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         if( Bytes == 0 ) {
  66                 Log_Warning("Heap", "Heap_Extend called with Bytes=%i", Bytes);
  67                 return NULL;
  68         }
  69
  70         // Bounds Check
  71         if( (tVAddr)gHeapEnd + ((Bytes+0xFFF)&~0xFFF) > MM_KHEAP_MAX ) {
  72                 Bytes = MM_KHEAP_MAX - (tVAddr)gHeapEnd;
  73                 return NULL;
  74         }
  75
  76         // Heap expands in pages
  77         for( i = 0; i < (Bytes+0xFFF) >> 12; i ++ )
  78         {
  79                 if( !MM_Allocate( (tVAddr)gHeapEnd+(i<<12) ) )
  80                 {
  81                         Warning("OOM - Heap_Extend");
  82                         return NULL;
  83                 }
  84         }
  85
  86         // Increas heap end
  87         gHeapEnd = (Uint8*)gHeapEnd + (i << 12);
  88
  89         // Create Block
  90         head->Size = (Bytes+0xFFF)&~0xFFF;
  91         head->Magic = MAGIC_FREE;
  92         foot = (void*)( (Uint)gHeapEnd - sizeof(tHeapFoot) );
  93         foot->Head = head;
  94         foot->Magic = MAGIC_FOOT;
  95
  96         return Heap_Merge(head);        // Merge with previous block
  97 }
  98
  99 /**
 100  * \fn void *Heap_Merge(tHeapHead *Head)
 101  * \brief Merges two ajacent heap blocks
 102  */
 103 void *Heap_Merge(tHeapHead *Head)
 104 {
 105         tHeapFoot       *foot;
 106         tHeapFoot       *thisFoot;
 107         tHeapHead       *head;
 108
 109         //Log("Heap_Merge: (Head=%p)", Head);
 110
 111         thisFoot = (void*)( (Uint)Head + Head->Size - sizeof(tHeapFoot) );
 112         if((Uint)thisFoot > (Uint)gHeapEnd)     return NULL;
 113
 114         // Merge Left (Down)
 115         foot = (void*)( (Uint)Head - sizeof(tHeapFoot) );
 116         if( ((Uint)foot < (Uint)gHeapEnd && (Uint)foot > (Uint)gHeapStart)
 117         && foot->Head->Magic == MAGIC_FREE) {
 118                 foot->Head->Size += Head->Size; // Increase size
 119                 thisFoot->Head = foot->Head;    // Change backlink
 120                 Head->Magic = 0;        // Clear old head
 121                 Head->Size = 0;
 122                 Head = foot->Head;      // Save new head address
 123                 foot->Head = NULL;      // Clear central footer
 124                 foot->Magic = 0;
 125         }
 126
 127         // Merge Right (Upwards)
 128         head = (void*)( (Uint)Head + Head->Size );
 129         if((Uint)head < (Uint)gHeapEnd && head->Magic == MAGIC_FREE)
 130         {
 131                 Head->Size += head->Size;
 132                 foot = (void*)( (Uint)Head + Head->Size - sizeof(tHeapFoot) );
 133                 foot->Head = Head;      // Update Backlink
 134                 thisFoot->Head = NULL;  // Clear old footer
 135                 thisFoot->Magic = 0;
 136                 head->Size = 0;         // Clear old header
 137                 head->Magic = 0;
 138         }
 139
 140         // Return new address
 141         return Head;
 142 }
 143
 144 /**
 145  * \brief Allocate memory from the heap
 146  * \param File  Allocating source file
 147  * \param Line  Source line
 148  * \param Bytes Size of region to allocate
 149  */
 150 void *Heap_Allocate(const char *File, int Line, size_t __Bytes)
 151 {
 152         tHeapHead       *head, *newhead;
 153         tHeapFoot       *foot, *newfoot;
 154         tHeapHead       *best = NULL;
 155         Uint    bestSize = 0;   // Speed hack
 156         size_t  Bytes;
 157
 158         if( __Bytes == 0 ) {
 159                 //return NULL;  // TODO: Return a known un-mapped range.
