Kernel/heap.c

   1 /*
   2  * AcessOS Microkernel Version
   3  * heap.c
   4  */
   5 #include <acess.h>
   6 #include <mm_virt.h>
   7 #include <heap_int.h>
   8
   9 #define WARNINGS        1
  10 #define DEBUG_TRACE     0
  11 #define VERBOSE_DUMP    0
  12
  13 // === CONSTANTS ===
  14 #define HEAP_INIT_SIZE  0x8000  // 32 KiB
  15 #define MIN_SIZE        (sizeof(void*))*8       // 8 Machine Words
  16 #define POW2_SIZES      0
  17 #define COMPACT_HEAP    0       // Use 4 byte header?
  18 #define FIRST_FIT       0
  19
  20 //#define       MAGIC_FOOT      0x2ACE5505
  21 //#define       MAGIC_FREE      0xACE55000
  22 //#define       MAGIC_USED      0x862B0505      // MAGIC_FOOT ^ MAGIC_FREE
  23 #define MAGIC_FOOT      0x544F4F46      // 'FOOT'
  24 #define MAGIC_FREE      0x45455246      // 'FREE'
  25 #define MAGIC_USED      0x44455355      // 'USED'
  26
  27 // === PROTOTYPES ===
  28 void    Heap_Install(void);
  29 void    *Heap_Extend(int Bytes);
  30 void    *Heap_Merge(tHeapHead *Head);
  31 void    *Heap_Allocate(const char *File, int Line, size_t Bytes);
  32 void    *Heap_AllocateZero(const char *File, int Line, size_t Bytes);
  33 void    *Heap_Reallocate(const char *File, int Line, void *Ptr, size_t Bytes);
  34 void    Heap_Deallocate(void *Ptr);
  35 void    Heap_Dump(void);
  36 void    Heap_Stats(void);
  37
  38 // === GLOBALS ===
  39 tMutex  glHeap;
  40 void    *gHeapStart;
  41 void    *gHeapEnd;
  42
  43 // === CODE ===
  44 void Heap_Install(void)
  45 {
  46         gHeapStart      = (void*)MM_KHEAP_BASE;
  47         gHeapEnd        = (void*)MM_KHEAP_BASE;
  48         Heap_Extend(HEAP_INIT_SIZE);
  49 }
  50
  51 /**
  52  * \fn void *Heap_Extend(int Bytes)
  53  * \brief Extend the size of the heap
  54  */
  55 void *Heap_Extend(int Bytes)
  56 {
  57         Uint    i;
  58         tHeapHead       *head = gHeapEnd;
  59         tHeapFoot       *foot;
  60
  61         // Bounds Check
  62         if( (tVAddr)gHeapEnd == MM_KHEAP_MAX )
  63                 return NULL;
  64
  65         // Bounds Check
  66         if( (tVAddr)gHeapEnd + ((Bytes+0xFFF)&~0xFFF) > MM_KHEAP_MAX ) {
  67                 Bytes = MM_KHEAP_MAX - (tVAddr)gHeapEnd;
  68                 return NULL;
  69         }
  70
  71         // Heap expands in pages
  72         for(i=0;i<(Bytes+0xFFF)>>12;i++)
  73                 MM_Allocate( (tVAddr)gHeapEnd+(i<<12) );
  74
  75         // Increas heap end
  76         gHeapEnd += i << 12;
  77
  78         // Create Block
  79         head->Size = (Bytes+0xFFF)&~0xFFF;
  80         head->Magic = MAGIC_FREE;
  81         foot = (void*)( (Uint)gHeapEnd - sizeof(tHeapFoot) );
  82         foot->Head = head;
  83         foot->Magic = MAGIC_FOOT;
  84
  85         return Heap_Merge(head);        // Merge with previous block
  86 }
  87
  88 /**
  89  * \fn void *Heap_Merge(tHeapHead *Head)
  90  * \brief Merges two ajacent heap blocks
  91  */
  92 void *Heap_Merge(tHeapHead *Head)
  93 {
  94         tHeapFoot       *foot;
  95         tHeapFoot       *thisFoot;
  96         tHeapHead       *head;
  97
  98         //Log("Heap_Merge: (Head=%p)", Head);
  99
 100         thisFoot = (void*)( (Uint)Head + Head->Size - sizeof(tHeapFoot) );
 101         if((Uint)thisFoot > (Uint)gHeapEnd)     return NULL;
 102
 103         // Merge Left (Down)
 104         foot = (void*)( (Uint)Head - sizeof(tHeapFoot) );
 105         if( ((Uint)foot < (Uint)gHeapEnd && (Uint)foot > (Uint)gHeapStart)
 106         && foot->Head->Magic == MAGIC_FREE) {
 107                 foot->Head->Size += Head->Size; // Increase size
 108                 thisFoot->Head = foot->Head;    // Change backlink
 109                 Head->Magic = 0;        // Clear old head
 110                 Head->Size = 0;
 111                 Head = foot->Head;      // Save new head address
