PMDK C++ bindings  1.10
This is the C++ bindings documentation for PMDK's libpmemobj.
concurrent_hash_map.hpp
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1 // SPDX-License-Identifier: BSD-3-Clause
2 /* Copyright 2019-2020, Intel Corporation */
3 
10 #ifndef PMEMOBJ_CONCURRENT_HASH_MAP_HPP
11 #define PMEMOBJ_CONCURRENT_HASH_MAP_HPP
12 
15 #include <libpmemobj++/detail/pair.hpp>
17 
18 #include <libpmemobj++/defrag.hpp>
20 #include <libpmemobj++/mutex.hpp>
21 #include <libpmemobj++/p.hpp>
24 
25 #include <libpmemobj++/detail/persistent_pool_ptr.hpp>
27 
29 
30 #include <atomic>
31 #include <cassert>
32 #include <functional>
33 #include <initializer_list>
34 #include <iterator> // for std::distance
35 #include <memory>
36 #include <mutex>
37 #include <thread>
38 #include <type_traits>
39 #include <utility>
40 #include <vector>
41 
42 namespace std
43 {
47 template <typename T>
48 struct hash<pmem::obj::p<T>> {
49  size_t
50  operator()(const pmem::obj::p<T> &x) const
51  {
52  return hash<T>()(x.get_ro());
53  }
54 };
55 } /* namespace std */
56 
57 namespace pmem
58 {
59 namespace obj
60 {
61 
62 namespace concurrent_hash_map_internal
63 {
64 template <typename SharedMutexT>
65 class shared_mutex_scoped_lock {
66  using rw_mutex_type = SharedMutexT;
67 
68 public:
69  shared_mutex_scoped_lock(const shared_mutex_scoped_lock &) = delete;
70  shared_mutex_scoped_lock &
71  operator=(const shared_mutex_scoped_lock &) = delete;
72 
74  shared_mutex_scoped_lock() : mutex(nullptr), is_writer(false)
75  {
76  }
77 
79  shared_mutex_scoped_lock(rw_mutex_type &m, bool write = true)
80  : mutex(nullptr)
81  {
82  acquire(m, write);
83  }
84 
86  ~shared_mutex_scoped_lock()
87  {
88  if (mutex)
89  release();
90  }
91 
93  void
94  acquire(rw_mutex_type &m, bool write = true)
95  {
96  is_writer = write;
97  mutex = &m;
98  if (write)
99  mutex->lock();
100  else
101  mutex->lock_shared();
102  }
103 
107  void
108  release()
109  {
110  assert(mutex);
111  rw_mutex_type *m = mutex;
112  mutex = nullptr;
113  if (is_writer) {
114  m->unlock();
115  } else {
116  m->unlock_shared();
117  }
118  }
119 
124  bool
125  try_acquire(rw_mutex_type &m, bool write = true)
126  {
127  assert(!mutex);
128  bool result;
129  is_writer = write;
130  result = write ? m.try_lock() : m.try_lock_shared();
131  if (result)
132  mutex = &m;
133  return result;
134  }
135 
136 protected:
141  rw_mutex_type *mutex;
146  bool is_writer;
147 }; /* class shared_mutex_scoped_lock */
148 
149 template <typename ScopedLockType>
150 using scoped_lock_upgrade_to_writer =
151  decltype(std::declval<ScopedLockType>().upgrade_to_writer());
152 
153 template <typename ScopedLockType>
154 using scoped_lock_has_upgrade_to_writer =
155  detail::supports<ScopedLockType, scoped_lock_upgrade_to_writer>;
156 
157 template <typename ScopedLockType>
158 using scoped_lock_downgrade_to_reader =
159  decltype(std::declval<ScopedLockType>().downgrade_to_reader());
160 
161 template <typename ScopedLockType>
162 using scoped_lock_has_downgrade_to_reader =
163  detail::supports<ScopedLockType, scoped_lock_downgrade_to_reader>;
164 
165 template <typename ScopedLockType,
166  bool = scoped_lock_has_upgrade_to_writer<ScopedLockType>::value
167  &&scoped_lock_has_downgrade_to_reader<ScopedLockType>::value>
168 class scoped_lock_traits {
169 public:
170  using scope_lock_type = ScopedLockType;
171 
172  static bool
173  initial_rw_state(bool write)
174  {
175  /* For upgradeable locks, initial state is always read */
176  return false;
177  }
178 
179  static bool
180  upgrade_to_writer(scope_lock_type &lock)
181  {
182  return lock.upgrade_to_writer();
183  }
184 
185  static bool
186  downgrade_to_reader(scope_lock_type &lock)
187  {
188  return lock.downgrade_to_reader();
189  }
190 };
191 
192 template <typename ScopedLockType>
193 class scoped_lock_traits<ScopedLockType, false> {
194 public:
195  using scope_lock_type = ScopedLockType;
196 
197  static bool
198  initial_rw_state(bool write)
199  {
200  /* For non-upgradeable locks, we take lock in required mode
201  * immediately */
202  return write;
203  }
204 
205  static bool
206  upgrade_to_writer(scope_lock_type &lock)
207  {
208  /* This overload is for locks which do not support upgrade
209  * operation. For those locks, upgrade_to_writer should not be
210  * called when holding a read lock */
211  return true;
212  }
213 
214  static bool
215  downgrade_to_reader(scope_lock_type &lock)
216  {
217  /* This overload is for locks which do not support downgrade
218  * operation. For those locks, downgrade_to_reader should never
219  * be called */
220  assert(false);
221 
222  return false;
223  }
224 };
225 }
226 
227 template <typename Key, typename T, typename Hash = std::hash<Key>,
228  typename KeyEqual = std::equal_to<Key>,
229  typename MutexType = pmem::obj::shared_mutex,
230  typename ScopedLockType = concurrent_hash_map_internal::
231  shared_mutex_scoped_lock<MutexType>>
232 class concurrent_hash_map;
233 
235 namespace concurrent_hash_map_internal
236 {
237 /* Helper method which throws an exception when called in a tx */
238 static inline void
239 check_outside_tx()
240 {
241  if (pmemobj_tx_stage() != TX_STAGE_NONE)
243  "Function called inside transaction scope.");
244 }
245 
246 template <typename Hash>
247 using transparent_key_equal = typename Hash::transparent_key_equal;
248 
249 template <typename Hash>
250 using has_transparent_key_equal = detail::supports<Hash, transparent_key_equal>;
251 
252 template <typename Hash, typename Pred,
253  bool = has_transparent_key_equal<Hash>::value>
254 struct key_equal_type {
255  using type = typename Hash::transparent_key_equal;
256 };
257 
258 template <typename Hash, typename Pred>
259 struct key_equal_type<Hash, Pred, false> {
260  using type = Pred;
261 };
262 
263 template <typename Mutex, typename ScopedLockType>
264 void
265 assert_not_locked(Mutex &mtx)
266 {
267 #ifndef NDEBUG
268  ScopedLockType scoped_lock;
269  assert(scoped_lock.try_acquire(mtx));
270  scoped_lock.release();
271 #else
272  (void)mtx;
273 #endif
274 }
275 
276 template <typename Key, typename T, typename MutexType, typename ScopedLockType>
277 struct hash_map_node {
279  using mutex_t = MutexType;
280 
282  using scoped_t = ScopedLockType;
283 
284  using value_type = detail::pair<const Key, T>;
285 
287  using node_ptr_t = detail::persistent_pool_ptr<
288  hash_map_node<Key, T, mutex_t, scoped_t>>;
289 
291  node_ptr_t next;
292 
294  mutex_t mutex;
295 
297  value_type item;
298 
299  hash_map_node(const node_ptr_t &_next, const Key &key)
300  : next(_next),
301  item(std::piecewise_construct, std::forward_as_tuple(key),
302  std::forward_as_tuple())
303  {
304  }
305 
306  hash_map_node(const node_ptr_t &_next, const Key &key, const T &t)
307  : next(_next), item(key, t)
308  {
309  }
310 
311  hash_map_node(const node_ptr_t &_next, value_type &&i)
312  : next(_next), item(std::move(i))
313  {
314  }
315 
316  template <typename... Args>
317  hash_map_node(const node_ptr_t &_next, Args &&... args)
318  : next(_next), item(std::forward<Args>(args)...)
319  {
320  }
321 
322  hash_map_node(const node_ptr_t &_next, const value_type &i)
323  : next(_next), item(i)
324  {
325  }
326 
328  hash_map_node(const hash_map_node &) = delete;
329 
331  hash_map_node &operator=(const hash_map_node &) = delete;
332 }; /* struct node */
333 
338 template <typename Bucket>
339 class segment_traits {
340 public:
342  using segment_index_t = size_t;
343  using size_type = size_t;
344  using bucket_type = Bucket;
345 
346 protected:
348  constexpr static size_type max_allocation_size = PMEMOBJ_MAX_ALLOC_SIZE;
349 
351  constexpr static segment_index_t first_big_block = 27;
352  /* TODO: avoid hardcoded value; need constexpr similar to:
353  * Log2(max_allocation_size / sizeof(bucket_type)) */
354 
356  constexpr static size_type big_block_size = size_type(1)
357  << first_big_block;
358 
359  /* Block size in bytes cannot exceed max_allocation_size */
360  static_assert((big_block_size * sizeof(bucket_type)) <
361  max_allocation_size,
362  "Block size exceeds max_allocation_size");
363 
365  constexpr static segment_index_t
366  first_block_in_segment(segment_index_t seg)
367  {
368  return seg < first_big_block
369  ? seg
370  : (first_big_block +
371  (segment_index_t(1) << (seg - first_big_block)) - 1);
372  }
373 
375  constexpr static size_type
376  blocks_in_segment(segment_index_t seg)
377  {
378  return seg < first_big_block
379  ? segment_index_t(1)
380  : segment_index_t(1) << (seg - first_big_block);
381  }
382 
384  constexpr static size_type
385  block_size(segment_index_t b)
386  {
387  return b < first_big_block ? segment_size(b ? b : 1)
388  : big_block_size;
389  }
390 
391 public:
393  constexpr static segment_index_t embedded_segments = 1;
394 
396  constexpr static size_type embedded_buckets = 1 << embedded_segments;
397 
399  constexpr static segment_index_t number_of_segments = 32;
400 
402  static const size_type first_block = 8;
403 
405  constexpr static segment_index_t
406  number_of_blocks()
407  {
408  return first_block_in_segment(number_of_segments);
409  }
410 
412  static segment_index_t
413  segment_index_of(size_type index)
414  {
415  return segment_index_t(detail::Log2(index | 1));
416  }
417 
419  constexpr static segment_index_t
420  segment_base(segment_index_t k)
421  {
422  return (segment_index_t(1) << k) & ~segment_index_t(1);
423  }
424 
426  constexpr static size_type
427  segment_size(segment_index_t k)
428  {
429  return size_type(1) << k; // fake value for k == 0
430  }
431  static_assert(
432  embedded_segments < first_big_block,
433  "Number of embedded segments cannot exceed max_allocation_size");
434 }; /* End of class segment_traits */
435 
452 template <typename BlockTable, typename SegmentTraits, bool is_const>
453 class segment_facade_impl : public SegmentTraits {
454 private:
455  using traits_type = SegmentTraits;
456  using traits_type::block_size;
457  using traits_type::blocks_in_segment;
458  using traits_type::embedded_buckets;
459  using traits_type::embedded_segments;
460  using traits_type::first_block;
461  using traits_type::first_block_in_segment;
462  using traits_type::segment_base;
463  using traits_type::segment_size;
464 
465 public:
466  using table_reference =
467  typename std::conditional<is_const, const BlockTable &,
468  BlockTable &>::type;
469 
470  using table_pointer =
471  typename std::conditional<is_const, const BlockTable *,
472  BlockTable *>::type;
473 
474  using bucket_type = typename traits_type::bucket_type;
