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//===-- sanitizer_list.h ----------------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file contains implementation of a list class to be used by
// ThreadSanitizer, etc run-times.
//
//===----------------------------------------------------------------------===//
#ifndef SANITIZER_LIST_H
#define SANITIZER_LIST_H
#include "sanitizer_internal_defs.h"
namespace __sanitizer {
// Intrusive singly-linked list with size(), push_back(), push_front()
// pop_front(), append_front() and append_back().
// This class should be a POD (so that it can be put into TLS)
// and an object with all zero fields should represent a valid empty list.
// This class does not have a CTOR, so clear() should be called on all
// non-zero-initialized objects before using.
template<class Item>
struct IntrusiveList {
friend class Iterator;
void clear() {
first_ = last_ = nullptr;
size_ = 0;
}
bool empty() const { return size_ == 0; }
uptr size() const { return size_; }
void push_back(Item *x) {
if (empty()) {
x->next = nullptr;
first_ = last_ = x;
size_ = 1;
} else {
x->next = nullptr;
last_->next = x;
last_ = x;
size_++;
}
}
void push_front(Item *x) {
if (empty()) {
x->next = nullptr;
first_ = last_ = x;
size_ = 1;
} else {
x->next = first_;
first_ = x;
size_++;
}
}
void pop_front() {
CHECK(!empty());
first_ = first_->next;
if (!first_)
last_ = nullptr;
size_--;
}
void extract(Item *prev, Item *x) {
CHECK(!empty());
CHECK_NE(prev, nullptr);
CHECK_NE(x, nullptr);
CHECK_EQ(prev->next, x);
prev->next = x->next;
if (last_ == x)
last_ = prev;
size_--;
}
Item *front() { return first_; }
const Item *front() const { return first_; }
Item *back() { return last_; }
const Item *back() const { return last_; }
void append_front(IntrusiveList<Item> *l) {
CHECK_NE(this, l);
if (l->empty())
return;
if (empty()) {
*this = *l;
} else if (!l->empty()) {
l->last_->next = first_;
first_ = l->first_;
size_ += l->size();
}
l->clear();
}
void append_back(IntrusiveList<Item> *l) {
CHECK_NE(this, l);
if (l->empty())
return;
if (empty()) {
*this = *l;
} else {
last_->next = l->first_;
last_ = l->last_;
size_ += l->size();
}
l->clear();
}
void CheckConsistency() {
if (size_ == 0) {
CHECK_EQ(first_, 0);
CHECK_EQ(last_, 0);
} else {
uptr count = 0;
for (Item *i = first_; ; i = i->next) {
count++;
if (i == last_) break;
}
CHECK_EQ(size(), count);
CHECK_EQ(last_->next, 0);
}
}
template<class ItemTy>
class IteratorBase {
public:
explicit IteratorBase(ItemTy *current) : current_(current) {}
IteratorBase &operator++() {
current_ = current_->next;
return *this;
}
bool operator!=(IteratorBase other) const {
return current_ != other.current_;
}
ItemTy &operator*() {
return *current_;
}
private:
ItemTy *current_;
};
typedef IteratorBase<Item> Iterator;
typedef IteratorBase<const Item> ConstIterator;
Iterator begin() { return Iterator(first_); }
Iterator end() { return Iterator(0); }
ConstIterator begin() const { return ConstIterator(first_); }
ConstIterator end() const { return ConstIterator(0); }
// private, don't use directly.
uptr size_;
Item *first_;
Item *last_;
};
} // namespace __sanitizer
#endif // SANITIZER_LIST_H