mirror of
https://github.com/darlinghq/darling-libcxx.git
synced 2024-11-23 11:59:52 +00:00
Refactor deque to centralize handling of spare blocks.
I have upcoming changes that modify how deque handles spare blocks. This cleanup is intended to make those changes easier to review and understand. This patch should have NFC. git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@367631 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Eric Fiselier
parent
590e3405ea
commit
f033db1b64
@ -934,7 +934,7 @@ public:
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typedef _Allocator allocator_type;
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typedef allocator_traits<allocator_type> __alloc_traits;
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typedef typename __alloc_traits::size_type size_type;
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protected:
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typedef _Tp value_type;
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typedef value_type& reference;
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typedef const value_type& const_reference;
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@ -1399,7 +1399,7 @@ public:
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_LIBCPP_INLINE_VISIBILITY
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bool __invariants() const {return __base::__invariants();}
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private:
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typedef typename __base::__map_const_pointer __map_const_pointer;
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_LIBCPP_INLINE_VISIBILITY
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@ -1412,16 +1412,54 @@ private:
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{
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return __base::__map_.size() == 0 ? 0 : __base::__map_.size() * __base::__block_size - 1;
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}
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_LIBCPP_INLINE_VISIBILITY
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size_type __block_count() const
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{
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return __base::__map_.size();
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}
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_LIBCPP_INLINE_VISIBILITY
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size_type __front_spare() const
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{
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return __base::__start_;
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}
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_LIBCPP_INLINE_VISIBILITY
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size_type __front_spare_blocks() const {
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return __front_spare() / __base::__block_size;
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}
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_LIBCPP_INLINE_VISIBILITY
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size_type __back_spare() const
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{
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return __capacity() - (__base::__start_ + __base::size());
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}
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_LIBCPP_INLINE_VISIBILITY
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size_type __back_spare_blocks() const {
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return __back_spare() / __base::__block_size;
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}
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private:
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_LIBCPP_INLINE_VISIBILITY
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bool __maybe_remove_front_spare(bool __keep_one = true) {
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if (__front_spare_blocks() >= 2 || (!__keep_one && __front_spare_blocks())) {
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__alloc_traits::deallocate(__base::__alloc(), __base::__map_.front(),
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__base::__block_size);
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__base::__map_.pop_front();
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__base::__start_ -= __base::__block_size;
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return true;
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}
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return false;
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}
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_LIBCPP_INLINE_VISIBILITY
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bool __maybe_remove_back_spare(bool __keep_one = true) {
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if (__back_spare_blocks() >= 2 || (!__keep_one && __back_spare_blocks())) {
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__alloc_traits::deallocate(__base::__alloc(), __base::__map_.back(),
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__base::__block_size);
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__base::__map_.pop_back();
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return true;
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}
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return false;
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}
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template <class _InpIter>
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void __append(_InpIter __f, _InpIter __l,
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@ -1727,17 +1765,8 @@ deque<_Tp, _Allocator>::shrink_to_fit() _NOEXCEPT
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}
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else
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{
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if (__front_spare() >= __base::__block_size)
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{
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__alloc_traits::deallocate(__a, __base::__map_.front(), __base::__block_size);
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__base::__map_.pop_front();
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__base::__start_ -= __base::__block_size;
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}
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if (__back_spare() >= __base::__block_size)
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{
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__alloc_traits::deallocate(__a, __base::__map_.back(), __base::__block_size);
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__base::__map_.pop_back();
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}
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__maybe_remove_front_spare(/*__keep_one=*/false);
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__maybe_remove_back_spare(/*__keep_one=*/false);
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}
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__base::__map_.shrink_to_fit();
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}
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@ -2596,12 +2625,8 @@ deque<_Tp, _Allocator>::pop_front()
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__base::__start_ / __base::__block_size) +
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__base::__start_ % __base::__block_size));
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--__base::size();
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if (++__base::__start_ >= 2 * __base::__block_size)
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{
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__alloc_traits::deallocate(__a, __base::__map_.front(), __base::__block_size);
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__base::__map_.pop_front();
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__base::__start_ -= __base::__block_size;
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}
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++__base::__start_;
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__maybe_remove_front_spare();
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}
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template <class _Tp, class _Allocator>
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@ -2615,11 +2640,7 @@ deque<_Tp, _Allocator>::pop_back()
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__p / __base::__block_size) +
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__p % __base::__block_size));
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--__base::size();
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if (__back_spare() >= 2 * __base::__block_size)
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{
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__alloc_traits::deallocate(__a, __base::__map_.back(), __base::__block_size);
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__base::__map_.pop_back();
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}
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__maybe_remove_back_spare();
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}
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// move assign [__f, __l) to [__r, __r + (__l-__f)).
