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 #ifndef NO_GETENV 34 #ifndef HAVE_STDLIB_H /* <stdlib.h> should declare getenv() */ 35 extern char * getenv JPP((const char * name)); 36 #endif 37 #endif 38 39 40 LOCAL(size_t) 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 */ 44 { 45 return ((a + b - 1) & (~(b - 1))); 46 } 47 48 49 /* 50 * Some important notes: 51 * The allocation routines provided here must never return NULL. 52 * They should exit to error_exit if unsuccessful. 53 * 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. 59 */ 60 61 62 /* 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 78 * such a compiler. 79 */ 80 81 #ifndef ALIGN_SIZE /* so can override from jconfig.h */ 82 #ifndef WITH_SIMD 83 #define ALIGN_SIZE SIZEOF(double) 84 #else 85 #define ALIGN_SIZE 16 /* Most SIMD implementations require this */ 86 #endif 87 #endif 88 89 /* 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. 96 */ 97 98 typedef struct small_pool_struct * small_pool_ptr; 99 100 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 */ 104 } small_pool_hdr; 105 106 typedef struct large_pool_struct FAR * large_pool_ptr; 107 108 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 */ 112 } large_pool_hdr; 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 size_t 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 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->next) { 203 fprintf(stderr, " Large chunk used %ld\n", 204 (long) lhdr_ptr->bytes_used); 205 } 206 207 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); 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 * 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 244 * adjustment. 245 */ 246 247 static const size_t first_pool_slop[JPOOL_NUMPOOLS] = 248 { 249 1600, /* first PERMANENT pool */ 250 16000 /* first IMAGE pool */ 251 }; 252 253 static const size_t extra_pool_slop[JPOOL_NUMPOOLS] = 254 { 255 0, /* additional PERMANENT pools */ 256 5000 /* additional IMAGE pools */ 257 }; 258 259 #define MIN_SLOP 50 /* greater than 0 to avoid futile looping */ 260 261 262 METHODDEF(void *) 263 alloc_small (j_common_ptr cinfo, int pool_id, size_t sizeofobject) 264 /* Allocate a "small" object */ 265 { 266 my_mem_ptr mem = (my_mem_ptr) cinfo->mem; 267 small_pool_ptr hdr_ptr, prev_hdr_ptr; 268 char * data_ptr; 269 size_t min_request, slop; 270 271 /* 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. 276 */ 277 sizeofobject = round_up_pow2(sizeofobject, ALIGN_SIZE); 278 279 /* 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 */ 282 283 /* 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 */ 286 prev_hdr_ptr = NULL; 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; 293 } 294 295 /* 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]; 301 else 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 */ 307 for (;;) { 308 hdr_ptr = (small_pool_ptr) jpeg_get_small(cinfo, min_request + slop); 309 if (hdr_ptr != NULL) 310 break; 311 slop /= 2; 312 if (slop < MIN_SLOP) /* give up when it gets real small */ 313 out_of_memory(cinfo, 2); /* jpeg_get_small failed */ 314 } 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; 322 else 323 prev_hdr_ptr->next = hdr_ptr; 324 } 325 326 /* 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; 334 335 return (void *) data_ptr; 336 } 337 338 339 /* 340 * Allocation of "large" objects. 341 * 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. 351 */ 352 353 METHODDEF(void FAR *) 354 alloc_large (j_common_ptr cinfo, int pool_id, size_t sizeofobject) 355 /* Allocate a "large" object */ 356 { 357 my_mem_ptr mem = (my_mem_ptr) cinfo->mem; 358 large_pool_ptr hdr_ptr; 359 char FAR * data_ptr; 360 361 /* 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 364 * alignment. 365 */ 366 sizeofobject = round_up_pow2(sizeofobject, ALIGN_SIZE); 367 368 /* 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 */ 371 372 /* 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 */ 375 376 hdr_ptr = (large_pool_ptr) jpeg_get_large(cinfo, sizeofobject + 377 SIZEOF(large_pool_hdr) + 378 ALIGN_SIZE - 1); 379 if (hdr_ptr == NULL) 380 out_of_memory(cinfo, 4); /* jpeg_get_large failed */ 381 mem->total_space_allocated += sizeofobject + SIZEOF(large_pool_hdr) + ALIGN_SIZE - 1; 382 383 /* 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. 387 */ 388 hdr_ptr->bytes_used = sizeofobject; 389 hdr_ptr->bytes_left = 0; 390 mem->large_list[pool_id] = hdr_ptr; 391 392 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; 396 397 return (void FAR *) data_ptr; 398 } 399 400 401 /* 402 * Creation of 2-D sample arrays. 