/* * 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...) */ #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 */ // bph id software added: #define NO_GETENV #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 */ #define ALIGN_TYPE double #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 ) { 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 /* 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 = 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 = 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 = 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 = MIN( rows, (long) ptr->first_undef_row - thisrow ); /* Transfer no more than fits in file */ rows = 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 = 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 = MIN( rows, (long) ptr->first_undef_row - thisrow ); /* Transfer no more than fits in file */ rows = 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 }