 160                 return INVLPTR;
 161         }
 162
 163         // Get required size
 164         #if POW2_SIZES
 165         Bytes = __Bytes + sizeof(tHeapHead) + sizeof(tHeapFoot);
 166         Bytes = 1UUL << LOG2(__Bytes);
 167         #else
 168         Bytes = (__Bytes + sizeof(tHeapHead) + sizeof(tHeapFoot) + MIN_SIZE-1) & ~(MIN_SIZE-1);
 169         #endif
 170
 171         // Lock Heap
 172         Mutex_Acquire(&glHeap);
 173
 174         // Traverse Heap
 175         for( head = gHeapStart;
 176                 (Uint)head < (Uint)gHeapEnd;
 177                 head = (void*)((Uint)head + head->Size)
 178                 )
 179         {
 180                 // Alignment Check
 181                 #if POW2_SIZES
 182                 if( head->Size != 1UUL << LOG2(head->Size) ) {
 183                 #else
 184                 if( head->Size & (MIN_SIZE-1) ) {
 185                 #endif
 186                         Mutex_Release(&glHeap); // Release spinlock
 187                         #if WARNINGS
 188                         Log_Warning("Heap", "Size of heap address %p is invalid not aligned (0x%x)", head, head->Size);
 189                         Heap_Dump();
 190                         #endif
 191                         return NULL;
 192                 }
 193
 194                 // Check if allocated
 195                 if(head->Magic == MAGIC_USED)   continue;
 196                 // Error check
 197                 if(head->Magic != MAGIC_FREE)   {
 198                         Mutex_Release(&glHeap); // Release spinlock
 199                         #if WARNINGS
 200                         Log_Warning("Heap", "Magic of heap address %p is invalid (0x%x)", head, head->Magic);
 201                         Heap_Dump();
 202                         #endif
 203                         return NULL;
 204                 }
 205
 206                 // Size check
 207                 if(head->Size < Bytes)  continue;
 208
 209                 // Perfect fit
 210                 if(head->Size == Bytes) {
 211                         head->Magic = MAGIC_USED;
 212                         head->File = File;
 213                         head->Line = Line;
 214                         head->ValidSize = __Bytes;
 215                         head->AllocateTime = now();
 216                         Mutex_Release(&glHeap); // Release spinlock
 217                         #if DEBUG_TRACE
 218                         Debug("[Heap   ] Malloc'd %p (%i bytes), returning to %p", head->Data, head->Size,  __builtin_return_address(0));
 219                         #endif
 220                         return head->Data;
 221                 }
 222
 223                 // Break out of loop
 224                 #if FIRST_FIT
 225                 best = head;
 226                 bestSize = head->Size;
 227                 break;
 228                 #else
 229                 // or check if the block is the best size
 230                 if(bestSize > head->Size) {
 231                         best = head;
 232                         bestSize = head->Size;
 233                 }
 234                 #endif
 235         }
 236
 237         // If no block large enough is found, create one
 238         if(!best)
 239         {
 240                 best = Heap_Extend( Bytes );
 241                 // Check for errors
 242                 if(!best) {
 243                         Mutex_Release(&glHeap); // Release spinlock
 244                         return NULL;
 245                 }
 246                 // Check size
 247                 if(best->Size == Bytes) {
 248                         best->Magic = MAGIC_USED;       // Mark block as used
 249                         best->File = File;
 250                         best->Line = Line;
 251                         best->ValidSize = __Bytes;
 252                         best->AllocateTime = now();
 253                         Mutex_Release(&glHeap); // Release spinlock
 254                         #if DEBUG_TRACE
 255                         Debug("[Heap   ] Malloc'd %p (%i bytes), returning to %s:%i", best->Data, best->Size, File, Line);
