MagickCore  6.9.12-67
Convert, Edit, Or Compose Bitmap Images
 All Data Structures
memory.c
1 /*
2 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
3 % %
4 % %
5 % %
6 % M M EEEEE M M OOO RRRR Y Y %
7 % MM MM E MM MM O O R R Y Y %
8 % M M M EEE M M M O O RRRR Y %
9 % M M E M M O O R R Y %
10 % M M EEEEE M M OOO R R Y %
11 % %
12 % %
13 % MagickCore Memory Allocation Methods %
14 % %
15 % Software Design %
16 % Cristy %
17 % July 1998 %
18 % %
19 % %
20 % Copyright 1999-2021 ImageMagick Studio LLC, a non-profit organization %
21 % dedicated to making software imaging solutions freely available. %
22 % %
23 % You may not use this file except in compliance with the License. You may %
24 % obtain a copy of the License at %
25 % %
26 % https://imagemagick.org/script/license.php %
27 % %
28 % Unless required by applicable law or agreed to in writing, software %
29 % distributed under the License is distributed on an "AS IS" BASIS, %
30 % WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. %
31 % See the License for the specific language governing permissions and %
32 % limitations under the License. %
33 % %
34 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
35 %
36 % We provide these memory allocators:
37 %
38 % AcquireCriticalMemory(): allocate a small memory request with
39 % AcquireMagickMemory(), however, on fail throw a fatal exception and exit.
40 % Free the memory reserve with RelinquishMagickMemory().
41 % AcquireAlignedMemory(): allocate a small memory request that is aligned
42 % on a cache line. On fail, return NULL for possible recovery.
43 % Free the memory reserve with RelinquishMagickMemory().
44 % AcquireMagickMemory()/ResizeMagickMemory(): allocate a small to medium
45 % memory request, typically with malloc()/realloc(). On fail, return NULL
46 % for possible recovery. Free the memory reserve with
47 % RelinquishMagickMemory().
48 % AcquireQuantumMemory()/ResizeQuantumMemory(): allocate a small to medium
49 % memory request. This is a secure memory allocator as it accepts two
50 % parameters, count and quantum, to ensure the request does not overflow.
51 % It also check to ensure the request does not exceed the maximum memory
52 % per the security policy. Free the memory reserve with
53 % RelinquishMagickMemory().
54 % AcquireVirtualMemory(): allocate a large memory request either in heap,
55 % memory-mapped, or memory-mapped on disk depending on whether heap
56 % allocation fails or if the request exceeds the maximum memory policy.
57 % Free the memory reserve with RelinquishVirtualMemory().
58 % ResetMagickMemory(): fills the bytes of the memory area with a constant
59 % byte.
60 %
61 % In addition, we provide hooks for your own memory constructor/destructors.
62 % You can also utilize our internal custom allocator as follows: Segregate
63 % our memory requirements from any program that calls our API. This should
64 % help reduce the risk of others changing our program state or causing memory
65 % corruption.
66 %
67 % Our custom memory allocation manager implements a best-fit allocation policy
68 % using segregated free lists. It uses a linear distribution of size classes
69 % for lower sizes and a power of two distribution of size classes at higher
70 % sizes. It is based on the paper, "Fast Memory Allocation using Lazy Fits."
71 % written by Yoo C. Chung.
72 %
73 % By default, C's standard library is used (e.g. malloc); use the
74 % custom memory allocator by defining MAGICKCORE_ANONYMOUS_MEMORY_SUPPORT
75 % to allocate memory with private anonymous mapping rather than from the
76 % heap.
77 %
78 */
79 
80 /*
81  Include declarations.
82 */
83 #include "magick/studio.h"
84 #include "magick/blob.h"
85 #include "magick/blob-private.h"
86 #include "magick/exception.h"
87 #include "magick/exception-private.h"
88 #include "magick/image-private.h"
89 #include "magick/memory_.h"
90 #include "magick/memory-private.h"
91 #include "magick/policy.h"
92 #include "magick/random_.h"
93 #include "magick/resource_.h"
94 #include "magick/semaphore.h"
95 #include "magick/string_.h"
96 #include "magick/string-private.h"
97 #include "magick/utility-private.h"
98 
99 /*
100  Define declarations.
101 */
102 #define BlockFooter(block,size) \
103  ((size_t *) ((char *) (block)+(size)-2*sizeof(size_t)))
104 #define BlockHeader(block) ((size_t *) (block)-1)
105 #define BlockThreshold 1024
106 #define MaxBlockExponent 16
107 #define MaxBlocks ((BlockThreshold/(4*sizeof(size_t)))+MaxBlockExponent+1)
108 #define MaxSegments 1024
109 #define NextBlock(block) ((char *) (block)+SizeOfBlock(block))
110 #define NextBlockInList(block) (*(void **) (block))
111 #define PreviousBlock(block) ((char *) (block)-(*((size_t *) (block)-2)))
112 #define PreviousBlockBit 0x01
113 #define PreviousBlockInList(block) (*((void **) (block)+1))
114 #define SegmentSize (2*1024*1024)
115 #define SizeMask (~0x01)
116 #define SizeOfBlock(block) (*BlockHeader(block) & SizeMask)
117 
118 /*
119  Typedef declarations.
120 */
121 typedef enum
122 {
123  UndefinedVirtualMemory,
124  AlignedVirtualMemory,
125  MapVirtualMemory,
126  UnalignedVirtualMemory
127 } VirtualMemoryType;
128 
129 typedef struct _DataSegmentInfo
130 {
131  void
132  *allocation,
133  *bound;
134 
135  MagickBooleanType
136  mapped;
137 
138  size_t
139  length;
140 
141  struct _DataSegmentInfo
142  *previous,
143  *next;
145 
146 typedef struct _MagickMemoryMethods
147 {
148  AcquireMemoryHandler
149  acquire_memory_handler;
150 
151  ResizeMemoryHandler
152  resize_memory_handler;
153 
154  DestroyMemoryHandler
155  destroy_memory_handler;
156 
157  AcquireAlignedMemoryHandler
158  acquire_aligned_memory_handler;
159 
160  RelinquishAlignedMemoryHandler
161  relinquish_aligned_memory_handler;
163 
165 {
166  char
167  filename[MagickPathExtent];
168 
169  VirtualMemoryType
170  type;
171 
172  size_t
173  length;
174 
175  void
176  *blob;
177 
178  size_t
179  signature;
180 };
181 
182 typedef struct _MemoryPool
183 {
184  size_t
185  allocation;
186 
187  void
188  *blocks[MaxBlocks+1];
189 
190  size_t
191  number_segments;
192 
194  *segments[MaxSegments],
195  segment_pool[MaxSegments];
196 } MemoryPool;
