/ src / memusage.h
memusage.h
  1  // Copyright (c) 2015-2022 The Bitcoin Core developers
  2  // Distributed under the MIT software license, see the accompanying
  3  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  4  
  5  #ifndef BITCOIN_MEMUSAGE_H
  6  #define BITCOIN_MEMUSAGE_H
  7  
  8  #include <indirectmap.h>
  9  #include <prevector.h>
 10  #include <support/allocators/pool.h>
 11  
 12  #include <cassert>
 13  #include <cstdlib>
 14  #include <list>
 15  #include <map>
 16  #include <memory>
 17  #include <set>
 18  #include <vector>
 19  #include <unordered_map>
 20  #include <unordered_set>
 21  
 22  
 23  namespace memusage
 24  {
 25  
 26  /** Compute the total memory used by allocating alloc bytes. */
 27  static size_t MallocUsage(size_t alloc);
 28  
 29  /** Dynamic memory usage for built-in types is zero. */
 30  static inline size_t DynamicUsage(const int8_t& v) { return 0; }
 31  static inline size_t DynamicUsage(const uint8_t& v) { return 0; }
 32  static inline size_t DynamicUsage(const int16_t& v) { return 0; }
 33  static inline size_t DynamicUsage(const uint16_t& v) { return 0; }
 34  static inline size_t DynamicUsage(const int32_t& v) { return 0; }
 35  static inline size_t DynamicUsage(const uint32_t& v) { return 0; }
 36  static inline size_t DynamicUsage(const int64_t& v) { return 0; }
 37  static inline size_t DynamicUsage(const uint64_t& v) { return 0; }
 38  static inline size_t DynamicUsage(const float& v) { return 0; }
 39  static inline size_t DynamicUsage(const double& v) { return 0; }
 40  template<typename X> static inline size_t DynamicUsage(X * const &v) { return 0; }
 41  template<typename X> static inline size_t DynamicUsage(const X * const &v) { return 0; }
 42  
 43  /** Compute the memory used for dynamically allocated but owned data structures.
 44   *  For generic data types, this is *not* recursive. DynamicUsage(vector<vector<int> >)
 45   *  will compute the memory used for the vector<int>'s, but not for the ints inside.
 46   *  This is for efficiency reasons, as these functions are intended to be fast. If
 47   *  application data structures require more accurate inner accounting, they should
 48   *  iterate themselves, or use more efficient caching + updating on modification.
 49   */
 50  
 51  static inline size_t MallocUsage(size_t alloc)
 52  {
 53      // Measured on libc6 2.19 on Linux.
 54      if (alloc == 0) {
 55          return 0;
 56      } else if (sizeof(void*) == 8) {
 57          return ((alloc + 31) >> 4) << 4;
 58      } else if (sizeof(void*) == 4) {
 59          return ((alloc + 15) >> 3) << 3;
 60      } else {
 61          assert(0);
 62      }
 63  }
 64  
 65  // STL data structures
 66  
 67  template<typename X>
 68  struct stl_tree_node
 69  {
 70  private:
 71      int color;
 72      void* parent;
 73      void* left;
 74      void* right;
 75      X x;
 76  };
 77  
 78  struct stl_shared_counter
 79  {
 80      /* Various platforms use different sized counters here.
