src/storage/FixedHeapAllocator.cxx

   1 #include <HeapAllocator.h>
   2 #include <ErrorType.h>
   3 #include <Debug.h>
   4
   5 void FixedHeapAllocator::initializeInfo(void *ptr)
   6 {
   7     *(void **)ptr = top;
   8     top = ptr;
   9     usedBytes = 0;
  10     offset = (char*)top+PAGEINFOSIZE;
  11     *(short*)((char*)offset+1) = pageSize- PAGEINFOSIZE-BLOCKINFOSIZE;
  12 }
  13
  14 void FixedHeapAllocator::init(int pSize,int allocSize)
  15 {
  16      void *ptr;
  17     ptr = ::calloc(pSize,1);
  18     if(ptr == NULL)
  19     {
  20         printError(ErrOS, "Unable to allocate %d bytes", pSize);
  21         return;
  22     }
  23     allocateSize = allocSize;
  24     pageSize = pSize;
  25     initializeInfo(ptr);
  26     isInitialized = 1;
  27     pageCounter++;
  28
  29 }
  30
  31 void* FixedHeapAllocator::allocate()
  32 {
  33     void *allocateptr, *ptr, *freeSpaceDetector, *pageDetector;
  34     short int pageSizeCounter = 0, add;
  35     short int isFound = 0;
  36
  37     if(isInitialized != 1)
  38     {
  39         printError(ErrBadCall, "Allocator is not initialized");
  40         return NULL;
  41     }
  42     if(allocateSize > ( pageSize - PAGEINFOSIZE-(2*BLOCKINFOSIZE) ))
  43     {
  44         printf("The requested size is greater than the page Size");
  45         return NULL;
  46     }
  47     //TODO::we will implement mode later for this fixed size allocator
  48     //printf("\ninside allocate offset = %u\tpagesize= %d\tusedmemory=%d\tmemoryrequested = %d",offset,pageSize,usedBytes, allocateSize  );
  49     if( ( usedBytes + allocateSize ) > ( pageSize - PAGEINFOSIZE ) )
  50     {
  51         printDebug(DM_Alloc, "Current page exhausted. allocating new page");
  52         ptr = calloc(pageSize,1);
  53         if(ptr == NULL)
  54         {
  55             printError(ErrOS, "Unable to allocate %d bytes", pageSize);
  56             return NULL;
  57         }
  58         pageCounter++;
  59         initializeInfo(ptr);
  60     }
  61     allocateptr = offset;
  62     offset = (char *)offset+allocateSize ;
  63     usedBytes += allocateSize ;
  64     //printf("\nafter allocate offset = %u\tusedmemory=%d\tmemoryrequested = %d\treturn ptr = %u",offset,usedBytes, allocateSize,allocateptr);
  65     return (allocateptr);
  66 }
  67
  68 void FixedHeapAllocator::deAllocate(void *ptr)
  69 {
  70 }
  71
  72 void FixedHeapAllocator::destroy()
  73 {
  74     void *ptr, *temp;
  75     ptr = top;
  76     unsigned int  add;
  77     while(ptr)
  78     {
  79         temp = ptr;
  80         ptr = *(void **)ptr;
  81         //printf("deallocating %u",temp);
  82         free(temp);
  83     }
  84 }
  85
  86 /*int main()
  87 {
  88     cout << "This is the main program";
  89     int bsize;
  90     FixedHeapAllocator mAllocator;
  91     mAllocator.init(50,10);
  92     int i = 0, choice;
  93     unsigned int ptr;
  94     while(true)
  95     {
  96         cout << "enter the choice that u want";
  97         cin>> choice;
  98         if(choice == 1)
  99         {
 100     //        cout << "please enter the memory in bytes that u want to allocate";
 101       //      cin >> bsize;
 102             mAllocator.allocate();
 103         }
 104         else if(choice == 2)
 105         {
 106             cout << "please enter the memory address to deallocate";
 107             cin >> ptr;
 108         }
 109         else
 110         {
 111         //              exit(1);
 112             break;
 113         }
 114     }
 115
 116     mAllocator.destroy();
 117     exit(1);
 118 }*/