475  using segment_index_t = typename traits_type::segment_index_t;
476  using size_type = typename traits_type::size_type;
477 
479  segment_facade_impl(table_reference table, segment_index_t s)
480  : my_table(&table), my_seg(s)
481  {
482  assert(my_seg < traits_type::number_of_segments);
483  }
484 
486  segment_facade_impl(const segment_facade_impl &src)
487  : my_table(src.my_table), my_seg(src.my_seg)
488  {
489  }
490 
491  segment_facade_impl(segment_facade_impl &&src) = default;
492 
494  segment_facade_impl &
495  operator=(const segment_facade_impl &src)
496  {
497  my_table = src.my_table;
498  my_seg = src.my_seg;
499  return *this;
500  }
501 
503  segment_facade_impl &
504  operator=(segment_facade_impl &&src)
505  {
506  my_table = src.my_table;
507  my_seg = src.my_seg;
508  return *this;
509  }
510 
517  bucket_type &operator[](size_type i) const
518  {
519  assert(i < size());
520 
521  segment_index_t table_block = first_block_in_segment(my_seg);
522  size_type b_size = block_size(table_block);
523 
524  table_block += i / b_size;
525  i = i % b_size;
526 
527  return (*my_table)[table_block][static_cast<std::ptrdiff_t>(i)];
528  }
529 
533  segment_facade_impl &
534  operator++()
535  {
536  ++my_seg;
537  return *this;
538  }
539 
543  segment_facade_impl
544  operator++(int)
545  {
546  segment_facade_impl tmp = *this;
547  ++(*this);
548  return tmp;
549  }
550 
554  segment_facade_impl &
555  operator--()
556  {
557  --my_seg;
558  return *this;
559  }
560 
564  segment_facade_impl
565  operator--(int)
566  {
567  segment_facade_impl tmp = *this;
568  --(*this);
569  return tmp;
570  }
571 
575  segment_facade_impl &
576  operator+=(segment_index_t off)
577  {
578  my_seg += off;
579  return *this;
580  }
581 
585  segment_facade_impl &
586  operator-=(segment_index_t off)
587  {
588  my_seg -= off;
589  return *this;
590  }
591 
595  segment_facade_impl
596  operator+(segment_index_t off) const
597  {
598  return segment_facade_impl(*(this->my_table),
599  this->my_seg + off);
600  }
601 
605  segment_facade_impl
606  operator-(segment_index_t off) const
607  {
608  return segment_facade_impl(*(this->my_table),
609  this->my_seg - off);
610  }
611 
615  void
616  enable(pool_base &pop)
617  {
618  assert(my_seg >= embedded_segments);
619 
620  if (my_seg < first_block) {
621  enable_first_block(pop);
622  } else {
623  enable_big_segment(pop);
624  }
625  }
626 
630  void
631  disable()
632  {
633  assert(my_seg >= embedded_segments);
634 
635  if (my_seg < first_block) {
636  if (my_seg == embedded_segments) {
637  size_type sz = segment_size(first_block) -
638  embedded_buckets;
639  delete_persistent<bucket_type[]>(
640  (*my_table)[my_seg], sz);
641  }
642  (*my_table)[my_seg] = nullptr;
643  } else {
644  block_range blocks = segment_blocks(my_seg);
645 
646  for (segment_index_t b = blocks.first;
647  b < blocks.second; ++b) {
648  if ((*my_table)[b] != nullptr) {
649  delete_persistent<bucket_type[]>(
650  (*my_table)[b], block_size(b));
651  (*my_table)[b] = nullptr;
652  }
653  }
654  }
655  }
656 
660  constexpr size_type
661  size() const
662  {
663  return segment_size(my_seg ? my_seg : 1);
664  }
665 
671  bool
672  is_valid() const
673  {
674  block_range blocks = segment_blocks(my_seg);
675 
676  for (segment_index_t b = blocks.first; b < blocks.second; ++b) {
677  if ((*my_table)[b] == nullptr)
678  return false;
679  }
680 
681  return true;
682  }
683 
684 private:
685  using block_range = std::pair<segment_index_t, segment_index_t>;
686 
690  static block_range
691  segment_blocks(segment_index_t seg)
692  {
693  segment_index_t begin = first_block_in_segment(seg);
694 
695  return block_range(begin, begin + blocks_in_segment(seg));
696  }
697 
698  void
699  enable_first_block(pool_base &pop)
700  {
701  assert(my_seg == embedded_segments);
702  {
703  transaction::manual tx(pop);
704 
705  size_type sz =
706  segment_size(first_block) - embedded_buckets;
707  (*my_table)[my_seg] =
708  make_persistent<bucket_type[]>(sz);
709 
710  persistent_ptr<bucket_type> base =
711  (*my_table)[embedded_segments].raw();
712 
713  for (segment_index_t s = my_seg + 1; s < first_block;
714  ++s) {
715  std::ptrdiff_t off =
716  static_cast<std::ptrdiff_t>(
717  segment_base(s) -
718  segment_base(my_seg));
719 
720  (*my_table)[s] = (base + off).raw();
721  }
722 
724  }
725  }
726 
727  void
728  enable_big_segment(pool_base &pop)
729  {
730  block_range blocks = segment_blocks(my_seg);
731  {
732  transaction::manual tx(pop);
733 
734  for (segment_index_t b = blocks.first;
735  b < blocks.second; ++b) {
736  assert((*my_table)[b] == nullptr);
737  (*my_table)[b] = make_persistent<bucket_type[]>(
738  block_size(b));
739  }
740 
742  }
743  }
744 
746  table_pointer my_table;
747 
749  segment_index_t my_seg;
750 }; /* End of class segment_facade_impl */
751 
758 template <typename Key, typename T, typename MutexType, typename ScopedLockType>
759 class hash_map_base {
760 public:
761  using mutex_t = MutexType;
762  using scoped_t = ScopedLockType;
763 
765  using size_type = size_t;
766 
768  using hashcode_type = size_t;
769 
771  using node = hash_map_node<Key, T, mutex_t, scoped_t>;
772 
774  using node_ptr_t = detail::persistent_pool_ptr<node>;
775 
777  struct bucket {
778  using mutex_t = MutexType;
779  using scoped_t = ScopedLockType;
780 
782  mutex_t mutex;
783 
785  p<std::atomic<uint64_t>> rehashed;
786 
788  node_ptr_t node_list;
789 
791  bucket() : node_list(nullptr)
792  {
793 #if LIBPMEMOBJ_CPP_VG_HELGRIND_ENABLED
794  VALGRIND_HG_DISABLE_CHECKING(&rehashed,
795  sizeof(rehashed));
796 #endif
797  rehashed.get_rw() = false;
798  }
799 
805  bool
806  is_rehashed(std::memory_order order)
807  {
808  return rehashed.get_ro().load(order);
809  }
810 
811  void
812  set_rehashed(std::memory_order order)
813  {
814  rehashed.get_rw().store(true, order);
815  }
816 
818  bucket(const bucket &) = delete;
819 
821  bucket &operator=(const bucket &) = delete;
822  }; /* End of struct bucket */
823 
825  using segment_traits_t = segment_traits<bucket>;
826 
828  using segment_index_t = typename segment_traits_t::segment_index_t;
829 
831  static const size_type embedded_buckets =
832  segment_traits_t::embedded_buckets;
833 
835  static const size_type first_block = segment_traits_t::first_block;
836 
838  constexpr static size_type block_table_size =
839  segment_traits_t::number_of_blocks();
840 
842  using segment_ptr_t = persistent_ptr<bucket[]>;
843 
845  using bucket_ptr_t = persistent_ptr<bucket>;
846 
848  using blocks_table_t = segment_ptr_t[block_table_size];
849 
851  using segment_enable_mutex_t = pmem::obj::mutex;
852 
854  struct tls_data_t {
855  p<int64_t> size_diff = 0;
856  std::aligned_storage<56, 8> padding;
857  };
858 
859  using tls_t = detail::enumerable_thread_specific<tls_data_t>;
860 
861  enum feature_flags : uint32_t { FEATURE_CONSISTENT_SIZE = 1 };
862 
864  struct features {
865  p<uint32_t> compat;
866  p<uint32_t> incompat;
867  };
868 
869  /* --------------------------------------------------------- */
870 
872  p<uint64_t> my_pool_uuid;
873 
876  features layout_features;
877 
880  std::aligned_storage<sizeof(size_t), sizeof(size_t)>::type
881  my_mask_reserved;
882 
884  /* my_mask always restored on restart. */
885  std::atomic<hashcode_type> my_mask;
886 
887  /* Size of value (key and value pair) stored in a pool */
888  std::size_t value_size;
889 
891  std::aligned_storage<24, 8>::type padding1;
892 
897  blocks_table_t my_table;
898 
899  /* It must be in separate cache line from my_mask due to performance
900  * effects */
902  std::atomic<size_type> my_size;
903 
905  std::aligned_storage<24, 8>::type padding2;
906 
908  persistent_ptr<tls_t> tls_ptr;
909 
915  p<size_t> on_init_size;
916 
918  std::aligned_storage<40, 8>::type reserved;
919 
921  segment_enable_mutex_t my_segment_enable_mutex;
922 
924  bucket my_embedded_segment[embedded_buckets];
925 
926  /* --------------------------------------------------------- */
927 
929  static constexpr features
930  header_features()
931  {
932  return {FEATURE_CONSISTENT_SIZE, 0};
933  }
934 
935  const std::atomic<hashcode_type> &
936  mask() const noexcept
937  {
938  return my_mask;
939  }
940 
941  std::atomic<hashcode_type> &
942  mask() noexcept
943  {
944  return my_mask;
945  }
946 
947  size_t
948  size() const
949  {
950  return my_size.load(std::memory_order_relaxed);
951  }
952 
953  p<int64_t> &
954  thread_size_diff()
955  {
956  assert(this->tls_ptr != nullptr);
957  return this->tls_ptr->local().size_diff;
958  }
959 
961  void
962  tls_restore()
963  {
964  assert(this->tls_ptr != nullptr);
965 
966  pool_base pop = pool_base{pmemobj_pool_by_ptr(this)};
967 
968  int64_t last_run_size = 0;
969  for (auto &data : *tls_ptr)
970  last_run_size += data.size_diff;
971 
972  /* Make sure that on_init_size + last_run_size >= 0 */
973  assert(last_run_size >= 0 ||
974  static_cast<int64_t>(static_cast<size_t>(last_run_size) +
975  on_init_size) >= 0);
976 
977  transaction::run(pop, [&] {
978  on_init_size += static_cast<size_t>(last_run_size);
979  tls_ptr->clear();
980  });
981 
982  this->my_size = on_init_size;
983  }
984 
986  using const_segment_facade_t =
987  segment_facade_impl<blocks_table_t, segment_traits_t, true>;
988 
990  using segment_facade_t =
991  segment_facade_impl<blocks_table_t, segment_traits_t, false>;
992 
994  hash_map_base()
995  {
996  static_assert(
997  sizeof(size_type) == sizeof(std::atomic<size_type>),
998  "std::atomic should have the same layout as underlying integral type");
999 
1000 #if LIBPMEMOBJ_CPP_VG_HELGRIND_ENABLED
1001  VALGRIND_HG_DISABLE_CHECKING(&my_mask, sizeof(my_mask));
1002 #endif
1003  layout_features = {0, 0};
1004 
1005  PMEMoid oid = pmemobj_oid(this);
1006 
1007  assert(!OID_IS_NULL(oid));
1008 
1009  my_pool_uuid = oid.pool_uuid_lo;
1010 
1011  pool_base pop = get_pool_base();
1012  /* enable embedded segments */
1013  for (size_type i = 0; i < segment_traits_t::embedded_segments;
1014  ++i) {
1015  my_table[i] =
1016  pmemobj_oid(my_embedded_segment +
1017  segment_traits_t::segment_base(i));
1018  segment_facade_t seg(my_table, i);
1019  mark_rehashed<false>(pop, seg);
1020  }
1021 
1022  on_init_size = 0;
1023 
1024  value_size = 0;
1025 
1026  this->tls_ptr = nullptr;
1027  }
1028 
1029  /*
1030  * Should be called before concurrent_hash_map destructor is called.
1031  * Otherwise, program can terminate if an exception occurs wile freeing
1032  * memory inside dtor.
