43 lines
1.3 KiB
C++
43 lines
1.3 KiB
C++
//===-- Implementation for freelist ---------------------------------------===//
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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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#include "freelist.h"
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namespace LIBC_NAMESPACE_DECL {
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void FreeList::push(Node *node) {
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if (begin_) {
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LIBC_ASSERT(Block::from_usable_space(node)->outer_size() ==
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begin_->block()->outer_size() &&
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"freelist entries must have the same size");
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// Since the list is circular, insert the node immediately before begin_.
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node->prev = begin_->prev;
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node->next = begin_;
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begin_->prev->next = node;
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begin_->prev = node;
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} else {
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begin_ = node->prev = node->next = node;
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}
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}
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void FreeList::remove(Node *node) {
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LIBC_ASSERT(begin_ && "cannot remove from empty list");
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if (node == node->next) {
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LIBC_ASSERT(node == begin_ &&
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"a self-referential node must be the only element");
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begin_ = nullptr;
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} else {
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node->prev->next = node->next;
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node->next->prev = node->prev;
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if (begin_ == node)
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begin_ = node->next;
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}
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}
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} // namespace LIBC_NAMESPACE_DECL
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