Bitcoin ABC  0.22.13
P2P Digital Currency
lockedpool.h
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1 // Copyright (c) 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_SUPPORT_LOCKEDPOOL_H
6 #define BITCOIN_SUPPORT_LOCKEDPOOL_H
7 
8 #include <cstdint>
9 #include <list>
10 #include <map>
11 #include <memory>
12 #include <mutex>
13 #include <unordered_map>
14 
20 public:
21  virtual ~LockedPageAllocator() {}
31  virtual void *AllocateLocked(size_t len, bool *lockingSuccess) = 0;
32 
37  virtual void FreeLocked(void *addr, size_t len) = 0;
38 
44  virtual size_t GetLimit() = 0;
45 };
46 
50 class Arena {
51 public:
52  Arena(void *base, size_t size, size_t alignment);
53  virtual ~Arena();
54 
55  Arena(const Arena &other) = delete; // non construction-copyable
56  Arena &operator=(const Arena &) = delete; // non copyable
57 
59  struct Stats {
60  size_t used;
61  size_t free;
62  size_t total;
63  size_t chunks_used;
64  size_t chunks_free;
65  };
66 
72  void *alloc(size_t size);
73 
79  void free(void *ptr);
80 
82  Stats stats() const;
83 
84 #ifdef ARENA_DEBUG
85  void walk() const;
86 #endif
87 
93  bool addressInArena(void *ptr) const { return ptr >= base && ptr < end; }
94 
95 private:
96  typedef std::multimap<size_t, char *> SizeToChunkSortedMap;
98  SizeToChunkSortedMap size_to_free_chunk;
99 
100  typedef std::unordered_map<char *, SizeToChunkSortedMap::const_iterator>
106 
108  std::unordered_map<char *, size_t> chunks_used;
109 
111  char *base;
113  char *end;
115  size_t alignment;
116 };
117 
132 class LockedPool {
133 public:
140  static const size_t ARENA_SIZE = 256 * 1024;
145  static const size_t ARENA_ALIGN = 16;
146 
150  typedef bool (*LockingFailed_Callback)();
151 
153  struct Stats {
154  size_t used;
155  size_t free;
156  size_t total;
157  size_t locked;
158  size_t chunks_used;
159  size_t chunks_free;
160  };
161 
171  explicit LockedPool(std::unique_ptr<LockedPageAllocator> allocator,
172  LockingFailed_Callback lf_cb_in = nullptr);
173  ~LockedPool();
174 
175  LockedPool(const LockedPool &other) = delete; // non construction-copyable
176  LockedPool &operator=(const LockedPool &) = delete; // non copyable
177 
183  void *alloc(size_t size);
184 
190  void free(void *ptr);
191 
193  Stats stats() const;
194 
195 private:
196  std::unique_ptr<LockedPageAllocator> allocator;
197 
199  class LockedPageArena : public Arena {
200  public:
201  LockedPageArena(LockedPageAllocator *alloc_in, void *base_in,
202  size_t size, size_t align);
203  ~LockedPageArena();
204 
205  private:
206  void *base;
207  size_t size;
209  };
210 
211  bool new_arena(size_t size, size_t align);
212 
213  std::list<LockedPageArena> arenas;
214  LockingFailed_Callback lf_cb;
219  mutable std::mutex mutex;
220 };
221 
234 public:
237  std::call_once(LockedPoolManager::init_flag,
240  }
241 
242 private:
243  explicit LockedPoolManager(std::unique_ptr<LockedPageAllocator> allocator);
244 
246  static void CreateInstance();
248  static bool LockingFailed();
249 
251  static std::once_flag init_flag;
252 };
253 
254 #endif // BITCOIN_SUPPORT_LOCKEDPOOL_H
size_t chunks_free
Definition: lockedpool.h:64
size_t chunks_used
Definition: lockedpool.h:63
static std::once_flag init_flag
Definition: lockedpool.h:251
size_t used
Definition: lockedpool.h:60
size_t alignment
Minimum chunk alignment.
Definition: lockedpool.h:115
std::mutex mutex
Mutex protects access to this pool&#39;s data structures, including arenas.
Definition: lockedpool.h:219
std::unordered_map< char *, SizeToChunkSortedMap::const_iterator > ChunkToSizeMap
Definition: lockedpool.h:101
std::list< LockedPageArena > arenas
Definition: lockedpool.h:213
static LockedPoolManager & Instance()
Return the current instance, or create it once.
Definition: lockedpool.h:236
std::unordered_map< char *, size_t > chunks_used
Map from begin of used chunk to its size.
Definition: lockedpool.h:108
virtual void * AllocateLocked(size_t len, bool *lockingSuccess)=0
Allocate and lock memory pages.
ChunkToSizeMap chunks_free
Map from begin of free chunk to its node in size_to_free_chunk.
Definition: lockedpool.h:103
LockingFailed_Callback lf_cb
Definition: lockedpool.h:214
size_t total
Definition: lockedpool.h:62
SizeToChunkSortedMap size_to_free_chunk
Map to enable O(log(n)) best-fit allocation, as it&#39;s sorted by size.
Definition: lockedpool.h:98
OS-dependent allocation and deallocation of locked/pinned memory pages.
Definition: lockedpool.h:19
bool addressInArena(void *ptr) const
Return whether a pointer points inside this arena.
Definition: lockedpool.h:93
LockedPageAllocator * allocator
Definition: lockedpool.h:208
Singleton class to keep track of locked (ie, non-swappable) memory, for use in std::allocator templat...
Definition: lockedpool.h:233
char * end
End address of arena.
Definition: lockedpool.h:113
static LockedPoolManager * _instance
Definition: lockedpool.h:250
virtual void FreeLocked(void *addr, size_t len)=0
Unlock and free memory pages.
virtual ~LockedPageAllocator()
Definition: lockedpool.h:21
size_t free
Definition: lockedpool.h:61
Pool for locked memory chunks.
Definition: lockedpool.h:132
Create an arena from locked pages.
Definition: lockedpool.h:199
char * base
Base address of arena.
Definition: lockedpool.h:111
virtual size_t GetLimit()=0
Get the total limit on the amount of memory that may be locked by this process, in bytes...
std::multimap< size_t, char * > SizeToChunkSortedMap
Definition: lockedpool.h:96
Memory statistics.
Definition: lockedpool.h:59
static void CreateInstance()
Create a new LockedPoolManager specialized to the OS.
Definition: lockedpool.cpp:396
An arena manages a contiguous region of memory by dividing it into chunks.
Definition: lockedpool.h:50
size_t cumulative_bytes_locked
Definition: lockedpool.h:215
ChunkToSizeMap chunks_free_end
Map from end of free chunk to its node in size_to_free_chunk.
Definition: lockedpool.h:105
std::unique_ptr< LockedPageAllocator > allocator
Definition: lockedpool.h:196
Memory statistics.
Definition: lockedpool.h:153