1033  */
1034  void
1035  free_tls()
1036  {
1037  auto pop = get_pool_base();
1038 
1039  if ((layout_features.compat & FEATURE_CONSISTENT_SIZE) &&
1040  tls_ptr) {
1041  transaction::run(pop, [&] {
1042  delete_persistent<tls_t>(tls_ptr);
1043  tls_ptr = nullptr;
1044  });
1045  }
1046  }
1047 
1051  void
1052  calculate_mask()
1053  {
1054 #if LIBPMEMOBJ_CPP_VG_HELGRIND_ENABLED
1055  VALGRIND_HG_DISABLE_CHECKING(&my_size, sizeof(my_size));
1056  VALGRIND_HG_DISABLE_CHECKING(&my_mask, sizeof(my_mask));
1057 #endif
1058 #if LIBPMEMOBJ_CPP_VG_PMEMCHECK_ENABLED
1059  VALGRIND_PMC_REMOVE_PMEM_MAPPING(&my_size, sizeof(my_size));
1060  VALGRIND_PMC_REMOVE_PMEM_MAPPING(&my_mask, sizeof(my_mask));
1061 #endif
1062 
1063  hashcode_type m = embedded_buckets - 1;
1064 
1065  const_segment_facade_t segment(
1066  my_table, segment_traits_t::embedded_segments);
1067 
1068  while (segment.is_valid()) {
1069  m += segment.size();
1070  ++segment;
1071  }
1072 
1073  mask().store(m, std::memory_order_relaxed);
1074  }
1075 
1079  template <bool Flush = true>
1080  void
1081  mark_rehashed(pool_base &pop, segment_facade_t &segment)
1082  {
1083  for (size_type i = 0; i < segment.size(); ++i) {
1084  bucket *b = &(segment[i]);
1085 
1086  assert_not_locked<mutex_t, scoped_t>(b->mutex);
1087 
1088  b->set_rehashed(std::memory_order_relaxed);
1089  }
1090 
1091  if (Flush) {
1092  /* Flush in separate loop to avoid read-after-flush */
1093  for (size_type i = 0; i < segment.size(); ++i) {
1094  bucket *b = &(segment[i]);
1095  pop.flush(b->rehashed);
1096  }
1097 
1098  pop.drain();
1099  }
1100  }
1101 
1105  void
1106  enable_segment(segment_index_t k, bool is_initial = false)
1107  {
1108  assert(k);
1109 
1110  pool_base pop = get_pool_base();
1111  size_type sz;
1112 
1113  if (k >= first_block) {
1114  segment_facade_t new_segment(my_table, k);
1115 
1116  sz = new_segment.size();
1117  if (!new_segment.is_valid())
1118  new_segment.enable(pop);
1119 
1120  if (is_initial) {
1121  mark_rehashed(pop, new_segment);
1122  }
1123 
1124  /* double it to get entire capacity of the container */
1125  sz <<= 1;
1126  } else {
1127  /* the first block */
1128  assert(k == segment_traits_t::embedded_segments);
1129 
1130  for (segment_index_t i = k; i < first_block; ++i) {
1131  segment_facade_t new_segment(my_table, i);
1132 
1133  if (!new_segment.is_valid())
1134  new_segment.enable(pop);
1135 
1136  if (is_initial) {
1137  mark_rehashed(pop, new_segment);
1138  }
1139  }
1140 
1141  sz = segment_traits_t::segment_size(first_block);
1142  }
1143 #if LIBPMEMOBJ_CPP_VG_HELGRIND_ENABLED
1144  ANNOTATE_HAPPENS_BEFORE(&my_mask);
1145 #endif
1146  mask().store(sz - 1, std::memory_order_release);
1147  }
1148 
1153  bucket *
1154  get_bucket(hashcode_type h) const
1155  {
1156  segment_index_t s = segment_traits_t::segment_index_of(h);
1157 
1158  h -= segment_traits_t::segment_base(s);
1159 
1160  const_segment_facade_t segment(my_table, s);
1161 
1162  assert(segment.is_valid());
1163 
1164  return &(segment[h]);
1165  }
1166 
1170  inline bool
1171  check_mask_race(hashcode_type h, hashcode_type &m) const
1172  {
1173  hashcode_type m_now, m_old = m;
1174 
1175  m_now = mask().load(std::memory_order_acquire);
1176 #if LIBPMEMOBJ_CPP_VG_HELGRIND_ENABLED
1177  ANNOTATE_HAPPENS_AFTER(&(this->my_mask));
1178 #endif
1179 
1180  if (m_old != m_now)
1181  return check_rehashing_collision(h, m_old, m = m_now);
1182 
1183  return false;
1184  }
1185 
1189  bool
1190  check_rehashing_collision(hashcode_type h, hashcode_type m_old,
1191  hashcode_type m) const
1192  {
1193  assert(m_old != m);
1194 
1195  if ((h & m_old) != (h & m)) {
1196  /* mask changed for this hashcode, rare event condition
1197  * above proves that 'h' has some other bits set beside
1198  * 'm_old', find next applicable mask after m_old */
1199 
1200  for (++m_old; !(h & m_old); m_old <<= 1)
1201  ;
1202 
1203  m_old = (m_old << 1) - 1; /* get full mask from a bit */
1204 
1205  assert((m_old & (m_old + 1)) == 0 && m_old <= m);
1206 
1207  /* check whether it is rehashing/ed */
1208  bucket *b = get_bucket(h & m_old);
1209  return b->is_rehashed(std::memory_order_acquire);
1210  }
1211 
1212  return false;
1213  }
1214 
1219  template <typename Node, typename... Args>
1220  void
1221  insert_new_node_internal(bucket *b,
1222  detail::persistent_pool_ptr<Node> &new_node,
1223  Args &&... args)
1224  {
1225  assert(pmemobj_tx_stage() == TX_STAGE_WORK);
1226 
1227  new_node = pmem::obj::make_persistent<Node>(
1228  b->node_list, std::forward<Args>(args)...);
1229  b->node_list = new_node; /* bucket is locked */
1230  }
1231 
1236  template <typename Node, typename... Args>
1237  size_type
1238  insert_new_node(bucket *b, detail::persistent_pool_ptr<Node> &new_node,
1239  Args &&... args)
1240  {
1241  pool_base pop = get_pool_base();
1242 
1243  /*
1244  * This is only true when called from singlethreaded methods
1245  * like swap() or operator=. In that case it's safe to directly
1246  * modify on_init_size.
1247  */
1248  if (pmemobj_tx_stage() == TX_STAGE_WORK) {
1249  insert_new_node_internal(b, new_node,
1250  std::forward<Args>(args)...);
1251  this->on_init_size++;
1252  } else {
1253  auto &size_diff = thread_size_diff();
1254 
1255  pmem::obj::transaction::run(pop, [&] {
1256  insert_new_node_internal(
1257  b, new_node,
1258  std::forward<Args>(args)...);
1259  ++size_diff;
1260  });
1261  }
1262 
1263  /* Increment volatile size */
1264  return ++(this->my_size);
1265  }
1266 
1271  bool
1272  check_growth(hashcode_type m, size_type sz)
1273  {
1274  if (sz >= m) {
1275  segment_index_t new_seg =
1276  static_cast<segment_index_t>(detail::Log2(
1277  m +
1278  1)); /* optimized segment_index_of */
1279 
1280  assert(segment_facade_t(my_table, new_seg - 1)
1281  .is_valid());
1282 
1283  std::unique_lock<segment_enable_mutex_t> lock(
1284  my_segment_enable_mutex, std::try_to_lock);
1285 
1286  if (lock) {
1287  if (mask().load(std::memory_order_relaxed) ==
1288  m) {
1289  /* Otherwise, other thread enable this
1290  * segment */
1291  enable_segment(new_seg);
1292 
1293  return true;
1294  }
1295  }
1296  }
1297 
1298  return false;
1299  }
1300 
1304  void
1305  reserve(size_type buckets)
1306  {
1307  if (buckets == 0)
1308  return;
1309 
1310  --buckets;
1311 
1312  bool is_initial = this->size() == 0;
1313 
1314  for (size_type m = mask(); buckets > m; m = mask())
1315  enable_segment(
1316  segment_traits_t::segment_index_of(m + 1),
1317  is_initial);
1318  }
1319 
1324  void
1325  internal_swap(hash_map_base<Key, T, mutex_t, scoped_t> &table)
1326  {
1327  pool_base p = get_pool_base();
1328  {
1329  transaction::manual tx(p);
1330 
1331  this->my_pool_uuid.swap(table.my_pool_uuid);
1332 
1333  /*
1334  * As internal_swap can only be called
1335  * from one thread, and there can be an outer
1336  * transaction we must make sure that mask and size
1337  * changes are transactional
1338  */
1339  transaction::snapshot((size_t *)&this->my_mask);
1340  transaction::snapshot((size_t *)&this->my_size);
1341 
1342  this->mask() = table.mask().exchange(
1343  this->mask(), std::memory_order_relaxed);
1344 
1345  this->my_size = table.my_size.exchange(
1346  this->my_size, std::memory_order_relaxed);
1347 
1348  /* Swap consistent size */
1349  std::swap(this->tls_ptr, table.tls_ptr);
1350 
1351  for (size_type i = 0; i < embedded_buckets; ++i)
1352  this->my_embedded_segment[i].node_list.swap(
1353  table.my_embedded_segment[i].node_list);
1354 
1355  for (size_type i = segment_traits_t::embedded_segments;
1356  i < block_table_size; ++i)
1357  this->my_table[i].swap(table.my_table[i]);
1358 
1360  }
1361  }
1362 
1367  pool_base
1368  get_pool_base()
1369  {
1370  PMEMobjpool *pop =
1371  pmemobj_pool_by_oid(PMEMoid{my_pool_uuid, 0});
1372 
1373  return pool_base(pop);
1374  }
1375 }; /* End of class hash_map_base */
1376 
1382 template <typename Container, bool is_const>
1383 class hash_map_iterator {
1384 public:
1385  using iterator_category = std::forward_iterator_tag;
1386  using difference_type = ptrdiff_t;
1387  using map_type = Container;
1388  using value_type = typename map_type::value_type;
1389  using node = typename map_type::node;
1390  using bucket = typename map_type::bucket;
1391  using map_ptr = typename std::conditional<is_const, const map_type *,
1392  map_type *>::type;
1393  using reference =
1394  typename std::conditional<is_const,
1395  typename map_type::const_reference,
1396  typename map_type::reference>::type;
1397  using pointer =
1398  typename std::conditional<is_const,
1399  typename map_type::const_pointer,
1400  typename map_type::pointer>::type;
1401 
1402  template <typename C, bool M, bool U>
1403  friend bool operator==(const hash_map_iterator<C, M> &i,
1404  const hash_map_iterator<C, U> &j);
1405 
1406  template <typename C, bool M, bool U>
1407  friend bool operator!=(const hash_map_iterator<C, M> &i,
1408  const hash_map_iterator<C, U> &j);
1409 
1410  friend class hash_map_iterator<map_type, true>;
1411 
1412 #if !defined(_MSC_VER) || defined(__INTEL_COMPILER)
1413 private:
1414  template <typename Key, typename T, typename Hash, typename KeyEqual,
1415  typename MutexType, typename ScopedLockType>
1416  friend class ::pmem::obj::concurrent_hash_map;
1417 #else
1418 public: /* workaround */
1419 #endif
1420  hash_map_iterator(map_ptr map, size_t index)
1421  : my_map(map), my_index(index), my_bucket(nullptr), my_node(nullptr)
1422  {
1423  if (my_index <= my_map->mask()) {
1424  bucket_accessor acc(my_map, my_index);
1425  my_bucket = acc.get();
1426  my_node = static_cast<node *>(
1427  my_bucket->node_list.get(my_map->my_pool_uuid));
1428 
1429  if (!my_node) {
1430  advance_to_next_bucket();
1431  }
1432  }
1433  }
1434 
1435 public:
1437  hash_map_iterator() = default;
1438 
1440  hash_map_iterator(const hash_map_iterator &other)
1441  : my_map(other.my_map),
1442  my_index(other.my_index),
1443  my_bucket(other.my_bucket),
1444  my_node(other.my_node)
1445  {
1446  }
1447 
1449  template <typename U = void,
1450  typename = typename std::enable_if<is_const, U>::type>
1451  hash_map_iterator(const hash_map_iterator<map_type, false> &other)
1452  : my_map(other.my_map),
1453  my_index(other.my_index),
1454  my_bucket(other.my_bucket),
1455  my_node(other.my_node)
1456  {
1457  }
1458 
1459  hash_map_iterator &operator=(const hash_map_iterator &it) = default;
1460 
1462  reference operator*() const
1463  {
1464  assert(my_node);
1465  return my_node->item;
1466  }
1467 
1469  pointer operator->() const
1470  {
1471  return &operator*();
1472  }
1473 
1475  hash_map_iterator &
1476  operator++()
1477  {
1478  my_node = static_cast<node *>(
1479  my_node->next.get((my_map->my_pool_uuid)));
1480 
1481  if (!my_node)
1482  advance_to_next_bucket();
1483 
1484  return *this;
1485  }
1486 
1488  hash_map_iterator
1489  operator++(int)
1490  {
1491  hash_map_iterator old(*this);
1492  operator++();
1493  return old;
1494  }
1495 
1496 private:
1498  map_ptr my_map = nullptr;
1499 
1501  size_t my_index = 0;
1502 
1504  bucket *my_bucket = nullptr;
1505 
1507  node *my_node = nullptr;
1508 
1509  class bucket_accessor {
1510  public:
1511  bucket_accessor(map_ptr m, size_t index)
1512  {
1513  my_bucket = m->get_bucket(index);
1514  }
1515 
1516  bucket *
1517  get() const
1518  {
1519  return my_bucket;
1520  }
1521 
1522  private:
1523  bucket *my_bucket;
1524  };
1525 
1526  void
1527  advance_to_next_bucket()
1528  {
1529  size_t k = my_index + 1;
1530 
1531  assert(my_bucket);
1532 
1533  while (k <= my_map->mask()) {
1534  bucket_accessor acc(my_map, k);
1535  my_bucket = acc.get();
1536 
1537  if (my_bucket->node_list) {
1538  my_node = static_cast<node *>(
1539  my_bucket->node_list.get(
1540  my_map->my_pool_uuid));
1541 
1542  my_index = k;
1543 
1544  return;
1545  }
1546 
1547  ++k;
1548  }
1549 
1550  my_bucket = 0;
1551  my_node = 0;
1552  my_index = k;
1553  }
1554 };
1555 
1556 template <typename Container, bool M, bool U>
1557 bool
