// * jmemmgr.c // * // * Copyright (C) 1991-1995, Thomas G. Lane. // * This file is part of the Independent JPEG Group's software. // * For conditions of distribution and use, see the accompanying README file. // * // * This file contains the JPEG system-independent memory management // * routines. This code is usable across a wide variety of machines; most // * of the system dependencies have been isolated in a separate file. // * The major functions provided here are: // * * pool-based allocation and freeing of memory; // * * policy decisions about how to divide available memory among the // * virtual arrays; // * * control logic for swapping virtual arrays between main memory and // * backing storage. // * The separate system-dependent file provides the actual backing-storage // * access code, and it contains the policy decision about how much total // * main memory to use. // * This file is system-dependent in the sense that some of its functions // * are unnecessary in some systems. For example, if there is enough virtual // * memory so that backing storage will never be used, much of the virtual // * array control logic could be removed. (Of course, if you have that much // * memory then you shouldn't care about a little bit of unused code...) #ifdef _MSC_VER #pragma warning(push) #pragma warning(disable: 4127) #endif #define JPEG_INTERNALS #define AM_MEMORY_MANAGER // we define jvirt_Xarray_control structs #include "JINCLUDE.h" #include "JPEGLIB.h" #include "JMEMSYS.h" // import the system-dependent declarations #ifndef NO_GETENV #ifndef HAVE_STDLIB_H // should declare getenv() extern char * getenv JPP((const char * name)); #endif #endif // * Some important notes: // * The allocation routines provided here must never return NULL. // * They should exit to error_exit if unsuccessful. // * // * It's not a good idea to try to merge the sarray and barray routines, // * even though they are textually almost the same, because samples are // * usually stored as bytes while coefficients are shorts or ints. Thus, // * in machines where byte pointers have a different representation from // * word pointers, the resulting machine code could not be the same. // * Many machines require storage alignment: longs must start on 4-byte // * boundaries, doubles on 8-byte boundaries, etc. On such machines, malloc() // * always returns pointers that are multiples of the worst-case alignment // * requirement, and we had better do so too. // * There isn't any really portable way to determine the worst-case alignment // * requirement. This module assumes that the alignment requirement is // * multiples of sizeof(ALIGN_TYPE). // * By default, we define ALIGN_TYPE as double. This is necessary on some // * workstations (where doubles really do need 8-byte alignment) and will work // * fine on nearly everything. If your machine has lesser alignment needs, // * you can save a few bytes by making ALIGN_TYPE smaller. // * The only place I know of where this will NOT work is certain Macintosh // * 680x0 compilers that define double as a 10-byte IEEE extended float. // * Doing 10-byte alignment is counterproductive because longwords won't be // * aligned well. Put "#define ALIGN_TYPE long" in jconfig.h if you have // * such a compiler. #ifndef ALIGN_TYPE // so can override from jconfig.h #ifdef PSX2_TARGET #define ALIGN_TYPE long // same size (8oct) but not double #else #define ALIGN_TYPE double #endif #endif // * We allocate objects from "pools", where each pool is gotten with a single // * request to jpeg_get_small() or jpeg_get_large(). There is no per-object // * overhead within a pool, except for alignment padding. Each pool has a // * header with a link to the next pool of the same class. // * Small and large pool headers are identical except that the latter's // * link pointer must be FAR on 80x86 machines. // * Notice that the "real" header fields are union'ed with a dummy ALIGN_TYPE // * field. This forces the compiler to make SIZEOF(small_pool_hdr) a multiple // * of the alignment requirement of ALIGN_TYPE. typedef union small_pool_struct * small_pool_ptr; typedef union small_pool_struct { struct { small_pool_ptr next; // next in list of pools size_t bytes_used; // how many bytes already used within pool size_t bytes_left; // bytes still available in this pool } hdr; ALIGN_TYPE dummy; // included in union to ensure alignment } small_pool_hdr; typedef union large_pool_struct FAR * large_pool_ptr; typedef union large_pool_struct { struct { large_pool_ptr next; // next in list of pools size_t bytes_used; // how many bytes already used within pool size_t bytes_left; // bytes still available in this pool } hdr; ALIGN_TYPE dummy; // included in union to ensure alignment } large_pool_hdr; // * Here is the full definition of a