197 
198 /*
199  Global declarations.
200 */
201 static size_t
202  max_memory_request = 0,
203  virtual_anonymous_memory = 0;
204 
205 #if defined _MSC_VER
206 static void *MSCMalloc(size_t size)
207 {
208  return(malloc(size));
209 }
210 
211 static void *MSCRealloc(void* ptr, size_t size)
212 {
213  return(realloc(ptr,size));
214 }
215 
216 static void MSCFree(void* ptr)
217 {
218  free(ptr);
219 }
220 #endif
221 
222 static MagickMemoryMethods
223  memory_methods =
224  {
225 #if defined _MSC_VER
226  (AcquireMemoryHandler) MSCMalloc,
227  (ResizeMemoryHandler) MSCRealloc,
228  (DestroyMemoryHandler) MSCFree,
229 #else
230  (AcquireMemoryHandler) malloc,
231  (ResizeMemoryHandler) realloc,
232  (DestroyMemoryHandler) free,
233 #endif
234  (AcquireAlignedMemoryHandler) NULL,
235  (RelinquishAlignedMemoryHandler) NULL
236  };
237 #if defined(MAGICKCORE_ANONYMOUS_MEMORY_SUPPORT)
238 static MemoryPool
239  memory_pool;
240 
241 static SemaphoreInfo
242  *memory_semaphore = (SemaphoreInfo *) NULL;
243 
244 static volatile DataSegmentInfo
245  *free_segments = (DataSegmentInfo *) NULL;
246 
247 /*
248  Forward declarations.
249 */
250 static MagickBooleanType
251  ExpandHeap(size_t);
252 #endif
253 
254 /*
255 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
256 % %
257 % %
258 % %
259 % A c q u i r e A l i g n e d M e m o r y %
260 % %
261 % %
262 % %
263 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
264 %
265 % AcquireAlignedMemory() returns a pointer to a block of memory whose size is
266 % at least (count*quantum) bytes, and whose address is aligned on a cache line.
267 %
268 % The format of the AcquireAlignedMemory method is:
269 %
270 % void *AcquireAlignedMemory(const size_t count,const size_t quantum)
271 %
272 % A description of each parameter follows:
273 %
274 % o count: the number of objects to allocate contiguously.
275 %
276 % o quantum: the size (in bytes) of each object.
277 %
278 */
279 #if defined(MAGICKCORE_HAVE_ALIGNED_MALLOC)
280 #define AcquireAlignedMemory_Actual AcquireAlignedMemory_STDC
281 static inline void *AcquireAlignedMemory_STDC(const size_t size)
282 {
283  size_t
284  extent = CACHE_ALIGNED(size);
285 
286  if (extent < size)
287  {
288  errno=ENOMEM;
289  return(NULL);
290  }
291  return(aligned_alloc(CACHE_LINE_SIZE,extent));
292 }
293 #elif defined(MAGICKCORE_HAVE_POSIX_MEMALIGN)
294 #define AcquireAlignedMemory_Actual AcquireAlignedMemory_POSIX
295 static inline void *AcquireAlignedMemory_POSIX(const size_t size)
296 {
297  void
298  *memory;
299 
300  if (posix_memalign(&memory,CACHE_LINE_SIZE,size))
301  return(NULL);
302  return(memory);
303 }
304 #elif defined(MAGICKCORE_HAVE__ALIGNED_MALLOC)
305 #define AcquireAlignedMemory_Actual AcquireAlignedMemory_WinAPI
306 static inline void *AcquireAlignedMemory_WinAPI(const size_t size)
307 {
308  return(_aligned_malloc(size,CACHE_LINE_SIZE));
309 }
310 #else
311 #define ALIGNMENT_OVERHEAD \
312  (MAGICKCORE_MAX_ALIGNMENT_PADDING(CACHE_LINE_SIZE) + MAGICKCORE_SIZEOF_VOID_P)
313 static inline void *reserve_space_for_actual_base_address(void *const p)
314 {
315  return((void **) p+1);
316 }
317 
318 static inline void **pointer_to_space_for_actual_base_address(void *const p)
319 {
320  return((void **) p-1);
321 }
322 
323 static inline void *actual_base_address(void *const p)
324 {
325  return(*pointer_to_space_for_actual_base_address(p));
326 }
327 
328 static inline void *align_to_cache(void *const p)
329 {
330  return((void *) CACHE_ALIGNED((MagickAddressType) p));
331 }
332 
333 static inline void *adjust(void *const p)
334 {
335  return(align_to_cache(reserve_space_for_actual_base_address(p)));
336 }
337 
338 #define AcquireAlignedMemory_Actual AcquireAlignedMemory_Generic
339 static inline void *AcquireAlignedMemory_Generic(const size_t size)
340 {
341  size_t
342  extent;
343 
344  void
345  *memory,
346  *p;
347 
348  #if SIZE_MAX < ALIGNMENT_OVERHEAD
349  #error "CACHE_LINE_SIZE is way too big."
350  #endif
351  extent=(size+ALIGNMENT_OVERHEAD);
352  if (extent <= size)
353  {
354  errno=ENOMEM;
355  return(NULL);
356  }
357  p=AcquireMagickMemory(extent);
358  if (p == NULL)
359  return(NULL);
360  memory=adjust(p);
361  *pointer_to_space_for_actual_base_address(memory)=p;
362  return(memory);
363 }
364 #endif
365 
366 MagickExport void *AcquireAlignedMemory(const size_t count,const size_t quantum)
367 {
368  size_t
369  size;
370 
371  if (HeapOverflowSanityCheckGetSize(count,quantum,&size) != MagickFalse)
372  {
373  errno=ENOMEM;
374  return(NULL);
375  }
376  if (memory_methods.acquire_aligned_memory_handler != (AcquireAlignedMemoryHandler) NULL)
377  return(memory_methods.acquire_aligned_memory_handler(size,CACHE_LINE_SIZE));
378  return(AcquireAlignedMemory_Actual(size));
379 }
380 
381 #if defined(MAGICKCORE_ANONYMOUS_MEMORY_SUPPORT)
382 /*
383 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
384 % %
385 % %
386 % %
387 + A c q u i r e B l o c k %
388 % %
389 % %
390 % %
391 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
392 %
393 % AcquireBlock() returns a pointer to a block of memory at least size bytes
394 % suitably aligned for any use.
395 %
396 % The format of the AcquireBlock method is:
397 %
398 % void *AcquireBlock(const size_t size)
399 %
400 % A description of each parameter follows:
401 %
402 % o size: the size of the memory in bytes to allocate.
