diff --git a/linearizability_tester/src/linearizability_tester.h b/linearizability_tester/src/linearizability_tester.h index 0323661..b34ae55 100755 --- a/linearizability_tester/src/linearizability_tester.h +++ b/linearizability_tester/src/linearizability_tester.h @@ -70,7 +70,7 @@ template std::unique_ptr make_unique(Args&& ...args) { - return std::unique_ptr(new T(std::forward(args)...)); + return std::unique_ptr(new T(std::forward(args)...)); } #else using std::make_unique; @@ -81,1917 +81,1917 @@ using std::make_unique; /// Linearizability tester namespace lt { - /************* Core data structures && algorithms *************/ - - template - class Entry; - - /// Doubly-linked list of log entries - - /// S - sequential data type - template - using EntryPtr = Entry*; - - /// Bounded stack of call entries that have been linearized - /// S - sequential data type - template - class Stack - { - private: - typedef std::tuple, S> Pair; - typedef std::vector Pairs; - typedef typename Pairs::size_type SizeType; - - // A constant-size vector - Pairs m_vector; - SizeType m_top; - - public: - /// Create a new stack of bounded height - - /// \post: if capacity is positive, then !is_full() - Stack(SizeType capacity) - : m_vector(capacity), m_top{ 0U } - { - assert(capacity == 0U || !is_full()); - } - - /// History length in the stack - SizeType size() const noexcept - { - return m_top; - } - - /// Is size() zero? - bool is_empty() const noexcept - { - return 0U == size(); - } - - /// Is size() equal to the stack's capacity? - bool is_full() const noexcept - { - return m_top == m_vector.size(); - } - - /// \pre: !is_empty() - const Pair& top() const noexcept - { - assert(!is_empty()); - return m_vector[m_top - 1U]; - } - - /// Add an entry to the top() of the stack - - /// \pre: !is_full() - /// \pre: ptr->is_call() - void push(EntryPtr, S&&); - - /// Remove count entries from the stack - - /// \pre: 0 < count <= size() - void pop(unsigned count = 1U) - { - assert(0U < count); - assert(count <= size()); - - m_top -= count; - } - - /// \internal - EntryPtr entry_ptr(std::size_t pos) - { - assert(pos < m_top); - return std::get<0>(m_vector[pos]); - } - }; - - enum class Option : unsigned char - { - NEVER_CACHE, - LRU_CACHE, - ALWAYS_CACHE, - }; - - template class Entry; - template class Log; - template class ConcurrentLog; - template class Slicer; - template class LinearizabilityTester; - - /// A kind of "functor" in C++ terminology - - /// S - sequential data type - template - class Op - { - private: - friend class Entry; - - // Is m_partition defined? - bool m_is_partitionable; - unsigned m_partition; - - // modified by Entry - unsigned ref_counter; +/************* Core data structures && algorithms *************/ + +template +class Entry; + +/// Doubly-linked list of log entries + +/// S - sequential data type +template +using EntryPtr = Entry*; + +/// Bounded stack of call entries that have been linearized +/// S - sequential data type +template +class Stack +{ + private: + typedef std::tuple, S> Pair; + typedef std::vector Pairs; + typedef typename Pairs::size_type SizeType; + + // A constant-size vector + Pairs m_vector; + SizeType m_top; + + public: + /// Create a new stack of bounded height + + /// \post: if capacity is positive, then !is_full() + Stack(SizeType capacity) + : m_vector(capacity), m_top{ 0U } + { + assert(capacity == 0U || !is_full()); + } + + /// History length in the stack + SizeType size() const noexcept + { + return