1558 operator==(const hash_map_iterator<Container, M> &i,
1559  const hash_map_iterator<Container, U> &j)
1560 {
1561  return i.my_node == j.my_node && i.my_map == j.my_map;
1562 }
1563 
1564 template <typename Container, bool M, bool U>
1565 bool
1566 operator!=(const hash_map_iterator<Container, M> &i,
1567  const hash_map_iterator<Container, U> &j)
1568 {
1569  return i.my_node != j.my_node || i.my_map != j.my_map;
1570 }
1571 } /* namespace concurrent_hash_map_internal */
1620 template <typename Key, typename T, typename Hash, typename KeyEqual,
1621  typename MutexType, typename ScopedLockType>
1623  : protected concurrent_hash_map_internal::hash_map_base<Key, T, MutexType,
1624  ScopedLockType> {
1625  template <typename Container, bool is_const>
1626  friend class concurrent_hash_map_internal::hash_map_iterator;
1627 
1628 public:
1629  using size_type = typename concurrent_hash_map_internal::hash_map_base<
1630  Key, T, MutexType, ScopedLockType>::size_type;
1631  using hashcode_type =
1632  typename concurrent_hash_map_internal::hash_map_base<
1633  Key, T, MutexType, ScopedLockType>::hashcode_type;
1634  using key_type = Key;
1635  using mapped_type = T;
1636  using value_type = typename concurrent_hash_map_internal::hash_map_base<
1637  Key, T, MutexType, ScopedLockType>::node::value_type;
1638  using difference_type = ptrdiff_t;
1639  using pointer = value_type *;
1640  using const_pointer = const value_type *;
1641  using reference = value_type &;
1642  using const_reference = const value_type &;
1643  using iterator = concurrent_hash_map_internal::hash_map_iterator<
1644  concurrent_hash_map, false>;
1645  using const_iterator = concurrent_hash_map_internal::hash_map_iterator<
1646  concurrent_hash_map, true>;
1647  using hasher = Hash;
1648  using key_equal = typename concurrent_hash_map_internal::key_equal_type<
1649  Hash, KeyEqual>::type;
1650 
1651 protected:
1652  using mutex_t = MutexType;
1653  using scoped_t = ScopedLockType;
1654  /*
1655  * Explicitly use methods and types from template base class
1656  */
1657  using hash_map_base =
1658  concurrent_hash_map_internal::hash_map_base<Key, T, mutex_t,
1659  scoped_t>;
1660  using hash_map_base::calculate_mask;
1661  using hash_map_base::check_growth;
1662  using hash_map_base::check_mask_race;
1663  using hash_map_base::embedded_buckets;
1664  using hash_map_base::FEATURE_CONSISTENT_SIZE;
1665  using hash_map_base::get_bucket;
1666  using hash_map_base::get_pool_base;
1667  using hash_map_base::header_features;
1668  using hash_map_base::insert_new_node;
1669  using hash_map_base::internal_swap;
1670  using hash_map_base::layout_features;
1671  using hash_map_base::mask;
1672  using hash_map_base::reserve;
1673  using tls_t = typename hash_map_base::tls_t;
1674  using node = typename hash_map_base::node;
1675  using node_mutex_t = typename node::mutex_t;
1676  using node_ptr_t = typename hash_map_base::node_ptr_t;
1677  using bucket = typename hash_map_base::bucket;
1678  using bucket_lock_type = typename bucket::scoped_t;
1679  using segment_index_t = typename hash_map_base::segment_index_t;
1680  using segment_traits_t = typename hash_map_base::segment_traits_t;
1681  using segment_facade_t = typename hash_map_base::segment_facade_t;
1682  using scoped_lock_traits_type =
1683  concurrent_hash_map_internal::scoped_lock_traits<scoped_t>;
1684 
1685  friend class const_accessor;
1686  using persistent_node_ptr_t = detail::persistent_pool_ptr<node>;
1687 
1688  void
1689  delete_node(const node_ptr_t &n)
1690  {
1691  delete_persistent<node>(
1692  detail::static_persistent_pool_pointer_cast<node>(n)
1693  .get_persistent_ptr(this->my_pool_uuid));
1694  }
1695 
1696  template <typename K>
1697  persistent_node_ptr_t
1698  search_bucket(const K &key, bucket *b) const
1699  {
1700  assert(b->is_rehashed(std::memory_order_relaxed));
1701 
1702  persistent_node_ptr_t n =
1703  detail::static_persistent_pool_pointer_cast<node>(
1704  b->node_list);
1705 
1706  while (n &&
1707  !key_equal{}(key,
1708  n.get(this->my_pool_uuid)->item.first)) {
1709  n = detail::static_persistent_pool_pointer_cast<node>(
1710  n.get(this->my_pool_uuid)->next);
1711  }
1712 
1713  return n;
1714  }
1715 
1720  class bucket_accessor : public bucket_lock_type {
1721  bucket *my_b;
1722 
1723  public:
1724  bucket_accessor(bucket_accessor &&b) noexcept : my_b(b.my_b)
1725  {
1726  bucket_lock_type::mutex = b.bucket_lock_type::mutex;
1727  bucket_lock_type::is_writer =
1728  b.bucket_lock_type::is_writer;
1729  b.my_b = nullptr;
1730  b.bucket_lock_type::mutex = nullptr;
1731  b.bucket_lock_type::is_writer = false;
1732  }
1733 
1735  const hashcode_type h, bool writer = false)
1736  {
1737  acquire(base, h, writer);
1738  }
1739 
1744  inline void
1745  acquire(concurrent_hash_map *base, const hashcode_type h,
1746  bool writer = false)
1747  {
1748  my_b = base->get_bucket(h);
1749 
1750  if (my_b->is_rehashed(std::memory_order_acquire) ==
1751  false &&
1752  bucket_lock_type::try_acquire(this->my_b->mutex,
1753  /*write=*/true)) {
1754  if (my_b->is_rehashed(
1755  std::memory_order_relaxed) ==
1756  false) {
1757  /* recursive rehashing */
1758  base->rehash_bucket<false>(my_b, h);
1759  }
1760  } else {
1761  bucket_lock_type::acquire(my_b->mutex, writer);
1762  }
1763 
1764  assert(my_b->is_rehashed(std::memory_order_relaxed));
1765  }
1766 
1770  bool
1771  is_writer() const
1772  {
1773  return bucket_lock_type::is_writer;
1774  }
1775 
1780  bucket *
1781  get() const
1782  {
1783  return my_b;
1784  }
1785 
1790  bucket *operator->() const
1791  {
1792  return this->get();
1793  }
1794  };
1795 
1800  bucket *my_b;
1801 
1802  public:
1804  const hashcode_type h,
1805  bool writer = false)
1806  {
1807  acquire(base, h, writer);
1808  }
1809 
1810  /*
1811  * Find a bucket by masked hashcode, optionally rehash
1812  */
1813  inline void
1814  acquire(concurrent_hash_map *base, const hashcode_type h,
1815  bool writer = false)
1816  {
1817  my_b = base->get_bucket(h);
1818 
1819  if (my_b->is_rehashed(std::memory_order_relaxed) ==
1820  false) {
1821  /* recursive rehashing */
1822  base->rehash_bucket<true>(my_b, h);
1823  }
1824 
1825  assert(my_b->is_rehashed(std::memory_order_relaxed));
1826  }
1827 
1834  bool
1835  is_writer() const
1836  {
1837  return true;
1838  }
1839 
1844  bucket *
1845  get() const
1846  {
1847  return my_b;
1848  }
1849 
1854  bucket *operator->() const
1855  {
1856  return this->get();
1857  }
1858  };
1859 
1860  hashcode_type
1861  get_hash_code(node_ptr_t &n)
1862  {
1863  return hasher{}(
1864  detail::static_persistent_pool_pointer_cast<node>(n)(
1865  this->my_pool_uuid)
1866  ->item.first);
1867  }
1868 
1869  template <bool serial>
1870  void
1871  rehash_bucket(bucket *b_new, const hashcode_type h)
1872  {
1873  using accessor_type = typename std::conditional<
1874  serial, serial_bucket_accessor, bucket_accessor>::type;
1875 
1876  using scoped_lock_traits_type =
1877  concurrent_hash_map_internal::scoped_lock_traits<
1878  accessor_type>;
1879 
1880  /* First two bucket should be always rehashed */
1881  assert(h > 1);
1882 
1883  pool_base pop = get_pool_base();
1884  node_ptr_t *p_new = &(b_new->node_list);
1885 
1886  /* This condition is only true when there was a failure just
1887  * before setting rehashed flag */
1888  if (*p_new != nullptr) {
1889  assert(!b_new->is_rehashed(std::memory_order_relaxed));
1890 
1891  b_new->set_rehashed(std::memory_order_relaxed);
1892  pop.persist(b_new->rehashed);
1893 
1894  return;
1895  }
1896 
1897  /* get parent mask from the topmost bit */
1898  hashcode_type mask = (1u << detail::Log2(h)) - 1;
1899  assert((h & mask) < h);
1900  accessor_type b_old(
1901  this, h & mask,
1902  scoped_lock_traits_type::initial_rw_state(true));
1903 
1904  pmem::obj::transaction::run(pop, [&] {
1905  /* get full mask for new bucket */
1906  mask = (mask << 1) | 1;
1907  assert((mask & (mask + 1)) == 0 && (h & mask) == h);
1908 
1909  restart:
1910  for (node_ptr_t *p_old = &(b_old->node_list),
1911  n = *p_old;
1912  n; n = *p_old) {
1913  hashcode_type c = get_hash_code(n);
1914 #ifndef NDEBUG
1915  hashcode_type bmask = h & (mask >> 1);
1916 
1917  bmask = bmask == 0
1918  ? 1 /* minimal mask of parent bucket */
1919  : (1u << (detail::Log2(bmask) + 1)) - 1;
1920 
1921  assert((c & bmask) == (h & bmask));
1922 #endif
1923 
1924  if ((c & mask) == h) {
1925  if (!b_old.is_writer() &&
1926  !scoped_lock_traits_type::
1927  upgrade_to_writer(b_old)) {
1928  goto restart;
1929  /* node ptr can be invalid due
1930  * to concurrent erase */
1931  }
1932 
1933  /* Add to new b_new */
1934  *p_new = n;
1935 
1936  /* exclude from b_old */
1937  *p_old = n(this->my_pool_uuid)->next;
1938 
1939  p_new = &(n(this->my_pool_uuid)->next);
1940  } else {
1941  /* iterate to next item */
1942  p_old = &(n(this->my_pool_uuid)->next);
1943  }
1944  }
1945 
1946  *p_new = nullptr;
1947  });
1948 
1949  /* mark rehashed */
1950  b_new->set_rehashed(std::memory_order_release);
1951  pop.persist(b_new->rehashed);
1952  }
1953 
1954  void
1955  check_incompat_features()
1956  {
1957  if (layout_features.incompat != header_features().incompat)
1958  throw pmem::layout_error(
1959  "Incompat flags mismatch, for more details go to: https://pmem.io/pmdk/cpp_obj/ \n");
1960 
1961  if ((layout_features.compat & FEATURE_CONSISTENT_SIZE) &&
1962  this->value_size != sizeof(value_type))
1963  throw pmem::layout_error(
1964  "Size of value_type is different than the one stored in the pool \n");
1965  }
1966 
1967 public:
1968  class accessor;
1973  : protected node::scoped_t /*which derived from no_copy*/ {
1974  friend class concurrent_hash_map<Key, T, Hash, KeyEqual,
1975  mutex_t, scoped_t>;
1976  friend class accessor;
1978  using node::scoped_t::try_acquire;
1979 
1980  public:
1984  using value_type =
1985  const typename concurrent_hash_map::value_type;
1986 
1991  bool
1992  empty() const
1993  {
1994  return !my_node;
1995  }
1996 
2003  void
2005  {
2006  concurrent_hash_map_internal::check_outside_tx();
2007 
2008  if (my_node) {
2009  node::scoped_t::release();
2010  my_node = 0;
2011  }
2012  }
2013 
2017  const_reference operator*() const
2018  {
2019  assert(my_node);
2020 
2021  return my_node->item;
2022  }
2023 
2027  const_pointer operator->() const
2028  {
2029  return &operator*();
2030  }
2031 
2037  const_accessor() : my_node(OID_NULL), my_hash()
2038  {
2039  concurrent_hash_map_internal::check_outside_tx();
2040  }
2041 
2046  {
2047  my_node = OID_NULL; // scoped lock's release() is called
2048  // in its destructor
2049  }
2050 
2051  protected:
2052  node_ptr_t my_node;
2053 
2054  hashcode_type my_hash;
2055  };
2056 
2061  class accessor : public const_accessor {
2062  public:
2064  using value_type = typename concurrent_hash_map::value_type;
2065 
2067  reference operator*() const
2068  {
2069  assert(this->my_node);
2070 
2071  return this->my_node->item;
2072  }
2073 
2075  pointer operator->() const
2076  {
2077  return &operator*();
2078  }
2079  };
2080 
2084  concurrent_hash_map() : hash_map_base()
2085  {
2087  }
2088 
2093  concurrent_hash_map(size_type n) : hash_map_base()
2094  {
2096 
2097  reserve(n);
2098  }
2099 
2103  concurrent_hash_map(const concurrent_hash_map &table) : hash_map_base()
2104  {
2106 
2107  reserve(table.size());
2108 
2109  internal_copy(table);
2110  }
2111 
2115  concurrent_hash_map(concurrent_hash_map &&table) : hash_map_base()
2116  {
2118 
2119  swap(table);
2120  }
2121 
2125  template <typename I>
2126  concurrent_hash_map(I first, I last)
2127  {
2129 
2130  reserve(static_cast<size_type>(std::distance(first, last)));
2131 
2132  internal_copy(first, last);
2133  }
2134 
2138  concurrent_hash_map(std::initializer_list<value_type> il)
2139  {
2141 
2142  reserve(il.size());
2143 
2144  internal_copy(il.begin(), il.end());
2145  }
2146 
2155  void
2157  {
2158  check_incompat_features();
2159 
2160  calculate_mask();
2161 
2162  /*
2163  * Handle case where hash_map was created without
2164  * FEATURE_CONSISTENT_SIZE.
