1 /* 2 * jmemmgr.c 3 * 4 * This file was part of the Independent JPEG Group's software: 5 * Copyright (C) 1991-1997, Thomas G. Lane. 6 * libjpeg-turbo Modifications: 7 * Copyright (C) 2016, D. R. Commander. 8 * For conditions of distribution and use, see the accompanying README.ijg 9 * file. 10 * 11 * This file contains the JPEG system-independent memory management 12 * routines. This code is usable across a wide variety of machines; most 13 * of the system dependencies have been isolated in a separate file. 14 * The major functions provided here are: 15 * * pool-based allocation and freeing of memory; 16 * * policy decisions about how to divide available memory among the 17 * virtual arrays; 18 * * control logic for swapping virtual arrays between main memory and 19 * backing storage. 20 * The separate system-dependent file provides the actual backing-storage 21 * access code, and it contains the policy decision about how much total 22 * main memory to use. 23 * This file is system-dependent in the sense that some of its functions 24 * are unnecessary in some systems. For example, if there is enough virtual 25 * memory so that backing storage will never be used, much of the virtual 26 * array control logic could be removed. (Of course, if you have that much 27 * memory then you shouldn't care about a little bit of unused code...) 28 */ 29 30 #define JPEG_INTERNALS 31 #define AM_MEMORY_MANAGER /* we define jvirt_Xarray_control structs */ 32 #include "jinclude.h" 33 #include "jpeglib.h" 34 #include "jmemsys.h" /* import the system-dependent declarations */ 35 #ifndef _WIN32 36 #include <stdint.h> 37 #endif 38 #include <limits.h> 39 40 #ifndef NO_GETENV 41 #ifndef HAVE_STDLIB_H /* <stdlib.h> should declare getenv() */ 42 extern char *getenv (const char *name); 43 #endif 44 #endif 45 46 47 LOCAL(size_t) 48 round_up_pow2 (size_t a, size_t b) 49 /* a rounded up to the next multiple of b, i.e. ceil(a/b)*b */ 50 /* Assumes a >= 0, b > 0, and b is a power of 2 */ 51 { 52 return ((a + b - 1) & (~(b - 1))); 53 } 54 55 56 /* 57 * Some important notes: 58 * The allocation routines provided here must never return NULL. 59 * They should exit to error_exit if unsuccessful. 60 * 61 * It's not a good idea to try to merge the sarray and barray routines, 62 * even though they are textually almost the same, because samples are 63 * usually stored as bytes while coefficients are shorts or ints. Thus, 64 * in machines where byte pointers have a different representation from 65 * word pointers, the resulting machine code could not be the same. 66 */ 67 68 69 /* 70 * Many machines require storage alignment: longs must start on 4-byte 71 * boundaries, doubles on 8-byte boundaries, etc. On such machines, malloc() 72 * always returns pointers that are multiples of the worst-case alignment 73 * requirement, and we had better do so too. 74 * There isn't any really portable way to determine the worst-case alignment 75 * requirement. This module assumes that the alignment requirement is 76 * multiples of ALIGN_SIZE. 77 * By default, we define ALIGN_SIZE as sizeof(double). This is necessary on 78 * some workstations (where doubles really do need 8-byte alignment) and will 79 * work fine on nearly everything. If your machine has lesser alignment needs, 80 * you can save a few bytes by making ALIGN_SIZE smaller. 81 * The only place I know of where this will NOT work is certain Macintosh 82 * 680x0 compilers that define double as a 10-byte IEEE extended float. 83 * Doing 10-byte alignment is counterproductive because longwords won't be 84 * aligned well. Put "#define ALIGN_SIZE 4" in jconfig.h if you have 85 * such a compiler. 86 */ 87 88 #ifndef ALIGN_SIZE /* so can override from jconfig.h */ 89 #ifndef WITH_SIMD 90 #define ALIGN_SIZE sizeof(double) 91 #else 92 #define ALIGN_SIZE 16 /* Most SIMD implementations require this */ 93 #endif 94 #endif 95 96 /* 97 * We allocate objects from "pools", where each pool is gotten with a single 98 * request to jpeg_get_small() or jpeg_get_large(). There is no per-object 99 * overhead within a pool, except for alignment padding. Each pool has a 100 * header with a link to the next pool of the same class. 101 * Small and large pool headers are identical. 102 */ 103 104 typedef struct small_pool_struct *small_pool_ptr; 105 106 typedef struct small_pool_struct { 107 small_pool_ptr next; /* next in list of pools */ 108 size_t bytes_used; /* how many bytes already used within pool */ 109 size_t bytes_left; /* bytes still available in this pool */ 110 } small_pool_hdr; 111 112 typedef struct large_pool_struct *large_pool_ptr; 113 114 typedef struct large_pool_struct { 115 large_pool_ptr next; /* next in list of pools */ 116 size_t bytes_used; /* how many bytes already used within pool */ 117 size_t bytes_left; /* bytes still available in this pool */ 118 } large_pool_hdr; 119 120 /* 121 * Here is the full definition of a memory manager object. 122 */ 123 124 typedef struct { 125 struct jpeg_memory_mgr pub; /* public fields */ 126 127 /* Each pool identifier (lifetime class) names a linked list of pools. */ 128 small_pool_ptr small_list[JPOOL_NUMPOOLS]; 129 large_pool_ptr large_list[JPOOL_NUMPOOLS]; 130 131 /* Since we only have one lifetime class of virtual arrays, only one 132 * linked list is necessary (for each datatype). Note that the virtual 133 * array control blocks being linked together are actually stored somewhere 134 * in the small-pool list. 135 */ 136 jvirt_sarray_ptr virt_sarray_list; 137 jvirt_barray_ptr virt_barray_list; 138 139 /* This counts total space obtained from jpeg_get_small/large */ 140 size_t total_space_allocated; 141 142 /* alloc_sarray and alloc_barray set this value for use by virtual 143 * array routines. 