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 #include <stdint.h> 36 #include <limits.h> 37 38 #ifndef NO_GETENV 39 #ifndef HAVE_STDLIB_H /* <stdlib.h> should declare getenv() */ 40 extern char *getenv (const char *name); 41 #endif 42 #endif 43 44 45 LOCAL(size_t) 46 round_up_pow2 (size_t a, size_t b) 47 /* a rounded up to the next multiple of b, i.e. ceil(a/b)*b */ 48 /* Assumes a >= 0, b > 0, and b is a power of 2 */ 49 { 50 return ((a + b - 1) & (~(b - 1))); 51 } 52 53 54 /* 55 * Some important notes: 56 * The allocation routines provided here must never return NULL. 57 * They should exit to error_exit if unsuccessful. 58 * 59 * It's not a good idea to try to merge the sarray and barray routines, 60 * even though they are textually almost the same, because samples are 61 * usually stored as bytes while coefficients are shorts or ints. Thus, 62 * in machines where byte pointers have a different representation from 63 * word pointers, the resulting machine code could not be the same. 64 */ 65 66 67 /* 68 * Many machines require storage alignment: longs must start on 4-byte 69 * boundaries, doubles on 8-byte boundaries, etc. On such machines, malloc() 70 * always returns pointers that are multiples of the worst-case alignment 71 * requirement, and we had better do so too. 72 * There isn't any really portable way to determine the worst-case alignment 73 * requirement. This module assumes that the alignment requirement is 74 * multiples of ALIGN_SIZE. 75 * By default, we define ALIGN_SIZE as sizeof(double). This is necessary on 76 * some workstations (where doubles really do need 8-byte alignment) and will 77 * work fine on nearly everything. If your machine has lesser alignment needs, 78 * you can save a few bytes by making ALIGN_SIZE smaller. 79 * The only place I know of where this will NOT work is certain Macintosh 80 * 680x0 compilers that define double as a 10-byte IEEE extended float. 81 * Doing 10-byte alignment is counterproductive because longwords won't be 82 * aligned well. Put "#define ALIGN_SIZE 4" in jconfig.h if you have 83 * such a compiler. 84 */ 85 86 #ifndef ALIGN_SIZE /* so can override from jconfig.h */ 87 #ifndef WITH_SIMD 88 #define ALIGN_SIZE sizeof(double) 89 #else 90 #define ALIGN_SIZE 16 /* Most SIMD implementations require this */ 91 #endif 92 #endif 93 94 /* 95 * We allocate objects from "pools", where each pool is gotten with a single 96 * request to jpeg_get_small() or jpeg_get_large(). There is no per-object 97 * overhead within a pool, except for alignment padding. Each pool has a 98 * header with a link to the next pool of the same class. 99 * Small and large pool headers are identical. 100 */ 101 102 typedef struct small_pool_struct *small_pool_ptr; 103 104 typedef struct small_pool_struct { 105 small_pool_ptr next; /* next in list of pools */ 106 size_t bytes_used; /* how many bytes already used within pool */ 107 size_t bytes_left; /* bytes still available in this pool */ 108 } small_pool_hdr; 109 110 typedef struct large_pool_struct *large_pool_ptr; 111 112 typedef struct large_pool_struct { 113 large_pool_ptr next; /* next in list of pools */ 114 size_t bytes_used; /* how many bytes already used within pool */ 115 size_t bytes_left; /* bytes still available in this pool */ 116 } large_pool_hdr; 117 118 /* 119 * Here is the full definition of a memory manager object. 120 */ 121 122 typedef struct { 123 struct jpeg_memory_mgr pub; /* public fields */ 124 125 /* Each pool identifier (lifetime class) names a linked list of pools. */ 126 small_pool_ptr small_list[JPOOL_NUMPOOLS]; 127 large_pool_ptr large_list[JPOOL_NUMPOOLS]; 128 129 /* Since we only have one lifetime class of virtual arrays, only one 130 * linked list is necessary (for each datatype). Note that the virtual 131 * array control blocks being linked together are actually stored somewhere 132 * in the small-pool list. 133 */ 134 jvirt_sarray_ptr virt_sarray_list; 135 jvirt_barray_ptr virt_barray_list; 136 137 /* This counts total space obtained from jpeg_get_small/large */ 138 size_t total_space_allocated; 139 140 /* alloc_sarray and alloc_barray set this value for use by virtual 141 * array routines. 142 */ 143 JDIMENSION last_rowsperchunk; /* from most recent alloc_sarray/barray */ 144 } my_memory_mgr; 145 146 typedef my_memory_mgr *my_mem_ptr; 147 148 149 /* 150 * The control blocks for virtual arrays. 151 * Note that these blocks are allocated in the "small" pool area. 152 * System-dependent info for the associated backing store (if any) is hidden 153 * inside the backing_store_info struct. 154 */ 155 156 struct jvirt_sarray_control { 157 JSAMPARRAY mem_buffer; /* => the in-memory buffer */ 158 JDIMENSION rows_in_array; /* total virtual array height */ 159 JDIMENSION samplesperrow; /* width of array (and of memory buffer) */ 160 JDIMENSION maxaccess; /* max rows accessed by access_virt_sarray */ 161 JDIMENSION rows_in_mem; /* height of memory buffer */ 162 JDIMENSION rowsperchunk; /* allocation chunk size in mem_buffer */ 163 JDIMENSION cur_start_row; /* first logical row # in the buffer */ 164 JDIMENSION first_undef_row; /* row # of first uninitialized row */ 165 boolean pre_zero; /* pre-zero mode requested? */ 166 boolean dirty; /* do current buffer contents need written? */ 167 boolean b_s_open; /* is backing-store data valid? */ 168 jvirt_sarray_ptr next; /* link to next virtual sarray