 112                 foot->Head = NULL;      // Clear central footer
 113                 foot->Magic = 0;
 114         }
 115
 116         // Merge Right (Upwards)
 117         head = (void*)( (Uint)Head + Head->Size );
 118         if((Uint)head < (Uint)gHeapEnd && head->Magic == MAGIC_FREE)
 119         {
 120                 Head->Size += head->Size;
 121                 foot = (void*)( (Uint)Head + Head->Size - sizeof(tHeapFoot) );
 122                 foot->Head = Head;      // Update Backlink
 123                 thisFoot->Head = NULL;  // Clear old footer
 124                 thisFoot->Magic = 0;
 125                 head->Size = 0;         // Clear old header
 126                 head->Magic = 0;
 127         }
 128
 129         // Return new address
 130         return Head;
 131 }
 132
 133 /**
 134  * \brief Allocate memory from the heap
 135  * \param File  Allocating source file
 136  * \param Line  Source line
 137  * \param Bytes Size of region to allocate
 138  */
 139 void *Heap_Allocate(const char *File, int Line, size_t __Bytes)
 140 {
 141         tHeapHead       *head, *newhead;
 142         tHeapFoot       *foot, *newfoot;
 143         tHeapHead       *best = NULL;
 144         Uint    bestSize = 0;   // Speed hack
 145         size_t  Bytes;
 146
 147         // Get required size
 148         #if POW2_SIZES
 149         Bytes = __Bytes + sizeof(tHeapHead) + sizeof(tHeapFoot);
 150         Bytes = 1UUL << LOG2(__Bytes);
 151         #else
 152         Bytes = (__Bytes + sizeof(tHeapHead) + sizeof(tHeapFoot) + MIN_SIZE-1) & ~(MIN_SIZE-1);
 153         #endif
 154
 155         // Lock Heap
 156         Mutex_Acquire(&glHeap);
 157
 158         // Traverse Heap
 159         for( head = gHeapStart;
 160                 (Uint)head < (Uint)gHeapEnd;
 161                 head = (void*)((Uint)head + head->Size)
 162                 )
 163         {
 164                 // Alignment Check
 165                 #if POW2_SIZES
 166                 if( head->Size != 1UUL << LOG2(head->Size) ) {
 167                 #else
 168                 if( head->Size & (MIN_SIZE-1) ) {
 169                 #endif
 170                         Mutex_Release(&glHeap); // Release spinlock
 171                         #if WARNINGS
 172                         Log_Warning("Heap", "Size of heap address %p is invalid not aligned (0x%x)", head, head->Size);
 173                         Heap_Dump();
 174                         #endif
 175                         return NULL;
 176                 }
 177
 178                 // Check if allocated
 179                 if(head->Magic == MAGIC_USED)   continue;
 180                 // Error check
 181                 if(head->Magic != MAGIC_FREE)   {
 182                         Mutex_Release(&glHeap); // Release spinlock
 183                         #if WARNINGS
 184                         Log_Warning("Heap", "Magic of heap address %p is invalid (0x%x)", head, head->Magic);
 185                         Heap_Dump();
 186                         #endif
 187                         return NULL;
 188                 }
 189
 190                 // Size check
 191                 if(head->Size < Bytes)  continue;
 192
 193                 // Perfect fit
 194                 if(head->Size == Bytes) {
 195                         head->Magic = MAGIC_USED;
 196                         head->File = File;
 197                         head->Line = Line;
 198                         Mutex_Release(&glHeap); // Release spinlock
 199                         #if DEBUG_TRACE
 200                         Log("[Heap   ] Malloc'd %p (%i bytes), returning to %p", head->Data, head->Size,  __builtin_return_address(0));
 201                         #endif
 202                         return head->Data;
 203                 }
 204
 205                 // Break out of loop