144 */ 145 JDIMENSION last_rowsperchunk; /* from most recent alloc_sarray/barray */ 146 } my_memory_mgr; 147 148 typedef my_memory_mgr *my_mem_ptr; 149 150 151 /* 152 * The control blocks for virtual arrays. 153 * Note that these blocks are allocated in the "small" pool area. 154 * System-dependent info for the associated backing store (if any) is hidden 155 * inside the backing_store_info struct. 156 */ 157 158 struct jvirt_sarray_control { 159 JSAMPARRAY mem_buffer; /* => the in-memory buffer */ 160 JDIMENSION rows_in_array; /* total virtual array height */ 161 JDIMENSION samplesperrow; /* width of array (and of memory buffer) */ 162 JDIMENSION maxaccess; /* max rows accessed by access_virt_sarray */ 163 JDIMENSION rows_in_mem; /* height of memory buffer */ 164 JDIMENSION rowsperchunk; /* allocation chunk size in mem_buffer */ 165 JDIMENSION cur_start_row; /* first logical row # in the buffer */ 166 JDIMENSION first_undef_row; /* row # of first uninitialized row */ 167 boolean pre_zero; /* pre-zero mode requested? */ 168 boolean dirty; /* do current buffer contents need written? */ 169 boolean b_s_open; /* is backing-store data valid? */ 170 jvirt_sarray_ptr next; /* link to next virtual sarray control block */ 171 backing_store_info b_s_info; /* System-dependent control info */ 172 }; 173 174 struct jvirt_barray_control { 175 JBLOCKARRAY mem_buffer; /* => the in-memory buffer */ 176 JDIMENSION rows_in_array; /* total virtual array height */ 177 JDIMENSION blocksperrow; /* width of array (and of memory buffer) */ 178 JDIMENSION maxaccess; /* max rows accessed by access_virt_barray */ 179 JDIMENSION rows_in_mem; /* height of memory buffer */ 180 JDIMENSION rowsperchunk; /* allocation chunk size in mem_buffer */ 181 JDIMENSION cur_start_row; /* first logical row # in the buffer */ 182 JDIMENSION first_undef_row; /* row # of first uninitialized row */ 183 boolean pre_zero; /* pre-zero mode requested? */ 184 boolean dirty; /* do current buffer contents need written? */ 185 boolean b_s_open; /* is backing-store data valid? */ 186 jvirt_barray_ptr next; /* link to next virtual barray control block */ 187 backing_store_info b_s_info; /* System-dependent control info */ 188 }; 189 190 191 #ifdef MEM_STATS /* optional extra stuff for statistics */ 192 193 LOCAL(void) 194 print_mem_stats (j_common_ptr cinfo, int pool_id) 195 { 196 my_mem_ptr mem = (my_mem_ptr) cinfo->mem; 197 small_pool_ptr shdr_ptr; 198 large_pool_ptr lhdr_ptr; 199 200 /* Since this is only a debugging stub, we can cheat a little by using 201 * fprintf directly rather than going through the trace message code. 202 * This is helpful because message parm array can't handle longs. 203 */ 204 fprintf(stderr, "Freeing pool %d, total space = %ld\n", 205 pool_id, mem->total_space_allocated); 206 207 for (lhdr_ptr = mem->large_list[pool_id]; lhdr_ptr != NULL; 208 lhdr_ptr = lhdr_ptr->next) { 209 fprintf(stderr, " Large chunk used %ld\n", 210 (long) lhdr_ptr->bytes_used); 211 } 212 213 for (shdr_ptr = mem->small_list[pool_id]; shdr_ptr != NULL; 214 shdr_ptr = shdr_ptr->next) { 215 fprintf(stderr, " Small chunk used %ld free %ld\n", 216 (long) shdr_ptr->bytes_used, 217 (long) shdr_ptr->bytes_left); 218 } 219 } 220 221 #endif /* MEM_STATS */ 222 223 224 LOCAL(void) 225 out_of_memory (j_common_ptr cinfo, int which) 226 /* Report an out-of-memory error and stop execution */ 227 /* If we compiled MEM_STATS support, report alloc requests before dying */ 228 { 229 #ifdef MEM_STATS 230 cinfo->err->trace_level = 2; /* force self_destruct to report stats */ 231 #endif 232 ERREXIT1(cinfo, JERR_OUT_OF_MEMORY, which); 233 } 234 235 236 /* 237 * Allocation of "small" objects. 238 * 239 * For these, we use pooled storage. When a new pool must be created, 240 * we try to get enough space for the current request plus a "slop" factor, 241 * where the slop will be the amount of leftover space in the new pool. 242 * The speed vs. space tradeoff is largely determined by the slop values. 243 * A different slop value is provided for each pool class (lifetime), 244 * and we also distinguish the first pool of a class from later ones. 245 * NOTE: the values given work fairly well on both 16- and 32-bit-int 246 * machines, but may be too small if longs are 64 bits or more. 247 * 248 * Since we do not know what alignment malloc() gives us, we have to 249 * allocate ALIGN_SIZE-1 extra space per pool to have room for alignment 250 * adjustment. 251 */ 252 253 static const size_t first_pool_slop[JPOOL_NUMPOOLS] = 254 { 255 1600, /* first PERMANENT pool */ 256 16000 /* first IMAGE pool */ 257 }; 258 259 static const size_t extra_pool_slop[JPOOL_NUMPOOLS] = 260 { 261 0, /* additional PERMANENT pools */ 262 5000 /* additional IMAGE pools */ 263 }; 264 265 #define MIN_SLOP 50 /* greater than 0 to avoid futile looping */ 266 267 268 METHODDEF(void *) 269 alloc_small (j_common_ptr cinfo, int pool_id, size_t sizeofobject) 270 /* Allocate a "small" object */ 271 { 272 my_mem_ptr mem = (my_mem_ptr) cinfo->mem; 273 small_pool_ptr hdr_ptr, prev_hdr_ptr; 274 char *data_ptr; 275 size_t min_request, slop; 276 277 /* 278 * Round up the requested size to a multiple of ALIGN_SIZE in order 279 * to assure alignment for the next object allocated in the same pool 280 * and so that algorithms can straddle outside the proper area up 281 * to the next alignment. 