control block */ 169 backing_store_info b_s_info; /* System-dependent control info */ 170 }; 171 172 struct jvirt_barray_control { 173 JBLOCKARRAY mem_buffer; /* => the in-memory buffer */ 174 JDIMENSION rows_in_array; /* total virtual array height */ 175 JDIMENSION blocksperrow; /* width of array (and of memory buffer) */ 176 JDIMENSION maxaccess; /* max rows accessed by access_virt_barray */ 177 JDIMENSION rows_in_mem; /* height of memory buffer */ 178 JDIMENSION rowsperchunk; /* allocation chunk size in mem_buffer */ 179 JDIMENSION cur_start_row; /* first logical row # in the buffer */ 180 JDIMENSION first_undef_row; /* row # of first uninitialized row */ 181 boolean pre_zero; /* pre-zero mode requested? */ 182 boolean dirty; /* do current buffer contents need written? */ 183 boolean b_s_open; /* is backing-store data valid? */ 184 jvirt_barray_ptr next; /* link to next virtual barray control block */ 185 backing_store_info b_s_info; /* System-dependent control info */ 186 }; 187 188 189 #ifdef MEM_STATS /* optional extra stuff for statistics */ 190 191 LOCAL(void) 192 print_mem_stats (j_common_ptr cinfo, int pool_id) 193 { 194 my_mem_ptr mem = (my_mem_ptr) cinfo->mem; 195 small_pool_ptr shdr_ptr; 196 large_pool_ptr lhdr_ptr; 197 198 /* Since this is only a debugging stub, we can cheat a little by using 199 * fprintf directly rather than going through the trace message code. 200 * This is helpful because message parm array can't handle longs. 201 */ 202 fprintf(stderr, "Freeing pool %d, total space = %ld\n", 203 pool_id, mem->total_space_allocated); 204 205 for (lhdr_ptr = mem->large_list[pool_id]; lhdr_ptr != NULL; 206 lhdr_ptr = lhdr_ptr->next) { 207 fprintf(stderr, " Large chunk used %ld\n", 208 (long) lhdr_ptr->bytes_used); 209 } 210 211 for (shdr_ptr = mem->small_list[pool_id]; shdr_ptr != NULL; 212 shdr_ptr = shdr_ptr->next) { 213 fprintf(stderr, " Small chunk used %ld free %ld\n", 214 (long) shdr_ptr->bytes_used, 215 (long) shdr_ptr->bytes_left); 216 } 217 } 218 219 #endif /* MEM_STATS */ 220 221 222 LOCAL(void) 223 out_of_memory (j_common_ptr cinfo, int which) 224 /* Report an out-of-memory error and stop execution */ 225 /* If we compiled MEM_STATS support, report alloc requests before dying */ 226 { 227 #ifdef MEM_STATS 228 cinfo->err->trace_level = 2; /* force self_destruct to report stats */ 229 #endif 230 ERREXIT1(cinfo, JERR_OUT_OF_MEMORY, which); 231 } 232 233 234 /* 235 * Allocation of "small" objects. 236 * 237 * For these, we use pooled storage. When a new pool must be created, 238 * we try to get enough space for the current request plus a "slop" factor, 239 * where the slop will be the amount of leftover space in the new pool. 240 * The speed vs. space tradeoff is largely determined by the slop values. 241 * A different slop value is provided for each pool class (lifetime), 242 * and we also distinguish the first pool of a class from later ones. 243 * NOTE: the values given work fairly well on both 16- and 32-bit-int 244 * machines, but may be too small if longs are 64 bits or more. 245 * 246 * Since we do not know what alignment malloc() gives us, we have to 247 * allocate ALIGN_SIZE-1 extra space per pool to have room for alignment 248 * adjustment. 249 */ 250 251 static const size_t first_pool_slop[JPOOL_NUMPOOLS] = 252 { 253 1600, /* first PERMANENT pool */ 254 16000 /* first IMAGE pool */ 255 }; 256 257 static const size_t extra_pool_slop[JPOOL_NUMPOOLS] = 258 { 259 0, /* additional PERMANENT pools */ 260 5000 /* additional IMAGE pools */ 261 }; 262 263 #define MIN_SLOP 50 /* greater than 0 to avoid futile looping */ 264 265 266 METHODDEF(void *) 267 alloc_small (j_common_ptr cinfo, int pool_id, size_t sizeofobject) 268 /* Allocate a "small" object */ 269 { 270 my_mem_ptr mem = (my_mem_ptr) cinfo->mem; 271 small_pool_ptr hdr_ptr, prev_hdr_ptr; 272 char *data_ptr; 273 size_t min_request, slop; 274 275 /* 276 * Round up the requested size to a multiple of ALIGN_SIZE in order 277 * to assure alignment for the next object allocated in the same pool 278 * and so that algorithms can straddle outside the proper area up 279 * to the next alignment. 280 */ 281 if (sizeofobject > MAX_ALLOC_CHUNK) { 282 /* This prevents overflow/wrap-around in round_up_pow2() if sizeofobject 283 is close to SIZE_MAX. */ 284 out_of_memory(cinfo, 7); 285 } 286 sizeofobject = round_up_pow2(sizeofobject, ALIGN_SIZE); 287 288 /* Check for unsatisfiable request (do now to ensure no overflow below) */ 289 if ((sizeof(small_pool_hdr) + sizeofobject + ALIGN_SIZE - 1) > 290 MAX_ALLOC_CHUNK) 291 out_of_memory(cinfo, 1); /* request exceeds malloc's ability */ 292 293 /* See if space is available in any existing pool */ 294 if (pool_id < 0 || pool_id >= JPOOL_NUMPOOLS) 295 ERREXIT1(cinfo, JERR_BAD_POOL_ID, pool_id); /* safety check */ 296 prev_hdr_ptr = NULL; 297 hdr_ptr = mem->small_list[pool_id]; 298 while (hdr_ptr != NULL) { 299 if (hdr_ptr->bytes_left >= sizeofobject) 300 break; /* found pool with enough space */ 301 prev_hdr_ptr = hdr_ptr; 302 hdr_ptr = hdr_ptr->next; 303 } 304 305 /* Time to make a new pool? */ 306 if (hdr_ptr == NULL) { 307 /* min_request is what we need now, slop is what will be leftover */ 308 min_request = sizeof(small_pool_hdr) + sizeofobject + ALIGN_SIZE - 1; 309 if (prev_hdr_ptr == NULL) /* first pool in class? */ 310 slop = first_pool_slop[pool_id]; 311 else 312 slop = extra_pool_slop[pool_id]; 