403 %
404 */
405 
406 static inline size_t AllocationPolicy(size_t size)
407 {
408  size_t
409  blocksize;
410 
411  /*
412  The linear distribution.
413  */
414  assert(size != 0);
415  assert(size % (4*sizeof(size_t)) == 0);
416  if (size <= BlockThreshold)
417  return(size/(4*sizeof(size_t)));
418  /*
419  Check for the largest block size.
420  */
421  if (size > (size_t) (BlockThreshold*(1L << (MaxBlockExponent-1L))))
422  return(MaxBlocks-1L);
423  /*
424  Otherwise use a power of two distribution.
425  */
426  blocksize=BlockThreshold/(4*sizeof(size_t));
427  for ( ; size > BlockThreshold; size/=2)
428  blocksize++;
429  assert(blocksize > (BlockThreshold/(4*sizeof(size_t))));
430  assert(blocksize < (MaxBlocks-1L));
431  return(blocksize);
432 }
433 
434 static inline void InsertFreeBlock(void *block,const size_t i)
435 {
436  void
437  *next,
438  *previous;
439 
440  size_t
441  size;
442 
443  size=SizeOfBlock(block);
444  previous=(void *) NULL;
445  next=memory_pool.blocks[i];
446  while ((next != (void *) NULL) && (SizeOfBlock(next) < size))
447  {
448  previous=next;
449  next=NextBlockInList(next);
450  }
451  PreviousBlockInList(block)=previous;
452  NextBlockInList(block)=next;
453  if (previous != (void *) NULL)
454  NextBlockInList(previous)=block;
455  else
456  memory_pool.blocks[i]=block;
457  if (next != (void *) NULL)
458  PreviousBlockInList(next)=block;
459 }
460 
461 static inline void RemoveFreeBlock(void *block,const size_t i)
462 {
463  void
464  *next,
465  *previous;
466 
467  next=NextBlockInList(block);
468  previous=PreviousBlockInList(block);
469  if (previous == (void *) NULL)
470  memory_pool.blocks[i]=next;
471  else
472  NextBlockInList(previous)=next;
473  if (next != (void *) NULL)
474  PreviousBlockInList(next)=previous;
475 }
476 
477 static void *AcquireBlock(size_t size)
478 {
479  size_t
480  i;
481 
482  void
483  *block;
484 
485  /*
486  Find free block.
487  */
488  size=(size_t) (size+sizeof(size_t)+6*sizeof(size_t)-1) & -(4U*sizeof(size_t));
489  i=AllocationPolicy(size);
490  block=memory_pool.blocks[i];
491  while ((block != (void *) NULL) && (SizeOfBlock(block) < size))
492  block=NextBlockInList(block);
493  if (block == (void *) NULL)
494  {
495  i++;
496  while (memory_pool.blocks[i] == (void *) NULL)
497  i++;
498  block=memory_pool.blocks[i];
499  if (i >= MaxBlocks)
500  return((void *) NULL);
501  }
502  assert((*BlockHeader(NextBlock(block)) & PreviousBlockBit) == 0);
503  assert(SizeOfBlock(block) >= size);
504  RemoveFreeBlock(block,AllocationPolicy(SizeOfBlock(block)));
505  if (SizeOfBlock(block) > size)
506  {
507  size_t
508  blocksize;
509 
510  void
511  *next;
512 
513  /*
514  Split block.
515  */
516  next=(char *) block+size;
517  blocksize=SizeOfBlock(block)-size;
518  *BlockHeader(next)=blocksize;
519  *BlockFooter(next,blocksize)=blocksize;
520  InsertFreeBlock(next,AllocationPolicy(blocksize));
521  *BlockHeader(block)=size | (*BlockHeader(block) & ~SizeMask);
522  }
523  assert(size == SizeOfBlock(block));
524  *BlockHeader(NextBlock(block))|=PreviousBlockBit;
525  memory_pool.allocation+=size;
526  return(block);
527 }
528 #endif
529 
530 /*
531 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
532 % %
533 % %
534 % %
535 % A c q u i r e M a g i c k M e m o r y %
536 % %
537 % %
538 % %
539 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
540 %
541 % AcquireMagickMemory() returns a pointer to a block of memory at least size
542 % bytes suitably aligned for any use.
543 %
544 % The format of the AcquireMagickMemory method is:
545 %
546 % void *AcquireMagickMemory(const size_t size)
547 %
548 % A description of each parameter follows:
549 %
550 % o size: the size of the memory in bytes to allocate.
551 %
552 */
553 MagickExport void *AcquireMagickMemory(const size_t size)
554 {
555  void
556  *memory;
557 
558 #if !defined(MAGICKCORE_ANONYMOUS_MEMORY_SUPPORT)
559  memory=memory_methods.acquire_memory_handler(size == 0 ? 1UL : size);
560 #else
561  if (memory_semaphore == (SemaphoreInfo *) NULL)
562  ActivateSemaphoreInfo(&memory_semaphore);
563  if (free_segments == (DataSegmentInfo *) NULL)
564  {
565  LockSemaphoreInfo(memory_semaphore);
566  if (free_segments == (DataSegmentInfo *) NULL)
567  {
568  ssize_t
569  i;
570 
571  assert(2*sizeof(size_t) > (size_t) (~SizeMask));
572  (void) memset(&memory_pool,0,sizeof(memory_pool));
573  memory_pool.allocation=SegmentSize;
574  memory_pool.blocks[MaxBlocks]=(void *) (-1);
575  for (i=0; i < MaxSegments; i++)
576  {
577  if (i != 0)
578  memory_pool.segment_pool[i].previous=
579  (&memory_pool.segment_pool[i-1]);
580  if (i != (MaxSegments-1))
581  memory_pool.segment_pool[i].next=(&memory_pool.segment_pool[i+1]);
582  }
583  free_segments=(&memory_pool.segment_pool[0]);
584  }
585  UnlockSemaphoreInfo(memory_semaphore);
586  }
587  LockSemaphoreInfo(memory_semaphore);
588  memory=AcquireBlock(size == 0 ? 1UL : size);
589  if (memory == (void *) NULL)
590  {
591  if (ExpandHeap(size == 0 ? 1UL : size) != MagickFalse)
592  memory=AcquireBlock(size == 0 ? 1UL : size);
593  }
594  UnlockSemaphoreInfo(memory_semaphore);
595 #endif
596  return(memory);
597 }
598 
599 /*
600 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
601 % %
602 % %
603 % %
604 % A c q u i r e C r i t i c a l M e m o r y %
605 % %
606 % %
607 % %
608 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
609 %
610 % AcquireCriticalMemory() is just like AcquireMagickMemory(), throws a fatal
611 % exception if the memory cannot be acquired.
612 %
613 % That is, AcquireCriticalMemory() returns a pointer to a block of memory that
614 % is at least size bytes, and that is suitably aligned for any use; however,
615 % if this is not possible, it throws an exception and terminates the program
616 % as unceremoniously as possible.
617 %
618 % The format of the AcquireCriticalMemory method is:
619 %
620 % void *AcquireCriticalMemory(const size_t size)
621 %
622 % A description of each parameter follows:
623 %
624 % o size: the size (in bytes) of the memory to allocate.