2165  */
2166  if (!(layout_features.compat & FEATURE_CONSISTENT_SIZE)) {
2167  auto actual_size =
2168  std::distance(this->begin(), this->end());
2169  assert(actual_size >= 0);
2170 
2171  this->my_size = static_cast<size_t>(actual_size);
2172 
2173  auto pop = get_pool_base();
2174  transaction::run(pop, [&] {
2175  this->tls_ptr = make_persistent<tls_t>();
2176  this->on_init_size =
2177  static_cast<size_t>(actual_size);
2178  this->value_size = sizeof(value_type);
2179 
2180  layout_features.compat |=
2181  FEATURE_CONSISTENT_SIZE;
2182  });
2183  } else {
2184  assert(this->tls_ptr != nullptr);
2185  this->tls_restore();
2186  }
2187 
2188  assert(this->size() ==
2189  size_type(std::distance(this->begin(), this->end())));
2190  }
2191 
2192  [[deprecated(
2193  "runtime_initialize(bool) is now deprecated, use runtime_initialize(void)")]] void
2194  runtime_initialize(bool graceful_shutdown)
2195  {
2196  check_incompat_features();
2197 
2198  calculate_mask();
2199 
2200  if (!graceful_shutdown) {
2201  auto actual_size =
2202  std::distance(this->begin(), this->end());
2203  assert(actual_size >= 0);
2204  this->my_size = static_cast<size_type>(actual_size);
2205  } else {
2206  assert(this->size() ==
2207  size_type(std::distance(this->begin(),
2208  this->end())));
2209  }
2210  }
2211 
2223  concurrent_hash_map &
2225  {
2226  if (this != &table) {
2227  clear();
2228  internal_copy(table);
2229  }
2230 
2231  return *this;
2232  }
2233 
2246  operator=(std::initializer_list<value_type> il)
2247  {
2248  clear();
2249 
2250  reserve(il.size());
2251 
2252  internal_copy(il.begin(), il.end());
2253 
2254  return *this;
2255  }
2256 
2265  void rehash(size_type n = 0);
2266 
2273  void clear();
2274 
2287  void
2289  {
2290  if (!this->tls_ptr)
2291  return;
2292 
2293  auto pop = get_pool_base();
2294 
2295  transaction::run(pop, [&] {
2296  clear();
2297  this->free_tls();
2298  });
2299  }
2300 
2310  {
2311  try {
2312  free_data();
2313  } catch (...) {
2314  std::terminate();
2315  }
2316  }
2317 
2318  //------------------------------------------------------------------------
2319  // STL support - not thread-safe methods
2320  //------------------------------------------------------------------------
2321 
2328  iterator
2330  {
2331  return iterator(this, 0);
2332  }
2333 
2338  iterator
2340  {
2341  return iterator(this, mask() + 1);
2342  }
2343 
2348  const_iterator
2349  begin() const
2350  {
2351  return const_iterator(this, 0);
2352  }
2353 
2358  const_iterator
2359  end() const
2360  {
2361  return const_iterator(this, mask() + 1);
2362  }
2363 
2367  size_type
2368  size() const
2369  {
2370  return hash_map_base::size();
2371  }
2372 
2376  bool
2377  empty() const
2378  {
2379  return this->size() == 0;
2380  }
2381 
2385  size_type
2386  max_size() const
2387  {
2388  return (~size_type(0)) / sizeof(node);
2389  }
2390 
2394  size_type
2396  {
2397  return mask() + 1;
2398  }
2399 
2403  void swap(concurrent_hash_map &table);
2404 
2405  //------------------------------------------------------------------------
2406  // concurrent map operations
2407  //------------------------------------------------------------------------
2408 
2414  size_type
2415  count(const Key &key) const
2416  {
2417  concurrent_hash_map_internal::check_outside_tx();
2418 
2419  return const_cast<concurrent_hash_map *>(this)->internal_find(
2420  key, nullptr, false);
2421  }
2422 
2434  template <typename K,
2435  typename = typename std::enable_if<
2436  concurrent_hash_map_internal::
2437  has_transparent_key_equal<hasher>::value,
2438  K>::type>
2439  size_type
2440  count(const K &key) const
2441  {
2442  concurrent_hash_map_internal::check_outside_tx();
2443 
2444  return const_cast<concurrent_hash_map *>(this)->internal_find(
2445  key, nullptr, false);
2446  }
2447 
2454  bool
2455  find(const_accessor &result, const Key &key) const
2456  {
2457  concurrent_hash_map_internal::check_outside_tx();
2458 
2459  result.release();
2460 
2461  return const_cast<concurrent_hash_map *>(this)->internal_find(
2462  key, &result, false);
2463  }
2464 
2478  template <typename K,
2479  typename = typename std::enable_if<
2480  concurrent_hash_map_internal::
2481  has_transparent_key_equal<hasher>::value,
2482  K>::type>
2483  bool
2484  find(const_accessor &result, const K &key) const
2485  {
2486  concurrent_hash_map_internal::check_outside_tx();
2487 
2488  result.release();
2489 
2490  return const_cast<concurrent_hash_map *>(this)->internal_find(
2491  key, &result, false);
2492  }
2493 
2500  bool
2501  find(accessor &result, const Key &key)
2502  {
2503  concurrent_hash_map_internal::check_outside_tx();
2504 
2505  result.release();
2506 
2507  return internal_find(key, &result, true);
2508  }
2509 
2523  template <typename K,
2524  typename = typename std::enable_if<
2525  concurrent_hash_map_internal::
2526  has_transparent_key_equal<hasher>::value,
2527  K>::type>
2528  bool
2529  find(accessor &result, const K &key)
2530  {
2531  concurrent_hash_map_internal::check_outside_tx();
2532 
2533  result.release();
2534 
2535  return internal_find(key, &result, true);
2536  }
2544  bool
2545  insert(const_accessor &result, const Key &key)
2546  {
2547  concurrent_hash_map_internal::check_outside_tx();
2548 
2549  result.release();
2550 
2551  return internal_insert(key, &result, false, key);
2552  }
2553 
2561  bool
2562  insert(accessor &result, const Key &key)
2563  {
2564  concurrent_hash_map_internal::check_outside_tx();
2565 
2566  result.release();
2567 
2568  return internal_insert(key, &result, true, key);
2569  }
2570 
2578  bool
2579  insert(const_accessor &result, const value_type &value)
2580  {
2581  concurrent_hash_map_internal::check_outside_tx();
2582 
2583  result.release();
2584 
2585  return internal_insert(value.first, &result, false, value);
2586  }
2587 
2595  bool
2596  insert(accessor &result, const value_type &value)
2597  {
2598  concurrent_hash_map_internal::check_outside_tx();
2599 
2600  result.release();
2601 
2602  return internal_insert(value.first, &result, true, value);
2603  }
2604 
2611  bool
2612  insert(const value_type &value)
2613  {
2614  concurrent_hash_map_internal::check_outside_tx();
2615 
2616  return internal_insert(value.first, nullptr, false, value);
2617  }
2618 
2626  bool
2627  insert(const_accessor &result, value_type &&value)
2628  {
2629  concurrent_hash_map_internal::check_outside_tx();
2630 
2631  result.release();
2632 
2633  return internal_insert(value.first, &result, false,
2634  std::move(value));
2635  }
2636 
2644  bool
2645  insert(accessor &result, value_type &&value)
2646  {
2647  concurrent_hash_map_internal::check_outside_tx();
2648 
2649  result.release();
2650 
2651  return internal_insert(value.first, &result, true,
2652  std::move(value));
2653  }
2654 
2661  bool
2662  insert(value_type &&value)
2663  {
2664  concurrent_hash_map_internal::check_outside_tx();
2665 
2666  return internal_insert(value.first, nullptr, false,
2667  std::move(value));
2668  }
2669 
2675  template <typename I>
2676  void
2677  insert(I first, I last)
2678  {
2679  concurrent_hash_map_internal::check_outside_tx();
2680 
2681  for (; first != last; ++first)
2682  insert(*first);
2683  }
2684 
2690  void
2691  insert(std::initializer_list<value_type> il)
2692  {
2693  concurrent_hash_map_internal::check_outside_tx();
2694 
2695  insert(il.begin(), il.end());
2696  }
2697 
2706  template <typename M>
2707  bool
2708  insert_or_assign(const key_type &key, M &&obj)
2709  {
2710  concurrent_hash_map_internal::check_outside_tx();
2711 
2712  accessor acc;
2713  auto result = internal_insert(key, &acc, true, key,
2714  std::forward<M>(obj));
2715 
2716  if (!result) {
2717  pool_base pop = get_pool_base();
2719  acc->second = std::forward<M>(obj);
2721  }
2722 
2723  return result;
2724  }
2725 
2734  template <typename M>
2735  bool
2736  insert_or_assign(key_type &&key, M &&obj)
2737  {
2738  concurrent_hash_map_internal::check_outside_tx();
2739 
2740  accessor acc;
2741  auto result = internal_insert(key, &acc, true, std::move(key),
2742  std::forward<M>(obj));
2743 
2744  if (!result) {
2745  pool_base pop = get_pool_base();
2747  acc->second = std::forward<M>(obj);
2749  }
2750 
2751  return result;
2752  }
2753 
2762  template <
2763  typename K, typename M,
2764  typename = typename std::enable_if<
2765  concurrent_hash_map_internal::has_transparent_key_equal<
2766  hasher>::value &&
2767  std::is_constructible<key_type, K>::value,
2768  K>::type>
2769  bool
2770  insert_or_assign(K &&key, M &&obj)
2771  {
2772  concurrent_hash_map_internal::check_outside_tx();
2773 
2774  accessor acc;
2775  auto result =
2776  internal_insert(key, &acc, true, std::forward<K>(key),
2777  std::forward<M>(obj));
2778 
2779  if (!result) {
2780  pool_base pop = get_pool_base();
2782  acc->second = std::forward<M>(obj);
2784  }
2785 
2786  return result;
2787  }
2788 
2797  bool
2798  erase(const Key &key)
2799  {
2800  concurrent_hash_map_internal::check_outside_tx();
2801 
2802  return internal_erase(key);
2803  }
2804 
2823  pobj_defrag_result
2824  defragment(double start_percent = 0, double amount_percent = 100)
2825  {
2826  double end_percent = start_percent + amount_percent;
2827  if (start_percent < 0 || start_percent >= 100 ||
2828  end_percent < 0 || end_percent > 100 ||
2829  start_percent >= end_percent) {
2830  throw std::range_error("incorrect range");
2831  }
2832 
2833  size_t max_index = mask().load(std::memory_order_acquire);
2834  size_t start_index =
2835  static_cast<size_t>((start_percent * max_index) / 100);
2836  size_t end_index =
2837  static_cast<size_t>((end_percent * max_index) / 100);
2838 
2839  /* Make sure we do not use too big index, even in case of
2840  * rounding errors. */
2841  end_index = (std::min)(end_index, max_index);
2842 
2843 #if LIBPMEMOBJ_CPP_VG_HELGRIND_ENABLED
2844  ANNOTATE_HAPPENS_AFTER(&(this->my_mask));
2845 #endif
2846 
2847  /* Create defrag object for elements in the current pool */
2848  pmem::obj::defrag my_defrag(this->get_pool_base());
2849  mutex_vector mv;
2850 
2851  /*
2852  * Locks are taken in the backward order to avoid deadlocks
2853  * with the rehashing of buckets.