313 /* Don't ask for more than MAX_ALLOC_CHUNK */ 314 if (slop > (size_t) (MAX_ALLOC_CHUNK-min_request)) 315 slop = (size_t) (MAX_ALLOC_CHUNK-min_request); 316 /* Try to get space, if fail reduce slop and try again */ 317 for (;;) { 318 hdr_ptr = (small_pool_ptr) jpeg_get_small(cinfo, min_request + slop); 319 if (hdr_ptr != NULL) 320 break; 321 slop /= 2; 322 if (slop < MIN_SLOP) /* give up when it gets real small */ 323 out_of_memory(cinfo, 2); /* jpeg_get_small failed */ 324 } 325 mem->total_space_allocated += min_request + slop; 326 /* Success, initialize the new pool header and add to end of list */ 327 hdr_ptr->next = NULL; 328 hdr_ptr->bytes_used = 0; 329 hdr_ptr->bytes_left = sizeofobject + slop; 330 if (prev_hdr_ptr == NULL) /* first pool in class? */ 331 mem->small_list[pool_id] = hdr_ptr; 332 else 333 prev_hdr_ptr->next = hdr_ptr; 334 } 335 336 /* OK, allocate the object from the current pool */ 337 data_ptr = (char *) hdr_ptr; /* point to first data byte in pool... */ 338 data_ptr += sizeof(small_pool_hdr); /* ...by skipping the header... */ 339 if ((size_t)data_ptr % ALIGN_SIZE) /* ...and adjust for alignment */ 340 data_ptr += ALIGN_SIZE - (size_t)data_ptr % ALIGN_SIZE; 341 data_ptr += hdr_ptr->bytes_used; /* point to place for object */ 342 hdr_ptr->bytes_used += sizeofobject; 343 hdr_ptr->bytes_left -= sizeofobject; 344 345 return (void *) data_ptr; 346 } 347 348 349 /* 350 * Allocation of "large" objects. 351 * 352 * The external semantics of these are the same as "small" objects. However, 353 * the pool management heuristics are quite different. We assume that each 354 * request is large enough that it may as well be passed directly to 355 * jpeg_get_large; the pool management just links everything together 356 * so that we can free it all on demand. 357 * Note: the major use of "large" objects is in JSAMPARRAY and JBLOCKARRAY 358 * structures. The routines that create these structures (see below) 359 * deliberately bunch rows together to ensure a large request size. 360 */ 361 362 METHODDEF(void *) 363 alloc_large (j_common_ptr cinfo, int pool_id, size_t sizeofobject) 364 /* Allocate a "large" object */ 365 { 366 my_mem_ptr mem = (my_mem_ptr) cinfo->mem; 367 large_pool_ptr hdr_ptr; 368 char *data_ptr; 369 370 /* 371 * Round up the requested size to a multiple of ALIGN_SIZE so that 372 * algorithms can straddle outside the proper area up to the next 373 * alignment. 374 */ 375 if (sizeofobject > MAX_ALLOC_CHUNK) { 376 /* This prevents overflow/wrap-around in round_up_pow2() if sizeofobject 377 is close to SIZE_MAX. */ 378 out_of_memory(cinfo, 8); 379 } 380 sizeofobject = round_up_pow2(sizeofobject, ALIGN_SIZE); 381 382 /* Check for unsatisfiable request (do now to ensure no overflow below) */ 383 if ((sizeof(large_pool_hdr) + sizeofobject + ALIGN_SIZE - 1) > 384 MAX_ALLOC_CHUNK) 385 out_of_memory(cinfo, 3); /* request exceeds malloc's ability */ 386 387 /* Always make a new pool */ 388 if (pool_id < 0 || pool_id >= JPOOL_NUMPOOLS) 389 ERREXIT1(cinfo, JERR_BAD_POOL_ID, pool_id); /* safety check */ 390 391 hdr_ptr = (large_pool_ptr) jpeg_get_large(cinfo, sizeofobject + 392 sizeof(large_pool_hdr) + 393 ALIGN_SIZE - 1); 394 if (hdr_ptr == NULL) 395 out_of_memory(cinfo, 4); /* jpeg_get_large failed */ 396 mem->total_space_allocated += sizeofobject + sizeof(large_pool_hdr) + 397 ALIGN_SIZE - 1; 398 399 /* Success, initialize the new pool header and add to list */ 400 hdr_ptr->next = mem->large_list[pool_id]; 401 /* We maintain space counts in each pool header for statistical purposes, 402 * even though they are not needed for allocation. 403 */ 404 hdr_ptr->bytes_used = sizeofobject; 405 hdr_ptr->bytes_left = 0; 406 mem->large_list[pool_id] = hdr_ptr; 407 408 data_ptr = (char *) hdr_ptr; /* point to first data byte in pool... */ 409 data_ptr += sizeof(small_pool_hdr); /* ...by skipping the header... */ 410 if ((size_t)data_ptr % ALIGN_SIZE) /* ...and adjust for alignment */ 411 data_ptr += ALIGN_SIZE - (size_t)data_ptr % ALIGN_SIZE; 412 413 return (void *) data_ptr; 414 } 415 416 417 /* 418 * Creation of 2-D sample arrays. 419 * 420 * To minimize allocation overhead and to allow I/O of large contiguous 421 * blocks, we allocate the sample rows in groups of as many rows as possible 422 * without exceeding MAX_ALLOC_CHUNK total bytes per allocation request. 423 * NB: the virtual array control routines, later in this file, know about 424 * this chunking of rows. The rowsperchunk value is left in the mem manager 425 * object so that it can be saved away if this sarray is the workspace for 426 * a virtual array. 