 206                 #if FIRST_FIT
 207                 best = head;
 208                 bestSize = head->Size;
 209                 break;
 210                 #else
 211                 // or check if the block is the best size
 212                 if(bestSize > head->Size) {
 213                         best = head;
 214                         bestSize = head->Size;
 215                 }
 216                 #endif
 217         }
 218
 219         // If no block large enough is found, create one
 220         if(!best)
 221         {
 222                 best = Heap_Extend( Bytes );
 223                 // Check for errors
 224                 if(!best) {
 225                         Mutex_Release(&glHeap); // Release spinlock
 226                         return NULL;
 227                 }
 228                 // Check size
 229                 if(best->Size == Bytes) {
 230                         best->Magic = MAGIC_USED;       // Mark block as used
 231                         best->File = File;
 232                         best->Line = Line;
 233                         Mutex_Release(&glHeap); // Release spinlock
 234                         #if DEBUG_TRACE
 235                         Log("[Heap   ] Malloc'd %p (%i bytes), returning to %p", best->Data, best->Size, __builtin_return_address(0));
 236                         #endif
 237                         return best->Data;
 238                 }
 239         }
 240
 241         // Split Block
 242         newhead = (void*)( (Uint)best + Bytes );
 243         newfoot = (void*)( (Uint)best + Bytes - sizeof(tHeapFoot) );
 244         foot = (void*)( (Uint)best + best->Size - sizeof(tHeapFoot) );
 245
 246         newfoot->Head = best;   // Create new footer
 247         newfoot->Magic = MAGIC_FOOT;
 248         newhead->Size = best->Size - Bytes;     // Create new header
 249         newhead->Magic = MAGIC_FREE;
 250         foot->Head = newhead;   // Update backlink in old footer
 251         best->Size = Bytes;             // Update size in old header
 252         best->ValidSize = __Bytes;
 253         best->Magic = MAGIC_USED;       // Mark block as used
 254         best->File = File;
 255         best->Line = Line;
 256
 257         Mutex_Release(&glHeap); // Release spinlock
 258         #if DEBUG_TRACE
 259         Log_Debug("Heap", "newhead(%p)->Size = 0x%x", newhead, newhead->Size);
 260         Log_Debug("Heap", "Malloc'd %p (0x%x bytes), returning to %s:%i",
 261                 best->Data, best->Size, File, Line);
 262         #endif
 263         return best->Data;
 264 }
 265
 266 /**
 267  * \fn void Heap_Deallocate(void *Ptr)
 268  * \brief Free an allocated memory block
 269  */
 270 void Heap_Deallocate(void *Ptr)
 271 {
 272         tHeapHead       *head;
 273         tHeapFoot       *foot;
 274
 275         #if DEBUG_TRACE
 276         Log_Log("Heap", "free: Ptr = %p", Ptr);
 277         Log_Log("Heap", "free: Returns to %p", __builtin_return_address(0));
 278         #endif
 279
 280         // Alignment Check
 281         if( (Uint)Ptr & (sizeof(Uint)-1) ) {
 282                 Log_Warning("Heap", "free - Passed a non-aligned address (%p)", Ptr);
 283                 return;
 284         }
 285
 286         // Sanity check
 287         if((Uint)Ptr < (Uint)gHeapStart || (Uint)Ptr > (Uint)gHeapEnd)
 288         {
 289                 Log_Warning("Heap", "free - Passed a non-heap address (%p < %p < %p)\n",
 290                         gHeapStart, Ptr, gHeapEnd);
 291                 return;
 292         }
 293
 294         // Check memory block - Header
 295         head = (void*)( (Uint)Ptr - sizeof(tHeapHead) );
 296         if(head->Magic == MAGIC_FREE) {
 297                 Log_Warning("Heap", "free - Passed a freed block (%p) by %p", head, __builtin_return_address(0));
 298                 return;