403 * The pointers are in near heap, the samples themselves in FAR heap. 404 * 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 411 * a virtual array. 412 * 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. 416 */ 417 418 METHODDEF(JSAMPARRAY) 419 alloc_sarray (j_common_ptr cinfo, int pool_id, 420 JDIMENSION samplesperrow, JDIMENSION numrows) 421 /* Allocate a 2-D sample array */ 422 { 423 my_mem_ptr mem = (my_mem_ptr) cinfo->mem; 424 JSAMPARRAY result; 425 JSAMPROW workspace; 426 JDIMENSION rowsperchunk, currow, i; 427 long ltemp; 428 429 /* 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)); 433 434 /* Calculate max # of rows allowed in one allocation chunk */ 435 ltemp = (MAX_ALLOC_CHUNK-SIZEOF(large_pool_hdr)) / 436 ((long) samplesperrow * SIZEOF(JSAMPLE)); 437 if (ltemp <= 0) 438 ERREXIT(cinfo, JERR_WIDTH_OVERFLOW); 439 if (ltemp < (long) numrows) 440 rowsperchunk = (JDIMENSION) ltemp; 441 else 442 rowsperchunk = numrows; 443 mem->last_rowsperchunk = rowsperchunk; 444 445 /* Get space for row pointers (small object) */ 446 result = (JSAMPARRAY) alloc_small(cinfo, pool_id, 447 (size_t) (numrows * SIZEOF(JSAMPROW))); 448 449 /* Get the rows themselves (large objects) */ 450 currow = 0; 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 455 * SIZEOF(JSAMPLE))); 456 for (i = rowsperchunk; i > 0; i--) { 457 result[currow++] = workspace; 458 workspace += samplesperrow; 459 } 460 } 461 462 return result; 463 } 464 465 466 /* 467 * Creation of 2-D coefficient-block arrays. 468 * This is essentially the same as the code for sample arrays, above. 469 */ 470 471 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 */ 475 { 476 my_mem_ptr mem = (my_mem_ptr) cinfo->mem; 477 JBLOCKARRAY result; 478 JBLOCKROW workspace; 479 JDIMENSION rowsperchunk, currow, i; 480 long ltemp; 481 482 /* Make sure each row is properly aligned */ 483 if ((SIZEOF(JBLOCK) % ALIGN_SIZE) != 0) 484 out_of_memory(cinfo, 6); /* safety check */ 485 486 /* Calculate max # of rows allowed in one allocation chunk */ 487 ltemp = (MAX_ALLOC_CHUNK-SIZEOF(large_pool_hdr)) / 488 ((long) blocksperrow * SIZEOF(JBLOCK)); 489 if (ltemp <= 0) 490 ERREXIT(cinfo, JERR_WIDTH_OVERFLOW); 491 if (ltemp < (long) numrows) 492 rowsperchunk = (JDIMENSION) ltemp; 493 else 494 rowsperchunk = numrows; 495 mem->last_rowsperchunk = rowsperchunk; 496 497 /* Get space for row pointers (small object) */ 498 result = (JBLOCKARRAY) alloc_small(cinfo, pool_id, 499 (size_t) (numrows * SIZEOF(JBLOCKROW))); 500 501 /* Get the rows themselves (large objects) */ 502 currow = 0; 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 507 * SIZEOF(JBLOCK))); 508 for (i = rowsperchunk; i > 0; i--) { 509 result[currow++] = workspace; 510 workspace += blocksperrow; 511 } 512 } 513 514 return result; 515 } 516 517 518 /* 519 * About virtual array management: 520 * 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. 528 * 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. 532 * 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. 537 * 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. 544 * 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. 552 */ 553 554 555 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 */ 560 { 561 my_mem_ptr mem = (my_mem_ptr) cinfo->mem; 562 jvirt_sarray_ptr result; 563 564 /* 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 */ 567 568 /* get control block */ 569 result = (jvirt_sarray_ptr) alloc_small(cinfo, pool_id, 570 SIZEOF(struct jvirt_sarray_control)); 571 572 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; 580 581 return result; 582 } 583 584 585 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 */ 590 { 591 my_mem_ptr mem = (my_mem_ptr) cinfo->mem; 592 jvirt_barray_ptr result; 593 594 /* 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 */ 597 598 /* get control block */ 599 result = (jvirt_barray_ptr) alloc_small(cinfo, pool_id, 600 SIZEOF(struct jvirt_barray_control)); 601 602 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; 610 611 return result; 612 } 613 614 615 METHODDEF(void) 616 realize_virt_arrays (j_common_ptr cinfo) 617 /* Allocate the in-memory buffers for any unrealized virtual arrays */ 618 { 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; 624 625 /* 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. 