427 * 428 * Since we are often upsampling with a factor 2, we align the size (not 429 * the start) to 2 * ALIGN_SIZE so that the upsampling routines don't have 430 * to be as careful about size. 431 */ 432 433 METHODDEF(JSAMPARRAY) 434 alloc_sarray (j_common_ptr cinfo, int pool_id, 435 JDIMENSION samplesperrow, JDIMENSION numrows) 436 /* Allocate a 2-D sample array */ 437 { 438 my_mem_ptr mem = (my_mem_ptr) cinfo->mem; 439 JSAMPARRAY result; 440 JSAMPROW workspace; 441 JDIMENSION rowsperchunk, currow, i; 442 long ltemp; 443 444 /* Make sure each row is properly aligned */ 445 if ((ALIGN_SIZE % sizeof(JSAMPLE)) != 0) 446 out_of_memory(cinfo, 5); /* safety check */ 447 448 if (samplesperrow > MAX_ALLOC_CHUNK) { 449 /* This prevents overflow/wrap-around in round_up_pow2() if sizeofobject 450 is close to SIZE_MAX. */ 451 out_of_memory(cinfo, 9); 452 } 453 samplesperrow = (JDIMENSION)round_up_pow2(samplesperrow, (2 * ALIGN_SIZE) / 454 sizeof(JSAMPLE)); 455 456 /* Calculate max # of rows allowed in one allocation chunk */ 457 ltemp = (MAX_ALLOC_CHUNK-sizeof(large_pool_hdr)) / 458 ((long) samplesperrow * sizeof(JSAMPLE)); 459 if (ltemp <= 0) 460 ERREXIT(cinfo, JERR_WIDTH_OVERFLOW); 461 if (ltemp < (long) numrows) 462 rowsperchunk = (JDIMENSION) ltemp; 463 else 464 rowsperchunk = numrows; 465 mem->last_rowsperchunk = rowsperchunk; 466 467 /* Get space for row pointers (small object) */ 468 result = (JSAMPARRAY) alloc_small(cinfo, pool_id, 469 (size_t) (numrows * sizeof(JSAMPROW))); 470 471 /* Get the rows themselves (large objects) */ 472 currow = 0; 473 while (currow < numrows) { 474 rowsperchunk = MIN(rowsperchunk, numrows - currow); 475 workspace = (JSAMPROW) alloc_large(cinfo, pool_id, 476 (size_t) ((size_t) rowsperchunk * (size_t) samplesperrow 477 * sizeof(JSAMPLE))); 478 for (i = rowsperchunk; i > 0; i--) { 479 result[currow++] = workspace; 480 workspace += samplesperrow; 481 } 482 } 483 484 return result; 485 } 486 487 488 /* 489 * Creation of 2-D coefficient-block arrays. 490 * This is essentially the same as the code for sample arrays, above. 491 */ 492 493 METHODDEF(JBLOCKARRAY) 494 alloc_barray (j_common_ptr cinfo, int pool_id, 495 JDIMENSION blocksperrow, JDIMENSION numrows) 496 /* Allocate a 2-D coefficient-block array */ 497 { 498 my_mem_ptr mem = (my_mem_ptr) cinfo->mem; 499 JBLOCKARRAY result; 500 JBLOCKROW workspace; 501 JDIMENSION rowsperchunk, currow, i; 502 long ltemp; 503 504 /* Make sure each row is properly aligned */ 505 if ((sizeof(JBLOCK) % ALIGN_SIZE) != 0) 506 out_of_memory(cinfo, 6); /* safety check */ 507 508 /* Calculate max # of rows allowed in one allocation chunk */ 509 ltemp = (MAX_ALLOC_CHUNK-sizeof(large_pool_hdr)) / 510 ((long) blocksperrow * sizeof(JBLOCK)); 511 if (ltemp <= 0) 512 ERREXIT(cinfo, JERR_WIDTH_OVERFLOW); 513 if (ltemp < (long) numrows) 514 rowsperchunk = (JDIMENSION) ltemp; 515 else 516 rowsperchunk = numrows; 517 mem->last_rowsperchunk = rowsperchunk; 518 519 /* Get space for row pointers (small object) */ 520 result = (JBLOCKARRAY) alloc_small(cinfo, pool_id, 521 (size_t) (numrows * sizeof(JBLOCKROW))); 522 523 /* Get the rows themselves (large objects) */ 524 currow = 0; 525 while (currow < numrows) { 526 rowsperchunk = MIN(rowsperchunk, numrows - currow); 527 workspace = (JBLOCKROW) alloc_large(cinfo, pool_id, 528 (size_t) ((size_t) rowsperchunk * (size_t) blocksperrow 529 * sizeof(JBLOCK))); 530 for (i = rowsperchunk; i > 0; i--) { 531 result[currow++] = workspace; 532 workspace += blocksperrow; 533 } 534 } 535 536 return result; 537 } 538 539 540 /* 541 * About virtual array management: 542 * 543 * The above "normal" array routines are only used to allocate strip buffers 544 * (as wide as the image, but just a few rows high). Full-image-sized buffers 545 * are handled as "virtual" arrays. The array is still accessed a strip at a 546 * time, but the memory manager must save the whole array for repeated 547 * accesses. The intended implementation is that there is a strip buffer in 548 * memory (as high as is possible given the desired memory limit), plus a 549 * backing file that holds the rest of the array. 550 * 551 * The request_virt_array routines are told the total size of the image and 552 * the maximum number of rows that will be accessed at once. The in-memory 553 * buffer must be at least as large as the maxaccess value. 554 * 555 * The request routines create control blocks but not the in-memory buffers. 556 * That is postponed until realize_virt_arrays is called. At that time the 557 * total amount of space needed is known (approximately, anyway), so free 558 * memory can be divided up fairly. 559 * 560 * The access_virt_array routines are responsible for making a specific strip 561 * area accessible (after reading or writing the backing file, if necessary). 562 * Note that the access routines are told whether the caller intends to modify 563 * the accessed strip; during a read-only pass this saves having to rewrite 564 * data to disk. The access routines are also responsible for pre-zeroing 565 * any newly accessed rows, if pre-zeroing was requested. 566 * 567 * In current usage, the access requests are usually for nonoverlapping 568 * strips; that is, successive access start_row numbers differ by exactly 569 * num_rows = maxaccess. This means we can get good performance with simple 570 * buffer dump/reload logic, by making the in-memory buffer be a multiple 571 * of the access height; then there will never be accesses across bufferload 572 * boundaries. The code will still work with overlapping access requests, 573 * but it doesn't handle bufferload overlaps very efficiently. 