 81       * Conservatively assume that they won't be larger than size_t. */
 82      void* class_type;
 83      size_t use_count;
 84      size_t weak_count;
 85  };
 86  
 87  template<typename X>
 88  static inline size_t DynamicUsage(const std::vector<X>& v)
 89  {
 90      return MallocUsage(v.capacity() * sizeof(X));
 91  }
 92  
 93  template<unsigned int N, typename X, typename S, typename D>
 94  static inline size_t DynamicUsage(const prevector<N, X, S, D>& v)
 95  {
 96      return MallocUsage(v.allocated_memory());
 97  }
 98  
 99  template<typename X, typename Y>
100  static inline size_t DynamicUsage(const std::set<X, Y>& s)
101  {
102      return MallocUsage(sizeof(stl_tree_node<X>)) * s.size();
103  }
104  
105  template<typename X, typename Y>
106  static inline size_t IncrementalDynamicUsage(const std::set<X, Y>& s)
107  {
108      return MallocUsage(sizeof(stl_tree_node<X>));
109  }
110  
111  template<typename X, typename Y, typename Z>
112  static inline size_t DynamicUsage(const std::map<X, Y, Z>& m)
113  {
114      return MallocUsage(sizeof(stl_tree_node<std::pair<const X, Y> >)) * m.size();
115  }
116  
117  template<typename X, typename Y, typename Z>
118  static inline size_t IncrementalDynamicUsage(const std::map<X, Y, Z>& m)
119  {
120      return MallocUsage(sizeof(stl_tree_node<std::pair<const X, Y> >));
121  }
122  
123  // indirectmap has underlying map with pointer as key
124  
125  template<typename X, typename Y>
126  static inline size_t DynamicUsage(const indirectmap<X, Y>& m)
127  {
128      return MallocUsage(sizeof(stl_tree_node<std::pair<const X*, Y> >)) * m.size();
129  }
130  
131  template<typename X, typename Y>
132  static inline size_t IncrementalDynamicUsage(const indirectmap<X, Y>& m)
133  {
134      return MallocUsage(sizeof(stl_tree_node<std::pair<const X*, Y> >));
135  }
136  
137  template<typename X>
138  static inline size_t DynamicUsage(const std::unique_ptr<X>& p)
139  {
140      return p ? MallocUsage(sizeof(X)) : 0;
141  }
142  
143  template<typename X>
144  static inline size_t DynamicUsage(const std::shared_ptr<X>& p)
145  {
146      // A shared_ptr can either use a single continuous memory block for both
147      // the counter and the storage (when using std::make_shared), or separate.
148      // We can't observe the difference, however, so assume the worst.
149      return p ? MallocUsage(sizeof(X)) + MallocUsage(sizeof(stl_shared_counter)) : 0;
150  }
151  
152  template<typename X>
153  struct list_node
154  {
155  private:
156      void* ptr_next;
157      void* ptr_prev;
158      X x;
159  };
160  
161  template<typename X>
162  static inline size_t DynamicUsage(const std::list<X>& l)
163  {
164      return MallocUsage(sizeof(list_node<X>)) * l.size();
165  }
166  
167  template<typename X>
168  struct unordered_node : private X
169  {
170  private:
171      void* ptr;
172  };
173  
174  template<typename X, typename Y>
175  static inline size_t DynamicUsage(const std::unordered_set<X, Y>& s)
176  {
177      return MallocUsage(sizeof(unordered_node<X>)) * s.size() + MallocUsage(sizeof(void*) * s.bucket_count());
178  }
179  
180  template<typename X, typename Y, typename Z>
181  static inline size_t DynamicUsage(const std::unordered_map<X, Y, Z>& m)
182  {
183      return MallocUsage(sizeof(unordered_node<std::pair<const X, Y> >)) * m.size() + MallocUsage(sizeof(void*) * m.bucket_count());
184  }
185  
186  template <class Key, class T, class Hash, class Pred, std::size_t MAX_BLOCK_SIZE_BYTES, std::size_t ALIGN_BYTES>
187  static inline size_t DynamicUsage(const std::unordered_map<Key,
188                                                             T,
189                                                             Hash,
190                                                             Pred,
191                                                             PoolAllocator<std::pair<const Key, T>,
192                                                                           MAX_BLOCK_SIZE_BYTES,
193                                                                           ALIGN_BYTES>>& m)
194  {
195      auto* pool_resource = m.get_allocator().resource();
196  
197      // The allocated chunks are stored in a std::list. Size per node should
198      // therefore be 3 pointers: next, previous, and a pointer to the chunk.
199      size_t estimated_list_node_size = MallocUsage(sizeof(void*) * 3);
200      size_t usage_resource = estimated_list_node_size * pool_resource->NumAllocatedChunks();
201      size_t usage_chunks = MallocUsage(pool_resource->ChunkSizeBytes()) * pool_resource->NumAllocatedChunks();
202      return usage_resource + usage_chunks + MallocUsage(sizeof(void*) * m.bucket_count());
203  }
204  
205  } // namespace memusage
206  
207  #endif // BITCOIN_MEMUSAGE_H