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@ -2768,23 +2789,14 @@ deque<_Tp, _Allocator>::erase(const_iterator __f)
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__alloc_traits::destroy(__a, _VSTD::addressof(*__b));
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--__base::size();
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++__base::__start_;
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if (__front_spare() >= 2 * __base::__block_size)
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{
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__alloc_traits::deallocate(__a, __base::__map_.front(), __base::__block_size);
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__base::__map_.pop_front();
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__base::__start_ -= __base::__block_size;
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}
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__maybe_remove_front_spare();
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}
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else
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{ // erase from back
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iterator __i = _VSTD::move(_VSTD::next(__p), __base::end(), __p);
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__alloc_traits::destroy(__a, _VSTD::addressof(*__i));
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--__base::size();
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if (__back_spare() >= 2 * __base::__block_size)
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{
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__alloc_traits::deallocate(__a, __base::__map_.back(), __base::__block_size);
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__base::__map_.pop_back();
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}
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__maybe_remove_back_spare();
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}
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return __base::begin() + __pos;
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}
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@ -2807,11 +2819,7 @@ deque<_Tp, _Allocator>::erase(const_iterator __f, const_iterator __l)
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__alloc_traits::destroy(__a, _VSTD::addressof(*__b));
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__base::size() -= __n;
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__base::__start_ += __n;
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while (__front_spare() >= 2 * __base::__block_size)
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{
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__alloc_traits::deallocate(__a, __base::__map_.front(), __base::__block_size);
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__base::__map_.pop_front();
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__base::__start_ -= __base::__block_size;
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while (__maybe_remove_front_spare()) {
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}
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}
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else
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@ -2820,10 +2828,7 @@ deque<_Tp, _Allocator>::erase(const_iterator __f, const_iterator __l)
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for (iterator __e = __base::end(); __i != __e; ++__i)
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__alloc_traits::destroy(__a, _VSTD::addressof(*__i));
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__base::size() -= __n;
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while (__back_spare() >= 2 * __base::__block_size)
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{
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__alloc_traits::deallocate(__a, __base::__map_.back(), __base::__block_size);
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__base::__map_.pop_back();
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while (__maybe_remove_back_spare()) {
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}
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}
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}
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@ -2844,10 +2849,7 @@ deque<_Tp, _Allocator>::__erase_to_end(const_iterator __f)
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for (iterator __p = __b + __pos; __p != __e; ++__p)
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__alloc_traits::destroy(__a, _VSTD::addressof(*__p));
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__base::size() -= __n;
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while (__back_spare() >= 2 * __base::__block_size)
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{
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__alloc_traits::deallocate(__a, __base::__map_.back(), __base::__block_size);
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__base::__map_.pop_back();
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while (__maybe_remove_back_spare()) {
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}
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}
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}
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@ -0,0 +1,284 @@
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//===----------------------------------------------------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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// UNSUPPORTED: c++98, c++03
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// <deque>
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// Test how deque manages the spare blocks it keeps. The exact values it tests
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// for are not always important, but are sometimes needed to ensure the container
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// resizes or shrinks at the correct time.