574 */ 575 576 577 METHODDEF(jvirt_sarray_ptr) 578 request_virt_sarray (j_common_ptr cinfo, int pool_id, boolean pre_zero, 579 JDIMENSION samplesperrow, JDIMENSION numrows, 580 JDIMENSION maxaccess) 581 /* Request a virtual 2-D sample array */ 582 { 583 my_mem_ptr mem = (my_mem_ptr) cinfo->mem; 584 jvirt_sarray_ptr result; 585 586 /* Only IMAGE-lifetime virtual arrays are currently supported */ 587 if (pool_id != JPOOL_IMAGE) 588 ERREXIT1(cinfo, JERR_BAD_POOL_ID, pool_id); /* safety check */ 589 590 /* get control block */ 591 result = (jvirt_sarray_ptr) alloc_small(cinfo, pool_id, 592 sizeof(struct jvirt_sarray_control)); 593 594 result->mem_buffer = NULL; /* marks array not yet realized */ 595 result->rows_in_array = numrows; 596 result->samplesperrow = samplesperrow; 597 result->maxaccess = maxaccess; 598 result->pre_zero = pre_zero; 599 result->b_s_open = FALSE; /* no associated backing-store object */ 600 result->next = mem->virt_sarray_list; /* add to list of virtual arrays */ 601 mem->virt_sarray_list = result; 602 603 return result; 604 } 605 606 607 METHODDEF(jvirt_barray_ptr) 608 request_virt_barray (j_common_ptr cinfo, int pool_id, boolean pre_zero, 609 JDIMENSION blocksperrow, JDIMENSION numrows, 610 JDIMENSION maxaccess) 611 /* Request a virtual 2-D coefficient-block array */ 612 { 613 my_mem_ptr mem = (my_mem_ptr) cinfo->mem; 614 jvirt_barray_ptr result; 615 616 /* Only IMAGE-lifetime virtual arrays are currently supported */ 617 if (pool_id != JPOOL_IMAGE) 618 ERREXIT1(cinfo, JERR_BAD_POOL_ID, pool_id); /* safety check */ 619 620 /* get control block */ 621 result = (jvirt_barray_ptr) alloc_small(cinfo, pool_id, 622 sizeof(struct jvirt_barray_control)); 623 624 result->mem_buffer = NULL; /* marks array not yet realized */ 625 result->rows_in_array = numrows; 626 result->blocksperrow = blocksperrow; 627 result->maxaccess = maxaccess; 628 result->pre_zero = pre_zero; 629 result->b_s_open = FALSE; /* no associated backing-store object */ 630 result->next = mem->virt_barray_list; /* add to list of virtual arrays */ 631 mem->virt_barray_list = result; 632 633 return result; 634 } 635 636 637 METHODDEF(void) 638 realize_virt_arrays (j_common_ptr cinfo) 639 /* Allocate the in-memory buffers for any unrealized virtual arrays */ 640 { 641 my_mem_ptr mem = (my_mem_ptr) cinfo->mem; 642 size_t space_per_minheight, maximum_space, avail_mem; 643 size_t minheights, max_minheights; 644 jvirt_sarray_ptr sptr; 645 jvirt_barray_ptr bptr; 646 647 /* Compute the minimum space needed (maxaccess rows in each buffer) 648 * and the maximum space needed (full image height in each buffer). 649 * These may be of use to the system-dependent jpeg_mem_available routine. 650 */ 651 space_per_minheight = 0; 652 maximum_space = 0; 653 for (sptr = mem->virt_sarray_list; sptr != NULL; sptr = sptr->next) { 654 if (sptr->mem_buffer == NULL) { /* if not realized yet */ 655 size_t new_space = (long) sptr->rows_in_array * 656 (long) sptr->samplesperrow * sizeof(JSAMPLE); 657 658 space_per_minheight += (long) sptr->maxaccess * 659 (long) sptr->samplesperrow * sizeof(JSAMPLE); 660 if (SIZE_MAX - maximum_space < new_space) 661 out_of_memory(cinfo, 10); 662 maximum_space += new_space; 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 size_t new_space = (long) bptr->rows_in_array * 668 (long) bptr->blocksperrow * sizeof(JBLOCK); 669 670 space_per_minheight += (long) bptr->maxaccess * 671 (long) bptr->blocksperrow * sizeof(JBLOCK); 672 if (SIZE_MAX - maximum_space < new_space) 673 out_of_memory(cinfo, 11); 674 maximum_space += new_space; 675 } 676 } 677 678 if (space_per_minheight <= 0) 679 return; /* no unrealized arrays, no work */ 680 681 /* Determine amount of memory to actually use; this is system-dependent. */ 682 avail_mem = jpeg_mem_available(cinfo, space_per_minheight, maximum_space, 683 mem->total_space_allocated); 684 685 /* If the maximum space needed is available, make all the buffers full 686 * height; otherwise parcel it out with the same number of minheights 687 * in each buffer. 688 */ 689 if (avail_mem >= maximum_space) 690 max_minheights = 1000000000L; 691 else { 692 max_minheights = avail_mem / space_per_minheight; 693 /* If there doesn't seem to be enough space, try to get the minimum 694 * anyway. This allows a "stub" implementation of jpeg_mem_available(). 695 */ 696 if (max_minheights <= 0) 697 max_minheights = 1; 698 } 699 700 /* Allocate the in-memory buffers and initialize backing store as needed. */ 701 702 for (sptr = mem->virt_sarray_list; sptr != NULL; sptr = sptr->next) { 703 if (sptr->mem_buffer == NULL) { /* if not realized yet */ 704 minheights = ((long) sptr->rows_in_array - 1L) / sptr->maxaccess + 1L; 705 if (minheights <= max_minheights) { 706 /* This buffer fits in memory */ 707 sptr->rows_in_mem = sptr->rows_in_array; 708 } else { 709 /* It doesn't fit in memory, create backing store. */ 710 sptr->rows_in_mem = (JDIMENSION) (max_minheights * sptr->maxaccess); 711 jpeg_open_backing_store(cinfo, & sptr->b_s_info, 712 (long) sptr->rows_in_array * 713 (long) sptr->samplesperrow * 714 (long) sizeof(JSAMPLE)); 715 sptr->b_s_open = TRUE; 716 } 717 sptr->mem_buffer = alloc_sarray(cinfo, JPOOL_IMAGE, 718 sptr->samplesperrow, sptr->rows_in_mem); 719 sptr->rowsperchunk = mem->last_rowsperchunk; 720 sptr->cur_start_row = 0; 721 sptr->first_undef_row = 0; 722 sptr->dirty = FALSE; 723 } 724 } 725 726 for (bptr = mem->virt_barray_list; bptr != NULL; bptr = bptr->next) { 727 if (bptr->mem_buffer == NULL) { /* if not realized yet */ 728 minheights = ((long) bptr->rows_in_array - 1L) / bptr->maxaccess + 1L; 729 if (minheights <= max_minheights) { 730 /* This buffer fits in memory */ 731 bptr->rows_in_mem = bptr->rows_in_array; 732 } else { 733 /* It doesn't fit in memory, create backing store. */ 734 bptr->rows_in_mem = (JDIMENSION) (max_minheights * bptr->maxaccess); 735 jpeg_open_backing_store(cinfo, & bptr->b_s_info, 736 (long) bptr->rows_in_array * 737 (long) bptr->blocksperrow * 738 (long) sizeof(JBLOCK)); 739 bptr->b_s_open = TRUE; 740 } 741 bptr->mem_buffer = alloc_barray(cinfo, JPOOL_IMAGE, 742 bptr->blocksperrow, bptr->rows_in_mem); 743 bptr->rowsperchunk = mem->last_rowsperchunk; 744 bptr->cur_start_row = 0; 745 bptr->first_undef_row = 0; 746 bptr->dirty = FALSE; 747 } 748 } 749 } 750 751 752 LOCAL(void) 753 do_sarray_io (j_common_ptr cinfo, jvirt_sarray_ptr ptr, boolean writing) 754 /* Do backing store read or write of a virtual sample array */ 755 { 756 long bytesperrow, file_offset, byte_count, rows, thisrow, i; 757 758 bytesperrow = (long) ptr->samplesperrow * sizeof(JSAMPLE); 759 file_offset = ptr->cur_start_row * bytesperrow; 760 /* Loop to read or write each allocation chunk in mem_buffer */ 761 for (i = 0; i < (long) ptr->rows_in_mem; i += ptr->rowsperchunk) { 762 /* One chunk, but check for short chunk at end of buffer */ 763 rows = MIN((long) ptr->rowsperchunk, (long) ptr->rows_in_mem - i); 764 /* Transfer no more than is currently defined */ 765 thisrow = (long) ptr->cur_start_row + i; 766 rows = MIN(rows, (long) ptr->first_undef_row - thisrow); 767 /* Transfer no more than fits in file */ 768 rows = MIN(rows, (long) ptr->rows_in_array - thisrow); 769 if (rows <= 0) /* this chunk might be past end of file! */ 770 break; 771 byte_count = rows * bytesperrow; 772 if (writing) 773 (*ptr->b_s_info.write_backing_store) (cinfo, & ptr->b_s_info, 774 (void *) ptr->mem_buffer[i], 775 file_offset, byte_count); 776 else 777 (*ptr->b_s_info.read_backing_store) (cinfo, & ptr->b_s_info, 778 (void *) ptr->mem_buffer[i], 779 file_offset, byte_count); 780 file_offset += byte_count; 781 } 782 } 783 784 785 LOCAL(void) 786 do_barray_io (j_common_ptr cinfo, jvirt_barray_ptr ptr, boolean writing) 787 /* Do backing store read or write of a virtual coefficient-block array */ 788 { 789 long bytesperrow, file_offset, byte_count, rows, thisrow, i; 790 791 bytesperrow = (long) ptr->blocksperrow * sizeof(JBLOCK); 792 file_offset = ptr->cur_start_row * bytesperrow; 793 /* Loop to read or write each allocation chunk in mem_buffer */ 794 for (i = 0; i < (long) ptr->rows_in_mem; i += ptr->rowsperchunk) { 795 /* One chunk, but check for short chunk at end of buffer */ 796 rows = MIN((long) ptr->rowsperchunk, (long) ptr->rows_in_mem - i); 797 /* Transfer no more than is currently defined */ 798 thisrow = (long) ptr->cur_start_row + i; 799 rows = MIN(rows, (long) ptr->first_undef_row - thisrow); 800 /* Transfer no more than fits in file */ 801 rows = MIN(rows, (long) ptr->rows_in_array - thisrow); 802 if (rows <= 0) /* this chunk might be past end of file! */ 803 break; 804 byte_count = rows * bytesperrow; 805 if (writing) 806 (*ptr->b_s_info.write_backing_store) (cinfo, & ptr->b_s_info, 807 (void *) ptr->mem_buffer[i], 808 file_offset, byte_count); 809 else 810 (*ptr->b_s_info.read_backing_store) (cinfo, & ptr->b_s_info, 811 (void *) ptr->mem_buffer[i], 812 file_offset, byte_count); 813 file_offset += byte_count; 814 } 815 } 816 817 818 METHODDEF(JSAMPARRAY) 819 access_virt_sarray (j_common_ptr cinfo, jvirt_sarray_ptr ptr, 820 JDIMENSION start_row, JDIMENSION num_rows, 821 boolean writable) 822 /* Access the part of a virtual sample array starting at start_row */ 823 /* and extending for num_rows rows. writable is true if */ 824 /* caller intends to modify the accessed area. */ 825 { 826 JDIMENSION end_row = start_row + num_rows; 827 JDIMENSION undef_row; 828 829 /* debugging check */ 830 if (end_row > ptr->rows_in_array || num_rows > ptr->maxaccess || 831 ptr->mem_buffer == NULL) 832 ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS); 833 834 /* Make the desired part of the virtual array accessible */ 835 if (start_row < ptr->cur_start_row || 836 end_row > ptr->cur_start_row+ptr->rows_in_mem) { 837 if (! ptr->b_s_open) 838 ERREXIT(cinfo, JERR_VIRTUAL_BUG); 839 /* Flush old buffer contents if necessary */ 840 if (ptr->dirty) { 841 do_sarray_io(cinfo, ptr, TRUE); 842 ptr->dirty = FALSE; 843 } 844 /* Decide what part of virtual array to access. 845 * Algorithm: if target address > current window, assume forward scan, 846 * load starting at target address. If target address < current window, 847 * assume backward scan, load so that target area is top of window. 848 * Note that when switching from forward write to forward read, will have 849 * start_row = 0, so the limiting case applies and we load from 0 anyway. 850 */ 851 if (start_row > ptr->cur_start_row) { 852 ptr->cur_start_row = start_row; 853 } else { 854 /* use long arithmetic here to avoid overflow & unsigned problems */ 855 long ltemp; 856 857 ltemp = (long) end_row - (long) ptr->rows_in_mem; 858 if (ltemp < 0) 859 ltemp = 0; /* don't fall off front end of file */ 860 ptr->cur_start_row = (JDIMENSION) ltemp; 861 } 862 /* Read in the selected part of the array. 863 * During the initial write pass, we will do no actual read 864 * because the selected part is all undefined. 865 */ 866 do_sarray_io(cinfo, ptr, FALSE); 867 } 868 /* Ensure the accessed part of the array is defined; prezero if needed. 869 * To improve locality of access, we only prezero the part of the array 870 * that the caller is about to access, not the entire in-memory array. 