m_top; + } + + /// Is size() zero? + bool is_empty() const noexcept + { + return 0U == size(); + } + + /// Is size() equal to the stack's capacity? + bool is_full() const noexcept + { + return m_top == m_vector.size(); + } + + /// \pre: !is_empty() + const Pair& top() const noexcept + { + assert(!is_empty()); + return m_vector[m_top - 1U]; + } + + /// Add an entry to the top() of the stack + + /// \pre: !is_full() + /// \pre: ptr->is_call() + void push(EntryPtr, S&&); + + /// Remove count entries from the stack + + /// \pre: 0 < count <= size() + void pop(unsigned count = 1U) + { + assert(0U < count); + assert(count <= size()); + + m_top -= count; + } + + /// \internal + EntryPtr entry_ptr(std::size_t pos) + { + assert(pos < m_top); + return std::get<0>(m_vector[pos]); + } +}; + +enum class Option : unsigned char +{ + NEVER_CACHE, + LRU_CACHE, + ALWAYS_CACHE, +}; + +template class Entry; +template class Log; +template class ConcurrentLog; +template class Slicer; +template class LinearizabilityTester; + +/// A kind of "functor" in C++ terminology + +/// S - sequential data type +template +class Op +{ + private: + friend class Entry; + + // Is m_partition defined? + bool m_is_partitionable; + unsigned m_partition; + + // modified by Entry + unsigned ref_counter; #ifdef _LT_DEBUG_ - virtual std::ostream& print(std::ostream&) const = 0; + virtual std::ostream& print(std::ostream&) const = 0; #endif - virtual std::pair internal_apply(const S&, const Op&) - { - return{}; - } - - public: - Op() - : m_is_partitionable{ false }, - m_partition{ 0U }, - ref_counter{ 0U } {} - - Op(unsigned partition) - : m_is_partitionable{ true }, - m_partition{ partition }, - ref_counter{ 0U } {} - - Op(bool is_partitionable, unsigned partition) - : m_is_partitionable{ is_partitionable }, - m_partition{ partition }, - ref_counter{ 0U } {} - - virtual ~Op() - { - assert(ref_counter == 0); - } - - /// Is partition() defined? - bool is_partitionable() const noexcept - { - return m_is_partitionable; - } - - /// \pre: is_partitionable() - unsigned partition() const - { - assert(m_is_partitionable); - return m_partition; - } - - /// Returns true exactly if the operation could be applied - std::pair apply(const S& s, const Op& op) - { - return internal_apply(s, op); - } + virtual std::pair internal_apply(const S&, const Op&) + { + return{}; + } + + public: + Op() + : m_is_partitionable{ false }, + m_partition{ 0U }, + ref_counter{ 0U } {} + + Op(unsigned partition) + : m_is_partitionable{ true }, + m_partition{ partition }, + ref_counter{ 0U } {} + + Op(bool is_partitionable, unsigned partition) + : m_is_partitionable{ is_partitionable }, + m_partition{ partition }, + ref_counter{ 0U } {} + + virtual ~Op() + { + assert(ref_counter == 0); + } + + /// Is partition() defined? + bool is_partitionable() const noexcept + { + return m_is_partitionable; + } + + /// \pre: is_partitionable() + unsigned partition() const + { + assert(m_is_partitionable); + return m_partition; + } + + /// Returns true exactly if the operation could be applied + std::pair apply(const S& s, const Op& op) + { + return internal_apply(s, op); + } #ifdef _LT_DEBUG_ - friend std::ostream& operator<<(std::ostream& os, const Op& op) - { - return op.print(os); - } + friend std::ostream& operator<<(std::ostream& os, const Op& op) + { + return op.print(os); + } #endif - }; - - /// Fixed-size set of bits with persistence features - class Bitset - { - public: - typedef std::size_t Pos; - - private: - friend struct BitsetHash; - friend class FlexibleBitset; - - typedef unsigned long Block; - typedef std::vector Blocks; - typedef Blocks::size_type BlockIndex; - - /// Accessible bits in a Block - typedef unsigned BlockWidth; - - static constexpr BlockWidth s_bits_per_block = - static_cast(sizeof(Block) * CHAR_BIT); - - static BlockIndex block_index(Pos pos) noexcept - { - return pos / s_bits_per_block; - } - - static BlockIndex blocks_size(Pos max_pos) noexcept - { - return block_index(max_pos) + 1U; - } - - static BlockWidth bit_index(Pos pos) noexcept - { - return static_cast(pos % s_bits_per_block); - } - - static Block bit_mask(Pos pos) noexcept - { - return Block(1U) << bit_index(pos); - } - - /// only resized by FlexibleBitset - Blocks m_blocks; - - std::size_t m_hash; - unsigned m_number_of_set_bits; - - Block& find_block(Pos pos) - { - BlockIndex i{ block_index(pos) }; - assert(i < m_blocks.size()); - return m_blocks[i]; - } - - // We exploit the fact that XOR forms an abelian group: - // first, clear hash of old block; then, hash new block. - void update_hash(Block old_block, Block new_block) - { - m_hash ^= old_block; - m_hash ^= new_block; - } - - public: - Bitset(Pos max_pos) - : m_blocks(blocks_size(max_pos)), - m_hash{ 0U }, - m_number_of_set_bits{ 0U } {} - - bool is_empty() const noexcept - { - return m_number_of_set_bits == 0U; - } - - bool set(Pos pos) - { - Block& block = find_block(pos); - const Block copy_block{ block }; - block |= bit_mask(pos); - - update_hash(copy_block, block); - - bool ok{ block != copy_block }; - m_number_of_set_bits += ok; - return ok; - } - - Bitset immutable_set(Pos pos) const - { - Bitset copy{ *this }; - copy.set(pos); - return copy; - } - - bool is_set(Pos pos) const - { - BlockIndex i{ block_index(pos) }; - if (i < m_blocks.size()) - return (m_blocks[i] & bit_mask(pos)) != 0U; - - return false; - } - - bool reset(Pos pos) - { - Block& block = find_block(pos); - const Block copy_block{ block }; - block &= ~bit_mask(pos); - - update_hash(copy_block, block); - - bool ok{ block != copy_block }; - m_number_of_set_bits -= ok; - return ok; - } - - Bitset immutable_reset(Pos pos) const - { - Bitset copy{ *this }; - copy.reset(pos); - return copy; - } - - // Same number of blocks && identical bits in all those blocks? - bool operator==(const Bitset& other) const noexcept - { - return m_number_of_set_bits == other.m_number_of_set_bits && - m_blocks == other.m_blocks; - } - - bool operator!=(const Bitset& other) const noexcept - { - return m_number_of_set_bits != other.m_number_of_set_bits || - m_blocks != other.m_blocks; - } - }; - - /// Constant-time, O(1), hash function - struct BitsetHash - { - std::size_t operator()(const Bitset& bitset) const noexcept - { - return bitset.m_hash; - } - }; - - /// States of abstract data types - namespace state - { - template - struct Hash - { - std::size_t operator()(const T&) const noexcept; - }; - } - - template - using OpPtr = std::unique_ptr>; - - /// Call/ret log entry - - /// S - sequential data type - template - class Entry - { - private: - friend class Log; - friend class Slicer; - friend class LinearizabilityTester; - friend class LinearizabilityTester; - friend class LinearizabilityTester; - - // Ref counted pointer because we need to copy logs so that we - // can experimentally compare different linearizability testers - // - // However, this is an implementation detail and the strict type - // of OpPtr enforces at compile-time