628 */ 629 space_per_minheight = 0; 630 maximum_space = 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); 637 } 638 } 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); 645 } 646 } 647 648 if (space_per_minheight <= 0) 649 return; /* no unrealized arrays, no work */ 650 651 /* 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); 654 655 /* If the maximum space needed is available, make all the buffers full 656 * height; otherwise parcel it out with the same number of minheights 657 * in each buffer. 658 */ 659 if (avail_mem >= maximum_space) 660 max_minheights = 1000000000L; 661 else { 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(). 665 */ 666 if (max_minheights <= 0) 667 max_minheights = 1; 668 } 669 670 /* Allocate the in-memory buffers and initialize backing store as needed. */ 671 672 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; 678 } else { 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; 686 } 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; 692 sptr->dirty = FALSE; 693 } 694 } 695 696 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; 702 } else { 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; 710 } 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; 716 bptr->dirty = FALSE; 717 } 718 } 719 } 720 721 722 LOCAL(void) 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 */ 725 { 726 long bytesperrow, file_offset, byte_count, rows, thisrow, i; 727 728 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! */ 740 break; 741 byte_count = rows * bytesperrow; 742 if (writing) 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); 746 else 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; 751 } 752 } 753 754 755 LOCAL(void) 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 */ 758 { 759 long bytesperrow, file_offset, byte_count, rows, thisrow, i; 760 761 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! */ 773 break; 774 byte_count = rows * bytesperrow; 775 if (writing) 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); 779 else 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; 784 } 785 } 786 787 788 METHODDEF(JSAMPARRAY) 789 access_virt_sarray (j_common_ptr cinfo, jvirt_sarray_ptr ptr, 790 JDIMENSION start_row, JDIMENSION num_rows, 791 boolean writable) 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. */ 795 { 796 JDIMENSION end_row = start_row + num_rows; 797 JDIMENSION undef_row; 798 799 /* 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); 803 804 /* 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) { 807 if (! ptr->b_s_open) 808 ERREXIT(cinfo, JERR_VIRTUAL_BUG); 809 /* Flush old buffer contents if necessary */ 810 if (ptr->dirty) { 811 do_sarray_io(cinfo, ptr, TRUE); 812 ptr->dirty = FALSE; 813 } 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. 820 */ 821 if (start_row > ptr->cur_start_row) { 822 ptr->cur_start_row = start_row; 823 } else { 824 /* use long arithmetic here to avoid overflow & unsigned problems */ 825 long ltemp; 826 827 ltemp = (long) end_row - (long) ptr->rows_in_mem; 828 if (ltemp < 0) 829 ltemp = 0; /* don't fall off front end of file */ 830 ptr->cur_start_row = (JDIMENSION) ltemp; 831 } 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. 835 */ 836 do_sarray_io(cinfo, ptr, FALSE); 837 } 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. 841 */ 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 */ 847 } else { 848 undef_row = ptr->first_undef_row; 849 } 850 if (writable) 851 ptr->first_undef_row = end_row; 852 if (ptr->pre_zero) { 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); 858 undef_row++; 859 } 860 } else { 861 if (! writable) /* reader looking at undefined data */ 862 ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS); 863 } 864 } 865 /* Flag the buffer dirty if caller will write in it */ 866 if (writable) 867 ptr->dirty = TRUE; 868 /* Return address of proper part of the buffer */ 869 return ptr->mem_buffer + (start_row - ptr->cur_start_row); 870 } 871 872 873 METHODDEF(JBLOCKARRAY) 874 access_virt_barray (j_common_ptr cinfo, jvirt_barray_ptr ptr, 875 JDIMENSION start_row, JDIMENSION num_rows, 876 boolean writable) 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. */ 880 { 881 JDIMENSION end_row = start_row + num_rows; 882 JDIMENSION undef_row; 883 884 /* 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); 888 889 /* 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) { 892 if (! ptr->b_s_open) 893 ERREXIT(cinfo, JERR_VIRTUAL_BUG); 894 /* Flush old buffer contents if necessary */ 895 if (ptr->dirty) { 896 do_barray_io(cinfo, ptr, TRUE); 897 ptr->dirty = FALSE; 898 } 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. 