memory manager object. typedef struct { struct jpeg_memory_mgr pub; // public fields // Each pool identifier (lifetime class) names a linked list of pools. small_pool_ptr small_list[JPOOL_NUMPOOLS]; large_pool_ptr large_list[JPOOL_NUMPOOLS]; // Since we only have one lifetime class of virtual arrays, only one // * linked list is necessary (for each datatype). Note that the virtual // * array control blocks being linked together are actually stored somewhere // * in the small-pool list. jvirt_sarray_ptr virt_sarray_list; jvirt_barray_ptr virt_barray_list; // This counts total space obtained from jpeg_get_small/large LONG total_space_allocated; // alloc_sarray and alloc_barray set this value for use by virtual // * array routines. JDIMENSION last_rowsperchunk; // from most recent alloc_sarray/barray } my_memory_mgr; typedef my_memory_mgr * my_mem_ptr; // * The control blocks for virtual arrays. // * Note that these blocks are allocated in the "small" pool area. // * System-dependent info for the associated backing store (if any) is hidden // * inside the backing_store_info struct. struct jvirt_sarray_control { JSAMPARRAY mem_buffer; // => the in-memory buffer JDIMENSION rows_in_array; // total virtual array height JDIMENSION samplesperrow; // width of array (and of memory buffer) JDIMENSION maxaccess; // max rows accessed by access_virt_sarray JDIMENSION rows_in_mem; // height of memory buffer JDIMENSION rowsperchunk; // allocation chunk size in mem_buffer JDIMENSION cur_start_row; // first logical row # in the buffer JDIMENSION first_undef_row; // row # of first uninitialized row boolean pre_zero; // pre-zero mode requested? boolean dirty; // do current buffer contents need written? boolean b_s_open; // is backing-store data valid? jvirt_sarray_ptr next; // link to next virtual sarray control block backing_store_info b_s_info; // System-dependent control info }; struct jvirt_barray_control { JBLOCKARRAY mem_buffer; // => the in-memory buffer JDIMENSION rows_in_array; // total virtual array height JDIMENSION blocksperrow; // width of array (and of memory buffer) JDIMENSION maxaccess; // max rows accessed by access_virt_barray JDIMENSION rows_in_mem; // height of memory buffer JDIMENSION rowsperchunk; // allocation chunk size in mem_buffer JDIMENSION cur_start_row; // first logical row # in the buffer JDIMENSION first_undef_row; // row # of first uninitialized row boolean pre_zero; // pre-zero mode requested? boolean dirty; // do current buffer contents need written? boolean b_s_open; // is backing-store data valid? jvirt_barray_ptr next; // link to next virtual barray control block backing_store_info b_s_info; // System-dependent control info }; #ifdef MEM_STATS // optional extra stuff for statistics LOCAL void print_mem_stats (j_common_ptr cinfo, int pool_id) { #ifndef ITF_FINAL my_mem_ptr mem = (my_mem_ptr) cinfo->mem; small_pool_ptr shdr_ptr; large_pool_ptr lhdr_ptr; // Since this is only a debugging stub, we can cheat a little by using // * fprintf directly rather than going through the trace message code. // * This is helpful because message parm array can't handle longs. fprintf(stderr, "Freeing pool %d, total space = %ld\n", pool_id, mem->total_space_allocated); for (lhdr_ptr = mem->large_list[pool_id]; lhdr_ptr != NULL; lhdr_ptr = lhdr_ptr->hdr.next) { fprintf(stderr, " Large chunk used %ld\n", (LONG) lhdr_ptr->hdr.bytes_used); } for (shdr_ptr = mem->small_list[pool_id]; shdr_ptr != NULL; shdr_ptr = shdr_ptr->hdr.next) { fprintf(stderr, " Small chunk used %ld free %ld\n", (LONG) shdr_ptr->hdr.bytes_used, (LONG) shdr_ptr->hdr.bytes_left); } #endif } #endif // MEM_STATS LOCAL void out_of_memory (j_common_ptr cinfo, int which) // Report an out-of-memory error and stop execution // If we compiled MEM_STATS support, report alloc requests before dying { #ifdef MEM_STATS cinfo->err->trace_level = 2; // force self_destruct to report stats #endif ERREXIT1(cinfo, JERR_OUT_OF_MEMORY, which); } // * Allocation of "small" objects. // * // * For these, we use pooled storage. When a new pool must be created, // * we try to get enough space for the current request plus a "slop" factor, // * where the slop will be the amount of leftover space in the new pool. // * The speed vs. space tradeoff is largely determined by the slop values. // * A different slop value is provided for each pool class (lifetime), // * and we also distinguish the first pool of a class from later ones. // * NOTE: the values given work fairly well on both 16- and 32-bit-int // * machines, but may be too small if longs are 64 bits or more. static const size_t first_pool_slop[JPOOL_NUMPOOLS] = { 1600, // first PERMANENT pool 16000 // first IMAGE pool }; static const size_t extra_pool_slop[JPOOL_NUMPOOLS] = { 0, // additional PERMANENT pools 5000 // additional IMAGE pools }; #define MIN_SLOP 50 // greater than 0 to avoid futile looping METHODDEF void * alloc_small (j_common_ptr cinfo, int pool_id, size_t sizeofobject) // Allocate a "small" object { my_mem_ptr mem = (my_mem_ptr) cinfo->mem; small_pool_ptr hdr_ptr, prev_hdr_ptr; char * data_ptr; size_t odd_bytes, min_request, slop; // Check for unsatisfiable request (do now to ensure no overflow below) if (sizeofobject > (size_t) (MAX_ALLOC_CHUNK-SIZEOF(small_pool_hdr))) out_of_memory(cinfo, 1); // request exceeds malloc's ability // Round up the requested size to a multiple of SIZEOF(ALIGN_TYPE) odd_bytes = sizeofobject % SIZEOF(ALIGN_TYPE); if (odd_bytes > 0) sizeofobject += SIZEOF(ALIGN_TYPE) - odd_bytes; // See if space is available in any existing pool if (pool_id < 0 || pool_id >= JPOOL_NUMPOOLS) ERREXIT1(cinfo, JERR_BAD_POOL_ID, pool_id); // safety check prev_hdr_ptr = NULL; hdr_ptr = mem->small_list[pool_id]; while (hdr_ptr != NULL) { if (hdr_ptr->hdr.bytes_left >= sizeofobject) break; // found pool with enough space prev_hdr_ptr = hdr_ptr; hdr_ptr = hdr_ptr->hdr.next; } // Time to make a new pool? if (hdr_ptr == NULL) { // min_request is what we need now, slop is what will be leftover min_request = sizeofobject + SIZEOF(small_pool_hdr); if (prev_hdr_ptr == NULL) // first pool in class? slop = first_pool_slop[pool_id]; else slop = extra_pool_slop[pool_id]; // Don't ask for more than MAX_ALLOC_CHUNK if (slop > (size_t) (MAX_ALLOC_CHUNK-min_request)) slop = (size_t) (MAX_ALLOC_CHUNK-min_request); // Try to get space, if fail reduce slop and try again for (;;) { hdr_ptr = (small_pool_ptr) jpeg_get_small(cinfo, min_request + slop); if (hdr_ptr != NULL) break; slop /= 2; if (slop < MIN_SLOP) // give up when it gets real small out_of_memory(cinfo, 2); // jpeg_get_small failed } mem->total_space_allocated += min_request + slop; // Success, initialize the new pool header and add to end of list hdr_ptr->hdr.next = NULL; hdr_ptr->hdr.bytes_used = 0; hdr_ptr->hdr.bytes_left = sizeofobject + slop; if (prev_hdr_ptr == NULL) // first pool in class? mem->small_list[pool_id] = hdr_ptr; else prev_hdr_ptr->hdr.next = hdr_ptr; } // OK, allocate the object from the current pool data_ptr = (char *) (hdr_ptr + 1); // point to first data byte in pool data_ptr += hdr_ptr->hdr.bytes_used; // point to place for object hdr_ptr->hdr.bytes_used += sizeofobject; hdr_ptr->hdr.bytes_left -= sizeofobject; return (void *) data_ptr; } // * Allocation of "large" objects. // * // * The external semantics of these are the same as "small" objects, // * except that FAR pointers are used on 80x86. However the pool // * management heuristics are quite different. We assume that each // * request is large enough that it may as well be passed directly to // * jpeg_get_large; the pool management just links everything together // * so that we can free it all on demand. // * Note: the major use of "large" objects is in JSAMPARRAY and JBLOCKARRAY // * structures. The routines that create these structures (see below) // * deliberately bunch rows together to ensure a large request size. METHODDEF void FAR * alloc_large (j_common_ptr cinfo, int pool_id, size_t sizeofobject) // Allocate a "large" object { my_mem_ptr mem = (my_mem_ptr) cinfo->mem; large_pool_ptr hdr_ptr; size_t odd_bytes; // Check for unsatisfiable request (do now to ensure no overflow below) if (sizeofobject > (size_t) (MAX_ALLOC_CHUNK-SIZEOF(large_pool_hdr))) out_of_memory(cinfo, 3); // request exceeds malloc's ability // Round up the requested size to a multiple of SIZEOF(ALIGN_TYPE) odd_bytes = sizeofobject % SIZEOF(ALIGN_TYPE); if (odd_bytes > 0) sizeofobject += SIZEOF(ALIGN_TYPE) - odd_bytes; // Always make a new pool if (pool_id < 0 || pool_id >= JPOOL_NUMPOOLS) ERREXIT1(cinfo, JERR_BAD_POOL_ID, pool_id); // safety check hdr_ptr = (large_pool_ptr) jpeg_get_large(cinfo, sizeofobject + SIZEOF(large_pool_hdr)); if (hdr_ptr == NULL) out_of_memory(cinfo, 4); // jpeg_get_large failed mem->total_space_allocated += sizeofobject + SIZEOF(large_pool_hdr); // Success, initialize the new pool header and add to list hdr_ptr->hdr.next = mem->large_list[pool_id]; // We maintain space counts in each pool header for statistical purposes, // * even though they are not needed for allocation. hdr_ptr->hdr.bytes_used = sizeofobject; hdr_ptr->hdr.bytes_left = 0; mem->large_list[pool_id] = hdr_ptr; return (void FAR *) (hdr_ptr + 1); // point to first data byte in pool } // * Creation of 2-D sample arrays. // * The pointers are in near heap, the samples themselves in FAR heap. // * // * To minimize allocation overhead and to allow I/O of large contiguous // * blocks, we allocate the sample rows in groups of as many rows as possible // * without exceeding MAX_ALLOC_CHUNK total bytes per allocation