Bitcoin Core  0.18.99
P2P Digital Currency
lockedpool.h
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1 // Copyright (c) 2016-2018 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 <stdint.h>
9 #include <list>
10 #include <map>
11 #include <mutex>
12 #include <memory>
13 #include <unordered_map>
14 
20 {
21 public:
22  virtual ~LockedPageAllocator() {}
31  virtual void* AllocateLocked(size_t len, bool *lockingSuccess) = 0;
32 
36  virtual void FreeLocked(void* addr, size_t len) = 0;
37 
42  virtual size_t GetLimit() = 0;
43 };
44 
45 /* An arena manages a contiguous region of memory by dividing it into
46  * chunks.
47  */
48 class Arena
49 {
50 public:
51  Arena(void *base, size_t size, size_t alignment);
52  virtual ~Arena();
53 
54  Arena(const Arena& other) = delete; // non construction-copyable
55  Arena& operator=(const Arena&) = delete; // non copyable
56 
58  struct Stats
59  {
60  size_t used;
61  size_t free;
62  size_t total;
63  size_t chunks_used;
64  size_t chunks_free;
65  };
66 
71  void* alloc(size_t size);
72 
77  void free(void *ptr);
78 
80  Stats stats() const;
81 
82 #ifdef ARENA_DEBUG
83  void walk() const;
84 #endif
85 
90  bool addressInArena(void *ptr) const { return ptr >= base && ptr < end; }
91 private:
92  typedef std::multimap<size_t, char*> SizeToChunkSortedMap;
94  SizeToChunkSortedMap size_to_free_chunk;
95 
96  typedef std::unordered_map<char*, SizeToChunkSortedMap::const_iterator> ChunkToSizeMap;
98  ChunkToSizeMap chunks_free;
100  ChunkToSizeMap chunks_free_end;
101 
103  std::unordered_map<char*, size_t> chunks_used;
104 
106  char* base;
108  char* end;
110  size_t alignment;
111 };
112 
127 {
128 public:
134  static const size_t ARENA_SIZE = 256*1024;
138  static const size_t ARENA_ALIGN = 16;
139 
142  typedef bool (*LockingFailed_Callback)();
143 
145  struct Stats
146  {
147  size_t used;
148  size_t free;
149  size_t total;
150  size_t locked;
151  size_t chunks_used;
152  size_t chunks_free;
153  };
154 
162  explicit LockedPool(std::unique_ptr<LockedPageAllocator> allocator, LockingFailed_Callback lf_cb_in = nullptr);
163  ~LockedPool();
164 
165  LockedPool(const LockedPool& other) = delete; // non construction-copyable
166  LockedPool& operator=(const LockedPool&) = delete; // non copyable
167 
172  void* alloc(size_t size);
173 
178  void free(void *ptr);
179 
181  Stats stats() const;
182 private:
183  std::unique_ptr<LockedPageAllocator> allocator;
184 
186  class LockedPageArena: public Arena
187  {
188  public:
189  LockedPageArena(LockedPageAllocator *alloc_in, void *base_in, size_t size, size_t align);
190  ~LockedPageArena();
191  private:
192  void *base;
193  size_t size;
195  };
196 
197  bool new_arena(size_t size, size_t align);
198 
199  std::list<LockedPageArena> arenas;
200  LockingFailed_Callback lf_cb;
204  mutable std::mutex mutex;
205 };
206 
219 {
220 public:
223  {
226  }
227 
228 private:
229  explicit LockedPoolManager(std::unique_ptr<LockedPageAllocator> allocator);
230 
232  static void CreateInstance();
234  static bool LockingFailed();
235 
237  static std::once_flag init_flag;
238 };
239 
240 #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:237
size_t used
Definition: lockedpool.h:60
size_t alignment
Minimum chunk alignment.
Definition: lockedpool.h:110
std::mutex mutex
Mutex protects access to this pool&#39;s data structures, including arenas.
Definition: lockedpool.h:204
std::multimap< size_t, char * > SizeToChunkSortedMap
Definition: lockedpool.h:92
std::list< LockedPageArena > arenas
Definition: lockedpool.h:199
static LockedPoolManager & Instance()
Return the current instance, or create it once.
Definition: lockedpool.h:222
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:98
LockingFailed_Callback lf_cb
Definition: lockedpool.h:200
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:94
std::unordered_map< char *, size_t > chunks_used
Map from begin of used chunk to its size.
Definition: lockedpool.h:103
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:90
LockedPageAllocator * allocator
Definition: lockedpool.h:194
Singleton class to keep track of locked (ie, non-swappable) memory, for use in std::allocator templat...
Definition: lockedpool.h:218
char * end
End address of arena.
Definition: lockedpool.h:108
static LockedPoolManager * _instance
Definition: lockedpool.h:236
virtual void FreeLocked(void *addr, size_t len)=0
Unlock and free memory pages.
std::unordered_map< char *, SizeToChunkSortedMap::const_iterator > ChunkToSizeMap
Definition: lockedpool.h:96
virtual ~LockedPageAllocator()
Definition: lockedpool.h:22
size_t free
Definition: lockedpool.h:61
Pool for locked memory chunks.
Definition: lockedpool.h:126
Create an arena from locked pages.
Definition: lockedpool.h:186
char * base
Base address of arena.
Definition: lockedpool.h:106
virtual size_t GetLimit()=0
Get the total limit on the amount of memory that may be locked by this process, in bytes...
Memory statistics.
Definition: lockedpool.h:58
static void CreateInstance()
Create a new LockedPoolManager specialized to the OS.
Definition: lockedpool.cpp:390
size_t cumulative_bytes_locked
Definition: lockedpool.h:201
ChunkToSizeMap chunks_free_end
Map from end of free chunk to its node in size_to_free_chunk.
Definition: lockedpool.h:100
std::unique_ptr< LockedPageAllocator > allocator
Definition: lockedpool.h:183
Memory statistics.
Definition: lockedpool.h:145