625 %
626 */
627 MagickExport void *AcquireCriticalMemory(const size_t size)
628 {
629  void
630  *memory;
631 
632  /*
633  Fail if memory request cannot be fulfilled.
634  */
635  memory=AcquireMagickMemory(size);
636  if (memory == (void *) NULL)
637  ThrowFatalException(ResourceLimitFatalError,"MemoryAllocationFailed");
638  return(memory);
639 }
640 
641 /*
642 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
643 % %
644 % %
645 % %
646 % A c q u i r e Q u a n t u m M e m o r y %
647 % %
648 % %
649 % %
650 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
651 %
652 % AcquireQuantumMemory() returns a pointer to a block of memory at least
653 % count * quantum bytes suitably aligned for any use.
654 %
655 % The format of the AcquireQuantumMemory method is:
656 %
657 % void *AcquireQuantumMemory(const size_t count,const size_t quantum)
658 %
659 % A description of each parameter follows:
660 %
661 % o count: the number of objects to allocate contiguously.
662 %
663 % o quantum: the size (in bytes) of each object.
664 %
665 */
666 MagickExport void *AcquireQuantumMemory(const size_t count,const size_t quantum)
667 {
668  size_t
669  size;
670 
671  if ((HeapOverflowSanityCheckGetSize(count,quantum,&size) != MagickFalse) ||
672  (size > GetMaxMemoryRequest()))
673  {
674  errno=ENOMEM;
675  return(NULL);
676  }
677  return(AcquireMagickMemory(size));
678 }
679 
680 /*
681 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
682 % %
683 % %
684 % %
685 % A c q u i r e V i r t u a l M e m o r y %
686 % %
687 % %
688 % %
689 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
690 %
691 % AcquireVirtualMemory() allocates a pointer to a block of memory at least
692 % size bytes suitably aligned for any use. In addition to heap, it also
693 % supports memory-mapped and file-based memory-mapped memory requests.
694 %
695 % The format of the AcquireVirtualMemory method is:
696 %
697 % MemoryInfo *AcquireVirtualMemory(const size_t count,const size_t quantum)
698 %
699 % A description of each parameter follows:
700 %
701 % o count: the number of objects to allocate contiguously.
702 %
703 % o quantum: the size (in bytes) of each object.
704 %
705 */
706 MagickExport MemoryInfo *AcquireVirtualMemory(const size_t count,
707  const size_t quantum)
708 {
709  char
710  *value;
711 
712  MemoryInfo
713  *memory_info;
714 
715  size_t
716  size;
717 
718  if (HeapOverflowSanityCheckGetSize(count,quantum,&size) != MagickFalse)
719  {
720  errno=ENOMEM;
721  return((MemoryInfo *) NULL);
722  }
723  if (virtual_anonymous_memory == 0)
724  {
725  virtual_anonymous_memory=1;
726  value=GetPolicyValue("system:memory-map");
727  if (LocaleCompare(value,"anonymous") == 0)
728  {
729  /*
730  The security policy sets anonymous mapping for the memory request.
731  */
732 #if defined(MAGICKCORE_HAVE_MMAP) && defined(MAP_ANONYMOUS)
733  virtual_anonymous_memory=2;
734 #endif
735  }
736  value=DestroyString(value);
737  }
738  memory_info=(MemoryInfo *) MagickAssumeAligned(AcquireAlignedMemory(1,
739  sizeof(*memory_info)));
740  if (memory_info == (MemoryInfo *) NULL)
741  ThrowFatalException(ResourceLimitFatalError,"MemoryAllocationFailed");
742  (void) memset(memory_info,0,sizeof(*memory_info));
743  memory_info->length=size;
744  memory_info->signature=MagickCoreSignature;
745  if ((virtual_anonymous_memory == 1) && (size <= GetMaxMemoryRequest()))
746  {
747  memory_info->blob=AcquireAlignedMemory(1,size);
748  if (memory_info->blob != NULL)
749  memory_info->type=AlignedVirtualMemory;
750  }
751  if (memory_info->blob == NULL)
752  {
753  /*
754  Acquire anonymous memory map.
755  */
756  memory_info->blob=NULL;
757  if (size <= GetMaxMemoryRequest())
758  memory_info->blob=MapBlob(-1,IOMode,0,size);
759  if (memory_info->blob != NULL)
760  memory_info->type=MapVirtualMemory;
761  else
762  {
763  int
764  file;
765 
766  /*
767  Anonymous memory mapping failed, try file-backed memory mapping.
768  */
769  file=AcquireUniqueFileResource(memory_info->filename);
770  if (file != -1)
771  {
772  MagickOffsetType
773  offset;
774 
775  offset=(MagickOffsetType) lseek(file,size-1,SEEK_SET);
776  if ((offset == (MagickOffsetType) (size-1)) &&
777  (write(file,"",1) == 1))
778  {
779 #if !defined(MAGICKCORE_HAVE_POSIX_FALLOCATE)
780  memory_info->blob=MapBlob(file,IOMode,0,size);
781 #else
782  if (posix_fallocate(file,0,(MagickOffsetType) size) == 0)
783  memory_info->blob=MapBlob(file,IOMode,0,size);
784 #endif
785  if (memory_info->blob != NULL)
786  memory_info->type=MapVirtualMemory;
787  else
788  {
789  (void) RelinquishUniqueFileResource(
790  memory_info->filename);
791  *memory_info->filename='\0';
792  }
793  }
794  (void) close(file);
795  }
796  }
797  }
798  if (memory_info->blob == NULL)
799  {
800  memory_info->blob=AcquireQuantumMemory(1,size);
801  if (memory_info->blob != NULL)
802  memory_info->type=UnalignedVirtualMemory;
803  }
804  if (memory_info->blob == NULL)
805  memory_info=RelinquishVirtualMemory(memory_info);
806  return(memory_info);
807 }
808 
809 /*
810 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
811 % %
812 % %
813 % %
814 % C o p y M a g i c k M e m o r y %
815 % %
816 % %
817 % %
818 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
819 %
820 % CopyMagickMemory() copies size bytes from memory area source to the
821 % destination. Copying between objects that overlap will take place
822 % correctly. It returns destination.
823 %
824 % The format of the CopyMagickMemory method is:
825 %
826 % void *CopyMagickMemory(void *magick_restrict destination,
827 % const void *magick_restrict source,const size_t size)
828 %
829 % A description of each parameter follows:
830 %
831 % o destination: the destination.
832 %
833 % o source: the source.
834 %
835 % o size: the size of the memory in bytes to allocate.