282 */ 283 if (sizeofobject > MAX_ALLOC_CHUNK) { 284 /* This prevents overflow/wrap-around in round_up_pow2() if sizeofobject 285 is close to SIZE_MAX. */ 286 out_of_memory(cinfo, 7); 287 } 288 sizeofobject = round_up_pow2(sizeofobject, ALIGN_SIZE); 289 290 /* Check for unsatisfiable request (do now to ensure no overflow below) */ 291 if ((sizeof(small_pool_hdr) + sizeofobject + ALIGN_SIZE - 1) > 292 MAX_ALLOC_CHUNK) 293 out_of_memory(cinfo, 1); /* request exceeds malloc's ability */ 294 295 /* See if space is available in any existing pool */ 296 if (pool_id < 0 || pool_id >= JPOOL_NUMPOOLS) 297 ERREXIT1(cinfo, JERR_BAD_POOL_ID, pool_id); /* safety check */ 298 prev_hdr_ptr = NULL; 299 hdr_ptr = mem->small_list[pool_id]; 300 while (hdr_ptr != NULL) { 301 if (hdr_ptr->bytes_left >= sizeofobject) 302 break; /* found pool with enough space */ 303 prev_hdr_ptr = hdr_ptr; 304 hdr_ptr = hdr_ptr->next; 305 } 306 307 /* Time to make a new pool? */ 308 if (hdr_ptr == NULL) { 309 /* min_request is what we need now, slop is what will be leftover */ 310 min_request = sizeof(small_pool_hdr) + sizeofobject + ALIGN_SIZE - 1; 311 if (prev_hdr_ptr == NULL) /* first pool in class? */ 312 slop = first_pool_slop[pool_id]; 313 else 314 slop = extra_pool_slop[pool_id]; 315 /* Don't ask for more than MAX_ALLOC_CHUNK */ 316 if (slop > (size_t) (MAX_ALLOC_CHUNK-min_request)) 317 slop = (size_t) (MAX_ALLOC_CHUNK-min_request); 318 /* Try to get space, if fail reduce slop and try again */ 319 for (;;) { 320 hdr_ptr = (small_pool_ptr) jpeg_get_small(cinfo, min_request + slop); 321 if (hdr_ptr != NULL) 322 break; 323 slop /= 2; 324 if (slop < MIN_SLOP) /* give up when it gets real small */ 325 out_of_memory(cinfo, 2); /* jpeg_get_small failed */ 326 } 327 mem->total_space_allocated += min_request + slop; 328 /* Success, initialize the new pool header and add to end of list */ 329 hdr_ptr->next = NULL; 330 hdr_ptr->bytes_used = 0; 331 hdr_ptr->bytes_left = sizeofobject + slop; 332 if (prev_hdr_ptr == NULL) /* first pool in class? */ 333 mem->small_list[pool_id] = hdr_ptr; 334 else 335 prev_hdr_ptr->next = hdr_ptr; 336 } 337 338 /* OK, allocate the object from the current pool */ 339 data_ptr = (char *) hdr_ptr; /* point to first data byte in pool... */ 340 data_ptr += sizeof(small_pool_hdr); /* ...by skipping the header... */ 341 if ((size_t)data_ptr % ALIGN_SIZE) /* ...and adjust for alignment */ 342 data_ptr += ALIGN_SIZE - (size_t)data_ptr % ALIGN_SIZE; 343 data_ptr += hdr_ptr->bytes_used; /* point to place for object */ 344 hdr_ptr->bytes_used += sizeofobject; 345 hdr_ptr->bytes_left -= sizeofobject; 346 347 return (void *) data_ptr; 348 } 349 350 351 /* 352 * Allocation of "large" objects. 353 * 354 * The external semantics of these are the same as "small" objects. However, 355 * the pool management heuristics are quite different. We assume that each 356 * request is large enough that it may as well be passed directly to 357 * jpeg_get_large; the pool management just links everything together 358 * so that we can free it all on demand. 359 * Note: the major use of "large" objects is in JSAMPARRAY and JBLOCKARRAY 360 * structures. The routines that create these structures (see below) 361 * deliberately bunch rows together to ensure a large request size. 362 */ 363 364 METHODDEF(void *) 365 alloc_large (j_common_ptr cinfo, int pool_id, size_t sizeofobject) 366 /* Allocate a "large" object */ 367 { 368 my_mem_ptr mem = (my_mem_ptr) cinfo->mem; 369 large_pool_ptr hdr_ptr; 370 char *data_ptr; 371 372 /* 373 * Round up the requested size to a multiple of ALIGN_SIZE so that 374 * algorithms can straddle outside the proper area up to the next 375 * alignment. 376 */ 377 if (sizeofobject > MAX_ALLOC_CHUNK) { 378 /* This prevents overflow/wrap-around in round_up_pow2() if sizeofobject 379 is close to SIZE_MAX. */ 380 out_of_memory(cinfo, 8); 381 } 382 sizeofobject = round_up_pow2(sizeofobject, ALIGN_SIZE); 383 384 /* Check for unsatisfiable request (do now to ensure no overflow below) */ 385 if ((sizeof(large_pool_hdr) + sizeofobject + ALIGN_SIZE - 1) > 386 MAX_ALLOC_CHUNK) 387 out_of_memory(cinfo, 3); /* request exceeds malloc's ability */ 388 389 /* Always make a new pool */ 390 if (pool_id < 0 || pool_id >= JPOOL_NUMPOOLS) 391 ERREXIT1(cinfo, JERR_BAD_POOL_ID, pool_id); /* safety check */ 392 393 hdr_ptr = (large_pool_ptr) jpeg_get_large(cinfo, sizeofobject + 394 sizeof(large_pool_hdr) + 395 ALIGN_SIZE - 1); 396 if (hdr_ptr == NULL) 397 out_of_memory(cinfo, 4); /* jpeg_get_large failed */ 398 mem->total_space_allocated += sizeofobject + sizeof(large_pool_hdr) + 399 ALIGN_SIZE - 1; 400 401 /* Success, initialize the new pool header and add to list */ 402 hdr_ptr->next = mem->large_list[pool_id]; 403 /* We maintain space counts in each pool header for statistical purposes, 404 * even though they are not needed for allocation. 405 */ 406 hdr_ptr->bytes_used = sizeofobject; 407 hdr_ptr->bytes_left = 0; 408 mem->large_list[pool_id] = hdr_ptr; 409 410 data_ptr = (char *) hdr_ptr; /* point to first data byte in pool... */ 411 data_ptr += sizeof(small_pool_hdr); /* ...by skipping the header... */ 412 if ((size_t)data_ptr % ALIGN_SIZE) /* ...and adjust for alignment */ 413 data_ptr += ALIGN_SIZE - (size_t)data_ptr % ALIGN_SIZE; 414 415 return (void *) data_ptr; 416 } 417 418 419 /* 420 * Creation of 2-D sample arrays. 