 #define MIN_SLOP 50 /* greater than 0 to avoid futile looping */ 256 257 258 METHODDEF(void *) 259 alloc_small (j_common_ptr cinfo, int pool_id, size_t sizeofobject) 260 /* Allocate a "small" object */ 261 { 262 my_mem_ptr mem = (my_mem_ptr) cinfo->mem; 263 small_pool_ptr hdr_ptr, prev_hdr_ptr; 264 char * data_ptr; 265 size_t odd_bytes, min_request, slop; 266 267 /* Check for unsatisfiable request (do now to ensure no overflow below) */ 268 if (sizeofobject > (size_t) (MAX_ALLOC_CHUNK-SIZEOF(small_pool_hdr))) 269 out_of_memory(cinfo, 1); /* request exceeds malloc's ability */ 270 271 /* Round up the requested size to a multiple of SIZEOF(ALIGN_TYPE) */ 272 odd_bytes = sizeofobject % SIZEOF(ALIGN_TYPE); 273 if (odd_bytes > 0) 274 sizeofobject += SIZEOF(ALIGN_TYPE) - odd_bytes; 275 276 /* See if space is available in any existing pool */ 277 if (pool_id < 0 || pool_id >= JPOOL_NUMPOOLS) 278 ERREXIT1(cinfo, JERR_BAD_POOL_ID, pool_id); /* safety check */ 279 prev_hdr_ptr = NULL; 280 hdr_ptr = mem->small_list[pool_id]; 281 while (hdr_ptr != NULL) { 282 if (hdr_ptr->hdr.bytes_left >= sizeofobject) 283 break; /* found pool with enough space */ 284 prev_hdr_ptr = hdr_ptr; 285 hdr_ptr = hdr_ptr->hdr.next; 286 } 287 288 /* Time to make a new pool? */ 289 if (hdr_ptr == NULL) { 290 /* min_request is what we need now, slop is what will be leftover */ 291 min_request = sizeofobject + SIZEOF(small_pool_hdr); 292 if (prev_hdr_ptr == NULL) /* first pool in class? */ 293 slop = first_pool_slop[pool_id]; 294 else 295 slop = extra_pool_slop[pool_id]; 296 /* Don't ask for more than MAX_ALLOC_CHUNK */ 297 if (slop > (size_t) (MAX_ALLOC_CHUNK-min_request)) 298 slop = (size_t) (MAX_ALLOC_CHUNK-min_request); 299 /* Try to get space, if fail reduce slop and try again */ 300 for (;;) { 301 hdr_ptr = (small_pool_ptr) jpeg_get_small(cinfo, min_request + slop); 302 if (hdr_ptr != NULL) 303 break; 304 slop /= 2; 305 if (slop < MIN_SLOP) /* give up when it gets real small */ 306 out_of_memory(cinfo, 2); /* jpeg_get_small failed */ 307 } 308 mem->total_space_allocated += min_request + slop; 309 /* Success, initialize the new pool header and add to end of list */ 310 hdr_ptr->hdr.next = NULL; 311 hdr_ptr->hdr.bytes_used = 0; 312 hdr_ptr->hdr.bytes_left = sizeofobject + slop; 313 if (prev_hdr_ptr == NULL) /* first pool in class? */ 314 mem->small_list[pool_id] = hdr_ptr; 315 else 316 prev_hdr_ptr->hdr.next = hdr_ptr; 317 } 318 319 /* OK, allocate the object from the current pool */ 320 data_ptr = (char *) (hdr_ptr + 1); /* point to first data byte in pool */ 321 data_ptr += hdr_ptr->hdr.bytes_used; /* point to place for object */ 322 hdr_ptr->hdr.bytes_used += sizeofobject; 323 hdr_ptr->hdr.bytes_left -= sizeofobject; 324 325 return (void *) data_ptr; 326 } 327 328 329 /* 330 * Allocation of "large" objects. 331 * 332 * The external semantics of these are the same as "small" objects, 333 * except that FAR pointers are used on 80x86. However the pool 334 * management heuristics are quite different. We assume that each 335 * request is large enough that it may as well be passed directly to 336 * jpeg_get_large; the pool management just links everything together 337 * so that we can free it all on demand. 338 * Note: the major use of "large" objects is in JSAMPARRAY and JBLOCKARRAY 339 * structures. The routines that create these structures (see below) 340 * deliberately bunch rows together to ensure a large request size. 341 */ 342 343 METHODDEF(void FAR *) 344 alloc_large (j_common_ptr cinfo, int pool_id, size_t sizeofobject) 345 /* Allocate a "large" object */ 346 { 347 my_mem_ptr mem = (my_mem_ptr) cinfo->mem; 348 large_pool_ptr hdr_ptr; 349 size_t odd_bytes; 350 351 /* Check for unsatisfiable request (do now to ensure no overflow below) */ 352 if (sizeofobject > (size_t) (MAX_ALLOC_CHUNK-SIZEOF(large_pool_hdr))) 353 out_of_memory(cinfo, 3); /* request exceeds malloc's ability */ 354 355 /* Round up the requested size to a multiple of SIZEOF(ALIGN_TYPE) */ 356 odd_bytes = sizeofobject % SIZEOF(ALIGN_TYPE); 357 if (odd_bytes > 0) 358 sizeofobject += SIZEOF(ALIGN_TYPE) - odd_bytes; 359 360 /* Always make a new pool */ 361 if (pool_id < 0 || pool_id >= JPOOL_NUMPOOLS) 362 ERREXIT1(cinfo, JERR_BAD_POOL_ID, pool_id); /* safety check */ 363 364 hdr_ptr = (large_pool_ptr) jpeg_get_large(cinfo, sizeofobject + 365 SIZEOF(large_pool_hdr)); 366 if (hdr_ptr == NULL) 367 out_of_memory(cinfo, 4); /* jpeg_get_large failed */ 368 mem->total_space_allocated += sizeofobject + SIZEOF(large_pool_hdr); 369 370 /* Success, initialize the new pool header and add to list */ 371 hdr_ptr->hdr.next = mem->large_list[pool_id]; 372 /* We maintain space counts in each pool header for statistical purposes, 373 * even though they are not needed for allocation. 374 */ 375 hdr_ptr->hdr.bytes_used = sizeofobject; 376 hdr_ptr->hdr.bytes_left = 0; 377 mem->large_list[pool_id] = hdr_ptr; 378 379 return (void FAR *) (hdr_ptr + 1); /* point to first data byte in pool */ 380 } 381 382 383 /* 384 * Creation of 2-D sample arrays. 385 * The pointers are in near heap, the samples themselves in FAR heap. 386 * 387 * To minimize allocation overhead and to allow I/O of large contiguous 388 * blocks, we allocate the sample rows in groups of as many rows as possible 389 * without exceeding MAX_ALLOC_CHUNK total bytes per allocation request. 390 * NB: the virtual array control routines, later in this file, know about 391 * this chunking of rows. The rowsperchunk value is left in the mem manager 392 * object so that it can be saved away if this sarray is the workspace for 393 * a virtual array. 394 */ 395 396 METHODDEF(JSAMPARRAY) 397 alloc_sarray (j_common_ptr cinfo, int pool_id, 398 JDIMENSION samplesperrow, JDIMENSION numrows) 399 /* Allocate a 2-D sample array */ 400 { 401 my_mem_ptr mem = (my_mem_ptr) cinfo->mem; 402 JSAMPARRAY result; 403 JSAMPROW workspace; 404 JDIMENSION rowsperchunk, currow, i; 405 long ltemp; 406 407 /* Calculate max # of rows allowed in one allocation chunk */ 408 ltemp = (MAX_ALLOC_CHUNK-SIZEOF(large_pool_hdr)) / 409 ((long) samplesperrow * SIZEOF(JSAMPLE)); 410 if (ltemp <= 0) 411 ERREXIT(cinfo, JERR_WIDTH_OVERFLOW); 412 if (ltemp < (long) numrows) 413 rowsperchunk = (JDIMENSION) ltemp; 414 else 415 rowsperchunk = numrows; 416 mem->last_rowsperchunk = rowsperchunk; 417 418 /* Get space for row pointers (small object) */ 419 result = (JSAMPARRAY) alloc_small(cinfo, pool_id, 420 (size_t) (numrows * SIZEOF(JSAMPROW))); 421 422 /* Get the rows themselves (large objects) */ 423 currow = 0; 424 while (currow < numrows) { 425 rowsperchunk = MIN(rowsperchunk, numrows - currow); 426 workspace = (JSAMPROW) alloc_large(cinfo, pool_id, 427 (size_t) ((size_t) rowsperchunk * (size_t) samplesperrow 428 * SIZEOF(JSAMPLE))); 429 for (i = rowsperchunk; i > 0; i--) { 430 result[currow++] = workspace; 431 workspace += samplesperrow; 432 } 433 } 434 435 return result; 436 } 437 438 439 /* 440 * Creation of 2-D coefficient-block arrays. 441 * This is essentially the same as the code for sample arrays, above. 442 */ 443 444 METHODDEF(JBLOCKARRAY) 445 alloc_barray (j_common_ptr cinfo, int pool_id, 446 JDIMENSION blocksperrow, JDIMENSION numrows) 447 /* Allocate a 2-D coefficient-block array */ 448 { 449 my_mem_ptr mem = (my_mem_ptr) cinfo->mem; 450 JBLOCKARRAY result; 451 JBLOCKROW workspace; 452 JDIMENSION rowsperchunk, currow, i; 453 long ltemp; 454 455 /* Calculate max # of rows allowed in one allocation chunk */ 456 ltemp = (MAX_ALLOC_CHUNK-SIZEOF(large_pool_hdr)) / 457 ((long) blocksperrow * SIZEOF(JBLOCK)); 458 if (ltemp <= 0) 459 ERREXIT(cinfo, JERR_WIDTH_OVERFLOW); 460 if (ltemp < (long) numrows) 461 rowsperchunk = (JDIMENSION) ltemp; 462 else 463 rowsperchunk = numrows; 464 mem->last_rowsperchunk = rowsperchunk; 465 466 /* Get space for row pointers (small object) */ 467 result = (JBLOCKARRAY) alloc_small(cinfo, pool_id, 468 (size_t) (numrows * SIZEOF(JBLOCKROW))); 469 470 /* Get the rows themselves (large objects) */ 471 currow = 0; 472 while (currow < numrows) { 473 rowsperchunk = MIN(rowsperchunk, numrows - currow); 474 workspace = (JBLOCKROW) alloc_large(cinfo, pool_id, 475 (size_t) ((size_t) rowsperchunk * (size_t) blocksperrow 476 * SIZEOF(JBLOCK))); 477 for (i = rowsperchunk; i > 0; i--) { 478 result[currow++] = workspace; 479 workspace += blocksperrow; 480 } 481 } 482 483 return result; 484 } 485 486 487 /* 488 * About virtual array management: 489 * 490 * The above "normal" array routines are only used to allocate strip buffers 491 * (as wide as the image, but just a few rows high). Full-image-sized buffers 492 * are handled as "virtual" arrays. The array is still accessed a strip at a 493 * time, but the memory manager must save the whole array for repeated 494 * accesses. The intended implementation is that there is a strip buffer in 495 * memory (as high as is possible given the desired memory limit), plus a 496 * backing file that holds the rest of the array. 497 * 498 * The request_virt_array routines are told the total size of the image and 499 * the maximum number of rows that will be accessed at once. The in-memory 500 * buffer must be at least as large as the maxaccess value. 501 * 502 * The request routines create control blocks but not the in-memory buffers. 503 * That is postponed until realize_virt_arrays is called. At that time the 504 * total amount of space needed is known (approximately, anyway), so free 505 * memory can be divided up fairly. 506 * 507 * The access_virt_array routines are responsible for making a specific strip 508 * area accessible (after reading or writing the backing file, if necessary). 509 * Note that the access routines are told whether the caller intends to modify 510 * the accessed strip; during a read-only pass this saves having to rewrite 511 * data to disk. The access routines are also responsible for pre-zeroing 512 * any newly accessed rows, if pre-zeroing was requested. 513 * 514 * In current usage, the access requests are usually for nonoverlapping 515 * strips; that is, successive access start_row numbers differ by exactly 516 * num_rows = maxaccess. This means we can get good performance with simple 517 * buffer dump/reload logic, by making the in-memory buffer be a multiple 518 * of the access height; then there will never be accesses across bufferload 519 * boundaries. The code will still work with overlapping access requests, 520 * but it doesn't handle bufferload overlaps very efficiently. 521 */ 522 523 524 METHODDEF(jvirt_sarray_ptr) 525 request_virt_sarray (j_common_ptr cinfo, int pool_id, boolean pre_zero, 526 JDIMENSION samplesperrow, JDIMENSION numrows, 527 JDIMENSION maxaccess) 528 /* Request a virtual 2-D sample array */ 529 { 530 my_mem_ptr mem = (my_mem_ptr) cinfo->mem; 531 jvirt_sarray_ptr result; 532 533 /* Only IMAGE-lifetime virtual arrays are currently supported */ 534 if (pool_id != JPOOL_IMAGE) 535 ERREXIT1(cinfo, JERR_BAD_POOL_ID, pool_id); /* safety check */ 536 537 /* get control block */ 538 result = (jvirt_sarray_ptr) alloc_small(cinfo, pool_id, 539 SIZEOF(struct jvirt_sarray_control)); 540 541 result->mem_buffer = NULL; /* marks array not yet realized */ 542 result->rows_in_array = numrows; 543 result->samplesperrow = samplesperrow; 544 result->maxaccess = maxaccess; 545 result->pre_zero = pre_zero; 546 result->b_s_open = FALSE; /* no associated backing-store object */ 547 result->next = mem->virt_sarray_list; /* add to list of virtual arrays */ 548 mem->virt_sarray_list = result; 549 550 return result; 551 } 552 553 554 METHODDEF(jvirt_barray_ptr) 555 request_virt_barray (j_common_ptr cinfo, int pool_id, boolean pre_zero, 556 JDIMENSION blocksperrow, JDIMENSION numrows, 557 JDIMENSION maxaccess) 558 /* Request a virtual 2-D coefficient-block array */ 559 { 560 my_mem_ptr mem = (my_mem_ptr) cinfo->mem; 561 jvirt_barray_ptr result; 562 563 /* 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 */ 566 567 /* get control block */ 568 result = (jvirt_barray_ptr) alloc_small(cinfo, pool_id, 569 SIZEOF(struct jvirt_barray_control)); 570 571 result->mem_buffer = NULL; /* marks array not yet realized */ 572 result->rows_in_array = numrows; 573 result->blocksperrow = blocksperrow; 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_barray_list; /* add to list of virtual arrays */ 578 mem->virt_barray_list = result; 579 580 return result; 581 } 582 583 584 METHODDEF(void) 585 realize_virt_arrays (j_common_ptr cinfo) 586 /* Allocate the in-memory buffers for any unrealized virtual arrays */ 587 { 588 my_mem_ptr mem = (my_mem_ptr) cinfo->mem; 589 long space_per_minheight, maximum_space, avail_mem; 590 long minheights, max_minheights; 591 jvirt_sarray_ptr sptr; 592 jvirt_barray_ptr bptr; 593 594 /* Compute the minimum space needed (maxaccess rows in each buffer) 595 * and the maximum space needed (full image height in each buffer). 596 * These may be of use to the system-dependent jpeg_mem_available routine. 597 */ 598 space_per_minheight = 0; 599 maximum_space = 0; 600 for (sptr = mem->virt_sarray_list; sptr != NULL; sptr = sptr->next) { 601 if (sptr->mem_buffer == NULL) { /* if not realized yet */ 602 space_per_minheight += (long) sptr->maxaccess * 603 (long) sptr->samplesperrow * SIZEOF(JSAMPLE); 604 maximum_space += (long) sptr->rows_in_array * 605 (long) sptr->samplesperrow * SIZEOF(JSAMPLE); 606 } 607 } 608 for (bptr = mem->virt_barray_list; bptr != NULL; bptr = bptr->next) { 609 if (bptr->mem_buffer == NULL) { /* if not realized yet */ 610 space_per_minheight += (long) bptr->maxaccess * 611 (long) bptr->blocksperrow * SIZEOF(JBLOCK); 612 maximum_space += (long) bptr->rows_in_array * 613 (long) bptr->blocksperrow * SIZEOF(JBLOCK); 614 } 615 } 616 617 if (space_per_minheight <= 0) 618 return; /* no unrealized arrays, no work */ 619 620 /* Determine amount of memory to actually use; this is system-dependent. */ 621 avail_mem = jpeg_mem_available(cinfo, space_per_minheight, maximum_space, 622 mem->total_space_allocated); 623 624 /* If the maximum space needed is available, make all the buffers full 625 * height; otherwise parcel it out with the same number of minheights 626 * in each buffer. 627 */ 628 if (avail_mem >= maximum_space) 629 max_minheights = 1000000000L; 630 else { 631 max_minheights = avail_mem / space_per_minheight; 632 /* If there doesn't seem to be enough space, try to get the minimum 633 * anyway. This allows a "stub" implementation of jpeg_mem_available(). 634 */ 635 if (max_minheights <= 0) 636 max_minheights = 1; 637 } 638 639 /* Allocate the in-memory buffers and initialize backing store as needed. */ 640 641 for (sptr = mem->virt_sarray_list; sptr != NULL; sptr = sptr->next) { 642 if (sptr->mem_buffer == NULL) { /* if not realized yet */ 643 minheights = ((long) sptr->rows_in_array - 1L) / sptr->maxaccess + 1L; 644 if (minheights <= max_minheights) { 645 /* This buffer fits in memory */ 646 sptr->rows_in_mem = sptr->rows_in_array; 647 } else { 648 /* It doesn't fit in memory, create backing store. */ 649 sptr->rows_in_mem = (JDIMENSION) (max_minheights * sptr->maxaccess); 650 jpeg_open_backing_store(cinfo, & sptr->b_s_info, 651 (long) sptr->rows_in_array * 652 (long) sptr->samplesperrow * 653 (long) SIZEOF(JSAMPLE)); 654 sptr->b_s_open = TRUE; 655 } 656 sptr->mem_buffer = alloc_sarray(cinfo, JPOOL_IMAGE, 657 sptr->samplesperrow, sptr->rows_in_mem); 658 sptr->rowsperchunk = mem->last_rowsperchunk; 659 sptr->cur_start_row = 0; 660 sptr->first_undef_row = 0; 661 sptr->dirty = FALSE; 662 } 663 } 664 665 for (bptr = mem->virt_barray_list; bptr != NULL; bptr = bptr->next) { 666 if (bptr->mem_buffer == NULL) { /* if not realized yet */ 667 minheights = ((long) bptr->rows_in_array - 1L) / bptr->maxaccess + 1L; 668 if (minheights <= max_minheights) { 669 /* This buffer fits in memory */ 670 bptr->rows_in_mem = bptr->rows_in_array; 671 } else { 672 /* It doesn't fit in memory, create backing store. */ 673 bptr->rows_in_mem = (JDIMENSION) (max_minheights * bptr->maxaccess); 674 jpeg_open_backing_store(cinfo, & bptr->b_s_info, 675 (long) bptr->rows_in_array * 676 (long) bptr->blocksperrow * 677 (long) SIZEOF(JBLOCK)); 