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#include <deque>
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#include <iostream>
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#include <memory>
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#include <stack>
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#include <queue>
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#include "min_allocator.h"
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#include "rapid-cxx-test.hpp"
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template <class Adaptor>
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struct ContainerAdaptor : public Adaptor {
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using Adaptor::Adaptor;
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typename Adaptor::container_type& GetContainer() { return Adaptor::c; }
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};
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template <class Deque>
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static void print(const Deque& d) {
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std::cout << d.size()
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<< " : __front_spare() == " << d.__front_spare()
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<< " : __back_spare() == " << d.__back_spare()
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<< " : __capacity() == " << d.__capacity()
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<< " : bytes allocated == "
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<< malloc_allocator_base::outstanding_bytes << '\n';
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}
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template <class T>
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using Deque = std::deque<T, malloc_allocator<T> >;
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template <class T>
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using BlockSize = std::__deque_block_size<T, std::ptrdiff_t>;
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struct LargeT {
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LargeT() = default;
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char buff[256] = {};
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};
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static_assert(BlockSize<LargeT>::value == 16, "");
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const auto& AllocBytes = malloc_allocator_base::outstanding_bytes;
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template <class DT>
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struct PrintOnFailure {
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explicit PrintOnFailure(DT const& d) : d(&d) {}
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~PrintOnFailure() {
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if (::rapid_cxx_test::get_reporter().current_failure().type
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!= ::rapid_cxx_test::failure_type::none) {
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print(*d);
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}
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}
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private:
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const DT* d;
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PrintOnFailure(PrintOnFailure const&) = delete;
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};
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TEST_SUITE(deque_spare_tests)
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TEST_CASE(push_back) {
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const auto BS = BlockSize<LargeT>::value;
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std::unique_ptr<Deque<LargeT>> dp(new Deque<LargeT>);
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auto& d = *dp;
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PrintOnFailure<Deque<LargeT>> on_fail(d);
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// Test nothing is allocated after default construction.
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{
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TEST_REQUIRE(d.size() == 0);
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TEST_REQUIRE(d.__capacity() == 0);
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TEST_REQUIRE(d.__block_count() == 0);
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}
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// First push back allocates one block.
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d.push_back({});
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{
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TEST_REQUIRE(d.size() == 1);
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TEST_REQUIRE(d.__front_spare() == 0);
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TEST_REQUIRE(d.__back_spare() == 14);
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TEST_REQUIRE(d.__back_spare_blocks() == 0);
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TEST_REQUIRE(d.__capacity() == BS - 1);
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TEST_REQUIRE(d.__block_count() == 1);
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}
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d.push_back({});
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{
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TEST_REQUIRE(d.size() == 2);
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TEST_REQUIRE(d.__front_spare() == 0);
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TEST_REQUIRE(d.__back_spare() == 13);
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TEST_REQUIRE(d.__back_spare_blocks() == 0);
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}
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// Push back until we need a new block.
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for (int RemainingCap = d.__capacity() - d.size(); RemainingCap >= 0; --RemainingCap)
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d.push_back({});
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{
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TEST_REQUIRE(d.__block_count() == 2);
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TEST_REQUIRE(d.__front_spare_blocks() == 0);
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TEST_REQUIRE(d.__back_spare_blocks() == 0);
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TEST_REQUIRE(d.__back_spare() == 15);
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}
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// Remove the only element in the new block. Test that we keep the empty
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// block as a spare.
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d.pop_back();
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{
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TEST_REQUIRE(d.__block_count() == 2);
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TEST_REQUIRE(d.__front_spare_blocks() == 0);
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TEST_REQUIRE(d.__back_spare_blocks() == 1);
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TEST_REQUIRE(d.__back_spare() == 16);
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}
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// Pop back again, keep the spare.
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d.pop_back();
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{
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TEST_REQUIRE(d.__block_count() == 2);
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TEST_REQUIRE(d.__front_spare() == 0);
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TEST_REQUIRE(d.__back_spare() == 17);
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TEST_REQUIRE(d.__back_spare_blocks() == 1);
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}
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dp.reset();
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TEST_REQUIRE(AllocBytes == 0);
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}
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TEST_CASE(push_front) {
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std::unique_ptr<Deque<LargeT>> dp(new Deque<LargeT>);
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auto& d = *dp;
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PrintOnFailure<Deque<LargeT>> on_fail(d);
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// Test nothing is allocated after default construction.
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{
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TEST_REQUIRE(d.size() == 0);
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TEST_REQUIRE(d.__capacity() == 0);
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TEST_REQUIRE(d.__block_count() == 0);
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}
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// First push front allocates one block, and we start the sequence in the
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// middle.
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d.push_front({});
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{
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TEST_REQUIRE(d.size() == 1);
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TEST_REQUIRE(d.__front_spare() == 7);
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TEST_REQUIRE(d.__back_spare() == 7);
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TEST_REQUIRE(d.__front_spare_blocks() == 0);
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TEST_REQUIRE(d.__back_spare_blocks() == 0);
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TEST_REQUIRE(d.__block_count() == 1);
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}
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d.push_front({});
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{
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TEST_REQUIRE(d.size() == 2);
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TEST_REQUIRE(d.__front_spare() == 6);
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TEST_REQUIRE(d.__back_spare() == 7);
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TEST_REQUIRE(d.__front_spare_blocks() == 0);
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TEST_REQUIRE(d.__back_spare_blocks() == 0);
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}
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// Push front until we need a new block.