2854  *
2855  * We do '+ 1' and '- 1' to handle the 'i == 0' case.
2856  */
2857  for (size_t i = end_index + 1; i >= start_index + 1; i--) {
2858  /*
2859  * All locks will be unlocked automatically
2860  * in the destructor of 'mv'.
2861  */
2862  bucket *b = mv.push_and_try_lock(this, i - 1);
2863  if (b == nullptr)
2864  continue;
2865 
2866  defrag_save_nodes(b, my_defrag);
2867  }
2868 
2869  return my_defrag.run();
2870  }
2871 
2886  template <typename K,
2887  typename = typename std::enable_if<
2888  concurrent_hash_map_internal::
2889  has_transparent_key_equal<hasher>::value,
2890  K>::type>
2891  bool
2892  erase(const K &key)
2893  {
2894  concurrent_hash_map_internal::check_outside_tx();
2895 
2896  return internal_erase(key);
2897  }
2898 
2899 protected:
2900  /*
2901  * Try to acquire the mutex for read or write.
2902  *
2903  * If acquiring succeeds returns true, otherwise retries for few times.
2904  * If acquiring fails after all attempts returns false.
2905  */
2906  bool try_acquire_item(const_accessor *result, node_mutex_t &mutex,
2907  bool write);
2908 
2914  public:
2915  using mutex_t = MutexType;
2916 
2918  bucket *
2919  push_and_try_lock(concurrent_hash_map *base, hashcode_type h)
2920  {
2921  vec.emplace_back(base, h, true /*writer*/);
2922  bucket *b = vec.back().get();
2923 
2924  auto node_ptr = static_cast<node *>(
2925  b->node_list.get(base->my_pool_uuid));
2926 
2927  while (node_ptr) {
2928  const_accessor ca;
2929  if (!base->try_acquire_item(&ca,
2930  node_ptr->mutex,
2931  /*write=*/true)) {
2932  vec.pop_back();
2933  return nullptr;
2934  }
2935 
2936  node_ptr =
2937  static_cast<node *>(node_ptr->next.get(
2938  (base->my_pool_uuid)));
2939  }
2940 
2941  return b;
2942  }
2943 
2944  private:
2945  std::vector<bucket_accessor> vec;
2946  };
2947 
2948  template <typename K>
2949  bool internal_find(const K &key, const_accessor *result, bool write);
2950 
2951  template <typename K, typename... Args>
2952  bool internal_insert(const K &key, const_accessor *result, bool write,
2953  Args &&... args);
2954 
2955  /* Obtain pointer to node and lock bucket */
2956  template <bool Bucket_rw_lock, typename K>
2957  persistent_node_ptr_t
2958  get_node(const K &key, bucket_accessor &b)
2959  {
2960  /* find a node */
2961  auto n = search_bucket(key, b.get());
2962 
2963  if (!n) {
2964  if (Bucket_rw_lock && !b.is_writer() &&
2965  !scoped_lock_traits_type::upgrade_to_writer(b)) {
2966  /* Rerun search_list, in case another
2967  * thread inserted the item during the
2968  * upgrade. */
2969  n = search_bucket(key, b.get());
2970  if (n) {
2971  /* unfortunately, it did */
2972  scoped_lock_traits_type::
2973  downgrade_to_reader(b);
2974  return n;
2975  }
2976  }
2977  }
2978 
2979  return n;
2980  }
2981 
2982  template <typename K>
2983  bool internal_erase(const K &key);
2984 
2985  void clear_segment(segment_index_t s);
2986 
2990  void internal_copy(const concurrent_hash_map &source);
2991 
2992  template <typename I>
2993  void internal_copy(I first, I last);
2994 
2999  void
3001  {
3002  auto node_ptr = static_cast<node *>(
3003  b->node_list.get(this->my_pool_uuid));
3004 
3005  while (node_ptr) {
3006  /*
3007  * We do not perform the defragmentation
3008  * on node pointers, because nodes
3009  * always have the same size.
3010  */
3011  defrag.add(node_ptr->item.first);
3012  defrag.add(node_ptr->item.second);
3013 
3014  node_ptr = static_cast<node *>(
3015  node_ptr->next.get((this->my_pool_uuid)));
3016  }
3017  }
3018 }; // class concurrent_hash_map
3019 
3020 template <typename Key, typename T, typename Hash, typename KeyEqual,
3021  typename MutexType, typename ScopedLockType>
3022 bool
3023 concurrent_hash_map<Key, T, Hash, KeyEqual, MutexType,
3024  ScopedLockType>::try_acquire_item(const_accessor *result,
3025  node_mutex_t &mutex,
3026  bool write)
3027 {
3028  /* acquire the item */
3029  if (!result->try_acquire(mutex, write)) {
3030  for (detail::atomic_backoff backoff(true);;) {
3031  if (result->try_acquire(mutex, write))
3032  break;
3033 
3034  if (!backoff.bounded_pause())
3035  return false;
3036  }
3037  }
3038 
3039  return true;
3040 }
3041 
3042 template <typename Key, typename T, typename Hash, typename KeyEqual,
3043  typename MutexType, typename ScopedLockType>
3044 template <typename K>
3045 bool
3046 concurrent_hash_map<Key, T, Hash, KeyEqual, MutexType,
3047  ScopedLockType>::internal_find(const K &key,
3048  const_accessor *result,
3049  bool write)
3050 {
3051  assert(!result || !result->my_node);
3052 
3053  hashcode_type m = mask().load(std::memory_order_acquire);
3054 #if LIBPMEMOBJ_CPP_VG_HELGRIND_ENABLED
3055  ANNOTATE_HAPPENS_AFTER(&(this->my_mask));
3056 #endif
3057 
3058  assert((m & (m + 1)) == 0);
3059 
3060  hashcode_type const h = hasher{}(key);
3061 
3062  persistent_node_ptr_t node;
3063 
3064  while (true) {
3065  /* get bucket and acquire the lock */
3066  bucket_accessor b(
3067  this, h & m,
3068  scoped_lock_traits_type::initial_rw_state(false));
3069  node = get_node<false>(key, b);
3070 
3071  if (!node) {
3072  /* Element was possibly relocated, try again */
3073  if (check_mask_race(h, m)) {
3074  b.release();
3075  continue;
3076  } else {
3077  return false;
3078  }
3079  }
3080 
3081  /* No need to acquire the item or item acquired */
3082  if (!result ||
3083  try_acquire_item(
3084  result, node.get(this->my_pool_uuid)->mutex, write))
3085  break;
3086 
3087  /* the wait takes really long, restart the
3088  * operation */
3089  b.release();
3090 
3091  std::this_thread::yield();
3092 
3093  m = mask().load(std::memory_order_acquire);
3094 #if LIBPMEMOBJ_CPP_VG_HELGRIND_ENABLED
3095  ANNOTATE_HAPPENS_AFTER(&(this->my_mask));
3096 #endif
3097  }
3098 
3099  if (result) {
3100  result->my_node = node.get_persistent_ptr(this->my_pool_uuid);
3101  result->my_hash = h;
3102  }
3103 
3104  return true;
3105 }
3106 
3107 template <typename Key, typename T, typename Hash, typename KeyEqual,
3108  typename MutexType, typename ScopedLockType>
3109 template <typename K, typename... Args>
3110 bool
3111 concurrent_hash_map<Key, T, Hash, KeyEqual, MutexType,
3112  ScopedLockType>::internal_insert(const K &key,
3113  const_accessor *result,
3114  bool write,
3115  Args &&... args)
3116 {
3117  assert(!result || !result->my_node);
3118 
3119  hashcode_type m = mask().load(std::memory_order_acquire);
3120 #if LIBPMEMOBJ_CPP_VG_HELGRIND_ENABLED
3121  ANNOTATE_HAPPENS_AFTER(&(this->my_mask));
3122 #endif
3123 
3124  assert((m & (m + 1)) == 0);
3125 
3126  hashcode_type const h = hasher{}(key);
3127 
3128  persistent_node_ptr_t node;
3129  size_t new_size = 0;
3130  bool inserted = false;
3131 
3132  while (true) {
3133  /* get bucket and acquire the lock */
3134  bucket_accessor b(
3135  this, h & m,
3136  scoped_lock_traits_type::initial_rw_state(true));
3137  node = get_node<true>(key, b);
3138 
3139  if (!node) {
3140  /* Element was possibly relocated, try again */
3141  if (check_mask_race(h, m)) {
3142  b.release();
3143  continue;
3144  }
3145 
3146  /* insert and set flag to grow the container */
3147  new_size = insert_new_node(b.get(), node,
3148  std::forward<Args>(args)...);
3149  inserted = true;
3150  }
3151 
3152  /* No need to acquire the item or item acquired */
3153  if (!result ||
3154  try_acquire_item(
3155  result, node.get(this->my_pool_uuid)->mutex, write))
3156  break;
3157 
3158  /* the wait takes really long, restart the
3159  * operation */
3160  b.release();
3161 
3162  std::this_thread::yield();
3163 
3164  m = mask().load(std::memory_order_acquire);
3165 #if LIBPMEMOBJ_CPP_VG_HELGRIND_ENABLED
3166  ANNOTATE_HAPPENS_AFTER(&(this->my_mask));
3167 #endif
3168  }
3169 
3170  if (result) {
3171  result->my_node = node.get_persistent_ptr(this->my_pool_uuid);
3172  result->my_hash = h;
3173  }
3174 
3175  check_growth(m, new_size);
3176 
3177  return inserted;
3178 }
3179 
3180 template <typename Key, typename T, typename Hash, typename KeyEqual,
3181  typename MutexType, typename ScopedLockType>
3182 template <typename K>
3183 bool
3184 concurrent_hash_map<Key, T, Hash, KeyEqual, MutexType,
3185  ScopedLockType>::internal_erase(const K &key)
3186 {
3187  node_ptr_t n;
3188  hashcode_type const h = hasher{}(key);
3189  hashcode_type m = mask().load(std::memory_order_acquire);
3190 #if LIBPMEMOBJ_CPP_VG_HELGRIND_ENABLED
3191  ANNOTATE_HAPPENS_AFTER(&(this->my_mask));
3192 #endif
3193 
3194  pool_base pop = get_pool_base();
3195 
3196 restart : {
3197  /* lock scope */
3198  /* get bucket */
3199  bucket_accessor b(this, h & m,
3200  scoped_lock_traits_type::initial_rw_state(true));
3201 
3202 search:
3203  node_ptr_t *p = &b->node_list;
3204  n = *p;
3205 
3206  while (n &&
3207  !key_equal{}(key,
3208  detail::static_persistent_pool_pointer_cast<node>(
3209  n)(this->my_pool_uuid)
3210  ->item.first)) {
3211  p = &n(this->my_pool_uuid)->next;
3212  n = *p;
3213  }
3214 
3215  if (!n) {
3216  /* not found, but mask could be changed */
3217  if (check_mask_race(h, m))
3218  goto restart;
3219 
3220  return false;
3221  } else if (!b.is_writer() &&
3222  !scoped_lock_traits_type::upgrade_to_writer(b)) {
3223  if (check_mask_race(h, m)) /* contended upgrade, check mask */
3224  goto restart;
3225 
3226  goto search;
3227  }
3228 
3229  persistent_ptr<node> del = n(this->my_pool_uuid);
3230 
3231  {
3232  /* We cannot remove this element immediately because
3233  * other threads might work with this element via
3234  * accessors. The item_locker required to wait while
3235  * other threads use the node. */
3236  const_accessor acc;
3237  if (!try_acquire_item(&acc, del->mutex, true)) {
3238  /* the wait takes really long, restart the operation */
3239  b.release();
3240 
3241  std::this_thread::yield();
3242 
3243  m = mask().load(std::memory_order_acquire);
3244 
3245  goto restart;
3246  }
3247  }
3248 
3249  assert(pmemobj_tx_stage() == TX_STAGE_NONE);
3250 