836 %
837 */
838 MagickExport void *CopyMagickMemory(void *magick_restrict destination,
839  const void *magick_restrict source,const size_t size)
840 {
841  const unsigned char
842  *p;
843 
844  unsigned char
845  *q;
846 
847  assert(destination != (void *) NULL);
848  assert(source != (const void *) NULL);
849  p=(const unsigned char *) source;
850  q=(unsigned char *) destination;
851  if (((q+size) < p) || (q > (p+size)))
852  switch (size)
853  {
854  default: return(memcpy(destination,source,size));
855  case 8: *q++=(*p++);
856  case 7: *q++=(*p++);
857  case 6: *q++=(*p++);
858  case 5: *q++=(*p++);
859  case 4: *q++=(*p++);
860  case 3: *q++=(*p++);
861  case 2: *q++=(*p++);
862  case 1: *q++=(*p++);
863  case 0: return(destination);
864  }
865  return(memmove(destination,source,size));
866 }
867 
868 /*
869 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
870 % %
871 % %
872 % %
873 + D e s t r o y M a g i c k M e m o r y %
874 % %
875 % %
876 % %
877 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
878 %
879 % DestroyMagickMemory() deallocates memory associated with the memory manager.
880 %
881 % The format of the DestroyMagickMemory method is:
882 %
883 % DestroyMagickMemory(void)
884 %
885 */
886 MagickExport void DestroyMagickMemory(void)
887 {
888 #if defined(MAGICKCORE_ANONYMOUS_MEMORY_SUPPORT)
889  ssize_t
890  i;
891 
892  if (memory_semaphore == (SemaphoreInfo *) NULL)
893  ActivateSemaphoreInfo(&memory_semaphore);
894  LockSemaphoreInfo(memory_semaphore);
895  for (i=0; i < (ssize_t) memory_pool.number_segments; i++)
896  if (memory_pool.segments[i]->mapped == MagickFalse)
897  memory_methods.destroy_memory_handler(
898  memory_pool.segments[i]->allocation);
899  else
900  (void) UnmapBlob(memory_pool.segments[i]->allocation,
901  memory_pool.segments[i]->length);
902  free_segments=(DataSegmentInfo *) NULL;
903  (void) memset(&memory_pool,0,sizeof(memory_pool));
904  UnlockSemaphoreInfo(memory_semaphore);
905  DestroySemaphoreInfo(&memory_semaphore);
906 #endif
907 }
908 
909 #if defined(MAGICKCORE_ANONYMOUS_MEMORY_SUPPORT)
910 /*
911 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
912 % %
913 % %
914 % %
915 + E x p a n d H e a p %
916 % %
917 % %
918 % %
919 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
920 %
921 % ExpandHeap() get more memory from the system. It returns MagickTrue on
922 % success otherwise MagickFalse.
923 %
924 % The format of the ExpandHeap method is:
925 %
926 % MagickBooleanType ExpandHeap(size_t size)
927 %
928 % A description of each parameter follows:
929 %
930 % o size: the size of the memory in bytes we require.
931 %
932 */
933 static MagickBooleanType ExpandHeap(size_t size)
934 {
936  *segment_info;
937 
938  MagickBooleanType
939  mapped;
940 
941  ssize_t
942  i;
943 
944  void
945  *block;
946 
947  size_t
948  blocksize;
949 
950  void
951  *segment;
952 
953  blocksize=((size+12*sizeof(size_t))+SegmentSize-1) & -SegmentSize;
954  assert(memory_pool.number_segments < MaxSegments);
955  segment=MapBlob(-1,IOMode,0,blocksize);
956  mapped=segment != (void *) NULL ? MagickTrue : MagickFalse;
957  if (segment == (void *) NULL)
958  segment=(void *) memory_methods.acquire_memory_handler(blocksize);
959  if (segment == (void *) NULL)
960  return(MagickFalse);
961  segment_info=(DataSegmentInfo *) free_segments;
962  free_segments=segment_info->next;
963  segment_info->mapped=mapped;
964  segment_info->length=blocksize;
965  segment_info->allocation=segment;
966  segment_info->bound=(char *) segment+blocksize;
967  i=(ssize_t) memory_pool.number_segments-1;
968  for ( ; (i >= 0) && (memory_pool.segments[i]->allocation > segment); i--)
969  memory_pool.segments[i+1]=memory_pool.segments[i];
970  memory_pool.segments[i+1]=segment_info;
971  memory_pool.number_segments++;
972  size=blocksize-12*sizeof(size_t);
973  block=(char *) segment_info->allocation+4*sizeof(size_t);
974  *BlockHeader(block)=size | PreviousBlockBit;
975  *BlockFooter(block,size)=size;
976  InsertFreeBlock(block,AllocationPolicy(size));
977  block=NextBlock(block);
978  assert(block < segment_info->bound);
979  *BlockHeader(block)=2*sizeof(size_t);
980  *BlockHeader(NextBlock(block))=PreviousBlockBit;
981  return(MagickTrue);
982 }
983 #endif
984 
985 /*
986 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
987 % %
988 % %
989 % %
990 % G e t M a g i c k M e m o r y M e t h o d s %
991 % %
992 % %
993 % %
994 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
995 %
996 % GetMagickMemoryMethods() gets the methods to acquire, resize, and destroy
997 % memory.
998 %
999 % The format of the GetMagickMemoryMethods() method is:
1000 %
1001 % void GetMagickMemoryMethods(AcquireMemoryHandler *acquire_memory_handler,
1002 % ResizeMemoryHandler *resize_memory_handler,
1003 % DestroyMemoryHandler *destroy_memory_handler)
1004 %
1005 % A description of each parameter follows:
1006 %
1007 % o acquire_memory_handler: method to acquire memory (e.g. malloc).
1008 %
1009 % o resize_memory_handler: method to resize memory (e.g. realloc).
1010 %
1011 % o destroy_memory_handler: method to destroy memory (e.g. free).
1012 %
1013 */
1014 MagickExport void GetMagickMemoryMethods(
1015  AcquireMemoryHandler *acquire_memory_handler,
1016  ResizeMemoryHandler *resize_memory_handler,
1017  DestroyMemoryHandler *destroy_memory_handler)
1018 {
1019  assert(acquire_memory_handler != (AcquireMemoryHandler *) NULL);
1020  assert(resize_memory_handler != (ResizeMemoryHandler *) NULL);
1021  assert(destroy_memory_handler != (DestroyMemoryHandler *) NULL);
1022  *acquire_memory_handler=memory_methods.acquire_memory_handler;
1023  *resize_memory_handler=memory_methods.resize_memory_handler;
1024  *destroy_memory_handler=memory_methods.destroy_memory_handler;
1025 }
1026 
1027 /*
1028 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1029 % %
1030 % %
1031 % %
1032 + G e t M a x M e m o r y R e q u e s t %
1033 % %
1034 % %
1035 % %
1036 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1037 %
1038 % GetMaxMemoryRequest() returns the max memory request value.