678 bptr->b_s_open = TRUE; 679 } 680 bptr->mem_buffer = alloc_barray(cinfo, JPOOL_IMAGE, 681 bptr->blocksperrow, bptr->rows_in_mem); 682 bptr->rowsperchunk = mem->last_rowsperchunk; 683 bptr->cur_start_row = 0; 684 bptr->first_undef_row = 0; 685 bptr->dirty = FALSE; 686 } 687 } 688 } 689 690 691 LOCAL(void) 692 do_sarray_io (j_common_ptr cinfo, jvirt_sarray_ptr ptr, boolean writing) 693 /* Do backing store read or write of a virtual sample array */ 694 { 695 long bytesperrow, file_offset, byte_count, rows, thisrow, i; 696 697 bytesperrow = (long) ptr->samplesperrow * SIZEOF(JSAMPLE); 698 file_offset = ptr->cur_start_row * bytesperrow; 699 /* Loop to read or write each allocation chunk in mem_buffer */ 700 for (i = 0; i < (long) ptr->rows_in_mem; i += ptr->rowsperchunk) { 701 /* One chunk, but check for short chunk at end of buffer */ 702 rows = MIN((long) ptr->rowsperchunk, (long) ptr->rows_in_mem - i); 703 /* Transfer no more than is currently defined */ 704 thisrow = (long) ptr->cur_start_row + i; 705 rows = MIN(rows, (long) ptr->first_undef_row - thisrow); 706 /* Transfer no more than fits in file */ 707 rows = MIN(rows, (long) ptr->rows_in_array - thisrow); 708 if (rows <= 0) /* this chunk might be past end of file! */ 709 break; 710 byte_count = rows * bytesperrow; 711 if (writing) 712 (*ptr->b_s_info.write_backing_store) (cinfo, & ptr->b_s_info, 713 (void FAR *) ptr->mem_buffer[i], 714 file_offset, byte_count); 715 else 716 (*ptr->b_s_info.read_backing_store) (cinfo, & ptr->b_s_info, 717 (void FAR *) ptr->mem_buffer[i], 718 file_offset, byte_count); 719 file_offset += byte_count; 720 } 721 } 722 723 724 LOCAL(void) 725 do_barray_io (j_common_ptr cinfo, jvirt_barray_ptr ptr, boolean writing) 726 /* Do backing store read or write of a virtual coefficient-block array */ 727 { 728 long bytesperrow, file_offset, byte_count, rows, thisrow, i; 729 730 bytesperrow = (long) ptr->blocksperrow * SIZEOF(JBLOCK); 731 file_offset = ptr->cur_start_row * bytesperrow; 732 /* Loop to read or write each allocation chunk in mem_buffer */ 733 for (i = 0; i < (long) ptr->rows_in_mem; i += ptr->rowsperchunk) { 734 /* One chunk, but check for short chunk at end of buffer */ 735 rows = MIN((long) ptr->rowsperchunk, (long) ptr->rows_in_mem - i); 736 /* Transfer no more than is currently defined */ 737 thisrow = (long) ptr->cur_start_row + i; 738 rows = MIN(rows, (long) ptr->first_undef_row - thisrow); 739 /* Transfer no more than fits in file */ 740 rows = MIN(rows, (long) ptr->rows_in_array - thisrow); 741 if (rows <= 0) /* this chunk might be past end of file! */ 742 break; 743 byte_count = rows * bytesperrow; 744 if (writing) 745 (*ptr->b_s_info.write_backing_store) (cinfo, & ptr->b_s_info, 746 (void FAR *) ptr->mem_buffer[i], 747 file_offset, byte_count); 748 else 749 (*ptr->b_s_info.read_backing_store) (cinfo, & ptr->b_s_info, 750 (void FAR *) ptr->mem_buffer[i], 751 file_offset, byte_count); 752 file_offset += byte_count; 753 } 754 } 755 756 757 METHODDEF(JSAMPARRAY) 758 access_virt_sarray (j_common_ptr cinfo, jvirt_sarray_ptr ptr, 759 JDIMENSION start_row, JDIMENSION num_rows, 760 boolean writable) 761 /* Access the part of a virtual sample array starting at start_row */ 762 /* and extending for num_rows rows. writable is true if */ 763 /* caller intends to modify the accessed area. */ 764 { 765 JDIMENSION end_row = start_row + num_rows; 766 JDIMENSION undef_row; 767 768 /* debugging check */ 769 if (end_row > ptr->rows_in_array || num_rows > ptr->maxaccess || 770 ptr->mem_buffer == NULL) 771 ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS); 772 773 /* Make the desired part of the virtual array accessible */ 774 if (start_row < ptr->cur_start_row || 775 end_row > ptr->cur_start_row+ptr->rows_in_mem) { 776 if (! ptr->b_s_open) 777 ERREXIT(cinfo, JERR_VIRTUAL_BUG); 778 /* Flush old buffer contents if necessary */ 779 if (ptr->dirty) { 780 do_sarray_io(cinfo, ptr, TRUE); 781 ptr->dirty = FALSE; 782 } 783 /* Decide what part of virtual array to access. 