3251  auto &size_diff = this->thread_size_diff();
3252 
3253  /* Only one thread can delete it due to write lock on the bucket
3254  */
3255  transaction::run(pop, [&] {
3256  *p = del->next;
3257  delete_node(del);
3258 
3259  --size_diff;
3260  });
3261 
3262  --(this->my_size);
3263 }
3264 
3265  return true;
3266 }
3267 
3268 template <typename Key, typename T, typename Hash, typename KeyEqual,
3269  typename MutexType, typename ScopedLockType>
3270 void
3273 {
3274  internal_swap(table);
3275 }
3276 
3277 template <typename Key, typename T, typename Hash, typename KeyEqual,
3278  typename MutexType, typename ScopedLockType>
3279 void
3281  size_type sz)
3282 {
3283  concurrent_hash_map_internal::check_outside_tx();
3284 
3285  reserve(sz);
3286  hashcode_type m = mask();
3287 
3288  /* only the last segment should be scanned for rehashing size or first
3289  * index of the last segment */
3290  hashcode_type b = (m + 1) >> 1;
3291 
3292  /* zero or power of 2 */
3293  assert((b & (b - 1)) == 0);
3294 
3295  for (; b <= m; ++b) {
3296  bucket *bp = get_bucket(b);
3297 
3298  concurrent_hash_map_internal::assert_not_locked<mutex_t,
3299  scoped_t>(
3300  bp->mutex);
3301  /* XXX Need to investigate if this statement is needed */
3302  if (bp->is_rehashed(std::memory_order_relaxed) == false)
3303  rehash_bucket<true>(bp, b);
3304  }
3305 }
3306 
3307 template <typename Key, typename T, typename Hash, typename KeyEqual,
3308  typename MutexType, typename ScopedLockType>
3309 void
3311 {
3312  hashcode_type m = mask();
3313 
3314  assert((m & (m + 1)) == 0);
3315 
3316 #ifndef NDEBUG
3317  /* check consistency */
3318  for (segment_index_t b = 0; b <= m; ++b) {
3319  bucket *bp = get_bucket(b);
3320  concurrent_hash_map_internal::assert_not_locked<mutex_t,
3321  scoped_t>(
3322  bp->mutex);
3323  }
3324 #endif
3325 
3326  pool_base pop = get_pool_base();
3327  { /* transaction scope */
3328 
3329  transaction::manual tx(pop);
3330 
3331  assert(this->tls_ptr != nullptr);
3332  this->tls_ptr->clear();
3333 
3334  this->on_init_size = 0;
3335 
3336  segment_index_t s = segment_traits_t::segment_index_of(m);
3337 
3338  assert(s + 1 == this->block_table_size ||
3339  !segment_facade_t(this->my_table, s + 1).is_valid());
3340 
3341  do {
3342  clear_segment(s);
3343  } while (s-- > 0);
3344 
3345  /*
3346  * As clear can only be called
3347  * from one thread, and there can be an outer
3348  * transaction we must make sure that mask and size
3349  * changes are transactional
3350  */
3351  transaction::snapshot((size_t *)&this->my_mask);
3352  transaction::snapshot((size_t *)&this->my_size);
3353 
3354  mask().store(embedded_buckets - 1, std::memory_order_relaxed);
3355  this->my_size = 0;
3356 
3358  }
3359 }
3360 
3361 template <typename Key, typename T, typename Hash, typename KeyEqual,
3362  typename MutexType, typename ScopedLockType>
3363 void
3364 concurrent_hash_map<Key, T, Hash, KeyEqual, MutexType,
3365  ScopedLockType>::clear_segment(segment_index_t s)
3366 {
3367  segment_facade_t segment(this->my_table, s);
3368 
3369  assert(segment.is_valid());
3370 
3371  size_type sz = segment.size();
3372  for (segment_index_t i = 0; i < sz; ++i) {
3373  for (node_ptr_t n = segment[i].node_list; n;
3374  n = segment[i].node_list) {
3375  segment[i].node_list = n(this->my_pool_uuid)->next;
3376  delete_node(n);
3377  }
3378  }
3379 
3380  if (s >= segment_traits_t::embedded_segments)
3381  segment.disable();
3382 }
3383 
3384 template <typename Key, typename T, typename Hash, typename KeyEqual,
3385  typename MutexType, typename ScopedLockType>
3386 void
3388  internal_copy(const concurrent_hash_map &source)
3389 {
3390  auto pop = get_pool_base();
3391 
3392  reserve(source.size());
3393  internal_copy(source.begin(), source.end());
3394 }
3395 
3396 template <typename Key, typename T, typename Hash, typename KeyEqual,
3397  typename MutexType, typename ScopedLockType>
3398 template <typename I>
3399 void
3400 concurrent_hash_map<Key, T, Hash, KeyEqual, MutexType,
3401  ScopedLockType>::internal_copy(I first, I last)
3402 {
3403  hashcode_type m = mask();
3404 
3405  for (; first != last; ++first) {
3406  hashcode_type h = hasher{}(first->first);
3407  bucket *b = get_bucket(h & m);
3408 
3409  assert(b->is_rehashed(std::memory_order_relaxed));
3410 
3411  detail::persistent_pool_ptr<node> p;
3412  insert_new_node(b, p, *first);
3413  }
3414 }
3415 
3416 template <typename Key, typename T, typename Hash, typename KeyEqual,
3417  typename MutexType, typename ScopedLockType>
3418 inline bool
3419 operator==(const concurrent_hash_map<Key, T, Hash, KeyEqual, MutexType,
3420  ScopedLockType> &a,
3421  const concurrent_hash_map<Key, T, Hash, KeyEqual, MutexType,
3422  ScopedLockType> &b)
3423 {
3424  if (a.size() != b.size())
3425  return false;
3426 
3427  typename concurrent_hash_map<Key, T, Hash, KeyEqual, MutexType,
3428  ScopedLockType>::const_iterator
3429  i(a.begin()),
3430  i_end(a.end());
3431 
3432  typename concurrent_hash_map<Key, T, Hash, KeyEqual, MutexType,
3433  ScopedLockType>::const_iterator j,
3434  j_end(b.end());
3435 
3436  for (; i != i_end; ++i) {
3437  j = b.equal_range(i->first).first;
3438 
3439  if (j == j_end || !(i->second == j->second))
3440  return false;
3441  }
3442 
3443  return true;
3444 }
3445 
3446 template <typename Key, typename T, typename Hash, typename KeyEqual,
3447  typename MutexType, typename ScopedLockType>
3448 inline bool
3449 operator!=(const concurrent_hash_map<Key, T, Hash, KeyEqual, MutexType,
3450  ScopedLockType> &a,
3451  const concurrent_hash_map<Key, T, Hash, KeyEqual, MutexType,
3452  ScopedLockType> &b)
3453 {
3454  return !(a == b);
3455 }
3456 
3457 template <typename Key, typename T, typename Hash, typename KeyEqual,
3458  typename MutexType, typename ScopedLockType>
3459 inline void
3460 swap(concurrent_hash_map<Key, T, Hash, KeyEqual, MutexType, ScopedLockType> &a,
3461  concurrent_hash_map<Key, T, Hash, KeyEqual, MutexType, ScopedLockType> &b)
3462 {
3463  a.swap(b);
3464 }
3465 
3466 } /* namespace obj */
3467 } /* namespace pmem */
3468 
3469 #endif /* PMEMOBJ_CONCURRENT_HASH_MAP_HPP */
pmem::obj::concurrent_hash_map::clear
void clear()
Clear hash map content Not thread safe.
Definition: concurrent_hash_map.hpp:3310
pmem::obj::concurrent_hash_map::insert
bool insert(value_type &&value)
Insert item by copying if there is no such key present already.
Definition: concurrent_hash_map.hpp:2662
pmem::obj::transaction::commit
static void commit()
Manually commit a transaction.
Definition: transaction.hpp:340
pmem::obj::operator+
persistent_ptr< T > operator+(persistent_ptr< T > const &lhs, std::ptrdiff_t s)
Addition operator for persistent pointers.
Definition: persistent_ptr.hpp:836
pmem::obj::mutex
Persistent memory resident mutex implementation.
Definition: mutex.hpp:31
pmem::obj::concurrent_hash_map::concurrent_hash_map
concurrent_hash_map(concurrent_hash_map &&table)
Move constructor.
Definition: concurrent_hash_map.hpp:2115
pmem::obj::concurrent_hash_map::erase
bool erase(const Key &key)
Remove element with corresponding key.
Definition: concurrent_hash_map.hpp:2798
pmem::obj::concurrent_hash_map::bucket_accessor
Bucket accessor is to find, rehash, acquire a lock, and access a bucket.
Definition: concurrent_hash_map.hpp:1720
pmem::obj::concurrent_hash_map::const_accessor::release
void release()
Release accessor.
Definition: concurrent_hash_map.hpp:2004
pmem::obj::concurrent_hash_map::bucket_accessor::is_writer
bool is_writer() const
Check whether bucket is locked for write.
Definition: concurrent_hash_map.hpp:1771
pmem::obj::concurrent_hash_map::count
size_type count(const Key &key) const
Definition: concurrent_hash_map.hpp:2415
pmem::obj::concurrent_hash_map::end
iterator end()
Definition: concurrent_hash_map.hpp:2339
pmem::obj::p::get_ro
const T & get_ro() const noexcept
Retrieves read-only const reference of the object.
Definition: p.hpp:128
pmem::obj::concurrent_hash_map::insert
bool insert(accessor &result, value_type &&value)
Insert item by copying if there is no such key present already and acquire a write lock on the item.
Definition: concurrent_hash_map.hpp:2645
pmem
Persistent memory namespace.
Definition: allocation_flag.hpp:15
pmem::obj::concurrent_hash_map::~concurrent_hash_map
~concurrent_hash_map()
free_data should be called before concurrent_hash_map destructor is called.
Definition: concurrent_hash_map.hpp:2309
pmem::obj::concurrent_hash_map::operator=
concurrent_hash_map & operator=(const concurrent_hash_map &table)
Assignment Not thread safe.
Definition: concurrent_hash_map.hpp:2224
pmem::obj::begin
pmem::obj::array< T, N >::iterator begin(pmem::obj::array< T, N > &a)
Non-member begin.
Definition: array.hpp:804
pmem::obj::concurrent_hash_map::const_accessor::operator*
const_reference operator*() const
Definition: concurrent_hash_map.hpp:2017
pmem::obj::concurrent_hash_map::accessor
Allows write access to elements and combines data access, locking, and garbage collection.
Definition: concurrent_hash_map.hpp:2061
common.hpp
Commonly used functionality.
pmem::obj::concurrent_hash_map::insert
bool insert(const_accessor &result, const value_type &value)
Insert item by copying if there is no such key present already and acquire a read lock on the item.
Definition: concurrent_hash_map.hpp:2579
template_helpers.hpp
Commonly used SFINAE helpers.
pmem::obj::concurrent_hash_map::insert_or_assign
bool insert_or_assign(key_type &&key, M &&obj)
Inserts item if there is no such key present already, assigns provided value otherwise.
Definition: concurrent_hash_map.hpp:2736
pmem::obj::concurrent_hash_map::runtime_initialize
void runtime_initialize()
Initialize persistent concurrent hash map after process restart.
Definition: concurrent_hash_map.hpp:2156
pmem::obj::transaction::snapshot
static void snapshot(const T *addr, size_t num=1)
Takes a “snapshot” of given elements of type T number (1 by default), located at the given address pt...