905 */ 906 if (start_row > ptr->cur_start_row) { 907 ptr->cur_start_row = start_row; 908 } else { 909 /* use long arithmetic here to avoid overflow & unsigned problems */ 910 long ltemp; 911 912 ltemp = (long) end_row - (long) ptr->rows_in_mem; 913 if (ltemp < 0) 914 ltemp = 0; /* don't fall off front end of file */ 915 ptr->cur_start_row = (JDIMENSION) ltemp; 916 } 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. 920 */ 921 do_barray_io(cinfo, ptr, FALSE); 922 } 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. 926 */ 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 */ 932 } else { 933 undef_row = ptr->first_undef_row; 934 } 935 if (writable) 936 ptr->first_undef_row = end_row; 937 if (ptr->pre_zero) { 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); 943 undef_row++; 944 } 945 } else { 946 if (! writable) /* reader looking at undefined data */ 947 ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS); 948 } 949 } 950 /* Flag the buffer dirty if caller will write in it */ 951 if (writable) 952 ptr->dirty = TRUE; 953 /* Return address of proper part of the buffer */ 954 return ptr->mem_buffer + (start_row - ptr->cur_start_row); 955 } 956 957 958 /* 959 * Release all objects belonging to a specified pool. 960 */ 961 962 METHODDEF(void) 963 free_pool (j_common_ptr cinfo, int pool_id) 964 { 965 my_mem_ptr mem = (my_mem_ptr) cinfo->mem; 966 small_pool_ptr shdr_ptr; 967 large_pool_ptr lhdr_ptr; 968 size_t space_freed; 969 970 if (pool_id < 0 || pool_id >= JPOOL_NUMPOOLS) 971 ERREXIT1(cinfo, JERR_BAD_POOL_ID, pool_id); /* safety check */ 972 973 #ifdef MEM_STATS 974 if (cinfo->err->trace_level > 1) 975 print_mem_stats(cinfo, pool_id); /* print pool's memory usage statistics */ 976 #endif 977 978 /* 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; 982 983 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); 987 } 988 } 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); 994 } 995 } 996 mem->virt_barray_list = NULL; 997 } 998 999 /* Release large objects */ 1000 lhdr_ptr = mem->large_list[pool_id]; 1001 mem->large_list[pool_id] = NULL; 1002 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; 1011 } 1012 1013 /* Release small objects */ 1014 shdr_ptr = mem->small_list[pool_id]; 1015 mem->small_list[pool_id] = NULL; 1016 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; 1025 } 1026 } 1027 1028 1029 /* 1030 * Close up shop entirely. 1031 * Note that this cannot be called unless cinfo->mem is non-NULL. 1032 */ 1033 1034 METHODDEF(void) 1035 self_destruct (j_common_ptr cinfo) 1036 { 1037 int pool; 1038 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. 1042 */ 1043 for (pool = JPOOL_NUMPOOLS-1; pool >= JPOOL_PERMANENT; pool--) { 1044 free_pool(cinfo, pool); 1045 } 1046 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 */ 1050 1051 jpeg_mem_term(cinfo); /* system-dependent cleanup */ 1052 } 1053 1054 1055 /* 1056 * Memory manager initialization. 1057 * When this is called, only the error manager pointer is valid in cinfo! 1058 */ 1059 1060 GLOBAL(void) 1061 jinit_memory_mgr (j_common_ptr cinfo) 1062 { 1063 my_mem_ptr mem; 1064 long max_to_use; 1065 int pool; 1066 size_t test_mac; 1067 1068 cinfo->mem = NULL; /* for safety if init fails */ 1069 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. 1076 */ 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. 1083 */ 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); 1088 1089 max_to_use = jpeg_mem_init(cinfo); /* system-dependent initialization */ 1090 1091 /* Attempt to allocate memory manager's control block */ 1092 mem = (my_mem_ptr) jpeg_get_small(cinfo, SIZEOF(my_memory_mgr)); 1093 1094 if (mem == NULL) { 1095 jpeg_mem_term(cinfo); /* system-dependent cleanup */ 1096 ERREXIT1(cinfo, JERR_OUT_OF_MEMORY, 0); 1097 } 1098 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; 1111 1112 /* Make MAX_ALLOC_CHUNK accessible to other modules */ 1113 mem->pub.max_alloc_chunk = MAX_ALLOC_CHUNK; 1114 1115 /* Initialize working state */ 1116 mem->pub.max_memory_to_use = max_to_use; 1117 1118 for (pool = JPOOL_NUMPOOLS-1; pool >= JPOOL_PERMANENT; pool--) { 1119 mem->small_list[pool] = NULL; 1120 mem->large_list[pool] = NULL; 1121 } 1122 mem->virt_sarray_list = NULL; 1123 mem->virt_barray_list = NULL; 1124 1125 mem->total_space_allocated = SIZEOF(my_memory_mgr); 1126 1127 /* Declare ourselves open for business */ 1128 cinfo->mem = & mem->pub; 1129 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 1134 * this feature. 1135 */ 1136 #ifndef NO_GETENV 1137 { char * memenv; 1138 1139 if ((memenv = getenv("JPEGMEM")) != NULL) { 1140 char ch = 'x'; 1141 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; 1146 } 1147 } 1148 } 1149 #endif 1150 1151 } 1152