784 * Algorithm: if target address > current window, assume forward scan, 785 * load starting at target address. If target address < current window, 786 * assume backward scan, load so that target area is top of window. 787 * Note that when switching from forward write to forward read, will have 788 * start_row = 0, so the limiting case applies and we load from 0 anyway. 789 */ 790 if (start_row > ptr->cur_start_row) { 791 ptr->cur_start_row = start_row; 792 } else { 793 /* use long arithmetic here to avoid overflow & unsigned problems */ 794 long ltemp; 795 796 ltemp = (long) end_row - (long) ptr->rows_in_mem; 797 if (ltemp < 0) 798 ltemp = 0; /* don't fall off front end of file */ 799 ptr->cur_start_row = (JDIMENSION) ltemp; 800 } 801 /* Read in the selected part of the array. 802 * During the initial write pass, we will do no actual read 803 * because the selected part is all undefined. 804 */ 805 do_sarray_io(cinfo, ptr, FALSE); 806 } 807 /* Ensure the accessed part of the array is defined; prezero if needed. 808 * To improve locality of access, we only prezero the part of the array 809 * that the caller is about to access, not the entire in-memory array. 810 */ 811 if (ptr->first_undef_row < end_row) { 812 if (ptr->first_undef_row < start_row) { 813 if (writable) /* writer skipped over a section of array */ 814 ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS); 815 undef_row = start_row; /* but reader is allowed to read ahead */ 816 } else { 817 undef_row = ptr->first_undef_row; 818 } 819 if (writable) 820 ptr->first_undef_row = end_row; 821 if (ptr->pre_zero) { 822 size_t bytesperrow = (size_t) ptr->samplesperrow * SIZEOF(JSAMPLE); 823 undef_row -= ptr->cur_start_row; /* make indexes relative to buffer */ 824 end_row -= ptr->cur_start_row; 825 while (undef_row < end_row) { 826 jzero_far((void FAR *) ptr->mem_buffer[undef_row], bytesperrow); 827 undef_row++; 828 } 829 } else { 830 if (! writable) /* reader looking at undefined data */ 831 ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS); 832 } 833 } 834 /* Flag the buffer dirty if caller will write in it */ 835 if (writable) 836 ptr->dirty = TRUE; 837 /* Return address of proper part of the buffer */ 838 return ptr->mem_buffer + (start_row - ptr->cur_start_row); 839 } 840 841 842 METHODDEF(JBLOCKARRAY) 843 access_virt_barray (j_common_ptr cinfo, jvirt_barray_ptr ptr, 844 JDIMENSION start_row, JDIMENSION num_rows, 845 boolean writable) 846 /* Access the part of a virtual block array starting at start_row */ 847 /* and extending for num_rows rows. writable is true if */ 848 /* caller intends to modify the accessed area. */ 849 { 850 JDIMENSION end_row = start_row + num_rows; 851 JDIMENSION undef_row; 852 853 /* debugging check */ 854 if (end_row > ptr->rows_in_array || num_rows > ptr->maxaccess || 855 ptr->mem_buffer == NULL) 856 ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS); 857 858 /* Make the desired part of the virtual array accessible */ 859 if (start_row < ptr->cur_start_row || 860 end_row > ptr->cur_start_row+ptr->rows_in_mem) { 861 if (! ptr->b_s_open) 862 ERREXIT(cinfo, JERR_VIRTUAL_BUG); 863 /* Flush old buffer contents if necessary */ 864 if (ptr->dirty) { 865 do_barray_io(cinfo, ptr, TRUE); 866 ptr->dirty = FALSE; 867 } 868 /* Decide what part of virtual array to access. 869 * Algorithm: if target address > current window, assume forward scan, 870 * load starting at target address. If target address < current window, 871 * assume backward scan, load so that target area is top of window. 872 * Note that when switching from forward write to forward read, will have 873 * start_row = 0, so the limiting case applies and we load from 0 anyway. 874 */ 875 if (start_row > ptr->cur_start_row) { 876 ptr->cur_start_row = start_row; 877 } else { 878 /* use long arithmetic here to avoid overflow & unsigned problems */ 879 long ltemp; 880 881 ltemp = (long) end_row - (long) ptr->rows_in_mem; 882 if (ltemp < 0) 883 ltemp = 0; /* don't fall off front end of file */ 884 ptr->cur_start_row = (JDIMENSION) ltemp; 885 } 886 /* Read in the selected part of the array. 