/*
- * Copyright 2016 Facebook, Inc.
+ * Copyright 2017 Facebook, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
#include <limits>
#include <memory>
#include <type_traits>
+
#include <boost/iterator/iterator_facade.hpp>
#include <glog/logging.h>
namespace folly {
-template<typename T,
- typename Comp = std::less<T>,
- // All nodes are allocated using provided SimpleAllocator,
- // it should be thread-safe.
- typename NodeAlloc = SysAlloc,
- int MAX_HEIGHT = 24>
+template <
+ typename T,
+ typename Comp = std::less<T>,
+ // All nodes are allocated using provided SimpleAllocator,
+ // it should be thread-safe.
+ typename NodeAlloc = SysAlloc,
+ int MAX_HEIGHT = 24>
class ConcurrentSkipList {
// MAX_HEIGHT needs to be at least 2 to suppress compiler
// warnings/errors (Werror=uninitialized tiggered due to preds_[1]
//===================================================================
~ConcurrentSkipList() {
- /* static */ if (NodeType::template destroyIsNoOp<NodeAlloc>()) {
+ /* static */ if (NodeType::template DestroyIsNoOp<NodeAlloc>::value) {
// Avoid traversing the list if using arena allocator.
return;
}
// if found, succs[0..foundLayer] need to point to the cached foundNode,
// as foundNode might be deleted at the same time thus pred->skip() can
- // return NULL or another node.
+ // return nullptr or another node.
succs[layer] = foundNode ? foundNode : node;
}
return foundLayer;
// Returns the node if found, nullptr otherwise.
NodeType* find(const value_type &data) {
auto ret = findNode(data);
- if (ret.second && !ret.first->markedForRemoval()) return ret.first;
+ if (ret.second && !ret.first->markedForRemoval()) {
+ return ret.first;
+ }
return nullptr;
}
// list with the same key.
// pair.second stores whether the data is added successfully:
// 0 means not added, otherwise reutrns the new size.
- template<typename U>
+ template <typename U>
std::pair<NodeType*, size_t> addOrGetData(U &&data) {
NodeType *preds[MAX_HEIGHT], *succs[MAX_HEIGHT];
NodeType *newNode;
nodeToDelete = succs[layer];
nodeHeight = nodeToDelete->height();
nodeGuard = nodeToDelete->acquireGuard();
- if (nodeToDelete->markedForRemoval()) return false;
+ if (nodeToDelete->markedForRemoval()) {
+ return false;
+ }
nodeToDelete->setMarkedForRemoval();
isMarked = true;
}
for (int layer = maxLayer(); layer >= 0; --layer) {
do {
node = pred->skip(layer);
- if (node) pred = node;
+ if (node) {
+ pred = node;
+ }
} while (node != nullptr);
}
return pred == head_.load(std::memory_order_relaxed)
while (!found) {
// stepping down
for (; ht > 0 && less(data, node = pred->skip(ht - 1)); --ht) {}
- if (ht == 0) return std::make_pair(node, 0); // not found
+ if (ht == 0) {
+ return std::make_pair(node, 0); // not found
+ }
// node <= data now, but we need to fix up ht
--ht;
std::atomic<size_t> size_;
};
-template<typename T, typename Comp, typename NodeAlloc, int MAX_HEIGHT>
+template <typename T, typename Comp, typename NodeAlloc, int MAX_HEIGHT>
class ConcurrentSkipList<T, Comp, NodeAlloc, MAX_HEIGHT>::Accessor {
typedef detail::SkipListNode<T> NodeType;
typedef ConcurrentSkipList<T, Comp, NodeAlloc, MAX_HEIGHT> SkipListType;
const_iterator cbegin() const { return begin(); }
const_iterator cend() const { return end(); }
- template<typename U,
- typename=typename std::enable_if<std::is_convertible<U, T>::value>::type>
+ template <
+ typename U,
+ typename =
+ typename std::enable_if<std::is_convertible<U, T>::value>::type>
std::pair<iterator, bool> insert(U&& data) {
auto ret = sl_->addOrGetData(std::forward<U>(data));
return std::make_pair(iterator(ret.first), ret.second);
};
// implements forward iterator concept.
-template<typename ValT, typename NodeT>
+template <typename ValT, typename NodeT>
class detail::csl_iterator :
public boost::iterator_facade<csl_iterator<ValT, NodeT>,
ValT, boost::forward_traversal_tag> {
explicit csl_iterator(NodeT* node = nullptr) : node_(node) {}
- template<typename OtherVal, typename OtherNode>
- csl_iterator(const csl_iterator<OtherVal, OtherNode> &other,
- typename std::enable_if<std::is_convertible<OtherVal, ValT>::value>::type*
- = 0) : node_(other.node_) {}
+ template <typename OtherVal, typename OtherNode>
+ csl_iterator(
+ const csl_iterator<OtherVal, OtherNode>& other,
+ typename std::enable_if<
+ std::is_convertible<OtherVal, ValT>::value>::type* = nullptr)
+ : node_(other.node_) {}
size_t nodeSize() const {
return node_ == nullptr ? 0 :
private:
friend class boost::iterator_core_access;
- template<class,class> friend class csl_iterator;
+ template <class, class> friend class csl_iterator;
- void increment() { node_ = node_->next(); };
+ void increment() { node_ = node_->next(); }
bool equal(const csl_iterator& other) const { return node_ == other.node_; }
value_type& dereference() const { return node_->data(); }
};
// Skipper interface
-template<typename T, typename Comp, typename NodeAlloc, int MAX_HEIGHT>
+template <typename T, typename Comp, typename NodeAlloc, int MAX_HEIGHT>
class ConcurrentSkipList<T, Comp, NodeAlloc, MAX_HEIGHT>::Skipper {
typedef detail::SkipListNode<T> NodeType;
typedef ConcurrentSkipList<T, Comp, NodeAlloc, MAX_HEIGHT> SkipListType;
}
int max_layer = maxLayer();
for (int i = 0; i < max_layer; ++i) {
- hints_[i] = i + 1;
+ hints_[i] = uint8_t(i + 1);
}
hints_[max_layer] = max_layer;
}
*/
bool to(const value_type &data) {
int layer = curHeight() - 1;
- if (layer < 0) return false; // reaches the end of the list
+ if (layer < 0) {
+ return false; // reaches the end of the list
+ }
int lyr = hints_[layer];
int max_layer = maxLayer();
int foundLayer = SkipListType::
findInsertionPoint(preds_[lyr], lyr, data, preds_, succs_);
- if (foundLayer < 0) return false;
+ if (foundLayer < 0) {
+ return false;
+ }
DCHECK(succs_[0] != nullptr) << "lyr=" << lyr
<< "; max_layer=" << max_layer;