diff --git a/libcxx/docs/ReleaseNotes/22.rst b/libcxx/docs/ReleaseNotes/22.rst index e56f0a88db138..2b928a3a26913 100644 --- a/libcxx/docs/ReleaseNotes/22.rst +++ b/libcxx/docs/ReleaseNotes/22.rst @@ -57,7 +57,6 @@ Improvements and New Features has been improved by up to 3x - The performance of ``insert(iterator, iterator)`` of ``map``, ``set``, ``multimap`` and ``multiset`` has been improved by up to 2.5x -- The performance of ``erase(iterator, iterator)`` in the unordered containers has been improved by up to 1.9x - The performance of ``map::insert_or_assign`` has been improved by up to 2x - ``ofstream::write`` has been optimized to pass through large strings to system calls directly instead of copying them diff --git a/libcxx/include/__hash_table b/libcxx/include/__hash_table index 2018b5a194e89..2b246f82ce36d 100644 --- a/libcxx/include/__hash_table +++ b/libcxx/include/__hash_table @@ -1036,21 +1036,7 @@ private: } _LIBCPP_HIDE_FROM_ABI void __move_assign_alloc(__hash_table&, false_type) _NOEXCEPT {} - _LIBCPP_HIDE_FROM_ABI void __deallocate_node(__node_pointer __nd) _NOEXCEPT { - auto& __alloc = __node_alloc(); - __node_traits::destroy(__alloc, std::addressof(__nd->__get_value())); - std::__destroy_at(std::__to_address(__nd)); - __node_traits::deallocate(__alloc, __nd, 1); - } - - _LIBCPP_HIDE_FROM_ABI void __deallocate_node_list(__next_pointer __np) _NOEXCEPT { - while (__np != nullptr) { - __next_pointer __next = __np->__next_; - __deallocate_node(__np->__upcast()); - __np = __next; - } - } - + _LIBCPP_HIDE_FROM_ABI void __deallocate_node(__next_pointer __np) _NOEXCEPT; _LIBCPP_HIDE_FROM_ABI __next_pointer __detach() _NOEXCEPT; template ::value, int> = 0> @@ -1188,7 +1174,7 @@ __hash_table<_Tp, _Hash, _Equal, _Alloc>::~__hash_table() { static_assert(is_copy_constructible::value, "Hasher must be copy-constructible."); #endif - __deallocate_node_list(__first_node_.__next_); + __deallocate_node(__first_node_.__next_); } template @@ -1264,7 +1250,7 @@ __hash_table<_Tp, _Hash, _Equal, _Alloc>::operator=(const __hash_table& __other) // At this point we either have consumed the whole incoming hash table, or we don't have any more nodes to reuse in // the destination. Either continue with constructing new nodes, or deallocate the left over nodes. if (__own_iter->__next_) { - __deallocate_node_list(__own_iter->__next_); + __deallocate_node(__own_iter->__next_); __own_iter->__next_ = nullptr; } else { __copy_construct(__other_iter, __own_iter, __current_chash); @@ -1275,6 +1261,19 @@ __hash_table<_Tp, _Hash, _Equal, _Alloc>::operator=(const __hash_table& __other) return *this; } +template +void __hash_table<_Tp, _Hash, _Equal, _Alloc>::__deallocate_node(__next_pointer __np) _NOEXCEPT { + __node_allocator& __na = __node_alloc(); + while (__np != nullptr) { + __next_pointer __next = __np->__next_; + __node_pointer __real_np = __np->__upcast(); + __node_traits::destroy(__na, std::addressof(__real_np->__get_value())); + std::__destroy_at(std::addressof(*__real_np)); + __node_traits::deallocate(__na, __real_np, 1); + __np = __next; + } +} + template typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::__next_pointer __hash_table<_Tp, _Hash, _Equal, _Alloc>::__detach() _NOEXCEPT { @@ -1330,11 +1329,11 @@ void __hash_table<_Tp, _Hash, _Equal, _Alloc>::__move_assign(__hash_table& __u, } #if _LIBCPP_HAS_EXCEPTIONS } catch (...) { - __deallocate_node_list(__cache); + __deallocate_node(__cache); throw; } #endif // _LIBCPP_HAS_EXCEPTIONS - __deallocate_node_list(__cache); + __deallocate_node(__cache); } const_iterator __i = __u.begin(); while (__u.size() != 0) @@ -1373,11 +1372,11 @@ void __hash_table<_Tp, _Hash, _Equal, _Alloc>::__assign_unique(_InputIterator __ } #if _LIBCPP_HAS_EXCEPTIONS } catch (...) { - __deallocate_node_list(__cache); + __deallocate_node(__cache); throw; } #endif // _LIBCPP_HAS_EXCEPTIONS - __deallocate_node_list(__cache); + __deallocate_node(__cache); } for (; __first != __last; ++__first) __emplace_unique(*__first); @@ -1403,11 +1402,11 @@ void __hash_table<_Tp, _Hash, _Equal, _Alloc>::__assign_multi(_InputIterator __f } #if _LIBCPP_HAS_EXCEPTIONS } catch (...) { - __deallocate_node_list(__cache); + __deallocate_node(__cache); throw; } #endif // _LIBCPP_HAS_EXCEPTIONS - __deallocate_node_list(__cache); + __deallocate_node(__cache); } for (; __first != __last; ++__first) __emplace_multi(*__first); @@ -1440,7 +1439,7 @@ __hash_table<_Tp, _Hash, _Equal, _Alloc>::end() const _NOEXCEPT { template void __hash_table<_Tp, _Hash, _Equal, _Alloc>::clear() _NOEXCEPT { if (size() > 0) { - __deallocate_node_list(__first_node_.