887 * During the initial write pass, we will do no actual read 888 * because the selected part is all undefined. 889 */ 890 do_barray_io(cinfo, ptr, FALSE); 891 } 892 /* Ensure the accessed part of the array is defined; prezero if needed. 893 * To improve locality of access, we only prezero the part of the array 894 * that the caller is about to access, not the entire in-memory array. 895 */ 896 if (ptr->first_undef_row < end_row) { 897 if (ptr->first_undef_row < start_row) { 898 if (writable) /* writer skipped over a section of array */ 899 ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS); 900 undef_row = start_row; /* but reader is allowed to read ahead */ 901 } else { 902 undef_row = ptr->first_undef_row; 903 } 904 if (writable) 905 ptr->first_undef_row = end_row; 906 if (ptr->pre_zero) { 907 size_t bytesperrow = (size_t) ptr->blocksperrow * SIZEOF(JBLOCK); 908 undef_row -= ptr->cur_start_row; /* make indexes relative to buffer */ 909 end_row -= ptr->cur_start_row; 910 while (undef_row < end_row) { 911 jzero_far((void FAR *) ptr->mem_buffer[undef_row], bytesperrow); 912 undef_row++; 913 } 914 } else { 915 if (! writable) /* reader looking at undefined data */ 916 ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS); 917 } 918 } 919 /* Flag the buffer dirty if caller will write in it */ 920 if (writable) 921 ptr->dirty = TRUE; 922 /* Return address of proper part of the buffer */ 923 return ptr->mem_buffer + (start_row - ptr->cur_start_row); 924 } 925 926 927 /* 928 * Release all objects belonging to a specified pool. 929 */ 930 931 METHODDEF(void) 932 free_pool (j_common_ptr cinfo, int pool_id) 933 { 934 my_mem_ptr mem = (my_mem_ptr) cinfo->mem; 935 small_pool_ptr shdr_ptr; 936 large_pool_ptr lhdr_ptr; 937 size_t space_freed; 938 939 if (pool_id < 0 || pool_id >= JPOOL_NUMPOOLS) 940 ERREXIT1(cinfo, JERR_BAD_POOL_ID, pool_id); /* safety check */ 941 942 #ifdef MEM_STATS 943 if (cinfo->err->trace_level > 1) 944 print_mem_stats(cinfo, pool_id); /* print pool's memory usage statistics */ 945 #endif 946 947 /* If freeing IMAGE pool, close any virtual arrays first */ 948 if (pool_id == JPOOL_IMAGE) { 949 jvirt_sarray_ptr sptr; 950 jvirt_barray_ptr bptr; 951 952 for (sptr = mem->virt_sarray_list; sptr != NULL; sptr = sptr->next) { 953 if (sptr->b_s_open) { /* there may be no backing store */ 954 sptr->b_s_open = FALSE; /* prevent recursive close if error */ 955 (*sptr->b_s_info.close_backing_store) (cinfo, & sptr->b_s_info); 956 } 957 } 958 mem->virt_sarray_list = NULL; 959 for (bptr = mem->virt_barray_list; bptr != NULL; bptr = bptr->next) { 960 if (bptr->b_s_open) { /* there may be no backing store */ 961 bptr->b_s_open = FALSE; /* prevent recursive close if error */ 962 (*bptr->b_s_info.close_backing_store) (cinfo, & bptr->b_s_info); 963 } 964 } 965 mem->virt_barray_list = NULL; 966 } 967 968 /* Release large objects */ 969 lhdr_ptr = mem->large_list[pool_id]; 970 mem->large_list[pool_id] = NULL; 971 972 while (lhdr_ptr != NULL) { 973 large_pool_ptr next_lhdr_ptr = lhdr_ptr->hdr.next; 974 space_freed = lhdr_ptr->hdr.bytes_used + 975 lhdr_ptr->hdr.bytes_left + 976 SIZEOF(large_pool_hdr); 977 jpeg_free_large(cinfo, (void FAR *) lhdr_ptr, space_freed); 978 mem->total_space_allocated -= space_freed; 979 lhdr_ptr = next_lhdr_ptr; 980 } 981 982 /* Release small objects */ 983 shdr_ptr = mem->small_list[pool_id]; 984 mem->small_list[pool_id] = NULL; 985 986 while (shdr_ptr != NULL) { 987 small_pool_ptr next_shdr_ptr = shdr_ptr->hdr.next; 988 space_freed = shdr_ptr->hdr.bytes_used + 989 shdr_ptr->hdr.bytes_left + 990 SIZEOF(small_pool_hdr); 991 jpeg_free_small(cinfo, (void *) shdr_ptr, space_freed); 992 mem->total_space_allocated -= space_freed; 993 shdr_ptr = next_shdr_ptr; 994 } 995 } 996 997 998 /* 999 * Close up shop entirely. 1000 * Note that this cannot be called unless cinfo->mem is non-NULL. 1001 */ 1002 1003 METHODDEF(void) 1004 self_destruct (j_common_ptr cinfo) 1005 { 1006 int pool; 1007 1008 /* Close all backing store, release all memory. 