1039 %
1040 % The format of the GetMaxMemoryRequest method is:
1041 %
1042 % size_t GetMaxMemoryRequest(void)
1043 %
1044 */
1045 MagickExport size_t GetMaxMemoryRequest(void)
1046 {
1047 #define MinMemoryRequest "16MiB"
1048 
1049  if (max_memory_request == 0)
1050  {
1051  char
1052  *value;
1053 
1054  max_memory_request=(size_t) MagickULLConstant(~0);
1055  value=GetPolicyValue("system:max-memory-request");
1056  if (value != (char *) NULL)
1057  {
1058  /*
1059  The security policy sets a max memory request limit.
1060  */
1061  max_memory_request=MagickMax(StringToSizeType(value,100.0),
1062  StringToSizeType(MinMemoryRequest,100.0));
1063  value=DestroyString(value);
1064  }
1065  }
1066  return(MagickMin(max_memory_request,MAGICK_SSIZE_MAX));
1067 }
1068 
1069 /*
1070 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1071 % %
1072 % %
1073 % %
1074 % G e t V i r t u a l M e m o r y B l o b %
1075 % %
1076 % %
1077 % %
1078 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1079 %
1080 % GetVirtualMemoryBlob() returns the virtual memory blob associated with the
1081 % specified MemoryInfo structure.
1082 %
1083 % The format of the GetVirtualMemoryBlob method is:
1084 %
1085 % void *GetVirtualMemoryBlob(const MemoryInfo *memory_info)
1086 %
1087 % A description of each parameter follows:
1088 %
1089 % o memory_info: The MemoryInfo structure.
1090 */
1091 MagickExport void *GetVirtualMemoryBlob(const MemoryInfo *memory_info)
1092 {
1093  assert(memory_info != (const MemoryInfo *) NULL);
1094  assert(memory_info->signature == MagickCoreSignature);
1095  return(memory_info->blob);
1096 }
1097 
1098 /*
1099 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1100 % %
1101 % %
1102 % %
1103 % R e l i n q u i s h A l i g n e d M e m o r y %
1104 % %
1105 % %
1106 % %
1107 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1108 %
1109 % RelinquishAlignedMemory() frees memory acquired with AcquireAlignedMemory()
1110 % or reuse.
1111 %
1112 % The format of the RelinquishAlignedMemory method is:
1113 %
1114 % void *RelinquishAlignedMemory(void *memory)
1115 %
1116 % A description of each parameter follows:
1117 %
1118 % o memory: A pointer to a block of memory to free for reuse.
1119 %
1120 */
1121 MagickExport void *RelinquishAlignedMemory(void *memory)
1122 {
1123  if (memory == (void *) NULL)
1124  return((void *) NULL);
1125  if (memory_methods.relinquish_aligned_memory_handler != (RelinquishAlignedMemoryHandler) NULL)
1126  {
1127  memory_methods.relinquish_aligned_memory_handler(memory);
1128  return(NULL);
1129  }
1130 #if defined(MAGICKCORE_HAVE_ALIGNED_MALLOC) || defined(MAGICKCORE_HAVE_POSIX_MEMALIGN)
1131  free(memory);
1132 #elif defined(MAGICKCORE_HAVE__ALIGNED_MALLOC)
1133  _aligned_free(memory);
1134 #else
1135  RelinquishMagickMemory(actual_base_address(memory));
1136 #endif
1137  return(NULL);
1138 }
1139 
1140 /*
1141 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1142 % %
1143 % %
1144 % %
1145 % R e l i n q u i s h M a g i c k M e m o r y %
1146 % %
1147 % %
1148 % %
1149 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1150 %
1151 % RelinquishMagickMemory() frees memory acquired with AcquireMagickMemory()
1152 % or AcquireQuantumMemory() for reuse.
1153 %
1154 % The format of the RelinquishMagickMemory method is:
1155 %
1156 % void *RelinquishMagickMemory(void *memory)
1157 %
1158 % A description of each parameter follows:
1159 %
1160 % o memory: A pointer to a block of memory to free for reuse.
1161 %
1162 */
1163 MagickExport void *RelinquishMagickMemory(void *memory)
1164 {
1165  if (memory == (void *) NULL)
1166  return((void *) NULL);
1167 #if !defined(MAGICKCORE_ANONYMOUS_MEMORY_SUPPORT)
1168  memory_methods.destroy_memory_handler(memory);
1169 #else
1170  LockSemaphoreInfo(memory_semaphore);
1171  assert((SizeOfBlock(memory) % (4*sizeof(size_t))) == 0);
1172  assert((*BlockHeader(NextBlock(memory)) & PreviousBlockBit) != 0);
1173  if ((*BlockHeader(memory) & PreviousBlockBit) == 0)
1174  {
1175  void
1176  *previous;
1177 
1178  /*
1179  Coalesce with previous adjacent block.
1180  */
1181  previous=PreviousBlock(memory);
1182  RemoveFreeBlock(previous,AllocationPolicy(SizeOfBlock(previous)));
1183  *BlockHeader(previous)=(SizeOfBlock(previous)+SizeOfBlock(memory)) |
1184  (*BlockHeader(previous) & ~SizeMask);
1185  memory=previous;
1186  }
1187  if ((*BlockHeader(NextBlock(NextBlock(memory))) & PreviousBlockBit) == 0)
1188  {
1189  void
1190  *next;
1191 
1192  /*
1193  Coalesce with next adjacent block.
1194  */
1195  next=NextBlock(memory);
1196  RemoveFreeBlock(next,AllocationPolicy(SizeOfBlock(next)));
1197  *BlockHeader(memory)=(SizeOfBlock(memory)+SizeOfBlock(next)) |
1198  (*BlockHeader(memory) & ~SizeMask);
1199  }
1200  *BlockFooter(memory,SizeOfBlock(memory))=SizeOfBlock(memory);
1201  *BlockHeader(NextBlock(memory))&=(~PreviousBlockBit);
1202  InsertFreeBlock(memory,AllocationPolicy(SizeOfBlock(memory)));
1203  UnlockSemaphoreInfo(memory_semaphore);
1204 #endif
1205  return((void *) NULL);
1206 }
1207 
1208 /*
1209 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1210 % %
1211 % %
1212 % %
1213 % R e l i n q u i s h V i r t u a l M e m o r y %
1214 % %
1215 % %
1216 % %
1217 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1218 %
1219 % RelinquishVirtualMemory() frees memory acquired with AcquireVirtualMemory().
1220 %
1221 % The format of the RelinquishVirtualMemory method is:
1222 %
1223 % MemoryInfo *RelinquishVirtualMemory(MemoryInfo *memory_info)
1224 %
1225 % A description of each parameter follows:
1226 %
1227 % o memory_info: A pointer to a block of memory to free for reuse.
