src/misc/ReferenceCounter.h

   1 #ifndef AESALON_MISC_REFERENCE_COUNTER_H
   2 #define AESALON_MISC_REFERENCE_COUNTER_H
   3
   4 #include <cstddef>
   5 #include <map>
   6
   7 #include "Singleton.h"
   8 #include "Exception.h"
   9 #include "StreamAsString.h"
  10
  11 namespace Aesalon {
  12
  13 namespace Interface {
  14 namespace GDB {
  15 class Controller;
  16 }
  17 }
  18
  19 namespace Misc {
  20
  21 class UntrackedMemoryException : public Exception {
  22 public:
  23     UntrackedMemoryException() : Exception(StreamAsString()
  24         << "Asked to decrement refcount on untracked block.") {}
  25 };
  26
  27 class ReferenceCounter : public Singleton<ReferenceCounter> {
  28 public:
  29     typedef std::size_t refcount_t;
  30 protected:
  31     class MemoryBlock {
  32     private:
  33         refcount_t refcount;
  34     public:
  35         refcount_t get_refcount() const { return refcount; }
  36         void set_refcount(refcount_t new_refcount) { refcount = new_refcount; }
  37     };
  38     typedef std::map<const void *, MemoryBlock> block_map_t;
  39 private:
  40     block_map_t block_map;
  41
  42 public:
  43     ReferenceCounter() {}
  44     virtual ~ReferenceCounter() {}
  45     template<typename Type> void increment_block(const Type *data);
  46     template<typename Type> void decrement_block(const Type *data);
  47
  48     template<typename Type> refcount_t get_block_references(const Type *data);
  49 };
  50
  51 template<typename Type>
  52 void ReferenceCounter::increment_block(const Type *data) {
  53     if(data == NULL) return;
  54
  55     block_map_t::iterator i = block_map.find(data);
  56     if(i == block_map.end()) {
  57         MemoryBlock new_block;
  58         new_block.set_refcount(1);
  59         block_map[data] = new_block;
  60     }
  61     else {
  62         (*i).second.set_refcount((*i).second.get_refcount()+1);
  63     }
  64 }
  65
  66 template<typename Type>
  67 void ReferenceCounter::decrement_block(const Type *data) {
  68     if(data == NULL) return;
  69
  70     block_map_t::iterator i = block_map.find(data);
  71     if(i == block_map.end()) {
  72         /* This memory isn't currently in the counter . . . */
  73         return;
  74     }
  75     else {
  76         (*i).second.set_refcount((*i).second.get_refcount()-1);
  77     }
  78     if((*i).second.get_refcount() == 0) {
  79         delete data;
  80     }
  81 }
  82
  83 template<typename Type>
  84 ReferenceCounter::refcount_t ReferenceCounter::get_block_references(const Type* data) {
  85     block_map_t::iterator i = block_map.find(data);
  86     if(i == block_map.end()) return 0;
  87     else return (*i).second.get_refcount();
  88 }
  89
  90
  91
  92 } // namespace Misc
  93 } // namespace Aesalon
  94
  95 #endif