 256                         #endif
 257                         return best->Data;
 258                 }
 259         }
 260
 261         // Split Block
 262         newhead = (void*)( (Uint)best + Bytes );
 263         newfoot = (void*)( (Uint)best + Bytes - sizeof(tHeapFoot) );
 264         foot = (void*)( (Uint)best + best->Size - sizeof(tHeapFoot) );
 265
 266         newfoot->Head = best;   // Create new footer
 267         newfoot->Magic = MAGIC_FOOT;
 268         newhead->Size = best->Size - Bytes;     // Create new header
 269         newhead->Magic = MAGIC_FREE;
 270         foot->Head = newhead;   // Update backlink in old footer
 271         best->Size = Bytes;             // Update size in old header
 272         best->ValidSize = __Bytes;
 273         best->Magic = MAGIC_USED;       // Mark block as used
 274         best->File = File;
 275         best->Line = Line;
 276         best->AllocateTime = now();
 277
 278         Mutex_Release(&glHeap); // Release spinlock
 279         #if DEBUG_TRACE
 280         Debug("[Heap   ] Malloc'd %p (0x%x bytes), returning to %s:%i",
 281                 best->Data, best->Size, File, Line);
 282         #endif
 283         return best->Data;
 284 }
 285
 286 /**
 287  * \fn void Heap_Deallocate(void *Ptr)
 288  * \brief Free an allocated memory block
 289  */
 290 void Heap_Deallocate(void *Ptr)
 291 {
 292         tHeapHead       *head = (void*)( (Uint)Ptr - sizeof(tHeapHead) );
 293         tHeapFoot       *foot;
 294
 295         // INVLPTR is returned from Heap_Allocate when the allocation
 296         // size is zero.
 297         if( Ptr == INVLPTR )    return;
 298
 299         #if DEBUG_TRACE
 300         Debug("[Heap   ] free: %p freed by %p (%i old)", Ptr, __builtin_return_address(0), now()-head->AllocateTime);
 301         #endif
 302
 303         // Alignment Check
 304         if( (Uint)Ptr & (sizeof(Uint)-1) ) {
 305                 Log_Warning("Heap", "free - Passed a non-aligned address (%p)", Ptr);
 306                 return;
 307         }
 308
 309         // Sanity check
 310         if((Uint)Ptr < (Uint)gHeapStart || (Uint)Ptr > (Uint)gHeapEnd)
 311         {
 312                 Log_Warning("Heap", "free - Passed a non-heap address (%p < %p < %p)\n",
 313                         gHeapStart, Ptr, gHeapEnd);
 314                 return;
 315         }
 316
 317         // Check memory block - Header
 318         head = (void*)( (Uint)Ptr - sizeof(tHeapHead) );
 319         if(head->Magic == MAGIC_FREE) {
 320                 Log_Warning("Heap", "free - Passed a freed block (%p) by %p", head, __builtin_return_address(0));
 321                 return;
 322         }
 323         if(head->Magic != MAGIC_USED) {
 324                 Log_Warning("Heap", "free - Magic value is invalid (%p, 0x%x)", head, head->Magic);
 325                 Log_Notice("Heap", "Allocated by %s:%i", head->File, head->Line);
 326                 return;
 327         }
 328
 329         // Check memory block - Footer
 330         foot = (void*)( (Uint)head + head->Size - sizeof(tHeapFoot) );
 331         if(foot->Head != head) {
 332                 Log_Warning("Heap", "free - Footer backlink is incorrect (%p, 0x%x)", head, foot->Head);
 333                 Log_Notice("Heap", "Allocated by %s:%i", head->File, head->Line);
 334                 return;
 335         }
 336         if(foot->Magic != MAGIC_FOOT) {
 337                 Log_Warning("Heap", "free - Footer magic is invalid (%p, %p = 0x%x)", head, &foot->Magic, foot->Magic);
 338                 Log_Notice("Heap", "Allocated by %s:%i", head->File, head->Line);
 339                 return;
 340         }
 341
 342         // Lock
 343         Mutex_Acquire( &glHeap );
 344
 345         // Mark as free
 346         head->Magic = MAGIC_FREE;
 347         //head->File = NULL;
 348         //head->Line = 0;
 349         head->ValidSize = 0;
 350         // Merge blocks
 351         Heap_Merge( head );
 352
 353         // Release
 354         Mutex_Release( &glHeap );