421 * 422 * To minimize allocation overhead and to allow I/O of large contiguous 423 * blocks, we allocate the sample rows in groups of as many rows as possible 424 * without exceeding MAX_ALLOC_CHUNK total bytes per allocation request. 425 * NB: the virtual array control routines, later in this file, know about 426 * this chunking of rows. The rowsperchunk value is left in the mem manager 427 * object so that it can be saved away if this sarray is the workspace for 428 * a virtual array. 429 * 430 * Since we are often upsampling with a factor 2, we align the size (not 431 * the start) to 2 * ALIGN_SIZE so that the upsampling routines don't have 432 * to be as careful about size. 433 */ 434 435 METHODDEF(JSAMPARRAY) 436 alloc_sarray (j_common_ptr cinfo, int pool_id, 437 JDIMENSION samplesperrow, JDIMENSION numrows) 438 /* Allocate a 2-D sample array */ 439 { 440 my_mem_ptr mem = (my_mem_ptr) cinfo->mem; 441 JSAMPARRAY result; 442 JSAMPROW workspace; 443 JDIMENSION rowsperchunk, currow, i; 444 long ltemp; 445 446 /* Make sure each row is properly aligned */ 447 if ((ALIGN_SIZE % sizeof(JSAMPLE)) != 0) 448 out_of_memory(cinfo, 5); /* safety check */ 449 450 if (samplesperrow > MAX_ALLOC_CHUNK) { 451 /* This prevents overflow/wrap-around in round_up_pow2() if sizeofobject 452 is close to SIZE_MAX. */ 453 out_of_memory(cinfo, 9); 454 } 455 samplesperrow = (JDIMENSION)round_up_pow2(samplesperrow, (2 * ALIGN_SIZE) / 456 sizeof(JSAMPLE)); 457 458 /* Calculate max # of rows allowed in one allocation chunk */ 459 ltemp = (MAX_ALLOC_CHUNK-sizeof(large_pool_hdr)) / 460 ((long) samplesperrow * sizeof(JSAMPLE)); 461 if (ltemp <= 0) 462 ERREXIT(cinfo, JERR_WIDTH_OVERFLOW); 463 if (ltemp < (long) numrows) 464 rowsperchunk = (JDIMENSION) ltemp; 465 else 466 rowsperchunk = numrows; 467 mem->last_rowsperchunk = rowsperchunk; 468 469 /* Get space for row pointers (small object) */ 470 result = (JSAMPARRAY) alloc_small(cinfo, pool_id, 471 (size_t) (numrows * sizeof(JSAMPROW))); 472 473 /* Get the rows themselves (large objects) */ 474 currow = 0; 475 while (currow < numrows) { 476 rowsperchunk = MIN(rowsperchunk, numrows - currow); 477 workspace = (JSAMPROW) alloc_large(cinfo, pool_id, 478 (size_t) ((size_t) rowsperchunk * (size_t) samplesperrow 479 * sizeof(JSAMPLE))); 480 for (i = rowsperchunk; i > 0; i--) { 481 result[currow++] = workspace; 482 workspace += samplesperrow; 483 } 484 } 485 486 return result; 487 } 488 489 490 /* 491 * Creation of 2-D coefficient-block arrays. 492 * This is essentially the same as the code for sample arrays, above. 493 */ 494 495 METHODDEF(JBLOCKARRAY) 496 alloc_barray (j_common_ptr cinfo, int pool_id, 497 JDIMENSION blocksperrow, JDIMENSION numrows) 498 /* Allocate a 2-D coefficient-block array */ 499 { 500 my_mem_ptr mem = (my_mem_ptr) cinfo->mem; 501 JBLOCKARRAY result; 502 JBLOCKROW workspace; 503 JDIMENSION rowsperchunk, currow, i; 504 long ltemp; 505 506 /* Make sure each row is properly aligned */ 507 if ((sizeof(JBLOCK) % ALIGN_SIZE) != 0) 508 out_of_memory(cinfo, 6); /* safety check */ 509 510 /* Calculate max # of rows allowed in one allocation chunk */ 511 ltemp = (MAX_ALLOC_CHUNK-sizeof(large_pool_hdr)) / 512 ((long) blocksperrow * sizeof(JBLOCK)); 513 if (ltemp <= 0) 514 ERREXIT(cinfo, JERR_WIDTH_OVERFLOW); 515 if (ltemp < (long) numrows) 516 rowsperchunk = (JDIMENSION) ltemp; 517 else 518 rowsperchunk = numrows; 519 mem->last_rowsperchunk = rowsperchunk; 520 521 /* Get space for row pointers (small object) */ 522 result = (JBLOCKARRAY) alloc_small(cinfo, pool_id, 523 (size_t) (numrows * sizeof(JBLOCKROW))); 524 525 /* Get the rows themselves (large objects) */ 526 currow = 0; 527 while (currow < numrows) { 528 rowsperchunk = MIN(rowsperchunk, numrows - currow); 529 workspace = (JBLOCKROW) alloc_large(cinfo, pool_id, 530 (size_t) ((size_t) rowsperchunk * (size_t) blocksperrow 531 * sizeof(JBLOCK))); 532 for (i = rowsperchunk; i > 0; i--) { 533 result[currow++] = workspace; 534 workspace += blocksperrow; 535 } 536 } 537 538 return result; 539 } 540 541 542 /* 543 * About virtual array management: 544 * 545 * The above "normal" array routines are only used to allocate strip buffers 546 * (as wide as the image, but just a few rows high). Full-image-sized buffers 547 * are handled as "virtual" arrays. The array is still accessed a strip at a 548 * time, but the memory manager must save the whole array for repeated 549 * accesses. The intended implementation is that there is a strip buffer in 550 * memory (as high as is possible given the desired memory limit), plus a 551 * backing file that holds the rest of the array. 552 * 553 * The request_virt_array routines are told the total size of the image and 554 * the maximum number of rows that will be accessed at once. The in-memory 555 * buffer must be at least as large as the maxaccess value. 556 * 557 * The request routines create control blocks but not the in-memory buffers. 558 * That is postponed until realize_virt_arrays is called. At that time the 559 * total amount of space needed is known (approximately, anyway), so free 560 * memory can be divided up fairly. 561 * 562 * The access_virt_array routines are responsible for making a specific strip 563 * area accessible (after reading or writing the backing file, if necessary). 564 * Note that the access routines are told whether the caller intends to modify 565 * the accessed strip; during a read-only pass this saves having to rewrite 566 * data to disk. The access routines are also responsible for pre-zeroing 567 * any newly accessed rows, if pre-zeroing was requested. 