 299         }
 300         if(head->Magic != MAGIC_USED) {
 301                 Log_Warning("Heap", "free - Magic value is invalid (%p, 0x%x)", head, head->Magic);
 302                 Log_Notice("Heap", "Allocated %s:%i", head->File, head->Line);
 303                 return;
 304         }
 305
 306         // Check memory block - Footer
 307         foot = (void*)( (Uint)head + head->Size - sizeof(tHeapFoot) );
 308         if(foot->Head != head) {
 309                 Log_Warning("Heap", "free - Footer backlink is incorrect (%p, 0x%x)", head, foot->Head);
 310                 Log_Notice("Heap", "Allocated %s:%i", head->File, head->Line);
 311                 return;
 312         }
 313         if(foot->Magic != MAGIC_FOOT) {
 314                 Log_Warning("Heap", "free - Footer magic is invalid (%p, %p = 0x%x)", head, &foot->Magic, foot->Magic);
 315                 Log_Notice("Heap", "Allocated %s:%i", head->File, head->Line);
 316                 return;
 317         }
 318
 319         // Lock
 320         Mutex_Acquire( &glHeap );
 321
 322         // Mark as free
 323         head->Magic = MAGIC_FREE;
 324         //head->File = NULL;
 325         //head->Line = 0;
 326         head->ValidSize = 0;
 327         // Merge blocks
 328         Heap_Merge( head );
 329
 330         // Release
 331         Mutex_Release( &glHeap );
 332 }
 333
 334 /**
 335  * \brief Increase/Decrease the size of an allocation
 336  * \param File  Calling File
 337  * \param Line  Calling Line
 338  * \param __ptr Old memory
 339  * \param __size        New Size
 340  */
 341 void *Heap_Reallocate(const char *File, int Line, void *__ptr, size_t __size)
 342 {
 343         tHeapHead       *head = (void*)( (Uint)__ptr-sizeof(tHeapHead) );
 344         tHeapHead       *nextHead;
 345         tHeapFoot       *foot;
 346         Uint    newSize = (__size + sizeof(tHeapFoot)+sizeof(tHeapHead)+MIN_SIZE-1)&~(MIN_SIZE-1);
 347
 348         // Check for reallocating NULL
 349         if(__ptr == NULL)       return Heap_Allocate(File, Line, __size);
 350
 351         // Check if resize is needed
 352         if(newSize <= head->Size)       return __ptr;
 353
 354         // Check if next block is free
 355         nextHead = (void*)( (Uint)head + head->Size );
 356
 357         // Extend into next block
 358         if(nextHead->Magic == MAGIC_FREE && nextHead->Size+head->Size >= newSize)
 359         {
 360                 Uint    size = nextHead->Size + head->Size;
 361                 foot = (void*)( (Uint)nextHead + nextHead->Size - sizeof(tHeapFoot) );
 362                 // Exact Fit
 363                 if(size == newSize) {
 364                         head->Size = newSize;
 365                         head->ValidSize = __size;
 366                         head->File = File;
 367                         head->Line = Line;
 368                         foot->Head = head;
 369                         nextHead->Magic = 0;
 370                         nextHead->Size = 0;
 371                         return __ptr;
 372                 }
 373                 // Create a new heap block
 374                 nextHead = (void*)( (Uint)head + newSize );
 375                 nextHead->Size = size - newSize;
 376                 nextHead->Magic = MAGIC_FREE;
 377                 foot->Head = nextHead;  // Edit 2nd footer
 378                 head->Size = newSize;   // Edit first header
 379                 head->File = File;
 380                 head->Line = Line;
 381                 head->ValidSize = __size;
 382                 // Create new footer
 383                 foot = (void*)( (Uint)head + newSize - sizeof(tHeapFoot) );
 384                 foot->Head = head;
 385                 foot->Magic = MAGIC_FOOT;
 386                 return __ptr;
 387         }
 388
 389         // Extend downwards?