Definition: transaction.hpp:484
pmem::obj::concurrent_hash_map::serial_bucket_accessor::operator->
bucket * operator->() const
Overloaded arrow operator.
Definition: concurrent_hash_map.hpp:1854
pmem::obj::concurrent_hash_map::insert
bool insert(const_accessor &result, value_type &&value)
Insert item by copying if there is no such key present already and acquire a read lock on the item.
Definition: concurrent_hash_map.hpp:2627
pmem::obj::operator++
p< T > & operator++(p< T > &pp)
Prefix increment operator overload.
Definition: pext.hpp:48
pmem::obj::concurrent_hash_map::find
bool find(accessor &result, const K &key)
Find item and acquire a write lock on the item.
Definition: concurrent_hash_map.hpp:2529
pmem::obj::operator==
bool operator==(standard_alloc_policy< T > const &, standard_alloc_policy< T2 > const &)
Determines if memory from another allocator can be deallocated from this one.
Definition: allocator.hpp:406
pmem::obj::concurrent_hash_map::serial_bucket_accessor::get
bucket * get() const
Get bucket pointer.
Definition: concurrent_hash_map.hpp:1845
pmem::obj::p
Resides on pmem class.
Definition: p.hpp:35
pmem::obj::defrag
Defrag class.
Definition: defrag.hpp:83
pmem::obj::concurrent_hash_map::free_data
void free_data()
Should be called before concurrent_hash_map destructor is called.
Definition: concurrent_hash_map.hpp:2288
pmem::obj::concurrent_hash_map::mutex_vector::push_and_try_lock
bucket * push_and_try_lock(concurrent_hash_map *base, hashcode_type h)
Save pointer to the lock in the vector and lock it.
Definition: concurrent_hash_map.hpp:2919
pmem::obj::concurrent_hash_map::const_accessor::~const_accessor
~const_accessor()
Destroy result after releasing the underlying reference.
Definition: concurrent_hash_map.hpp:2045
pmem::obj::concurrent_hash_map::bucket_count
size_type bucket_count() const
Definition: concurrent_hash_map.hpp:2395
defrag.hpp
Defragmentation class.
pmem::obj::concurrent_hash_map::size
size_type size() const
Definition: concurrent_hash_map.hpp:2368
make_persistent.hpp
Persistent_ptr transactional allocation functions for objects.
pmem::obj::concurrent_hash_map::concurrent_hash_map
concurrent_hash_map(std::initializer_list< value_type > il)
Construct table with initializer list.
Definition: concurrent_hash_map.hpp:2138
pmem::obj::concurrent_hash_map::mutex_vector
Vector of locks to be unlocked at the destruction time.
Definition: concurrent_hash_map.hpp:2913
pmem::obj::transaction::run
static void run(pool_base &pool, std::function< void()> tx, Locks &... locks)
Execute a closure-like transaction and lock locks.
Definition: transaction.hpp:393
pmem::obj::concurrent_hash_map::concurrent_hash_map
concurrent_hash_map(size_type n)
Construct empty table with n preallocated buckets.
Definition: concurrent_hash_map.hpp:2093
pmem::obj::concurrent_hash_map::count
size_type count(const K &key) const
This overload only participates in overload resolution if the qualified-id Hash::transparent_key_equa...
Definition: concurrent_hash_map.hpp:2440
pmem::obj::concurrent_hash_map::insert
bool insert(accessor &result, const Key &key)
Insert item (if not already present) and acquire a write lock on the item.
Definition: concurrent_hash_map.hpp:2562
pmem::obj::concurrent_hash_map::find
bool find(accessor &result, const Key &key)
Find item and acquire a write lock on the item.
Definition: concurrent_hash_map.hpp:2501
pmem::obj::operator-
persistent_ptr< T > operator-(persistent_ptr< T > const &lhs, std::ptrdiff_t s)
Subtraction operator for persistent pointers.
Definition: persistent_ptr.hpp:850
pmem::obj::swap
void swap(pmem::obj::array< T, N > &lhs, pmem::obj::array< T, N > &rhs)
Non-member swap function.
Definition: array.hpp:884
pmem::obj::operator+=
p< T > & operator+=(p< T > &lhs, const p< Y > &rhs)
Addition assignment operator overload.
Definition: pext.hpp:94
pmem::obj::concurrent_hash_map::insert
void insert(std::initializer_list< value_type > il)
Insert initializer list.
Definition: concurrent_hash_map.hpp:2691
pmem::obj::operator!=
bool operator!=(const allocator< T, P, Tr > &lhs, const OtherAllocator &rhs)
Determines if memory from another allocator can be deallocated from this one.
Definition: allocator.hpp:522
pmem::obj::defrag::run
pobj_defrag_result run()
Starts defragmentation with previously stored pointers.
Definition: defrag.hpp:188
pmem::obj::concurrent_hash_map::concurrent_hash_map
concurrent_hash_map(const concurrent_hash_map &table)
Copy constructor.
Definition: concurrent_hash_map.hpp:2103
pmem::obj::concurrent_hash_map::max_size
size_type max_size() const
Upper bound on size.
Definition: concurrent_hash_map.hpp:2386
pmem::obj::concurrent_hash_map::concurrent_hash_map
concurrent_hash_map()
Construct empty table.
Definition: concurrent_hash_map.hpp:2084
pmem::obj::operator-=
p< T > & operator-=(p< T > &lhs, const p< Y > &rhs)
Subtraction assignment operator overload.
Definition: pext.hpp:116
transaction.hpp
C++ pmemobj transactions.
pmem::obj::concurrent_hash_map::begin
const_iterator begin() const
Definition: concurrent_hash_map.hpp:2349
pmem::obj::concurrent_hash_map::bucket_accessor::acquire
void acquire(concurrent_hash_map *base, const hashcode_type h, bool writer=false)
Find a bucket by masked hashcode, optionally rehash, and acquire the lock.
Definition: concurrent_hash_map.hpp:1745
pmem::obj::concurrent_hash_map::insert_or_assign
bool insert_or_assign(const key_type &key, M &&obj)
Inserts item if there is no such key present already, assigns provided value otherwise.
Definition: concurrent_hash_map.hpp:2708
pmem::obj::concurrent_hash_map::erase
bool erase(const K &key)
Remove element with corresponding key.
Definition: concurrent_hash_map.hpp:2892
pmem::obj::persistent_ptr< node >
shared_mutex.hpp
Pmem-resident shared mutex.
pmem::obj::concurrent_hash_map::insert_or_assign
bool insert_or_assign(K &&key, M &&obj)
Inserts item if there is no such key-comparable type present already, assigns provided value otherwis...
Definition: concurrent_hash_map.hpp:2770
pmem::obj::concurrent_hash_map::insert
bool insert(accessor &result, const value_type &value)
Insert item by copying if there is no such key present already and acquire a write lock on the item.
Definition: concurrent_hash_map.hpp:2596
p.hpp
Resides on pmem property template.
pmem::obj::concurrent_hash_map::const_accessor::operator->
const_pointer operator->() const
Definition: concurrent_hash_map.hpp:2027
pmem::obj::concurrent_hash_map::operator=
concurrent_hash_map & operator=(std::initializer_list< value_type > il)
Assignment Not thread safe.
Definition: concurrent_hash_map.hpp:2246
pmem::obj::concurrent_hash_map::accessor::operator->
pointer operator->() const
Return pointer to associated value in hash table.
Definition: concurrent_hash_map.hpp:2075
pmem::obj::get
T & get(pmem::obj::array< T, N > &a)
Non-member get function.
Definition: array.hpp:894
pmem::layout_error
Custom layout error class.
Definition: pexceptions.hpp:178
pmem::obj::concurrent_hash_map::bucket_accessor::get
bucket * get() const
Get bucket pointer.
Definition: concurrent_hash_map.hpp:1781
pmem::obj::concurrent_hash_map::const_accessor::value_type
const typename concurrent_hash_map::value_type value_type
Type of value.
Definition: concurrent_hash_map.hpp:1985
pmem::obj::concurrent_hash_map::serial_bucket_accessor::is_writer
bool is_writer() const
This method is added for consistency with bucket_accessor class.
Definition: concurrent_hash_map.hpp:1835
pmem::transaction_scope_error
Custom transaction error class.
Definition: pexceptions.hpp:158
pmem::obj::concurrent_hash_map::defragment
pobj_defrag_result defragment(double start_percent=0, double amount_percent=100)
Defragment the given (by 'start_percent' and 'amount_percent') part of buckets of the hash map.
Definition: concurrent_hash_map.hpp:2824
pmem::obj::concurrent_hash_map::internal_copy
void internal_copy(const concurrent_hash_map &source)
Copy "source" to *this, where *this must start out empty.
Definition: concurrent_hash_map.hpp:3388
pmem::obj::concurrent_hash_map::empty
bool empty() const
Definition: concurrent_hash_map.hpp:2377
pmem::obj::defrag::add
std::enable_if< is_defragmentable< T >), void >::type add(T &t)
Stores address of the referenced object to the defragmentation queue.
Definition: defrag.hpp:112
pmem::obj::concurrent_hash_map::find
bool find(const_accessor &result, const K &key) const
Find item and acquire a read lock on the item.
Definition: concurrent_hash_map.hpp:2484
pmem::obj::concurrent_hash_map::insert
bool insert(const value_type &value)
Insert item by copying if there is no such key present already.
Definition: concurrent_hash_map.hpp:2612
pmem::obj::concurrent_hash_map::concurrent_hash_map
concurrent_hash_map(I first, I last)
Construction table with copying iteration range.
Definition: concurrent_hash_map.hpp:2126
pmem::obj::pool_base
The non-template pool base class.
Definition: pool.hpp:46
atomic_backoff.hpp
Atomic backoff, for time delay.
pmem::obj::concurrent_hash_map::insert
bool insert(const_accessor &result, const Key &key)
Insert item (if not already present) and acquire a read lock on the item.
Definition: concurrent_hash_map.hpp:2545
pmem::obj::concurrent_hash_map::const_accessor
Combines data access, locking, and garbage collection.
Definition: concurrent_hash_map.hpp:1973
pmem::obj::concurrent_hash_map::begin
iterator begin()
Definition: concurrent_hash_map.hpp:2329
persistent_ptr.hpp
Persistent smart pointer.
pmem::obj::concurrent_hash_map::bucket_accessor::operator->
bucket * operator->() const
Overloaded arrow operator.
Definition: concurrent_hash_map.hpp:1790
pmem::obj::concurrent_hash_map::accessor::operator*
reference operator*() const
Return reference to associated value in hash table.
Definition: concurrent_hash_map.hpp:2067
pmem::obj::concurrent_hash_map::swap
void swap(concurrent_hash_map &table)
Swap two instances.
Definition: concurrent_hash_map.hpp:3271
pmem::obj::concurrent_hash_map::insert
void insert(I first, I last)
Insert range [first, last)
Definition: concurrent_hash_map.hpp:2677
pmem::obj::transaction::manual
C++ manual scope transaction class.
Definition: transaction.hpp:71
pmem::obj::operator--
p< T > & operator--(p< T > &pp)
Prefix decrement operator overload.
Definition: pext.hpp:59
pmem::obj::concurrent_hash_map::const_accessor::const_accessor
const_accessor()
Create empty result.
Definition: concurrent_hash_map.hpp:2037
pmem::obj::concurrent_hash_map::find
bool find(const_accessor &result, const Key &key) const
Find item and acquire a read lock on the item.
Definition: concurrent_hash_map.hpp:2455
pmem::obj::concurrent_hash_map
Persistent memory aware implementation of Intel TBB concurrent_hash_map.
Definition: concurrent_hash_map.hpp:1624
enumerable_thread_specific.hpp
A persistent version of thread-local storage.
pmem::obj::concurrent_hash_map::rehash
void rehash(size_type n=0)
Rehashes and optionally resizes the whole table.
Definition: concurrent_hash_map.hpp:3280
mutex.hpp
Pmem-resident mutex.
pmem::obj::concurrent_hash_map::serial_bucket_accessor
Serial bucket accessor used to access bucket in a serial operations.
Definition: concurrent_hash_map.hpp:1799
pmem::obj::concurrent_hash_map::const_accessor::empty
bool empty() const
Definition: concurrent_hash_map.hpp:1992
pmem::obj::concurrent_hash_map::end
const_iterator end() const
Definition: concurrent_hash_map.hpp:2359
pmem::obj::concurrent_hash_map::defrag_save_nodes
void defrag_save_nodes(bucket *b, pmem::obj::defrag &defrag)
Internal method used by defragment().
Definition: concurrent_hash_map.hpp:3000