 355 }
 356
 357 /**
 358  * \brief Increase/Decrease the size of an allocation
 359  * \param File  Calling File
 360  * \param Line  Calling Line
 361  * \param __ptr Old memory
 362  * \param __size        New Size
 363  */
 364 void *Heap_Reallocate(const char *File, int Line, void *__ptr, size_t __size)
 365 {
 366         tHeapHead       *head = (void*)( (Uint)__ptr-sizeof(tHeapHead) );
 367         tHeapHead       *nextHead;
 368         tHeapFoot       *foot;
 369         Uint    newSize = (__size + sizeof(tHeapFoot)+sizeof(tHeapHead)+MIN_SIZE-1)&~(MIN_SIZE-1);
 370
 371         // Check for reallocating NULL
 372         if(__ptr == NULL)       return Heap_Allocate(File, Line, __size);
 373
 374         // Check if resize is needed
 375         if(newSize <= head->Size)       return __ptr;
 376
 377         // Check if next block is free
 378         nextHead = (void*)( (Uint)head + head->Size );
 379
 380         // Extend into next block
 381         if(nextHead->Magic == MAGIC_FREE && nextHead->Size+head->Size >= newSize)
 382         {
 383                 Uint    size = nextHead->Size + head->Size;
 384                 foot = (void*)( (Uint)nextHead + nextHead->Size - sizeof(tHeapFoot) );
 385                 // Exact Fit
 386                 if(size == newSize) {
 387                         head->Size = newSize;
 388                         head->ValidSize = __size;
 389                         head->File = File;
 390                         head->Line = Line;
 391                         foot->Head = head;
 392                         nextHead->Magic = 0;
 393                         nextHead->Size = 0;
 394                         return __ptr;
 395                 }
 396                 // Create a new heap block
 397                 nextHead = (void*)( (Uint)head + newSize );
 398                 nextHead->Size = size - newSize;
 399                 nextHead->Magic = MAGIC_FREE;
 400                 foot->Head = nextHead;  // Edit 2nd footer
 401                 head->Size = newSize;   // Edit first header
 402                 head->File = File;
 403                 head->Line = Line;
 404                 head->ValidSize = __size;
 405                 // Create new footer
 406                 foot = (void*)( (Uint)head + newSize - sizeof(tHeapFoot) );
 407                 foot->Head = head;
 408                 foot->Magic = MAGIC_FOOT;
 409                 return __ptr;
 410         }
 411
 412         // Extend downwards?
 413         foot = (void*)( (Uint)head - sizeof(tHeapFoot) );
 414         nextHead = foot->Head;
 415         if(nextHead->Magic == MAGIC_FREE && nextHead->Size+head->Size >= newSize)
 416         {
 417                 Uint    size = nextHead->Size + head->Size;
 418                 // Inexact fit, split things up
 419                 if(size > newSize)
 420                 {
 421                         // TODO
 422                         Warning("[Heap   ] TODO: Space efficient realloc when new size is smaller");
 423                 }
 424
 425                 // Exact fit
 426                 if(size >= newSize)
 427                 {
 428                         Uint    oldDataSize;
 429                         // Set 1st (new/lower) header
 430                         nextHead->Magic = MAGIC_USED;
 431                         nextHead->Size = newSize;
 432                         nextHead->File = File;
 433                         nextHead->Line = Line;
 434                         nextHead->ValidSize = __size;
 435                         // Get 2nd (old) footer
 436                         foot = (void*)( (Uint)nextHead + newSize );
 437                         foot->Head = nextHead;
 438                         // Save old data size
 439                         oldDataSize = head->Size - sizeof(tHeapFoot) - sizeof(tHeapHead);
 440                         // Clear old header
 441                         head->Size = 0;
 442                         head->Magic = 0;
 443                         // Copy data
 444                         memcpy(nextHead->Data, __ptr, oldDataSize);