568 * 569 * In current usage, the access requests are usually for nonoverlapping 570 * strips; that is, successive access start_row numbers differ by exactly 571 * num_rows = maxaccess. This means we can get good performance with simple 572 * buffer dump/reload logic, by making the in-memory buffer be a multiple 573 * of the access height; then there will never be accesses across bufferload 574 * boundaries. The code will still work with overlapping access requests, 575 * but it doesn't handle bufferload overlaps very efficiently. 576 */ 577 578 579 METHODDEF(jvirt_sarray_ptr) 580 request_virt_sarray (j_common_ptr cinfo, int pool_id, boolean pre_zero, 581 JDIMENSION samplesperrow, JDIMENSION numrows, 582 JDIMENSION maxaccess) 583 /* Request a virtual 2-D sample array */ 584 { 585 my_mem_ptr mem = (my_mem_ptr) cinfo->mem; 586 jvirt_sarray_ptr result; 587 588 /* Only IMAGE-lifetime virtual arrays are currently supported */ 589 if (pool_id != JPOOL_IMAGE) 590 ERREXIT1(cinfo, JERR_BAD_POOL_ID, pool_id); /* safety check */ 591 592 /* get control block */ 593 result = (jvirt_sarray_ptr) alloc_small(cinfo, pool_id, 594 sizeof(struct jvirt_sarray_control)); 595 596 result->mem_buffer = NULL; /* marks array not yet realized */ 597 result->rows_in_array = numrows; 598 result->samplesperrow = samplesperrow; 599 result->maxaccess = maxaccess; 600 result->pre_zero = pre_zero; 601 result->b_s_open = FALSE; /* no associated backing-store object */ 602 result->next = mem->virt_sarray_list; /* add to list of virtual arrays */ 603 mem->virt_sarray_list = result; 604 605 return result; 606 } 607 608 609 METHODDEF(jvirt_barray_ptr) 610 request_virt_barray (j_common_ptr cinfo, int pool_id, boolean pre_zero, 611 JDIMENSION blocksperrow, JDIMENSION numrows, 612 JDIMENSION maxaccess) 613 /* Request a virtual 2-D coefficient-block array */ 614 { 615 my_mem_ptr mem = (my_mem_ptr) cinfo->mem; 616 jvirt_barray_ptr result; 617 618 /* Only IMAGE-lifetime virtual arrays are currently supported */ 619 if (pool_id != JPOOL_IMAGE) 620 ERREXIT1(cinfo, JERR_BAD_POOL_ID, pool_id); /* safety check */ 621 622 /* get control block */ 623 result = (jvirt_barray_ptr) alloc_small(cinfo, pool_id, 624 sizeof(struct jvirt_barray_control)); 625 626 result->mem_buffer = NULL; /* marks array not yet realized */ 627 result->rows_in_array = numrows; 628 result->blocksperrow = blocksperrow; 629 result->maxaccess = maxaccess; 630 result->pre_zero = pre_zero; 631 result->b_s_open = FALSE; /* no associated backing-store object */ 632 result->next = mem->virt_barray_list; /* add to list of virtual arrays */ 633 mem->virt_barray_list = result; 634 635 return result; 636 } 637 638 639 METHODDEF(void) 640 realize_virt_arrays (j_common_ptr cinfo) 641 /* Allocate the in-memory buffers for any unrealized virtual arrays */ 642 { 643 my_mem_ptr mem = (my_mem_ptr) cinfo->mem; 644 size_t space_per_minheight, maximum_space, avail_mem; 645 size_t minheights, max_minheights; 646 jvirt_sarray_ptr sptr; 647 jvirt_barray_ptr bptr; 648 649 /* Compute the minimum space needed (maxaccess rows in each buffer) 650 * and the maximum space needed (full image height in each buffer). 651 * These may be of use to the system-dependent jpeg_mem_available routine. 652 */ 653 space_per_minheight = 0; 654 maximum_space = 0; 655 for (sptr = mem->virt_sarray_list; sptr != NULL; sptr = sptr->next) { 656 if (sptr->mem_buffer == NULL) { /* if not realized yet */ 657 size_t new_space = (long) sptr->rows_in_array * 658 (long) sptr->samplesperrow * sizeof(JSAMPLE); 659 660 space_per_minheight += (long) sptr->maxaccess * 661 (long) sptr->samplesperrow * sizeof(JSAMPLE); 662 if (SIZE_MAX - maximum_space < new_space) 663 out_of_memory(cinfo, 10); 664 maximum_space += new_space; 665 } 666 } 667 for (bptr = mem->virt_barray_list; bptr != NULL; bptr = bptr->next) { 668 if (bptr->mem_buffer == NULL) { /* if not realized yet */ 669 size_t new_space = (long) bptr->rows_in_array * 670 (long) bptr->blocksperrow * sizeof(JBLOCK); 671 672 space_per_minheight += (long) bptr->maxaccess * 673 (long) bptr->blocksperrow * sizeof(JBLOCK); 674 if (SIZE_MAX - maximum_space < new_space) 675 out_of_memory(cinfo, 11); 676 maximum_space += new_space; 677 } 678 } 679 680 if (space_per_minheight <= 0) 681 return; /* no unrealized arrays, no work */ 682 683 /* Determine amount of memory to actually use; this is system-dependent. */ 684 avail_mem = jpeg_mem_available(cinfo, space_per_minheight, maximum_space, 685 mem->total_space_allocated); 686 687 /* If the maximum space needed is available, make all the buffers full 688 * height; otherwise parcel it out with the same number of minheights 689 * in each buffer. 690 */ 691 if (avail_mem >= maximum_space) 692 max_minheights = 1000000000L; 693 else { 694 max_minheights = avail_mem / space_per_minheight; 695 /* If there doesn't seem to be enough space, try to get the minimum 696 * anyway. This allows a "stub" implementation of jpeg_mem_available(). 