1228 %
1229 */
1230 MagickExport MemoryInfo *RelinquishVirtualMemory(MemoryInfo *memory_info)
1231 {
1232  assert(memory_info != (MemoryInfo *) NULL);
1233  assert(memory_info->signature == MagickCoreSignature);
1234  if (memory_info->blob != (void *) NULL)
1235  switch (memory_info->type)
1236  {
1237  case AlignedVirtualMemory:
1238  {
1239  (void) ShredMagickMemory(memory_info->blob,memory_info->length);
1240  memory_info->blob=RelinquishAlignedMemory(memory_info->blob);
1241  break;
1242  }
1243  case MapVirtualMemory:
1244  {
1245  (void) UnmapBlob(memory_info->blob,memory_info->length);
1246  memory_info->blob=NULL;
1247  if (*memory_info->filename != '\0')
1248  (void) RelinquishUniqueFileResource(memory_info->filename);
1249  break;
1250  }
1251  case UnalignedVirtualMemory:
1252  default:
1253  {
1254  (void) ShredMagickMemory(memory_info->blob,memory_info->length);
1255  memory_info->blob=RelinquishMagickMemory(memory_info->blob);
1256  break;
1257  }
1258  }
1259  memory_info->signature=(~MagickCoreSignature);
1260  memory_info=(MemoryInfo *) RelinquishAlignedMemory(memory_info);
1261  return(memory_info);
1262 }
1263 
1264 /*
1265 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1266 % %
1267 % %
1268 % %
1269 % R e s e t M a g i c k M e m o r y %
1270 % %
1271 % %
1272 % %
1273 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1274 %
1275 % ResetMagickMemory() fills the first size bytes of the memory area pointed to
1276 % by memory with the constant byte c. We use a volatile pointer when
1277 % updating the byte string. Most compilers will avoid optimizing away access
1278 % to a volatile pointer, even if the pointer appears to be unused after the
1279 % call.
1280 %
1281 % The format of the ResetMagickMemory method is:
1282 %
1283 % void *ResetMagickMemory(void *memory,int c,const size_t size)
1284 %
1285 % A description of each parameter follows:
1286 %
1287 % o memory: a pointer to a memory allocation.
1288 %
1289 % o c: set the memory to this value.
1290 %
1291 % o size: size of the memory to reset.
1292 %
1293 */
1294 MagickExport void *ResetMagickMemory(void *memory,int c,const size_t size)
1295 {
1296  volatile unsigned char
1297  *p = (volatile unsigned char *) memory;
1298 
1299  size_t
1300  n = size;
1301 
1302  assert(memory != (void *) NULL);
1303  while (n-- != 0)
1304  *p++=(unsigned char) c;
1305  return(memory);
1306 }
1307 
1308 /*
1309 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1310 % %
1311 % %
1312 % %
1313 + R e s e t M a x M e m o r y R e q u e s t %
1314 % %
1315 % %
1316 % %
1317 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1318 %
1319 % ResetMaxMemoryRequest() resets the max_memory_request value.
1320 %
1321 % The format of the ResetMaxMemoryRequest method is:
1322 %
1323 % void ResetMaxMemoryRequest(void)
1324 %
1325 */
1326 MagickPrivate void ResetMaxMemoryRequest(void)
1327 {
1328  max_memory_request=0;
1329 }
1330 
1331 /*
1332 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1333 % %
1334 % %
1335 % %
1336 + R e s e t V i r t u a l A n o n y m o u s M e m o r y %
1337 % %
1338 % %
1339 % %
1340 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1341 %
1342 % ResetVirtualAnonymousMemory() resets the virtual_anonymous_memory value.
1343 %
1344 % The format of the ResetVirtualAnonymousMemory method is:
1345 %
1346 % void ResetVirtualAnonymousMemory(void)
1347 %
1348 */
1349 MagickPrivate void ResetVirtualAnonymousMemory(void)
1350 {
1351  virtual_anonymous_memory=0;
1352 }
1353 
1354 /*
1355 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1356 % %
1357 % %
1358 % %
1359 % R e s i z e M a g i c k M e m o r y %
1360 % %
1361 % %
1362 % %
1363 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1364 %
1365 % ResizeMagickMemory() changes the size of the memory and returns a pointer to
1366 % the (possibly moved) block. The contents will be unchanged up to the
1367 % lesser of the new and old sizes.
1368 %
1369 % The format of the ResizeMagickMemory method is:
1370 %
1371 % void *ResizeMagickMemory(void *memory,const size_t size)
1372 %
1373 % A description of each parameter follows:
1374 %
1375 % o memory: A pointer to a memory allocation.
1376 %
1377 % o size: the new size of the allocated memory.
1378 %
1379 */
1380 
1381 #if defined(MAGICKCORE_ANONYMOUS_MEMORY_SUPPORT)
1382 static inline void *ResizeBlock(void *block,size_t size)
1383 {
1384  void
1385  *memory;
1386 
1387  if (block == (void *) NULL)
1388  return(AcquireBlock(size));
1389  memory=AcquireBlock(size);
1390  if (memory == (void *) NULL)
1391  return((void *) NULL);
1392  if (size <= (SizeOfBlock(block)-sizeof(size_t)))
1393  (void) memcpy(memory,block,size);
1394  else
1395  (void) memcpy(memory,block,SizeOfBlock(block)-sizeof(size_t));
1396  memory_pool.allocation+=size;
1397  return(memory);
1398 }
1399 #endif
1400 
1401 MagickExport void *ResizeMagickMemory(void *memory,const size_t size)
1402 {
1403  void
1404  *block;
1405 
1406  if (memory == (void *) NULL)
1407  return(AcquireMagickMemory(size));
1408 #if !defined(MAGICKCORE_ANONYMOUS_MEMORY_SUPPORT)
1409  block=memory_methods.resize_memory_handler(memory,size == 0 ? 1UL : size);
1410  if (block == (void *) NULL)
1411  memory=RelinquishMagickMemory(memory);
1412 #else
1413  LockSemaphoreInfo(memory_semaphore);
1414  block=ResizeBlock(memory,size == 0 ? 1UL : size);
1415  if (block == (void *) NULL)
1416  {
1417  if (ExpandHeap(size == 0 ? 1UL : size) == MagickFalse)
1418  {
1419  UnlockSemaphoreInfo(memory_semaphore);
1420  memory=RelinquishMagickMemory(memory);
1421  ThrowFatalException(ResourceLimitFatalError,"MemoryAllocationFailed");
1422  }
1423  block=ResizeBlock(memory,size == 0 ? 1UL : size);
1424  assert(block != (void *) NULL);
1425  }
1426  UnlockSemaphoreInfo(memory_semaphore);
1427  memory=RelinquishMagickMemory(memory);
1428 #endif
1429  return(block);
1430 }
1431 
1432 /*
1433 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1434 % %
1435 % %
1436 % %
1437 % R e s i z e Q u a n t u m M e m o r y %
1438 % %
1439 % %
1440 % %
1441 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1442 %
1443 % ResizeQuantumMemory() changes the size of the memory and returns a pointer
1444 % to the (possibly moved) block. The contents will be unchanged up to the
1445 % lesser of the new and old sizes.
1446 %
1447 % The format of the ResizeQuantumMemory method is:
1448 %
1449 % void *ResizeQuantumMemory(void *memory,const size_t count,
1450 % const size_t quantum)
1451 %
1452 % A description of each parameter follows:
1453 %
1454 % o memory: A pointer to a memory allocation.