 445                         // Return
 446                         return nextHead->Data;
 447                 }
 448                 // On to the expensive then
 449         }
 450
 451         // Well, darn
 452         nextHead = Heap_Allocate( File, Line, __size );
 453         nextHead -= 1;
 454         nextHead->File = File;
 455         nextHead->Line = Line;
 456         nextHead->ValidSize = __size;
 457
 458         memcpy(
 459                 nextHead->Data,
 460                 __ptr,
 461                 head->Size - sizeof(tHeapFoot) - sizeof(tHeapHead)
 462                 );
 463
 464         free(__ptr);
 465
 466         return nextHead->Data;
 467 }
 468
 469 /**
 470  * \fn void *Heap_AllocateZero(const char *File, int Line, size_t Bytes)
 471  * \brief Allocate and Zero a buffer in memory
 472  * \param File  Allocating file
 473  * \param Line  Line of allocation
 474  * \param Bytes Size of the allocation
 475  */
 476 void *Heap_AllocateZero(const char *File, int Line, size_t Bytes)
 477 {
 478         void    *ret = Heap_Allocate(File, Line, Bytes);
 479         if(ret == NULL) return NULL;
 480
 481         memset( ret, 0, Bytes );
 482
 483         return ret;
 484 }
 485
 486 /**
 487  * \fn int Heap_IsHeapAddr(void *Ptr)
 488  * \brief Checks if an address is a heap pointer
 489  */
 490 int Heap_IsHeapAddr(void *Ptr)
 491 {
 492         tHeapHead       *head;
 493         if((Uint)Ptr < (Uint)gHeapStart)        return 0;
 494         if((Uint)Ptr > (Uint)gHeapEnd)  return 0;
 495         if((Uint)Ptr & (sizeof(Uint)-1))        return 0;
 496
 497         head = (void*)( (Uint)Ptr - sizeof(tHeapHead) );
 498         if(head->Magic != MAGIC_USED && head->Magic != MAGIC_FREE)
 499                 return 0;
 500
 501         return 1;
 502 }
 503
 504 /**
 505  */
 506 void Heap_Validate(void)
 507 {
 508         Heap_Dump();
 509 }
 510
 511 #if WARNINGS
 512 void Heap_Dump(void)
 513 {
 514         tHeapHead       *head, *badHead;
 515         tHeapFoot       *foot = NULL;
 516
 517         head = gHeapStart;
 518         while( (Uint)head < (Uint)gHeapEnd )
 519         {
 520                 foot = (void*)( (Uint)head + head->Size - sizeof(tHeapFoot) );
 521                 #if VERBOSE_DUMP
 522                 Log_Log("Heap", "%p (0x%llx): 0x%08lx (%i) %4C",
 523                         head, MM_GetPhysAddr((Uint)head), head->Size, head->ValidSize, &head->Magic);
 524                 Log_Log("Heap", "%p %4C", foot->Head, &foot->Magic);
 525                 if(head->File) {
 526                         Log_Log("Heap", "%sowned by %s:%i",
 527                                 (head->Magic==MAGIC_FREE?"was ":""), head->File, head->Line);
 528                 }
 529                 #endif
 530
 531                 // Sanity Check Header
 532                 if(head->Size == 0) {
 533                         Log_Warning("Heap", "HALTED - Size is zero");
 534                         break;
 535                 }
 536                 if(head->Size & (MIN_SIZE-1)) {
 537                         Log_Warning("Heap", "HALTED - Size is malaligned");
 538                         break;
 539                 }
 540                 if(head->Magic != MAGIC_FREE && head->Magic != MAGIC_USED) {
 541                         Log_Warning("Heap", "HALTED - Head Magic is Bad");
 542                         break;
 543                 }
 544
 545                 // Check footer
 546                 if(foot->Magic != MAGIC_FOOT) {
 547                         Log_Warning("Heap", "HALTED - Foot Magic is Bad");
 548                         break;
 549                 }
 550                 if(head != foot->Head) {
 551                         Log_Warning("Heap", "HALTED - Footer backlink is invalid");
 552                         break;
 553                 }
 554
 555                 #if VERBOSE_DUMP
 556                 Log_Log("Heap", "");
 557                 #endif
 558
 559                 // All OK? Go to next
 560                 head = foot->NextHead;
 561         }
 562
 563         // If the heap is valid, ok!