 390         foot = (void*)( (Uint)head - sizeof(tHeapFoot) );
 391         nextHead = foot->Head;
 392         if(nextHead->Magic == MAGIC_FREE && nextHead->Size+head->Size >= newSize)
 393         {
 394                 Uint    size = nextHead->Size + head->Size;
 395                 // Inexact fit, split things up
 396                 if(size > newSize)
 397                 {
 398                         // TODO
 399                         Warning("[Heap   ] TODO: Space efficient realloc when new size is smaller");
 400                 }
 401
 402                 // Exact fit
 403                 if(size >= newSize)
 404                 {
 405                         Uint    oldDataSize;
 406                         // Set 1st (new/lower) header
 407                         nextHead->Magic = MAGIC_USED;
 408                         nextHead->Size = newSize;
 409                         nextHead->File = File;
 410                         nextHead->Line = Line;
 411                         nextHead->ValidSize = __size;
 412                         // Get 2nd (old) footer
 413                         foot = (void*)( (Uint)nextHead + newSize );
 414                         foot->Head = nextHead;
 415                         // Save old data size
 416                         oldDataSize = head->Size - sizeof(tHeapFoot) - sizeof(tHeapHead);
 417                         // Clear old header
 418                         head->Size = 0;
 419                         head->Magic = 0;
 420                         // Copy data
 421                         memcpy(nextHead->Data, __ptr, oldDataSize);
 422                         // Return
 423                         return nextHead->Data;
 424                 }
 425                 // On to the expensive then
 426         }
 427
 428         // Well, darn
 429         nextHead = Heap_Allocate( File, Line, __size );
 430         nextHead -= 1;
 431         nextHead->File = File;
 432         nextHead->Line = Line;
 433         nextHead->ValidSize = __size;
 434
 435         memcpy(
 436                 nextHead->Data,
 437                 __ptr,
 438                 head->Size - sizeof(tHeapFoot) - sizeof(tHeapHead)
 439                 );
 440
 441         free(__ptr);
 442
 443         return nextHead->Data;
 444 }
 445
 446 /**
 447  * \fn void *Heap_AllocateZero(const char *File, int Line, size_t Bytes)
 448  * \brief Allocate and Zero a buffer in memory
 449  * \param File  Allocating file
 450  * \param Line  Line of allocation
 451  * \param Bytes Size of the allocation
 452  */
 453 void *Heap_AllocateZero(const char *File, int Line, size_t Bytes)
 454 {
 455         void    *ret = Heap_Allocate(File, Line, Bytes);
 456         if(ret == NULL) return NULL;
 457
 458         memset( ret, 0, Bytes );
 459
 460         return ret;
 461 }
 462
 463 /**
 464  * \fn int Heap_IsHeapAddr(void *Ptr)
 465  * \brief Checks if an address is a heap pointer
 466  */
 467 int Heap_IsHeapAddr(void *Ptr)
 468 {
 469         tHeapHead       *head;
 470         if((Uint)Ptr < (Uint)gHeapStart)        return 0;
 471         if((Uint)Ptr > (Uint)gHeapEnd)  return 0;
 472         if((Uint)Ptr & (sizeof(Uint)-1))        return 0;
 473
 474         head = (void*)( (Uint)Ptr - sizeof(tHeapHead) );
 475         if(head->Magic != MAGIC_USED && head->Magic != MAGIC_FREE)
 476                 return 0;
 477
 478         return 1;
 479 }
 480
 481 /**
 482  */
 483 void Heap_Validate(void)
 484 {
 485         Heap_Dump();
 486 }
 487
 488 #if WARNINGS
 489 void Heap_Dump(void)
 490 {
 491         tHeapHead       *head, *badHead;
 492         tHeapFoot       *foot = NULL;
 493
 494         head = gHeapStart;
 495         while( (Uint)head < (Uint)gHeapEnd )
 496         {
 497                 foot = (void*)( (Uint)head + head->Size - sizeof(tHeapFoot) );
 498                 #if VERBOSE_DUMP
 499                 Log_Log("Heap", "%p (0x%llx): 0x%08lx (%i) %4C",
 500                         head, MM_GetPhysAddr((Uint)head), head->Size, head->ValidSize, &head->Magic);
 501                 Log_Log("Heap", "%p %4C", foot->Head, &foot->Magic);
 502                 if(head->File) {
 503                         Log_Log("Heap", "%sowned by %s:%i",
 504                                 (head->Magic==MAGIC_FREE?"was ":""), head->File, head->Line);
 505                 }
 506                 #endif
 507
 508                 // Sanity Check Header
 509                 if(head->Size == 0) {
 510                         Log_Warning("Heap", "HALTED - Size is zero");
 511                         break;
 512                 }
 513                 if(head->Size & (MIN_SIZE-1)) {
 514                         Log_Warning("Heap", "HALTED - Size is malaligned");
 515                         break;
 516                 }
 517                 if(head->Magic != MAGIC_FREE && head->Magic != MAGIC_USED) {
 518                         Log_Warning("Heap", "HALTED - Head Magic is Bad");
 519                         break;
 520                 }
 521
 522                 // Check footer
 523                 if(foot->Magic != MAGIC_FOOT) {
 524                         Log_Warning("Heap", "HALTED - Foot Magic is Bad");
 525                         break;
 526                 }
 527                 if(head != foot->Head) {
 528                         Log_Warning("Heap", "HALTED - Footer backlink is invalid");
 529                         break;
 530                 }
 531
 532                 #if VERBOSE_DUMP
 533                 Log_Log("Heap", "");
 534                 #endif
 535
 536                 // All OK? Go to next
 537                 head = foot->NextHead;
 538         }
 539
 540         // If the heap is valid, ok!