871 */ 872 if (ptr->first_undef_row < end_row) { 873 if (ptr->first_undef_row < start_row) { 874 if (writable) /* writer skipped over a section of array */ 875 ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS); 876 undef_row = start_row; /* but reader is allowed to read ahead */ 877 } else { 878 undef_row = ptr->first_undef_row; 879 } 880 if (writable) 881 ptr->first_undef_row = end_row; 882 if (ptr->pre_zero) { 883 size_t bytesperrow = (size_t) ptr->samplesperrow * sizeof(JSAMPLE); 884 undef_row -= ptr->cur_start_row; /* make indexes relative to buffer */ 885 end_row -= ptr->cur_start_row; 886 while (undef_row < end_row) { 887 jzero_far((void *) ptr->mem_buffer[undef_row], bytesperrow); 888 undef_row++; 889 } 890 } else { 891 if (! writable) /* reader looking at undefined data */ 892 ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS); 893 } 894 } 895 /* Flag the buffer dirty if caller will write in it */ 896 if (writable) 897 ptr->dirty = TRUE; 898 /* Return address of proper part of the buffer */ 899 return ptr->mem_buffer + (start_row - ptr->cur_start_row); 900 } 901 902 903 METHODDEF(JBLOCKARRAY) 904 access_virt_barray (j_common_ptr cinfo, jvirt_barray_ptr ptr, 905 JDIMENSION start_row, JDIMENSION num_rows, 906 boolean writable) 907 /* Access the part of a virtual block array starting at start_row */ 908 /* and extending for num_rows rows. writable is true if */ 909 /* caller intends to modify the accessed area. */ 910 { 911 JDIMENSION end_row = start_row + num_rows; 912 JDIMENSION undef_row; 913 914 /* debugging check */ 915 if (end_row > ptr->rows_in_array || num_rows > ptr->maxaccess || 916 ptr->mem_buffer == NULL) 917 ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS); 918 919 /* Make the desired part of the virtual array accessible */ 920 if (start_row < ptr->cur_start_row || 921 end_row > ptr->cur_start_row+ptr->rows_in_mem) { 922 if (! ptr->b_s_open) 923 ERREXIT(cinfo, JERR_VIRTUAL_BUG); 924 /* Flush old buffer contents if necessary */ 925 if (ptr->dirty) { 926 do_barray_io(cinfo, ptr, TRUE); 927 ptr->dirty = FALSE; 928 } 929 /* Decide what part of virtual array to access. 930 * Algorithm: if target address > current window, assume forward scan, 931 * load starting at target address. If target address < current window, 932 * assume backward scan, load so that target area is top of window. 933 * Note that when switching from forward write to forward read, will have 934 * start_row = 0, so the limiting case applies and we load from 0 anyway. 935 */ 936 if (start_row > ptr->cur_start_row) { 937 ptr->cur_start_row = start_row; 938 } else { 939 /* use long arithmetic here to avoid overflow & unsigned problems */ 940 long ltemp; 941 942 ltemp = (long) end_row - (long) ptr->rows_in_mem; 943 if (ltemp < 0) 944 ltemp = 0; /* don't fall off front end of file */ 945 ptr->cur_start_row = (JDIMENSION) ltemp; 946 } 947 /* Read in the selected part of the array. 948 * During the initial write pass, we will do no actual read 949 * because the selected part is all undefined. 950 */ 951 do_barray_io(cinfo, ptr, FALSE); 952 } 953 /* Ensure the accessed part of the array is defined; prezero if needed. 954 * To improve locality of access, we only prezero the part of the array 955 * that the caller is about to access, not the entire in-memory array. 956 */ 957 if (ptr->first_undef_row < end_row) { 958 if (ptr->first_undef_row < start_row) { 959 if (writable) /* writer skipped over a section of array */ 960 ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS); 961 undef_row = start_row; /* but reader is allowed to read ahead */ 962 } else { 963 undef_row = ptr->first_undef_row; 964 } 965 if (writable) 966 ptr->first_undef_row = end_row; 967 if (ptr->pre_zero) { 968 size_t bytesperrow = (size_t) ptr->blocksperrow * sizeof(JBLOCK); 969 undef_row -= ptr->cur_start_row; /* make indexes relative to buffer */ 970 end_row -= ptr->cur_start_row; 971 while (undef_row < end_row) { 972 jzero_far((void *) ptr->mem_buffer[undef_row], bytesperrow); 973 undef_row++; 974 } 975 } else { 976 if (! writable) /* reader looking at undefined data */ 977 ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS); 978 } 979 } 980 /* Flag the buffer dirty if caller will write in it */ 981 if (writable) 982 ptr->dirty = TRUE; 983 /* Return address of proper part of the buffer */ 984 return ptr->mem_buffer + (start_row - ptr->cur_start_row); 985 } 986 987 988 /* 989 * Release all objects belonging to a specified pool. 990 */ 991 992 METHODDEF(void) 993 free_pool (j_common_ptr cinfo, int pool_id) 994 { 995 my_mem_ptr mem = (my_mem_ptr) cinfo->mem; 996 small_pool_ptr shdr_ptr; 997 large_pool_ptr lhdr_ptr; 998 size_t space_freed; 999 1000 if (pool_id < 0 || pool_id >= JPOOL_NUMPOOLS) 1001 ERREXIT1(cinfo, JERR_BAD_POOL_ID, pool_id); /* safety check */ 1002 1003 #ifdef MEM_STATS 1004 if (cinfo->err->trace_level > 1) 1005 print_mem_stats(cinfo, pool_id); /* print pool's memory usage statistics */ 1006 #endif 1007 1008 /* If freeing IMAGE pool, close any virtual arrays first */ 1009 if (pool_id == JPOOL_IMAGE) { 1010 jvirt_sarray_ptr sptr; 1011 jvirt_barray_ptr bptr; 1012 1013 for (sptr = mem->virt_sarray_list; sptr != NULL; sptr = sptr->next) { 1014 if (sptr->b_s_open) { /* there may be no backing store */ 1015 sptr->b_s_open = FALSE; /* prevent recursive close if error */ 1016 (*sptr->b_s_info.close_backing_store) (cinfo, & sptr->b_s_info); 1017 } 1018 } 1019 mem->virt_sarray_list = NULL; 1020 for (bptr = mem->virt_barray_list; bptr != NULL; bptr = bptr->next) { 1021 