697 */ 698 if (max_minheights <= 0) 699 max_minheights = 1; 700 } 701 702 /* Allocate the in-memory buffers and initialize backing store as needed. */ 703 704 for (sptr = mem->virt_sarray_list; sptr != NULL; sptr = sptr->next) { 705 if (sptr->mem_buffer == NULL) { /* if not realized yet */ 706 minheights = ((long) sptr->rows_in_array - 1L) / sptr->maxaccess + 1L; 707 if (minheights <= max_minheights) { 708 /* This buffer fits in memory */ 709 sptr->rows_in_mem = sptr->rows_in_array; 710 } else { 711 /* It doesn't fit in memory, create backing store. */ 712 sptr->rows_in_mem = (JDIMENSION) (max_minheights * sptr->maxaccess); 713 jpeg_open_backing_store(cinfo, & sptr->b_s_info, 714 (long) sptr->rows_in_array * 715 (long) sptr->samplesperrow * 716 (long) sizeof(JSAMPLE)); 717 sptr->b_s_open = TRUE; 718 } 719 sptr->mem_buffer = alloc_sarray(cinfo, JPOOL_IMAGE, 720 sptr->samplesperrow, sptr->rows_in_mem); 721 sptr->rowsperchunk = mem->last_rowsperchunk; 722 sptr->cur_start_row = 0; 723 sptr->first_undef_row = 0; 724 sptr->dirty = FALSE; 725 } 726 } 727 728 for (bptr = mem->virt_barray_list; bptr != NULL; bptr = bptr->next) { 729 if (bptr->mem_buffer == NULL) { /* if not realized yet */ 730 minheights = ((long) bptr->rows_in_array - 1L) / bptr->maxaccess + 1L; 731 if (minheights <= max_minheights) { 732 /* This buffer fits in memory */ 733 bptr->rows_in_mem = bptr->rows_in_array; 734 } else { 735 /* It doesn't fit in memory, create backing store. */ 736 bptr->rows_in_mem = (JDIMENSION) (max_minheights * bptr->maxaccess); 737 jpeg_open_backing_store(cinfo, & bptr->b_s_info, 738 (long) bptr->rows_in_array * 739 (long) bptr->blocksperrow * 740 (long) sizeof(JBLOCK)); 741 bptr->b_s_open = TRUE; 742 } 743 bptr->mem_buffer = alloc_barray(cinfo, JPOOL_IMAGE, 744 bptr->blocksperrow, bptr->rows_in_mem); 745 bptr->rowsperchunk = mem->last_rowsperchunk; 746 bptr->cur_start_row = 0; 747 bptr->first_undef_row = 0; 748 bptr->dirty = FALSE; 749 } 750 } 751 } 752 753 754 LOCAL(void) 755 do_sarray_io (j_common_ptr cinfo, jvirt_sarray_ptr ptr, boolean writing) 756 /* Do backing store read or write of a virtual sample array */ 757 { 758 long bytesperrow, file_offset, byte_count, rows, thisrow, i; 759 760 bytesperrow = (long) ptr->samplesperrow * sizeof(JSAMPLE); 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! */ 772 break; 773 byte_count = rows * bytesperrow; 774 if (writing) 775 (*ptr->b_s_info.write_backing_store) (cinfo, & ptr->b_s_info, 776 (void *) ptr->mem_buffer[i], 777 file_offset, byte_count); 778 else 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; 783 } 784 } 785 786 787 LOCAL(void) 788 do_barray_io (j_common_ptr cinfo, jvirt_barray_ptr ptr, boolean writing) 789 /* Do backing store read or write of a virtual coefficient-block array */ 790 { 791 long bytesperrow, file_offset, byte_count, rows, thisrow, i; 792 793 bytesperrow = (long) ptr->blocksperrow * sizeof(JBLOCK); 794 file_offset = ptr->cur_start_row * bytesperrow; 795 /* Loop to read or write each allocation chunk in mem_buffer */ 796 for (i = 0; i < (long) ptr->rows_in_mem; i += ptr->rowsperchunk) { 797 /* One chunk, but check for short chunk at end of buffer */ 798 rows = MIN((long) ptr->rowsperchunk, (long) ptr->rows_in_mem - i); 799 /* Transfer no more than is currently defined */ 800 thisrow = (long) ptr->cur_start_row + i; 801 rows = MIN(rows, (long) ptr->first_undef_row - thisrow); 802 /* Transfer no more than fits in file */ 803 rows = MIN(rows, (long) ptr->rows_in_array - thisrow); 804 if (rows <= 0) /* this chunk might be past end of file! */ 805 break; 806 byte_count = rows * bytesperrow; 807 if (writing) 808 (*ptr->b_s_info.write_backing_store) (cinfo, & ptr->b_s_info, 809 (void *) ptr->mem_buffer[i], 810 file_offset, byte_count); 811 else 812 (*ptr->b_s_info.read_backing_store) (cinfo, & ptr->b_s_info, 813 (void *) ptr->mem_buffer[i], 814 file_offset, byte_count); 815 file_offset += byte_count; 816 } 817 } 818 819 820 METHODDEF(JSAMPARRAY) 821 access_virt_sarray (j_common_ptr cinfo, jvirt_sarray_ptr ptr, 822 JDIMENSION start_row, JDIMENSION num_rows, 823 boolean writable) 824 /* Access the part of a virtual sample array starting at start_row */ 825 /* and extending for num_rows rows. writable is true if */ 826 /* caller intends to modify the accessed area. */ 827 { 828 JDIMENSION end_row = start_row + num_rows; 829 JDIMENSION undef_row; 830 831 /* debugging check */ 832 if (end_row > ptr->rows_in_array || num_rows > ptr->maxaccess || 833 ptr->mem_buffer == NULL) 834 ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS); 835 836 /* Make the desired part of the virtual array accessible */ 837 if (start_row < ptr->cur_start_row || 838 end_row > ptr->cur_start_row+ptr->rows_in_mem) { 839 if (! ptr->b_s_open) 840 ERREXIT(cinfo, JERR_VIRTUAL_BUG); 841 /* Flush old buffer contents if necessary */ 842 if (ptr->dirty) { 843 do_sarray_io(cinfo, ptr, TRUE); 844 ptr->dirty = FALSE; 845 } 846 /* Decide what part of virtual array to access. 847 * Algorithm: if target address > current window, assume forward scan, 848 * load starting at target address. If target address < current window, 849 * assume backward scan, load so that target area is top of window. 850 * Note that when switching from forward write to forward read, will have 851 * start_row = 0, so the limiting case applies and we load from 0 anyway. 852 */ 853 if (start_row > ptr->cur_start_row) { 854 ptr->cur_start_row = start_row; 855 } else { 856 /* use long arithmetic here to avoid overflow & unsigned problems */ 857 long ltemp; 858 859 ltemp = (long) end_row - (long) ptr->rows_in_mem; 860 if (ltemp < 0) 861 ltemp = 0; /* don't fall off front end of file */ 862 ptr->cur_start_row = (JDIMENSION) ltemp; 863 } 864 /* Read in the selected part of the array. 865 * During the initial write pass, we will do no actual read 866 * because the selected part is all undefined. 867 */ 868 do_sarray_io(cinfo, ptr, FALSE); 869 } 870 /* Ensure the accessed part of the array is defined; prezero if needed. 