1455 %
1456 % o count: the number of objects to allocate contiguously.
1457 %
1458 % o quantum: the size (in bytes) of each object.
1459 %
1460 */
1461 MagickExport void *ResizeQuantumMemory(void *memory,const size_t count,
1462  const size_t quantum)
1463 {
1464  size_t
1465  size;
1466 
1467  if ((HeapOverflowSanityCheckGetSize(count,quantum,&size) != MagickFalse) ||
1468  (size > GetMaxMemoryRequest()))
1469  {
1470  errno=ENOMEM;
1471  memory=RelinquishMagickMemory(memory);
1472  return(NULL);
1473  }
1474  if (size > GetMaxMemoryRequest())
1475  return(NULL);
1476  return(ResizeMagickMemory(memory,size));
1477 }
1478 
1479 /*
1480 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1481 % %
1482 % %
1483 % %
1484 % S e t M a g i c k A l i g n e d M e m o r y M e t h o d s %
1485 % %
1486 % %
1487 % %
1488 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1489 %
1490 % SetMagickAlignedMemoryMethods() sets the methods to acquire and relinquish
1491 % aligned memory.
1492 %
1493 % The format of the SetMagickAlignedMemoryMethods() method is:
1494 %
1495 % SetMagickAlignedMemoryMethods(
1496 % AcquireAlignedMemoryHandler acquire_aligned_memory_handler,
1497 % RelinquishAlignedMemoryHandler relinquish_aligned_memory_handler)
1498 %
1499 % A description of each parameter follows:
1500 %
1501 % o acquire_memory_handler: method to acquire aligned memory.
1502 %
1503 % o relinquish_aligned_memory_handler: method to relinquish aligned memory.
1504 %
1505 */
1506 MagickExport void SetMagickAlignedMemoryMethods(
1507  AcquireAlignedMemoryHandler acquire_aligned_memory_handler,
1508  RelinquishAlignedMemoryHandler relinquish_aligned_memory_handler)
1509 {
1510  memory_methods.acquire_aligned_memory_handler=acquire_aligned_memory_handler;
1511  memory_methods.relinquish_aligned_memory_handler=
1512  relinquish_aligned_memory_handler;
1513 }
1514 
1515 /*
1516 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1517 % %
1518 % %
1519 % %
1520 % S e t M a g i c k M e m o r y M e t h o d s %
1521 % %
1522 % %
1523 % %
1524 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1525 %
1526 % SetMagickMemoryMethods() sets the methods to acquire, resize, and destroy
1527 % memory. Your custom memory methods must be set prior to the
1528 % MagickCoreGenesis() method.
1529 %
1530 % The format of the SetMagickMemoryMethods() method is:
1531 %
1532 % SetMagickMemoryMethods(AcquireMemoryHandler acquire_memory_handler,
1533 % ResizeMemoryHandler resize_memory_handler,
1534 % DestroyMemoryHandler destroy_memory_handler)
1535 %
1536 % A description of each parameter follows:
1537 %
1538 % o acquire_memory_handler: method to acquire memory (e.g. malloc).
1539 %
1540 % o resize_memory_handler: method to resize memory (e.g. realloc).
1541 %
1542 % o destroy_memory_handler: method to destroy memory (e.g. free).
1543 %
1544 */
1545 MagickExport void SetMagickMemoryMethods(
1546  AcquireMemoryHandler acquire_memory_handler,
1547  ResizeMemoryHandler resize_memory_handler,
1548  DestroyMemoryHandler destroy_memory_handler)
1549 {
1550  /*
1551  Set memory methods.
1552  */
1553  if (acquire_memory_handler != (AcquireMemoryHandler) NULL)
1554  memory_methods.acquire_memory_handler=acquire_memory_handler;
1555  if (resize_memory_handler != (ResizeMemoryHandler) NULL)
1556  memory_methods.resize_memory_handler=resize_memory_handler;
1557  if (destroy_memory_handler != (DestroyMemoryHandler) NULL)
1558  memory_methods.destroy_memory_handler=destroy_memory_handler;
1559 }
1560 
1561 /*
1562 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1563 % %
1564 % %
1565 % %
1566 % S h r e d F i l e %
1567 % %
1568 % %
1569 % %
1570 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1571 %
1572 % ShredMagickMemory() overwrites the specified memory buffer with random data.
1573 % The overwrite is optional and is only required to help keep the contents of
1574 % the memory buffer private.
1575 %
1576 % The format of the ShredMagickMemory method is:
1577 %
1578 % MagickBooleanType ShredMagickMemory(void *memory,const size_t length)
1579 %
1580 % A description of each parameter follows.
1581 %
1582 % o memory: Specifies the memory buffer.
1583 %
1584 % o length: Specifies the length of the memory buffer.
1585 %
1586 */
1587 MagickPrivate MagickBooleanType ShredMagickMemory(void *memory,
1588  const size_t length)
1589 {
1590  RandomInfo
1591  *random_info;
1592 
1593  size_t
1594  quantum;
1595 
1596  ssize_t
1597  i;
1598 
1599  StringInfo
1600  *key;
1601 
1602  static ssize_t
1603  passes = -1;
1604 
1605  if ((memory == NULL) || (length == 0))
1606  return(MagickFalse);
1607  if (passes == -1)
1608  {
1609  char
1610  *property;
1611 
1612  passes=0;
1613  property=GetEnvironmentValue("MAGICK_SHRED_PASSES");
1614  if (property != (char *) NULL)
1615  {
1616  passes=(ssize_t) StringToInteger(property);
1617  property=DestroyString(property);
1618  }
1619  property=GetPolicyValue("system:shred");
1620  if (property != (char *) NULL)
1621  {
1622  passes=(ssize_t) StringToInteger(property);
1623  property=DestroyString(property);
1624  }
1625  }
1626  if (passes == 0)
1627  return(MagickTrue);
1628  /*
1629  Overwrite the memory buffer with random data.
1630  */
1631  quantum=(size_t) MagickMin(length,MagickMinBufferExtent);
1632  random_info=AcquireRandomInfo();
1633  key=GetRandomKey(random_info,quantum);
1634  for (i=0; i < passes; i++)
1635  {
1636  size_t
1637  j;
1638 
1639  unsigned char
1640  *p = (unsigned char *) memory;
1641 
1642  for (j=0; j < length; j+=quantum)
1643  {
1644  if (i != 0)
1645  SetRandomKey(random_info,quantum,GetStringInfoDatum(key));
1646  (void) memcpy(p,GetStringInfoDatum(key),(size_t)
1647  MagickMin(quantum,length-j));
1648  p+=quantum;
1649  }
1650  if (j < length)
1651  break;
1652  }
1653  key=DestroyStringInfo(key);
1654  random_info=DestroyRandomInfo(random_info);
1655  return(i < passes ? MagickFalse : MagickTrue);
1656 }