request. // * NB: the virtual array control routines, later in this file, know about // * this chunking of rows. The rowsperchunk value is left in the mem manager // * object so that it can be saved away if this sarray is the workspace for // * a virtual array. METHODDEF JSAMPARRAY alloc_sarray (j_common_ptr cinfo, int pool_id, JDIMENSION samplesperrow, JDIMENSION numrows) // Allocate a 2-D sample array { my_mem_ptr mem = (my_mem_ptr) cinfo->mem; JSAMPARRAY result; JSAMPROW workspace; JDIMENSION rowsperchunk, currow, i; LONG ltemp; // Calculate max # of rows allowed in one allocation chunk ltemp = (MAX_ALLOC_CHUNK-SIZEOF(large_pool_hdr)) / ((LONG) samplesperrow * SIZEOF(JSAMPLE)); if (ltemp <= 0) ERREXIT(cinfo, JERR_WIDTH_OVERFLOW); if (ltemp < (LONG) numrows) rowsperchunk = (JDIMENSION) ltemp; else rowsperchunk = numrows; mem->last_rowsperchunk = rowsperchunk; // Get space for row pointers (small object) result = (JSAMPARRAY) alloc_small(cinfo, pool_id, (size_t) (numrows * SIZEOF(JSAMPROW))); // Get the rows themselves (large objects) currow = 0; while (currow < numrows) { rowsperchunk = BAS_Min(rowsperchunk, numrows - currow); workspace = (JSAMPROW) alloc_large(cinfo, pool_id, (size_t) ((size_t) rowsperchunk * (size_t) samplesperrow * SIZEOF(JSAMPLE))); for (i = rowsperchunk; i > 0; i--) { result[currow++] = workspace; workspace += samplesperrow; } } return result; } // * Creation of 2-D coefficient-block arrays. // * This is essentially the same as the code for sample arrays, above. METHODDEF JBLOCKARRAY alloc_barray (j_common_ptr cinfo, int pool_id, JDIMENSION blocksperrow, JDIMENSION numrows) // Allocate a 2-D coefficient-block array { my_mem_ptr mem = (my_mem_ptr) cinfo->mem; JBLOCKARRAY result; JBLOCKROW workspace; JDIMENSION rowsperchunk, currow, i; LONG ltemp; // Calculate max # of rows allowed in one allocation chunk ltemp = (MAX_ALLOC_CHUNK-SIZEOF(large_pool_hdr)) / ((LONG) blocksperrow * SIZEOF(JBLOCK)); if (ltemp <= 0) ERREXIT(cinfo, JERR_WIDTH_OVERFLOW); if (ltemp < (LONG) numrows) rowsperchunk = (JDIMENSION) ltemp; else rowsperchunk = numrows; mem->last_rowsperchunk = rowsperchunk; // Get space for row pointers (small object) result = (JBLOCKARRAY) alloc_small(cinfo, pool_id, (size_t) (numrows * SIZEOF(JBLOCKROW))); // Get the rows themselves (large objects) currow = 0; while (currow < numrows) { rowsperchunk = BAS_Min(rowsperchunk, numrows - currow); workspace = (JBLOCKROW) alloc_large(cinfo, pool_id, (size_t) ((size_t) rowsperchunk * (size_t) blocksperrow * SIZEOF(JBLOCK))); for (i = rowsperchunk; i > 0; i--) { result[currow++] = workspace; workspace += blocksperrow; } } return result; } // * About virtual array management: // * // * The above "normal" array routines are only used to allocate strip buffers // * (as wide as the image, but just a few rows high). Full-image-sized buffers // * are handled as "virtual" arrays. The array is still accessed a strip at a // * time, but the memory manager must save the whole array for repeated // * accesses. The intended implementation is that there is a strip buffer in // * memory (as high as is possible given the desired memory limit), plus a // * backing file that holds the rest of the array. // * // * The request_virt_array routines are told the total size of the image and // * the maximum number of rows that will be accessed at once. The in-memory // * buffer must be at least as large as the maxaccess value. // * // * The request routines create control blocks but not the in-memory buffers. // * That is postponed until realize_virt_arrays is called. At that time the // * total amount of space needed is known (approximately, anyway), so free // * memory can be divided up fairly. // * // * The access_virt_array routines are responsible for making a specific strip // * area accessible (after reading or writing the backing file, if necessary). // * Note that the access routines are told whether the caller intends to modify // * the accessed strip; during a read-only pass this saves having to rewrite // * data to disk. The access routines are also responsible for pre-zeroing // * any newly accessed rows, if pre-zeroing was requested. // * // * In current usage, the access requests are usually for nonoverlapping // * strips; that is, successive access start_row numbers differ by exactly // * num_rows = maxaccess. This means we can get good performance with simple // * buffer dump/reload logic, by making the in-memory buffer be a multiple // * of the access height; then there will never be accesses across bufferload // * boundaries. The code will still work with overlapping access requests, // * but it doesn't handle bufferload overlaps very efficiently. METHODDEF jvirt_sarray_ptr request_virt_sarray (j_common_ptr cinfo, int pool_id, boolean