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for (int RemainingCap = d.__front_spare(); RemainingCap >= 0; --RemainingCap)
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d.push_front({});
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{
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TEST_REQUIRE(d.__block_count() == 2);
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TEST_REQUIRE(d.__front_spare() == 15);
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TEST_REQUIRE(d.__back_spare() == 7);
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TEST_REQUIRE(d.__front_spare_blocks() == 0);
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TEST_REQUIRE(d.__back_spare_blocks() == 0);
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}
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// Remove the only element in the new block. Test that we keep the empty
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// block as a spare.
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d.pop_front();
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{
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TEST_REQUIRE(d.__block_count() == 2);
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TEST_REQUIRE(d.__front_spare_blocks() == 1);
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TEST_REQUIRE(d.__back_spare_blocks() == 0);
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TEST_REQUIRE(d.__back_spare() == 7);
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}
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// Pop back again, keep the spare.
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d.pop_front();
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{
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TEST_REQUIRE(d.__block_count() == 2);
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TEST_REQUIRE(d.__front_spare_blocks() == 1);
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TEST_REQUIRE(d.__back_spare() == 7);
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}
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dp.reset();
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TEST_REQUIRE(AllocBytes == 0);
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}
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TEST_CASE(std_queue) {
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using D = Deque<LargeT>;
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using Queue = std::queue<LargeT, D>;
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ContainerAdaptor<Queue> CA;
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const D& d = CA.GetContainer();
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Queue &q = CA;
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PrintOnFailure<Deque<LargeT>> on_fail(d);
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while (d.__block_count() < 4)
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q.push({});
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{
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TEST_REQUIRE(d.__block_count() == 4);
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TEST_REQUIRE(d.__front_spare() == 0);
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TEST_REQUIRE(d.__back_spare() == 15);
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TEST_REQUIRE(d.__back_spare_blocks() == 0);
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}
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while (d.__back_spare()) {
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q.push({});
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}
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{
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TEST_REQUIRE(d.__block_count() == 4);
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TEST_REQUIRE(d.__front_spare() == 0);
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TEST_REQUIRE(d.__back_spare() == 0);
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}
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q.pop();
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{
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TEST_REQUIRE(d.__block_count() == 4);
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TEST_REQUIRE(d.__front_spare() == 1);
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TEST_REQUIRE(d.__back_spare() == 0);
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}
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// Pop until we create a spare block at the front.
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while (d.__front_spare() <= 15)
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q.pop();
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{
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TEST_REQUIRE(d.__block_count() == 4);
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TEST_REQUIRE(d.__front_spare_blocks() == 1);
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TEST_REQUIRE(d.__front_spare() == 16);
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TEST_REQUIRE(d.__back_spare() == 0);
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}
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// Push at the end -- should re-use new spare block at front
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q.push({});
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{
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TEST_REQUIRE(d.__block_count() == 4);
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TEST_REQUIRE(d.__front_spare_blocks() == 0);
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TEST_REQUIRE(d.__front_spare() == 0);
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TEST_REQUIRE(d.__back_spare() == 15);
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}
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while (!q.empty()) {
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q.pop();
|
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TEST_REQUIRE(d.__front_spare_blocks() + d.__back_spare_blocks() <= 2);
|
||||
}
|
||||
|
||||
// The empty state has two blocks
|
||||
{
|
||||
TEST_REQUIRE(d.__front_spare() == 16);
|
||||
TEST_REQUIRE(d.__back_spare() == 15);
|
||||
TEST_REQUIRE(d.__capacity() == 31);
|
||||
}
|
||||
}
|
||||
|
||||
TEST_CASE(pop_front_push_back) {
|
||||
Deque<char> d(32 * 1024, 'a');
|
||||
bool take_from_front = true;
|
||||
while (d.size() > 0) {
|
||||
if (take_from_front) {
|
||||
d.pop_front();
|
||||
take_from_front = false;
|
||||
} else {
|
||||
d.pop_back();
|
||||
take_from_front = true;
|
||||
}
|
||||
if (d.size() % 1000 == 0 || d.size() < 50) {
|
||||
print(d);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
TEST_SUITE_END()
|
||||
|
||||
|
||||
Loading…
Reference in New Issue
Block a user