__next_); + __deallocate_node(__first_node_.__next_); __first_node_.__next_ = nullptr; size_type __bc = bucket_count(); for (size_type __i = 0; __i < __bc; ++__i) @@ -1900,57 +1899,12 @@ __hash_table<_Tp, _Hash, _Equal, _Alloc>::erase(const_iterator __p) { template typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator __hash_table<_Tp, _Hash, _Equal, _Alloc>::erase(const_iterator __first, const_iterator __last) { - if (__first == __last) - return iterator(__last.__node_); - - // current node - __next_pointer __current = __first.__node_; - size_type __bucket_count = bucket_count(); - size_t __chash = std::__constrain_hash(__current->__hash(), __bucket_count); - // find previous node - __next_pointer __before_first = __bucket_list_[__chash]; - for (; __before_first->__next_ != __current; __before_first = __before_first->__next_) - ; - - __next_pointer __last_node = __last.__node_; - - // If __before_first is in the same bucket (i.e. the first element we erase is not the first in the bucket), clear - // this bucket first without re-linking it - if (__before_first != __first_node_.__ptr() && - std::__constrain_hash(__before_first->__hash(), __bucket_count) == __chash) { - while (__current != __last_node) { - if (auto __next_chash = std::__constrain_hash(__current->__hash(), __bucket_count); __next_chash != __chash) { - __chash = __next_chash; - break; - } - auto __next = __current->__next_; - __deallocate_node(__current->__upcast()); - __current = __next; - --__size_; - } + for (const_iterator __p = __first; __first != __last; __p = __first) { + ++__first; + erase(__p); } - - while (__current != __last_node) { - auto __next = __current->__next_; - __deallocate_node(__current->__upcast()); - __current = __next; - --__size_; - - // When switching buckets, set the old bucket to be empty and update the next bucket to have __before_first as its - // before-first element - if (__next) { - if (auto __next_chash = std::__constrain_hash(__next->__hash(), __bucket_count); __next_chash != __chash) { - __bucket_list_[__chash] = nullptr; - __chash = __next_chash; - __bucket_list_[__chash] = __before_first; - } - } - } - - // re-link __before_first with __last - __before_first->__next_ = __current; - - return iterator(__last.__node_); + __next_pointer __np = __last.__node_; + return iterator(__np); } template diff --git a/libcxx/test/std/containers/unord/unord.multimap/unord.multimap.modifiers/erase_range.pass.cpp b/libcxx/test/std/containers/unord/unord.multimap/unord.multimap.modifiers/erase_range.pass.cpp index a8a9f5fdbb428..f8a2bdd3fee73 100644 --- a/libcxx/test/std/containers/unord/unord.multimap/unord.multimap.modifiers/erase_range.pass.cpp +++ b/libcxx/test/std/containers/unord/unord.multimap/unord.multimap.modifiers/erase_range.pass.cpp @@ -91,20 +91,6 @@ int main(int, char**) { assert(c.size() == 0); assert(k == c.end()); } - { // Make sure we're properly destroying the elements when erasing - { // When erasing part of a bucket - std::unordered_multimap map; - map.insert(std::make_pair(1, "This is a long string to make sure ASan can detect a memory leak")); - map.insert(std::make_pair(1, "This is another long string to make sure ASan can detect a memory leak")); - map.erase(++map.begin(), map.end()); - } - { // When erasing the whole bucket - std::unordered_multimap map; - map.insert(std::make_pair(1, "This is a long string to make sure ASan can detect a memory leak")); - map.insert(std::make_pair(1, "This is another long string to make sure ASan can detect a memory leak")); - map.erase(map.begin(), map.end()); - } - } #if TEST_STD_VER >= 11 { typedef std::unordered_multimap