if (bptr->b_s_open) { /* there may be no backing store */ 1022 bptr->b_s_open = FALSE; /* prevent recursive close if error */ 1023 (*bptr->b_s_info.close_backing_store) (cinfo, & bptr->b_s_info); 1024 } 1025 } 1026 mem->virt_barray_list = NULL; 1027 } 1028 1029 /* Release large objects */ 1030 lhdr_ptr = mem->large_list[pool_id]; 1031 mem->large_list[pool_id] = NULL; 1032 1033 while (lhdr_ptr != NULL) { 1034 large_pool_ptr next_lhdr_ptr = lhdr_ptr->next; 1035 space_freed = lhdr_ptr->bytes_used + 1036 lhdr_ptr->bytes_left + 1037 sizeof(large_pool_hdr); 1038 jpeg_free_large(cinfo, (void *) lhdr_ptr, space_freed); 1039 mem->total_space_allocated -= space_freed; 1040 lhdr_ptr = next_lhdr_ptr; 1041 } 1042 1043 /* Release small objects */ 1044 shdr_ptr = mem->small_list[pool_id]; 1045 mem->small_list[pool_id] = NULL; 1046 1047 while (shdr_ptr != NULL) { 1048 small_pool_ptr next_shdr_ptr = shdr_ptr->next; 1049 space_freed = shdr_ptr->bytes_used + 1050 shdr_ptr->bytes_left + 1051 sizeof(small_pool_hdr); 1052 jpeg_free_small(cinfo, (void *) shdr_ptr, space_freed); 1053 mem->total_space_allocated -= space_freed; 1054 shdr_ptr = next_shdr_ptr; 1055 } 1056 } 1057 1058 1059 /* 1060 * Close up shop entirely. 1061 * Note that this cannot be called unless cinfo->mem is non-NULL. 1062 */ 1063 1064 METHODDEF(void) 1065 self_destruct (j_common_ptr cinfo) 1066 { 1067 int pool; 1068 1069 /* Close all backing store, release all memory. 1070 * Releasing pools in reverse order might help avoid fragmentation 1071 * with some (brain-damaged) malloc libraries. 1072 */ 1073 for (pool = JPOOL_NUMPOOLS-1; pool >= JPOOL_PERMANENT; pool--) { 1074 free_pool(cinfo, pool); 1075 } 1076 1077 /* Release the memory manager control block too. */ 1078 jpeg_free_small(cinfo, (void *) cinfo->mem, sizeof(my_memory_mgr)); 1079 cinfo->mem = NULL; /* ensures I will be called only once */ 1080 1081 jpeg_mem_term(cinfo); /* system-dependent cleanup */ 1082 } 1083 1084 1085 /* 1086 * Memory manager initialization. 1087 * When this is called, only the error manager pointer is valid in cinfo! 1088 */ 1089 1090 GLOBAL(void) 1091 jinit_memory_mgr (j_common_ptr cinfo) 1092 { 1093 my_mem_ptr mem; 1094 long max_to_use; 1095 int pool; 1096 size_t test_mac; 1097 1098 cinfo->mem = NULL; /* for safety if init fails */ 1099 1100 /* Check for configuration errors. 1101 * sizeof(ALIGN_TYPE) should be a power of 2; otherwise, it probably 1102 * doesn't reflect any real hardware alignment requirement. 1103 * The test is a little tricky: for X>0, X and X-1 have no one-bits 1104 * in common if and only if X is a power of 2, ie has only one one-bit. 1105 * Some compilers may give an "unreachable code" warning here; ignore it. 1106 */ 1107 if ((ALIGN_SIZE & (ALIGN_SIZE-1)) != 0) 1108 ERREXIT(cinfo, JERR_BAD_ALIGN_TYPE); 1109 /* MAX_ALLOC_CHUNK must be representable as type size_t, and must be 1110 * a multiple of ALIGN_SIZE. 1111 * Again, an "unreachable code" warning may be ignored here. 1112 * But a "constant too large" warning means you need to fix MAX_ALLOC_CHUNK. 1113 */ 1114 test_mac = (size_t) MAX_ALLOC_CHUNK; 1115 if ((long) test_mac != MAX_ALLOC_CHUNK || 1116 (MAX_ALLOC_CHUNK % ALIGN_SIZE) != 0) 1117 ERREXIT(cinfo, JERR_BAD_ALLOC_CHUNK); 1118 1119 max_to_use = jpeg_mem_init(cinfo); /* system-dependent initialization */ 1120 1121 /* Attempt to allocate memory manager's control block */ 1122 mem = (my_mem_ptr) jpeg_get_small(cinfo, sizeof(my_memory_mgr)); 1123 1124 if (mem == NULL) { 1125 jpeg_mem_term(cinfo); /* system-dependent cleanup */ 1126 ERREXIT1(cinfo, JERR_OUT_OF_MEMORY, 0); 1127 } 1128 1129 /* OK, fill in the method pointers */ 1130 mem->pub.alloc_small = alloc_small; 1131 mem->pub.alloc_large = alloc_large; 1132 mem->pub.alloc_sarray = alloc_sarray; 1133 mem->pub.alloc_barray = alloc_barray; 1134 mem->pub.request_virt_sarray = request_virt_sarray; 1135 mem->pub.request_virt_barray = request_virt_barray; 1136 mem->pub.realize_virt_arrays = realize_virt_arrays; 1137 mem->pub.access_virt_sarray = access_virt_sarray; 1138 mem->pub.access_virt_barray = access_virt_barray; 1139 mem->pub.free_pool = free_pool; 1140 mem->pub.self_destruct = self_destruct; 1141 1142 /* Make MAX_ALLOC_CHUNK accessible to other modules */ 1143 mem->pub.max_alloc_chunk = MAX_ALLOC_CHUNK; 1144 1145 /* Initialize working state */ 1146 mem->pub.max_memory_to_use = max_to_use; 1147 1148 for (pool = JPOOL_NUMPOOLS-1; pool >= JPOOL_PERMANENT; pool--) { 1149 mem->small_list[pool] = NULL; 1150 mem->large_list[pool] = NULL; 1151 } 1152 mem->virt_sarray_list = NULL; 1153 mem->virt_barray_list = NULL; 1154 1155 mem->total_space_allocated = sizeof(my_memory_mgr); 1156 1157 /* Declare ourselves open for business */ 1158 cinfo->mem = & mem->pub; 1159 1160 /* Check for an environment variable JPEGMEM; if found, override the 1161 * default max_memory setting from jpeg_mem_init. Note that the 1162 * surrounding application may again override this value. 1163 * If your system doesn't support getenv(), define NO_GETENV to disable 1164 * this feature. 1165 */ 1166 #ifndef NO_GETENV 1167 { char *memenv; 1168 1169 if ((memenv = getenv("JPEGMEM")) != NULL) { 1170 char ch = 'x'; 1171 1172 if (sscanf(memenv, "%ld%c", &max_to_use, &ch) > 0) { 1173 if (ch == 'm' || ch == 'M') 1174 max_to_use *= 1000L; 1175 mem->pub.max_memory_to_use = max_to_use * 1000L; 1176 } 1177 } 1178 } 1179 #endif 1180 1181 } 1182