 564         if( (tVAddr)head == (tVAddr)gHeapEnd )
 565                 return ;
 566
 567         // Check for a bad return
 568         if( (tVAddr)head >= (tVAddr)gHeapEnd )
 569                 return ;
 570
 571         #if !VERBOSE_DUMP
 572         Log_Log("Heap", "%p (%P): 0x%08lx %i %4C",
 573                 head, MM_GetPhysAddr((Uint)head), head->Size, head->ValidSize, &head->Magic);
 574         if(foot)
 575                 Log_Log("Heap", "Backlink = %p %4C", foot->Head, &foot->Magic);
 576         if(head->File) {
 577                 Log_Log("Heap", "%sowned by %s:%i",
 578                         (head->Magic==MAGIC_FREE?"was ":""), head->File, head->Line);
 579         }
 580         Log_Log("Heap", "");
 581         #endif
 582
 583
 584         badHead = head;
 585
 586         // Work backwards
 587         foot = (void*)( (tVAddr)gHeapEnd - sizeof(tHeapFoot) );
 588         Log_Log("Heap", "==== Going Backwards ==== (from %p)", foot);
 589         head = foot->Head;
 590         while( (tVAddr)head >= (tVAddr)badHead )
 591         {
 592                 Log_Log("Heap", "%p (%P): 0x%08lx %i %4C",
 593                         head, MM_GetPhysAddr((Uint)head), head->Size, head->ValidSize, &head->Magic);
 594                 Log_Log("Heap", "%p %4C", foot->Head, &foot->Magic);
 595                 if(head->File)
 596                         Log_Log("Heap", "%sowned by %s:%i",
 597                                 (head->Magic!=MAGIC_USED?"was ":""),
 598                                 head->File, head->Line);
 599                 Log_Log("Heap", "");
 600
 601                 // Sanity Check Header
 602                 if(head->Size == 0) {
 603                         Log_Warning("Heap", "HALTED - Size is zero");
 604                         break;
 605                 }
 606                 if(head->Size & (MIN_SIZE-1)) {
 607                         Log_Warning("Heap", " - Size is malaligned (&0x%x)", ~(MIN_SIZE-1));
 608                         break ;
 609                 }
 610                 if(head->Magic != MAGIC_FREE && head->Magic != MAGIC_USED) {
 611                         Log_Warning("Heap", "HALTED - Head Magic is Bad");
 612                         break;
 613                 }
 614
 615                 // Check footer
 616                 if(foot->Magic != MAGIC_FOOT) {
 617                         Log_Warning("Heap", "HALTED - Foot Magic is Bad");
 618                         break;
 619                 }
 620                 if(head != foot->Head) {
 621                         Log_Warning("Heap", "HALTED - Footer backlink is invalid");
 622                         break;
 623                 }
 624
 625                 if(head == badHead)     break;
 626
 627                 foot = (void*)( (tVAddr)head - sizeof(tHeapFoot) );
 628                 head = foot->Head;
 629                 Log_Debug("Heap", "head=%p", head);
 630         }
 631
 632         Panic("Heap_Dump - Heap is corrupted, kernel panic!");
 633 }
 634 #endif
 635
 636 #if 1
 637 void Heap_Stats(void)
 638 {
 639         tHeapHead       *head;
 640          int    nBlocks = 0;
 641          int    nFree = 0;
 642          int    totalBytes = 0;
 643          int    freeBytes = 0;
 644          int    maxAlloc=0, minAlloc=-1;
 645          int    avgAlloc, frag, overhead;
 646
 647         for(head = gHeapStart;
 648                 (Uint)head < (Uint)gHeapEnd;
 649                 head = (void*)( (Uint)head + head->Size )
 650                 )
 651         {
 652                 nBlocks ++;
 653                 totalBytes += head->Size;
 654                 if( head->Magic == MAGIC_FREE )
 655                 {
 656                         nFree ++;
 657                         freeBytes += head->Size;
 658                 }
 659                 else if( head->Magic == MAGIC_USED) {
 660                         if(maxAlloc < head->Size)       maxAlloc = head->Size;
 661                         if(minAlloc == -1 || minAlloc > head->Size)
 662                                 minAlloc = head->Size;
 663                 }
 664                 else {
 665                         Log_Warning("Heap", "Magic on %p invalid, skipping remainder of heap", head);
 666                         break;
 667                 }
 668
 669                 // Print the block info?