871 * To improve locality of access, we only prezero the part of the array 872 * that the caller is about to access, not the entire in-memory array. 873 */ 874 if (ptr->first_undef_row < end_row) { 875 if (ptr->first_undef_row < start_row) { 876 if (writable) /* writer skipped over a section of array */ 877 ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS); 878 undef_row = start_row; /* but reader is allowed to read ahead */ 879 } else { 880 undef_row = ptr->first_undef_row; 881 } 882 if (writable) 883 ptr->first_undef_row = end_row; 884 if (ptr->pre_zero) { 885 size_t bytesperrow = (size_t) ptr->samplesperrow * sizeof(JSAMPLE); 886 undef_row -= ptr->cur_start_row; /* make indexes relative to buffer */ 887 end_row -= ptr->cur_start_row; 888 while (undef_row < end_row) { 889 jzero_far((void *) ptr->mem_buffer[undef_row], bytesperrow); 890 undef_row++; 891 } 892 } else { 893 if (! writable) /* reader looking at undefined data */ 894 ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS); 895 } 896 } 897 /* Flag the buffer dirty if caller will write in it */ 898 if (writable) 899 ptr->dirty = TRUE; 900 /* Return address of proper part of the buffer */ 901 return ptr->mem_buffer + (start_row - ptr->cur_start_row); 902 } 903 904 905 METHODDEF(JBLOCKARRAY) 906 access_virt_barray (j_common_ptr cinfo, jvirt_barray_ptr ptr, 907 JDIMENSION start_row, JDIMENSION num_rows, 908 boolean writable) 909 /* Access the part of a virtual block array starting at start_row */ 910 /* and extending for num_rows rows. writable is true if */ 911 /* caller intends to modify the accessed area. */ 912 { 913 JDIMENSION end_row = start_row + num_rows; 914 JDIMENSION undef_row; 915 916 /* debugging check */ 917 if (end_row > ptr->rows_in_array || num_rows > ptr->maxaccess || 918 ptr->mem_buffer == NULL) 919 ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS); 920 921 /* Make the desired part of the virtual array accessible */ 922 if (start_row < ptr->cur_start_row || 923 end_row > ptr->cur_start_row+ptr->rows_in_mem) { 924 if (! ptr->b_s_open) 925 ERREXIT(cinfo, JERR_VIRTUAL_BUG); 926 /* Flush old buffer contents if necessary */ 927 if (ptr->dirty) { 928 do_barray_io(cinfo, ptr, TRUE); 929 ptr->dirty = FALSE; 930 } 931 /* Decide what part of virtual array to access. 932 * Algorithm: if target address > current window, assume forward scan, 933 * load starting at target address. If target address < current window, 934 * assume backward scan, load so that target area is top of window. 935 * Note that when switching from forward write to forward read, will have 936 * start_row = 0, so the limiting case applies and we load from 0 anyway. 937 */ 938 if (start_row > ptr->cur_start_row) { 939 ptr->cur_start_row = start_row; 940 } else { 941 /* use long arithmetic here to avoid overflow & unsigned problems */ 942 long ltemp; 943 944 ltemp = (long) end_row - (long) ptr->rows_in_mem; 945 if (ltemp < 0) 946 ltemp = 0; /* don't fall off front end of file */ 947 ptr->cur_start_row = (JDIMENSION) ltemp; 948 } 949 /* Read in the selected part of the array. 950 * During the initial write pass, we will do no actual read 951 * because the selected part is all undefined. 952 */ 953 do_barray_io(cinfo, ptr, FALSE); 954 } 955 /* Ensure the accessed part of the array is defined; prezero if needed. 956 * To improve locality of access, we only prezero the part of the array 957 * that the caller is about to access, not the entire in-memory array. 958 */ 959 if (ptr->first_undef_row < end_row) { 960 if (ptr->first_undef_row < start_row) { 961 if (writable) /* writer skipped over a section of array */ 962 ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS); 963 undef_row = start_row; /* but reader is allowed to read ahead */ 964 } else { 965 undef_row = ptr->first_undef_row; 966 } 967 if (writable) 968 ptr->first_undef_row = end_row; 969 if (ptr->pre_zero) { 970 size_t bytesperrow = (size_t) ptr->blocksperrow * sizeof(JBLOCK); 971 undef_row -= ptr->cur_start_row; /* make indexes relative to buffer */ 972 end_row -= ptr->cur_start_row; 973 while (undef_row < end_row) { 974 jzero_far((void *) ptr->mem_buffer[undef_row], bytesperrow); 975 undef_row++; 976 } 977 } else { 978 if (! writable) /* reader looking at undefined data */ 979 ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS); 980 } 981 } 982 /* Flag the buffer dirty if caller will write in it */ 983 if (writable) 984 ptr->dirty = TRUE; 985 /* Return address of proper part of the buffer */ 986 return ptr->mem_buffer + (start_row - ptr->cur_start_row); 987 } 988 989 990 /* 991 * Release all objects belonging to a specified pool. 992 */ 993 994 METHODDEF(void) 995 free_pool (j_common_ptr cinfo, int pool_id) 996 { 997 my_mem_ptr mem = (my_mem_ptr) cinfo->mem; 998 small_pool_ptr shdr_ptr; 999 large_pool_ptr lhdr_ptr; 1000 size_t space_freed; 1001 1002 if (pool_id < 0 || pool_id >= JPOOL_NUMPOOLS) 1003 ERREXIT1(cinfo, JERR_BAD_POOL_ID, pool_id); /* safety check */ 1004 1005 #ifdef MEM_STATS 1006 if (cinfo->err->trace_level > 1) 1007 print_mem_stats(cinfo, pool_id); /* print pool's memory usage statistics */ 1008 #endif 1009 1010 /* If freeing IMAGE pool, close any virtual arrays first */ 1011 if (pool_id == JPOOL_IMAGE) { 1012 jvirt_sarray_ptr sptr; 1013 jvirt_barray_ptr bptr; 1014 1015 for (sptr = mem->virt_sarray_list; sptr != NULL; sptr = sptr->next) { 1016 if (sptr->b_s_open) { /* there may be no backing store */ 1017 sptr->b_s_open = FALSE; /* prevent recursive close if error */ 1018 (*sptr->b_s_info.close_backing_store) (cinfo, & sptr->b_s_info); 1019 } 