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