 670                 #if 1
 671                 if( head->Magic == MAGIC_FREE )
 672                         Log_Debug("Heap", "%p (%P) - 0x%x free",
 673                                 head->Data, MM_GetPhysAddr((tVAddr)&head->Data), head->Size);
 674                 else
 675                         Log_Debug("Heap", "%p (%P) - 0x%x (%i) Owned by %s:%i (%lli ms old)",
 676                                 head->Data, MM_GetPhysAddr((tVAddr)&head->Data), head->Size, head->ValidSize, head->File, head->Line,
 677                                 now() - head->AllocateTime
 678                                 );
 679                 #endif
 680         }
 681
 682         Log_Log("Heap", "%i blocks (0x%x bytes)", nBlocks, totalBytes);
 683         Log_Log("Heap", "%i free blocks (0x%x bytes)", nFree, freeBytes);
 684         if(nBlocks != 0)
 685                 frag = (nFree-1)*10000/nBlocks;
 686         else
 687                 frag = 0;
 688         Log_Log("Heap", "%i.%02i%% Heap Fragmentation", frag/100, frag%100);
 689         avgAlloc = (totalBytes-freeBytes)/(nBlocks-nFree);
 690         if(avgAlloc != 0)
 691                 overhead = (sizeof(tHeapFoot)+sizeof(tHeapHead))*10000/avgAlloc;
 692         else
 693                 overhead = 0;
 694         Log_Log("Heap", "Average allocation: %i bytes, Average Overhead: %i.%02i%%",
 695                 avgAlloc, overhead/100, overhead%100
 696                 );
 697         Log_Log("Heap", "Smallest Block: %i bytes, Largest: %i bytes",
 698                 minAlloc, maxAlloc);
 699
 700         // Scan and get distribution
 701         #if 1
 702         {
 703                 struct {
 704                         Uint    Size;
 705                         Uint    Count;
 706                 }       sizeCounts[nBlocks];
 707                  int    i;
 708
 709                 memset(sizeCounts, 0, nBlocks*sizeof(sizeCounts[0]));
 710
 711                 for(head = gHeapStart;
 712                         (Uint)head < (Uint)gHeapEnd;
 713                         head = (void*)( (Uint)head + head->Size )
 714                         )
 715                 {
 716                         for( i = 0; i < nBlocks; i ++ ) {
 717                                 if( sizeCounts[i].Size == 0 )
 718                                         break;
 719                                 if( sizeCounts[i].Size == head->Size )
 720                                         break;
 721                         }
 722                         // Should never reach this part (in a non-concurrent case)
 723                         if( i == nBlocks )      continue;
 724                         sizeCounts[i].Size = head->Size;
 725                         sizeCounts[i].Count ++;
 726                         #if 1
 727                         //Log("Heap_Stats: %i %p - 0x%x bytes (%s) (%i)", nBlocks, head,
 728                         //      head->Size, (head->Magic==MAGIC_FREE?"FREE":"used"), i
 729                         //      );
 730                         //Log("Heap_Stats: sizeCounts[%i] = {Size:0x%x, Count: %i}", i,
 731                         //      sizeCounts[i].Size, sizeCounts[i].Count);
 732                         #endif
 733                 }
 734
 735                 for( i = 0; i < nBlocks && sizeCounts[i].Count; i ++ )
 736                 {
 737                         Log("Heap_Stats: 0x%x - %i blocks",
 738                                 sizeCounts[i].Size, sizeCounts[i].Count
 739                                 );
 740                 }
 741         }
 742         #endif
 743 }
 744 #endif
 745
 746 // === EXPORTS ===
 747 EXPORT(Heap_Allocate);
 748 EXPORT(Heap_AllocateZero);
 749 EXPORT(Heap_Reallocate);
 750 EXPORT(Heap_Deallocate);
 751 EXPORT(Heap_IsHeapAddr);