1020 } 1021 mem->virt_sarray_list = NULL; 1022 for (bptr = mem->virt_barray_list; bptr != NULL; bptr = bptr->next) { 1023 if (bptr->b_s_open) { /* there may be no backing store */ 1024 bptr->b_s_open = FALSE; /* prevent recursive close if error */ 1025 (*bptr->b_s_info.close_backing_store) (cinfo, & bptr->b_s_info); 1026 } 1027 } 1028 mem->virt_barray_list = NULL; 1029 } 1030 1031 /* Release large objects */ 1032 lhdr_ptr = mem->large_list[pool_id]; 1033 mem->large_list[pool_id] = NULL; 1034 1035 while (lhdr_ptr != NULL) { 1036 large_pool_ptr next_lhdr_ptr = lhdr_ptr->next; 1037 space_freed = lhdr_ptr->bytes_used + 1038 lhdr_ptr->bytes_left + 1039 sizeof(large_pool_hdr); 1040 jpeg_free_large(cinfo, (void *) lhdr_ptr, space_freed); 1041 mem->total_space_allocated -= space_freed; 1042 lhdr_ptr = next_lhdr_ptr; 1043 } 1044 1045 /* Release small objects */ 1046 shdr_ptr = mem->small_list[pool_id]; 1047 mem->small_list[pool_id] = NULL; 1048 1049 while (shdr_ptr != NULL) { 1050 small_pool_ptr next_shdr_ptr = shdr_ptr->next; 1051 space_freed = shdr_ptr->bytes_used + 1052 shdr_ptr->bytes_left + 1053 sizeof(small_pool_hdr); 1054 jpeg_free_small(cinfo, (void *) shdr_ptr, space_freed); 1055 mem->total_space_allocated -= space_freed; 1056 shdr_ptr = next_shdr_ptr; 1057 } 1058 } 1059 1060 1061 /* 1062 * Close up shop entirely. 1063 * Note that this cannot be called unless cinfo->mem is non-NULL. 1064 */ 1065 1066 METHODDEF(void) 1067 self_destruct (j_common_ptr cinfo) 1068 { 1069 int pool; 1070 1071 /* Close all backing store, release all memory. 1072 * Releasing pools in reverse order might help avoid fragmentation 1073 * with some (brain-damaged) malloc libraries. 1074 */ 1075 for (pool = JPOOL_NUMPOOLS-1; pool >= JPOOL_PERMANENT; pool--) { 1076 free_pool(cinfo, pool); 1077 } 1078 1079 /* Release the memory manager control block too. */ 1080 jpeg_free_small(cinfo, (void *) cinfo->mem, sizeof(my_memory_mgr)); 1081 cinfo->mem = NULL; /* ensures I will be called only once */ 1082 1083 jpeg_mem_term(cinfo); /* system-dependent cleanup */ 1084 } 1085 1086 1087 /* 1088 * Memory manager initialization. 1089 * When this is called, only the error manager pointer is valid in cinfo! 1090 */ 1091 1092 GLOBAL(void) 1093 jinit_memory_mgr (j_common_ptr cinfo) 1094 { 1095 my_mem_ptr mem; 1096 long max_to_use; 1097 int pool; 1098 size_t test_mac; 1099 1100 cinfo->mem = NULL; /* for safety if init fails */ 1101 1102 /* Check for configuration errors. 1103 * sizeof(ALIGN_TYPE) should be a power of 2; otherwise, it probably 1104 * doesn't reflect any real hardware alignment requirement. 1105 * The test is a little tricky: for X>0, X and X-1 have no one-bits 1106 * in common if and only if X is a power of 2, ie has only one one-bit. 1107 * Some compilers may give an "unreachable code" warning here; ignore it. 1108 */ 1109 if ((ALIGN_SIZE & (ALIGN_SIZE-1)) != 0) 1110 ERREXIT(cinfo, JERR_BAD_ALIGN_TYPE); 1111 /* MAX_ALLOC_CHUNK must be representable as type size_t, and must be 1112 * a multiple of ALIGN_SIZE. 1113 * Again, an "unreachable code" warning may be ignored here. 1114 * But a "constant too large" warning means you need to fix MAX_ALLOC_CHUNK. 1115 */ 1116 test_mac = (size_t) MAX_ALLOC_CHUNK; 1117 if ((long) test_mac != MAX_ALLOC_CHUNK || 1118 (MAX_ALLOC_CHUNK % ALIGN_SIZE) != 0) 1119 ERREXIT(cinfo, JERR_BAD_ALLOC_CHUNK); 1120 1121 max_to_use = jpeg_mem_init(cinfo); /* system-dependent initialization */ 1122 1123 /* Attempt to allocate memory manager's control block */ 1124 mem = (my_mem_ptr) jpeg_get_small(cinfo, sizeof(my_memory_mgr)); 1125 1126 if (mem == NULL) { 1127 jpeg_mem_term(cinfo); /* system-dependent cleanup */ 1128 ERREXIT1(cinfo, JERR_OUT_OF_MEMORY, 0); 1129 } 1130 1131 /* OK, fill in the method pointers */ 1132 mem->pub.alloc_small = alloc_small; 1133 mem->pub.alloc_large = alloc_large; 1134 mem->pub.alloc_sarray = alloc_sarray; 1135 mem->pub.alloc_barray = alloc_barray; 1136 mem->pub.request_virt_sarray = request_virt_sarray; 1137 mem->pub.request_virt_barray = request_virt_barray; 1138 mem->pub.realize_virt_arrays = realize_virt_arrays; 1139 mem->pub.access_virt_sarray = access_virt_sarray; 1140 mem->pub.access_virt_barray = access_virt_barray; 1141 mem->pub.free_pool = free_pool; 1142 mem->pub.self_destruct = self_destruct; 1143 1144 /* Make MAX_ALLOC_CHUNK accessible to other modules */ 1145 mem->pub.max_alloc_chunk = MAX_ALLOC_CHUNK; 1146 1147 /* Initialize working state */ 1148 mem->pub.max_memory_to_use = max_to_use; 1149 1150 for (pool = JPOOL_NUMPOOLS-1; pool >= JPOOL_PERMANENT; pool--) { 1151 mem->small_list[pool] = NULL; 1152 mem->large_list[pool] = NULL; 1153 } 1154 mem->virt_sarray_list = NULL; 1155 mem->virt_barray_list = NULL; 1156 1157 mem->total_space_allocated = sizeof(my_memory_mgr); 1158 1159 /* Declare ourselves open for business */ 1160 cinfo->mem = & mem->pub; 1161 1162 /* Check for an environment variable JPEGMEM; if found, override the 1163 * default max_memory setting from jpeg_mem_init. Note that the 1164 * surrounding application may again override this value. 1165 * If your system doesn't support getenv(), define NO_GETENV to disable 1166 * this feature. 1167 */ 1168 #ifndef NO_GETENV 1169 { char *memenv; 1170 1171 if ((memenv = getenv("JPEGMEM")) != NULL) { 1172 char ch = 'x'; 1173 1174 if (sscanf(memenv, "%ld%c", &max_to_use, &ch) > 0) { 1175 if (ch == 'm' || ch == 'M') 1176 max_to_use *= 1000L; 1177 mem->pub.max_memory_to_use = max_to_use * 1000L; 1178 } 1179 } 1180 } 1181 #endif 1182 1183 } 1184
