src/memusage.h

   1 // Copyright (c) 2015-2016 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
  10 #include <stdlib.h>
  11
  12 #include <map>
  13 #include <set>
  14 #include <vector>
  15
  16 #include <boost/foreach.hpp>
  17 #include <boost/unordered_set.hpp>
  18 #include <boost/unordered_map.hpp>
  19
  20 namespace memusage
  21 {
  22
  23 /** Compute the total memory used by allocating alloc bytes. */
  24 static size_t MallocUsage(size_t alloc);
  25
  26 /** Dynamic memory usage for built-in types is zero. */
  27 static inline size_t DynamicUsage(const int8_t& v) { return 0; }
  28 static inline size_t DynamicUsage(const uint8_t& v) { return 0; }
  29 static inline size_t DynamicUsage(const int16_t& v) { return 0; }
  30 static inline size_t DynamicUsage(const uint16_t& v) { return 0; }
  31 static inline size_t DynamicUsage(const int32_t& v) { return 0; }
  32 static inline size_t DynamicUsage(const uint32_t& v) { return 0; }
  33 static inline size_t DynamicUsage(const int64_t& v) { return 0; }
  34 static inline size_t DynamicUsage(const uint64_t& v) { return 0; }
  35 static inline size_t DynamicUsage(const float& v) { return 0; }
  36 static inline size_t DynamicUsage(const double& v) { return 0; }
  37 template<typename X> static inline size_t DynamicUsage(X * const &v) { return 0; }
  38 template<typename X> static inline size_t DynamicUsage(const X * const &v) { return 0; }
  39
  40 /** Compute the memory used for dynamically allocated but owned data structures.
  41  *  For generic data types, this is *not* recursive. DynamicUsage(vector<vector<int> >)
  42  *  will compute the memory used for the vector<int>'s, but not for the ints inside.
  43  *  This is for efficiency reasons, as these functions are intended to be fast. If
  44  *  application data structures require more accurate inner accounting, they should
  45  *  iterate themselves, or use more efficient caching + updating on modification.
  46  */
  47
  48 static inline size_t MallocUsage(size_t alloc)
  49 {
  50     // Measured on libc6 2.19 on Linux.
  51     if (alloc == 0) {
  52         return 0;
  53     } else if (sizeof(void*) == 8) {
  54         return ((alloc + 31) >> 4) << 4;
  55     } else if (sizeof(void*) == 4) {
  56         return ((alloc + 15) >> 3) << 3;
  57     } else {
  58         assert(0);
  59     }
  60 }
  61
  62 // STL data structures
  63
  64 template<typename X>
  65 struct stl_tree_node
  66 {
  67 private:
  68     int color;
  69     void* parent;
  70     void* left;
  71     void* right;
  72     X x;
  73 };
  74
  75 struct stl_shared_counter
  76 {
  77     /* Various platforms use different sized counters here.
  78      * Conservatively assume that they won't be larger than size_t. */
  79     void* class_type;
  80     size_t use_count;
  81     size_t weak_count;
  82 };
  83
  84 template<typename X>
  85 static inline size_t DynamicUsage(const std::vector<X>& v)
  86 {
  87     return MallocUsage(v.capacity() * sizeof(X));
  88 }
  89
  90 template<unsigned int N, typename X, typename S, typename D>
  91 static inline size_t DynamicUsage(const prevector<N, X, S, D>& v)
  92 {
  93     return MallocUsage(v.allocated_memory());
  94 }
  95
  96 template<typename X, typename Y>
  97 static inline size_t DynamicUsage(const std::set<X, Y>& s)
  98 {
  99     return MallocUsage(sizeof(stl_tree_node<X>)) * s.size();
 100 }
 101
 102 template<typename X, typename Y>
 103 static inline size_t IncrementalDynamicUsage(const std::set<X, Y>& s)
 104 {
 105     return MallocUsage(sizeof(stl_tree_node<X>));
 106 }
 107
 108 template<typename X, typename Y, typename Z>
 109 static inline size_t DynamicUsage(const std::map<X, Y, Z>& m)
 110 {
 111     return MallocUsage(sizeof(stl_tree_node<std::pair<const X, Y> >)) * m.size();
 112 }
 113
 114 template<typename X, typename Y, typename Z>
 115 static inline size_t IncrementalDynamicUsage(const std::map<X, Y, Z>& m)
 116 {
 117     return MallocUsage(sizeof(stl_tree_node<std::pair<const X, Y> >));
 118 }
 119
 120 // indirectmap has underlying map with pointer as key
 121
 122 template<typename X, typename Y>
 123 static inline size_t DynamicUsage(const indirectmap<X, Y>& m)
 124 {
 125     return MallocUsage(sizeof(stl_tree_node<std::pair<const X*, Y> >)) * m.size();
 126 }
 127
 128 template<typename X, typename Y>
 129 static inline size_t IncrementalDynamicUsage(const indirectmap<X, Y>& m)
 130 {
 131     return MallocUsage(sizeof(stl_tree_node<std::pair<const X*, Y> >));
 132 }
 133
 134 template<typename X>
 135 static inline size_t DynamicUsage(const std::unique_ptr<X>& p)
 136 {
 137     return p ? MallocUsage(sizeof(X)) : 0;
 138 }
 139
 140 template<typename X>
 141 static inline size_t DynamicUsage(const std::shared_ptr<X>& p)
 142 {
 143     // A shared_ptr can either use a single continuous memory block for both
 144     // the counter and the storage (when using std::make_shared), or separate.
 145     // We can't observe the difference, however, so assume the worst.
 146     return p ? MallocUsage(sizeof(X)) + MallocUsage(sizeof(stl_shared_counter)) : 0;
 147 }
 148
 149 // Boost data structures
 150
 151 template<typename X>
 152 struct boost_unordered_node : private X
 153 {
 154 private:
 155     void* ptr;
 156 };
 157
 158 template<typename X, typename Y>
 159 static inline size_t DynamicUsage(const boost::unordered_set<X, Y>& s)
 160 {
 161     return MallocUsage(sizeof(boost_unordered_node<X>)) * s.size() + MallocUsage(sizeof(void*) * s.bucket_count());
 162 }
 163
 164 template<typename X, typename Y, typename Z>
 165 static inline size_t DynamicUsage(const boost::unordered_map<X, Y, Z>& m)
 166 {
 167     return MallocUsage(sizeof(boost_unordered_node<std::pair<const X, Y> >)) * m.size() + MallocUsage(sizeof(void*) * m.bucket_count());
 168 }
 169
 170 }
 171
 172 #endif // BITCOIN_MEMUSAGE_H