 541         if( (tVAddr)head == (tVAddr)gHeapEnd )
 542                 return ;
 543
 544         // Check for a bad return
 545         if( (tVAddr)head >= (tVAddr)gHeapEnd )
 546                 return ;
 547
 548         #if !VERBOSE_DUMP
 549         Log_Log("Heap", "%p (0x%llx): 0x%08lx (%i) %4C",
 550                 head, MM_GetPhysAddr((Uint)head), head->Size, head->ValidSize, &head->Magic);
 551         Log_Log("Heap", "%p %4C", foot->Head, &foot->Magic);
 552         if(head->File) {
 553                 Log_Log("Heap", "%sowned by %s:%i",
 554                         (head->Magic==MAGIC_FREE?"was ":""), head->File, head->Line);
 555         }
 556         Log_Log("Heap", "");
 557         #endif
 558
 559
 560         badHead = head;
 561
 562         // Work backwards
 563         foot = (void*)( (tVAddr)gHeapEnd - sizeof(tHeapFoot) );
 564         Log_Log("Heap", "==== Going Backwards ==== (from %p)", foot);
 565         head = foot->Head;
 566         while( (tVAddr)head >= (tVAddr)badHead )
 567         {
 568                 Log_Log("Heap", "%p (0x%llx): 0x%08lx %i %4C",
 569                         head, MM_GetPhysAddr((Uint)head), head->Size, head->ValidSize, &head->Magic);
 570                 Log_Log("Heap", "%p %4C", foot->Head, &foot->Magic);
 571                 if(head->File)
 572                         Log_Log("Heap", "%sowned by %s:%i",
 573                                 (head->Magic!=MAGIC_USED?"was ":""),
 574                                 head->File, head->Line);
 575                 Log_Log("Heap", "");
 576
 577                 // Sanity Check Header
 578                 if(head->Size == 0) {
 579                         Log_Warning("Heap", "HALTED - Size is zero");
 580                         break;
 581                 }
 582                 if(head->Size & (MIN_SIZE-1)) {
 583                         Log_Warning("Heap", " - Size is malaligned (&0x%x)", ~(MIN_SIZE-1));
 584                         break ;
 585                 }
 586                 if(head->Magic != MAGIC_FREE && head->Magic != MAGIC_USED) {
 587                         Log_Warning("Heap", "HALTED - Head Magic is Bad");
 588                         break;
 589                 }
 590
 591                 // Check footer
 592                 if(foot->Magic != MAGIC_FOOT) {
 593                         Log_Warning("Heap", "HALTED - Foot Magic is Bad");
 594                         break;
 595                 }
 596                 if(head != foot->Head) {
 597                         Log_Warning("Heap", "HALTED - Footer backlink is invalid");
 598                         break;
 599                 }
 600
 601                 if(head == badHead)     break;
 602
 603                 foot = (void*)( (tVAddr)head - sizeof(tHeapFoot) );
 604                 head = foot->Head;
 605                 Log_Debug("Heap", "head=%p", head);
 606         }
 607
 608         Panic("Heap_Dump - Heap is corrupted, kernel panic!");
 609 }
 610 #endif
 611
 612 #if 1
 613 void Heap_Stats(void)
 614 {
 615         tHeapHead       *head;
 616          int    nBlocks = 0;
 617          int    nFree = 0;
 618          int    totalBytes = 0;
 619          int    freeBytes = 0;
 620          int    maxAlloc=0, minAlloc=-1;
 621          int    avgAlloc, frag, overhead;
 622
 623         for(head = gHeapStart;
 624                 (Uint)head < (Uint)gHeapEnd;
 625                 head = (void*)( (Uint)head + head->Size )
 626                 )
 627         {
 628                 nBlocks ++;
 629                 totalBytes += head->Size;
 630                 if( head->Magic == MAGIC_FREE )
 631                 {
 632                         nFree ++;
 633                         freeBytes += head->Size;
 634                 }
 635                 else if( head->Magic == MAGIC_USED) {
 636                         if(maxAlloc < head->Size)       maxAlloc = head->Size;
 637                         if(minAlloc == -1 || minAlloc > head->Size)
 638                                 minAlloc = head->Size;
 639                 }
 640                 else {
 641                         Log_Warning("Heap", "Magic on %p invalid, skipping remainder of heap", head);
 642                         break;
 643                 }
 644
 645                 // Print the block info?