pre_zero, JDIMENSION samplesperrow, JDIMENSION numrows, JDIMENSION maxaccess) // Request a virtual 2-D sample array { my_mem_ptr mem = (my_mem_ptr) cinfo->mem; jvirt_sarray_ptr result; // Only IMAGE-lifetime virtual arrays are currently supported if (pool_id != JPOOL_IMAGE) ERREXIT1(cinfo, JERR_BAD_POOL_ID, pool_id); // safety check // get control block result = (jvirt_sarray_ptr) alloc_small(cinfo, pool_id, SIZEOF(struct jvirt_sarray_control)); result->mem_buffer = NULL; // marks array not yet realized result->rows_in_array = numrows; result->samplesperrow = samplesperrow; result->maxaccess = maxaccess; result->pre_zero = pre_zero; result->b_s_open = FALSE; // no associated backing-store object result->next = mem->virt_sarray_list; // add to list of virtual arrays mem->virt_sarray_list = result; return result; } METHODDEF jvirt_barray_ptr request_virt_barray (j_common_ptr cinfo, int pool_id, boolean pre_zero, JDIMENSION blocksperrow, JDIMENSION numrows, JDIMENSION maxaccess) // Request a virtual 2-D coefficient-block array { my_mem_ptr mem = (my_mem_ptr) cinfo->mem; jvirt_barray_ptr result; // Only IMAGE-lifetime virtual arrays are currently supported if (pool_id != JPOOL_IMAGE) ERREXIT1(cinfo, JERR_BAD_POOL_ID, pool_id); // safety check // get control block result = (jvirt_barray_ptr) alloc_small(cinfo, pool_id, SIZEOF(struct jvirt_barray_control)); result->mem_buffer = NULL; // marks array not yet realized result->rows_in_array = numrows; result->blocksperrow = blocksperrow; result->maxaccess = maxaccess; result->pre_zero = pre_zero; result->b_s_open = FALSE; // no associated backing-store object result->next = mem->virt_barray_list; // add to list of virtual arrays mem->virt_barray_list = result; return result; } METHODDEF void realize_virt_arrays (j_common_ptr cinfo) // Allocate the in-memory buffers for any unrealized virtual arrays { my_mem_ptr mem = (my_mem_ptr) cinfo->mem; LONG space_per_minheight, maximum_space, avail_mem; LONG minheights, max_minheights; jvirt_sarray_ptr sptr; jvirt_barray_ptr bptr; // Compute the minimum space needed (maxaccess rows in each buffer) // * and the maximum space needed (full image height in each buffer). // * These may be of use to the system-dependent jpeg_mem_available routine. space_per_minheight = 0; maximum_space = 0; for (sptr = mem->virt_sarray_list; sptr != NULL; sptr = sptr->next) { if (sptr->mem_buffer == NULL) { // if not realized yet space_per_minheight += (LONG) sptr->maxaccess * (LONG) sptr->samplesperrow * SIZEOF(JSAMPLE); maximum_space += (LONG) sptr->rows_in_array * (LONG) sptr->samplesperrow * SIZEOF(JSAMPLE); } } for (bptr = mem->virt_barray_list; bptr != NULL; bptr = bptr->next) { if (bptr->mem_buffer == NULL) { // if not realized yet space_per_minheight += (LONG) bptr->maxaccess * (LONG) bptr->blocksperrow * SIZEOF(JBLOCK); maximum_space += (LONG) bptr->rows_in_array * (LONG) bptr->blocksperrow * SIZEOF(JBLOCK); } } if (space_per_minheight <= 0) return; // no unrealized arrays, no work // Determine amount of memory to actually use; this is system-dependent. avail_mem = jpeg_mem_available(cinfo, space_per_minheight, maximum_space, mem->total_space_allocated); // If the maximum space needed is available, make all the buffers full // * height; otherwise parcel it out with the same number of minheights // * in each buffer. if (avail_mem >= maximum_space) max_minheights = 1000000000L; else { max_minheights = avail_mem / space_per_minheight; // If there doesn't seem to be enough space, try to get the minimum // * anyway. This allows a "stub" implementation of jpeg_mem_available(). if (max_minheights <= 0) max_minheights = 1; } // Allocate the in-memory buffers and initialize backing store as needed. for (sptr = mem->virt_sarray_list; sptr != NULL; sptr = sptr->next) { if (sptr->mem_buffer == NULL) { // if not realized yet minheights = ((LONG) sptr->rows_in_array - 1L) / sptr->maxaccess + 1L; if (minheights <= max_minheights) { // This buffer fits in memory sptr->rows_in_mem = sptr->rows_in_array; } else { // It doesn't fit in memory, create backing store. sptr->rows_in_mem = (JDIMENSION) (max_minheights * sptr->maxaccess); jpeg_open_backing_store(cinfo, & sptr->b_s_info, (LONG) sptr->rows_in_array * (LONG) sptr->samplesperrow * (LONG) SIZEOF(JSAMPLE)); sptr->b_s_open = TRUE; } sptr->mem_buffer = alloc_sarray(cinfo, JPOOL_IMAGE, sptr->samplesperrow, sptr->rows_in_mem); sptr->rowsperchunk = mem->last_rowsperchunk; sptr->cur_start_row = 0; sptr->first_undef_row = 0; sptr->dirty = FALSE; } } for (bptr = mem->virt_barray_list; bptr != NULL; bptr = bptr->next) { if (bptr->mem_buffer == NULL) { // if not realized yet minheights = ((LONG) bptr->rows_in_array - 1L) / bptr->maxaccess + 1L; if (minheights <= max_minheights) { // This buffer fits in memory bptr->rows_in_mem = bptr->rows_in_array; } else { // It doesn't fit in memory, create backing store. bptr->rows_in_mem = (JDIMENSION) (max_minheights * bptr->maxaccess); jpeg_open_backing_store(cinfo, & bptr->b_s_info, (LONG) bptr->rows_in_array * (LONG) bptr->blocksperrow * (LONG) SIZEOF(JBLOCK)); bptr->b_s_open = TRUE; } bptr->mem_buffer = alloc_barray(cinfo, JPOOL_IMAGE, bptr->blocksperrow, bptr->rows_in_mem); bptr->rowsperchunk = mem->last_rowsperchunk; bptr->cur_start_row = 0; bptr->first_undef_row = 0; bptr->dirty = FALSE; } } } LOCAL void do_sarray_io (j_common_ptr cinfo, jvirt_sarray_ptr ptr, boolean writing) // Do backing store read or write of a virtual sample array { LONG bytesperrow, file_offset, byte_count, rows, thisrow, i; bytesperrow = (LONG) ptr->samplesperrow * SIZEOF(JSAMPLE); file_offset = ptr->cur_start_row * bytesperrow; // Loop to read or write each allocation chunk in mem_buffer for (i = 0; i < (LONG) ptr->rows_in_mem; i += ptr->rowsperchunk) { // One chunk, but check for short chunk at end of buffer rows = BAS_Min((LONG) ptr->rowsperchunk, (LONG) ptr->rows_in_mem - i); // Transfer no more than is currently defined thisrow = (LONG) ptr->cur_start_row + i; rows = BAS_Min(rows, (LONG) ptr->first_undef_row - thisrow); // Transfer no more than fits in file rows = BAS_Min(rows, (LONG) ptr->rows_in_array - thisrow); if (rows <= 0) // this chunk might be past end of file! break; byte_count = rows * bytesperrow; if (writing) (*ptr->b_s_info.write_backing_store) (cinfo, & ptr->b_s_info, (void FAR *) ptr->mem_buffer[i], file_offset, byte_count); else (*ptr->b_s_info.read_backing_store) (cinfo, & ptr->b_s_info, (void FAR *) ptr->mem_buffer[i], file_offset, byte_count); file_offset += byte_count; } } LOCAL void do_barray_io (j_common_ptr cinfo, jvirt_barray_ptr ptr, boolean writing) // Do backing store read or write of a virtual coefficient-block array { LONG bytesperrow, file_offset, byte_count, rows, thisrow, i; bytesperrow = (LONG) ptr->blocksperrow * SIZEOF(JBLOCK); file_offset = ptr->cur_start_row * bytesperrow; // Loop to read or write each allocation chunk in mem_buffer for (i = 0; i < (LONG) ptr->rows_in_mem; i += ptr->rowsperchunk) { // One chunk, but check for short chunk at end of buffer rows = BAS_Min((LONG) ptr->rowsperchunk, (LONG) ptr->rows_in_mem - i); // Transfer no more than is currently defined thisrow = (LONG) ptr->cur_start_row + i; rows = BAS_Min(rows, (LONG) ptr->first_undef_row - thisrow); // Transfer no more than fits in file rows = BAS_Min(rows, (LONG) ptr->rows_in_array - thisrow); if (rows <= 0) // this chunk might be past end of file! break; byte_count = rows * bytesperrow; if (writing) (*ptr->b_s_info.write_backing_store) (cinfo, & ptr->b_s_info, (void FAR *) ptr->mem_buffer[i], file_offset, byte_count); else (*ptr->b_s_info.read_backing_store) (cinfo, & ptr->b_s_info, (void FAR *) ptr->mem_buffer[i], file_offset, byte_count); file_offset += byte_count; } } METHODDEF JSAMPARRAY access_virt_sarray (j_common_ptr cinfo, jvirt_sarray_ptr ptr, JDIMENSION start_row, JDIMENSION num_rows, boolean writable) // Access the part of a virtual sample array starting at start_row // and extending for num_rows rows. writable is true if // caller intends to modify the accessed area. { JDIMENSION end_row = start_row + num_rows; JDIMENSION undef_row; // debugging check if (end_row > ptr->rows_in_array || num_rows > ptr->maxaccess || ptr->mem_buffer == NULL) ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS); // Make the desired part of the virtual array accessible if (start_row < ptr->cur_start_row || end_row > ptr->cur_start_row+ptr->rows_in_mem) { if (! ptr->b_s_open) ERREXIT(cinfo, JERR_VIRTUAL_BUG); // Flush old buffer contents if necessary if (ptr->dirty) { do_sarray_io(cinfo, ptr, TRUE); ptr->dirty = FALSE; } // Decide what part of virtual array to access. // * Algorithm: if target address > current window, assume forward scan, // * load starting at target address. If target address < current window, // * assume backward scan, load so that target area is top of window. // * Note that when switching from forward write to forward read, will have // * start_row = 0, so the limiting case applies and we load from 0 anyway. if (start_row > ptr->cur_start_row) { ptr->cur_start_row = start_row; } else { // use long arithmetic here to avoid overflow & unsigned problems LONG ltemp; ltemp = (LONG) end_row - (LONG) ptr->rows_in_mem; if (ltemp < 0) ltemp = 0; // don't fall off front end of file ptr->cur_start_row = (JDIMENSION) ltemp; } // Read in the selected part of the array. // * During the initial write pass, we will do no actual read // * because the selected part is all undefined. do_sarray_io(cinfo, ptr, FALSE); } // Ensure the accessed part of the array is defined; prezero if needed. // * To