1009 * Releasing pools in reverse order might help avoid fragmentation 1010 * with some (brain-damaged) malloc libraries. 1011 */ 1012 for (pool = JPOOL_NUMPOOLS-1; pool >= JPOOL_PERMANENT; pool--) { 1013 free_pool(cinfo, pool); 1014 } 1015 1016 /* Release the memory manager control block too. */ 1017 jpeg_free_small(cinfo, (void *) cinfo->mem, SIZEOF(my_memory_mgr)); 1018 cinfo->mem = NULL; /* ensures I will be called only once */ 1019 1020 jpeg_mem_term(cinfo); /* system-dependent cleanup */ 1021 } 1022 1023 1024 /* 1025 * Memory manager initialization. 1026 * When this is called, only the error manager pointer is valid in cinfo! 1027 */ 1028 1029 GLOBAL(void) 1030 jinit_memory_mgr (j_common_ptr cinfo) 1031 { 1032 my_mem_ptr mem; 1033 long max_to_use; 1034 int pool; 1035 size_t test_mac; 1036 1037 cinfo->mem = NULL; /* for safety if init fails */ 1038 1039 /* Check for configuration errors. 1040 * SIZEOF(ALIGN_TYPE) should be a power of 2; otherwise, it probably 1041 * doesn't reflect any real hardware alignment requirement. 1042 * The test is a little tricky: for X>0, X and X-1 have no one-bits 1043 * in common if and only if X is a power of 2, ie has only one one-bit. 1044 * Some compilers may give an "unreachable code" warning here; ignore it. 1045 */ 1046 if ((SIZEOF(ALIGN_TYPE) & (SIZEOF(ALIGN_TYPE)-1)) != 0) 1047 ERREXIT(cinfo, JERR_BAD_ALIGN_TYPE); 1048 /* MAX_ALLOC_CHUNK must be representable as type size_t, and must be 1049 * a multiple of SIZEOF(ALIGN_TYPE). 1050 * Again, an "unreachable code" warning may be ignored here. 1051 * But a "constant too large" warning means you need to fix MAX_ALLOC_CHUNK. 1052 */ 1053 test_mac = (size_t) MAX_ALLOC_CHUNK; 1054 if ((long) test_mac != MAX_ALLOC_CHUNK || 1055 (MAX_ALLOC_CHUNK % SIZEOF(ALIGN_TYPE)) != 0) 1056 ERREXIT(cinfo, JERR_BAD_ALLOC_CHUNK); 1057 1058 max_to_use = jpeg_mem_init(cinfo); /* system-dependent initialization */ 1059 1060 /* Attempt to allocate memory manager's control block */ 1061 mem = (my_mem_ptr) jpeg_get_small(cinfo, SIZEOF(my_memory_mgr)); 1062 1063 if (mem == NULL) { 1064 jpeg_mem_term(cinfo); /* system-dependent cleanup */ 1065 ERREXIT1(cinfo, JERR_OUT_OF_MEMORY, 0); 1066 } 1067 1068 /* OK, fill in the method pointers */ 1069 mem->pub.alloc_small = alloc_small; 1070 mem->pub.alloc_large = alloc_large; 1071 mem->pub.alloc_sarray = alloc_sarray; 1072 mem->pub.alloc_barray = alloc_barray; 1073 mem->pub.request_virt_sarray = request_virt_sarray; 1074 mem->pub.request_virt_barray = request_virt_barray; 1075 mem->pub.realize_virt_arrays = realize_virt_arrays; 1076 mem->pub.access_virt_sarray = access_virt_sarray; 1077 mem->pub.access_virt_barray = access_virt_barray; 1078 mem->pub.free_pool = free_pool; 1079 mem->pub.self_destruct = self_destruct; 1080 1081 /* Make MAX_ALLOC_CHUNK accessible to other modules */ 1082 mem->pub.max_alloc_chunk = MAX_ALLOC_CHUNK; 1083 1084 /* Initialize working state */ 1085 mem->pub.max_memory_to_use = max_to_use; 1086 1087 for (pool = JPOOL_NUMPOOLS-1; pool >= JPOOL_PERMANENT; pool--) { 1088 mem->small_list[pool] = NULL; 1089 mem->large_list[pool] = NULL; 1090 } 1091 mem->virt_sarray_list = NULL; 1092 mem->virt_barray_list = NULL; 1093 1094 mem->total_space_allocated = SIZEOF(my_memory_mgr); 1095 1096 /* Declare ourselves open for business */ 1097 cinfo->mem = & mem->pub; 1098 1099 /* Check for an environment variable JPEGMEM; if found, override the 1100 * default max_memory setting from jpeg_mem_init. Note that the 1101 * surrounding application may again override this value. 1102 * If your system doesn't support getenv(), define NO_GETENV to disable 1103 * this feature. 1104 */ 1105 #ifndef NO_GETENV 1106 { char * memenv; 1107 1108 if ((memenv = getenv("JPEGMEM")) != NULL) { 1109 char ch = 'x'; 1110 1111 if (sscanf(memenv, "%ld%c", &max_to_use, &ch) > 0) { 1112 if (ch == 'm' || ch == 'M') 1113 max_to_use *= 1000L; 1114 mem->pub.max_memory_to_use = max_to_use * 1000L; 1115 } 1116 } 1117 } 1118 #endif 1119 1120 } 1121