 646                 #if 1
 647                 Log_Debug("Heap", "%p - 0x%x Owned by %s:%i",
 648                         head, head->Size, head->File, head->Line);
 649                 #endif
 650         }
 651
 652         Log_Log("Heap", "%i blocks (0x%x bytes)", nBlocks, totalBytes);
 653         Log_Log("Heap", "%i free blocks (0x%x bytes)", nFree, freeBytes);
 654         frag = (nFree-1)*10000/nBlocks;
 655         Log_Log("Heap", "%i.%02i%% Heap Fragmentation", frag/100, frag%100);
 656         avgAlloc = (totalBytes-freeBytes)/(nBlocks-nFree);
 657         overhead = (sizeof(tHeapFoot)+sizeof(tHeapHead))*10000/avgAlloc;
 658         Log_Log("Heap", "Average allocation: %i bytes, Average Overhead: %i.%02i%%",
 659                 avgAlloc, overhead/100, overhead%100
 660                 );
 661         Log_Log("Heap", "Smallest Block: %i bytes, Largest: %i bytes",
 662                 minAlloc, maxAlloc);
 663
 664         // Scan and get distribution
 665         #if 1
 666         {
 667                 struct {
 668                         Uint    Size;
 669                         Uint    Count;
 670                 }       sizeCounts[nBlocks];
 671                  int    i;
 672
 673                 memset(sizeCounts, 0, nBlocks*sizeof(sizeCounts[0]));
 674
 675                 for(head = gHeapStart;
 676                         (Uint)head < (Uint)gHeapEnd;
 677                         head = (void*)( (Uint)head + head->Size )
 678                         )
 679                 {
 680                         for( i = 0; i < nBlocks; i ++ ) {
 681                                 if( sizeCounts[i].Size == 0 )
 682                                         break;
 683                                 if( sizeCounts[i].Size == head->Size )
 684                                         break;
 685                         }
 686                         // Should never reach this part (in a non-concurrent case)
 687                         if( i == nBlocks )      continue;
 688                         sizeCounts[i].Size = head->Size;
 689                         sizeCounts[i].Count ++;
 690                         #if 1
 691                         //Log("Heap_Stats: %i %p - 0x%x bytes (%s) (%i)", nBlocks, head,
 692                         //      head->Size, (head->Magic==MAGIC_FREE?"FREE":"used"), i
 693                         //      );
 694                         //Log("Heap_Stats: sizeCounts[%i] = {Size:0x%x, Count: %i}", i,
 695                         //      sizeCounts[i].Size, sizeCounts[i].Count);
 696                         #endif
 697                 }
 698
 699                 for( i = 0; i < nBlocks && sizeCounts[i].Count; i ++ )
 700                 {
 701                         Log("Heap_Stats: 0x%x - %i blocks",
 702                                 sizeCounts[i].Size, sizeCounts[i].Count
 703                                 );
 704                 }
 705         }
 706         #endif
 707 }
 708 #endif
 709
 710 // === EXPORTS ===
 711 EXPORT(Heap_Allocate);
 712 EXPORT(Heap_AllocateZero);
 713 EXPORT(Heap_Reallocate);
 714 EXPORT(Heap_Deallocate);
 715 EXPORT(Heap_IsHeapAddr);