improve locality of access, we only prezero the part of the array // * that the caller is about to access, not the entire in-memory array. if (ptr->first_undef_row < end_row) { if (ptr->first_undef_row < start_row) { if (writable) // writer skipped over a section of array ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS); undef_row = start_row; // but reader is allowed to read ahead } else { undef_row = ptr->first_undef_row; } if (writable) ptr->first_undef_row = end_row; if (ptr->pre_zero) { size_t bytesperrow = (size_t) ptr->samplesperrow * SIZEOF(JSAMPLE); undef_row -= ptr->cur_start_row; // make indexes relative to buffer end_row -= ptr->cur_start_row; while (undef_row < end_row) { jzero_far((void FAR *) ptr->mem_buffer[undef_row], bytesperrow); undef_row++; } } else { if (! writable) // reader looking at undefined data ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS); } } // Flag the buffer dirty if caller will write in it if (writable) ptr->dirty = TRUE; // Return address of proper part of the buffer return ptr->mem_buffer + (start_row - ptr->cur_start_row); } METHODDEF JBLOCKARRAY access_virt_barray (j_common_ptr cinfo, jvirt_barray_ptr ptr, JDIMENSION start_row, JDIMENSION num_rows, boolean writable) // Access the part of a virtual block array starting at start_row // and extending for num_rows rows. writable is true if // caller intends to modify the accessed area. { JDIMENSION end_row = start_row + num_rows; JDIMENSION undef_row; // debugging check if (end_row > ptr->rows_in_array || num_rows > ptr->maxaccess || ptr->mem_buffer == NULL) ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS); // Make the desired part of the virtual array accessible if (start_row < ptr->cur_start_row || end_row > ptr->cur_start_row+ptr->rows_in_mem) { if (! ptr->b_s_open) ERREXIT(cinfo, JERR_VIRTUAL_BUG); // Flush old buffer contents if necessary if (ptr->dirty) { do_barray_io(cinfo, ptr, TRUE); ptr->dirty = FALSE; } // Decide what part of virtual array to access. // * Algorithm: if target address > current window, assume forward scan, // * load starting at target address. If target address < current window, // * assume backward scan, load so that target area is top of window. // * Note that when switching from forward write to forward read, will have // * start_row = 0, so the limiting case applies and we load from 0 anyway. if (start_row > ptr->cur_start_row) { ptr->cur_start_row = start_row; } else { // use long arithmetic here to avoid overflow & unsigned problems LONG ltemp; ltemp = (LONG) end_row - (LONG) ptr->rows_in_mem; if (ltemp < 0) ltemp = 0; // don't fall off front end of file ptr->cur_start_row = (JDIMENSION) ltemp; } // Read in the selected part of the array. // * During the initial write pass, we will do no actual read // * because the selected part is all undefined. do_barray_io(cinfo, ptr, FALSE); } // Ensure the accessed part of the array is defined; prezero if needed. // * To improve locality of access, we only prezero the part of the array // * that the caller is about to access, not the entire in-memory array. if (ptr->first_undef_row < end_row) { if (ptr->first_undef_row < start_row) { if (writable) // writer skipped over a section of array ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS); undef_row = start_row; // but reader is allowed to read ahead } else { undef_row = ptr->first_undef_row; } if (writable) ptr->first_undef_row = end_row; if (ptr->pre_zero) { size_t bytesperrow = (size_t) ptr->blocksperrow * SIZEOF(JBLOCK); undef_row -= ptr->cur_start_row; // make indexes relative to buffer end_row -= ptr->cur_start_row; while (undef_row < end_row) { jzero_far((void FAR *) ptr->mem_buffer[undef_row], bytesperrow); undef_row++; } } else { if (! writable) // reader looking at undefined data ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS); } } // Flag the buffer dirty if caller will write in it if (writable) ptr->dirty = TRUE; // Return address of proper part of the buffer return ptr->mem_buffer + (start_row - ptr->cur_start_row); } // * Release all objects belonging to a specified pool. METHODDEF void free_pool (j_common_ptr cinfo, int pool_id) { my_mem_ptr mem = (my_mem_ptr) cinfo->mem; small_pool_ptr shdr_ptr; large_pool_ptr lhdr_ptr; size_t space_freed; if (pool_id < 0 || pool_id >= JPOOL_NUMPOOLS) ERREXIT1(cinfo, JERR_BAD_POOL_ID, pool_id); // safety check #ifdef MEM_STATS if (cinfo->err->trace_level > 1) print_mem_stats(cinfo, pool_id); // print pool's memory usage statistics #endif // If freeing IMAGE pool, close any virtual arrays first if (pool_id == JPOOL_IMAGE) { jvirt_sarray_ptr sptr; jvirt_barray_ptr bptr; for (sptr = mem->virt_sarray_list; sptr != NULL; sptr = sptr->next) { if (sptr->b_s_open) { // there may be no backing store sptr->b_s_open = FALSE; // prevent recursive close if error (*sptr->b_s_info.close_backing_store) (cinfo, & sptr->b_s_info); } } mem->virt_sarray_list = NULL; for (bptr = mem->virt_barray_list; bptr != NULL; bptr = bptr->next) { if (bptr->b_s_open) { // there may be no backing store bptr->b_s_open = FALSE; // prevent recursive close if error (*bptr->b_s_info.close_backing_store) (cinfo, & bptr->b_s_info); } } mem->virt_barray_list = NULL; } // Release large objects lhdr_ptr = mem->large_list[pool_id]; mem->large_list[pool_id] = NULL; while (lhdr_ptr != NULL) { large_pool_ptr next_lhdr_ptr = lhdr_ptr->hdr.next; space_freed = lhdr_ptr->hdr.bytes_used + lhdr_ptr->hdr.bytes_left + SIZEOF(large_pool_hdr); jpeg_free_large(cinfo, (void FAR *) lhdr_ptr, space_freed); mem->total_space_allocated -= space_freed; lhdr_ptr = next_lhdr_ptr; } // Release small objects shdr_ptr = mem->small_list[pool_id]; mem->small_list[pool_id] = NULL; while (shdr_ptr != NULL) { small_pool_ptr next_shdr_ptr = shdr_ptr->hdr.next; space_freed = shdr_ptr->hdr.bytes_used + shdr_ptr->hdr.bytes_left + SIZEOF(small_pool_hdr); jpeg_free_small(cinfo, (void *) shdr_ptr, space_freed); mem->total_space_allocated -= space_freed; shdr_ptr = next_shdr_ptr; } } // * Close up shop entirely. // * Note that this cannot be called unless cinfo->mem is non-NULL. METHODDEF void self_destruct (j_common_ptr cinfo) { int pool; // Close all backing store, release all memory. // * Releasing pools in reverse order might help avoid fragmentation // * with some (brain-damaged) malloc libraries. for (pool = JPOOL_NUMPOOLS-1; pool >= JPOOL_PERMANENT; pool--) { free_pool(cinfo, pool); } // Release the memory manager control block too. jpeg_free_small(cinfo, (void *) cinfo->mem, SIZEOF(my_memory_mgr)); cinfo->mem = NULL; // ensures I will be called only once jpeg_mem_term(cinfo); // system-dependent cleanup } // * Memory manager initialization. // * When this is called, only the error manager pointer is valid in cinfo! GLOBAL void jinit_memory_mgr (j_common_ptr cinfo) { my_mem_ptr mem; LONG max_to_use; int pool; size_t test_mac; cinfo->mem = NULL; // for safety if init fails // Check for configuration errors. // * SIZEOF(ALIGN_TYPE) should be a power of 2; otherwise, it probably // * doesn't reflect any real hardware alignment requirement. // * The test is a little tricky: for X>0, X and X-1 have no one-bits // * in common if and only if X is a power of 2, ie has only one one-bit. // * Some compilers may give an "unreachable code" warning here; ignore it. if ((SIZEOF(ALIGN_TYPE) & (SIZEOF(ALIGN_TYPE)-1)) != 0) ERREXIT(cinfo, JERR_BAD_ALIGN_TYPE); // MAX_ALLOC_CHUNK must be representable as type size_t, and must be // * a multiple of SIZEOF(ALIGN_TYPE). // * Again, an "unreachable code" warning may be ignored here. // * But a "constant too large" warning means you need to fix MAX_ALLOC_CHUNK. test_mac = (size_t) MAX_ALLOC_CHUNK; if ((LONG) test_mac != MAX_ALLOC_CHUNK || (MAX_ALLOC_CHUNK % SIZEOF(ALIGN_TYPE)) != 0) ERREXIT(cinfo, JERR_BAD_ALLOC_CHUNK); max_to_use = jpeg_mem_init(cinfo); // system-dependent initialization // Attempt to allocate memory manager's control block mem = (my_mem_ptr) jpeg_get_small(cinfo, SIZEOF(my_memory_mgr)); if (mem == NULL) { jpeg_mem_term(cinfo); // system-dependent cleanup ERREXIT1(cinfo, JERR_OUT_OF_MEMORY, 0); } // OK, fill in the method pointers mem->pub.alloc_small = alloc_small; mem->pub.alloc_large = alloc_large; mem->pub.alloc_sarray = alloc_sarray; mem->pub.alloc_barray = alloc_barray; mem->pub.request_virt_sarray = request_virt_sarray; mem->pub.request_virt_barray = request_virt_barray; mem->pub.realize_virt_arrays = realize_virt_arrays; mem->pub.access_virt_sarray = access_virt_sarray; mem->pub.access_virt_barray = access_virt_barray; mem->pub.free_pool = free_pool; mem->pub.self_destruct = self_destruct; // Initialize working state mem->pub.max_memory_to_use = max_to_use; for (pool = JPOOL_NUMPOOLS-1; pool >= JPOOL_PERMANENT; pool--) { mem->small_list[pool] = NULL; mem->large_list[pool] = NULL; } mem->virt_sarray_list = NULL; mem->virt_barray_list = NULL; mem->total_space_allocated = SIZEOF(my_memory_mgr); // Declare ourselves open for business cinfo->mem = & mem->pub; // Check for an environment variable JPEGMEM; if found, override the // * default max_memory setting from jpeg_mem_init. Note that the // * surrounding application may again override this value. // * If your system doesn't support getenv(), define NO_GETENV to disable // * this feature. #ifndef NO_GETENV { char * memenv; if ((memenv = getenv("JPEGMEM")) != NULL) { char ch = 'x'; if (sscanf(memenv, "%ld%c", &max_to_use, &ch) > 0) { if (ch == 'm' || ch == 'M') max_to_use *= 1000L; mem->pub.max_memory_to_use = max_to_use * 1000L; } } } #endif } #ifdef _MSC_VER #pragma warning(pop) #endif