that we manage the - // ownership of these kind of pointers on the user's behalf. - Op* m_op_ptr; - unsigned m_entry_id; - std::thread::id m_thread_id; - EntryPtr m_match; - bool m_is_call; - - void inc_ref_counter() const noexcept - { - if (m_op_ptr != nullptr) - ++m_op_ptr->ref_counter; - } - - void dec_ref_counter() const - { - assert(m_op_ptr == nullptr || 0 < m_op_ptr->ref_counter); - - if (m_op_ptr != nullptr && --m_op_ptr->ref_counter == 0) - delete m_op_ptr; - } - - /// Log head - - /// \post: if _next is !nullptr, then _next->prev == this - Entry(EntryPtr _next) - : m_op_ptr{ nullptr }, - m_entry_id{}, - m_thread_id{}, - m_match{ nullptr }, - m_is_call{ false }, - prev{ nullptr }, - next{ _next } - { - if (_next != nullptr) - _next->prev = this; - } - - public: - ~Entry() - { - dec_ref_counter(); - } - - EntryPtr prev; - EntryPtr next; - - Entry() - : m_op_ptr{ nullptr }, - m_entry_id{}, - m_thread_id{}, - m_match{ nullptr }, - m_is_call{ false }, - prev{ nullptr }, - next{ nullptr } {} - - Entry(const Entry& entry) - : m_op_ptr{ entry.m_op_ptr }, - m_entry_id{ entry.m_entry_id }, - m_thread_id{ entry.m_thread_id }, - m_match{ entry.m_match }, - m_is_call{ entry.m_is_call }, - prev{ entry.prev }, - next{ entry.next } - { - inc_ref_counter(); - } - - Entry& operator=(const Entry& entry) - { - entry.inc_ref_counter(); - dec_ref_counter(); - - m_op_ptr = entry.m_op_ptr; - m_entry_id = entry.m_entry_id; - m_thread_id = entry.m_thread_id; - m_match = entry.m_match; - m_is_call = entry.m_is_call; - prev = entry.prev; - next = entry.next; - - return *this; - } - - Entry& operator=(Entry&& entry) - { - // only decrement required (due to move semantics) - dec_ref_counter(); - - m_op_ptr = entry.m_op_ptr; - m_entry_id = entry.m_entry_id; - m_thread_id = entry.m_thread_id; - m_match = entry.m_match; - m_is_call = entry.m_is_call; - prev = entry.prev; - next = entry.next; - - entry.m_op_ptr = nullptr; - entry.m_entry_id = 0; - entry.m_thread_id = 0; - entry.m_match = nullptr; - entry.m_is_call = false; - entry.prev = nullptr; - entry.next = nullptr; - - return *this; - } - - /// \pre: set_match && set_op have been called with non-null arguments - bool is_partitionable() const - { - assert(m_match != nullptr); - assert(m_match->m_op_ptr != nullptr); - assert(m_op_ptr->m_is_partitionable == m_match->m_op_ptr->m_is_partitionable); - assert(m_op_ptr->m_partition == m_match->m_op_ptr->m_partition); - - return m_op_ptr->m_is_partitionable; - } - - void set_op(OpPtr&& op_ptr) noexcept - { - m_op_ptr = op_ptr.release(); - inc_ref_counter(); - } - - Op& op() const - { - assert(m_op_ptr != nullptr); - return *m_op_ptr; - } - - const Op* const op_ptr() const noexcept - { - return m_op_ptr; - } - - void set_entry_id(unsigned entry_id) noexcept - { - m_entry_id = entry_id; - } - - unsigned entry_id() const noexcept - { - return m_entry_id; - } - - void set_thread_id(std::thread::id thread_id) noexcept - { - m_thread_id = thread_id; - } - - std::thread::id thread_id() const noexcept - { - return m_thread_id; - } - - /// \pre: ret_entry_ptr->match() == nullptr - /// \pre: !ret_entry_ptr->is_call() - /// - /// \post: this->is_call() - /// \post: this == ret_entry_ptr->match() - /// \post: this->match() == ret_entry_ptr - /// \post: this->entry_id() == ret_entry_ptr->entry_id() - /// \post: if this->is_partitionable() || ret_entry_ptr->is_partitionable(), - /// then this->op().partition() == ret_entry_ptr->op().partition() - void set_match(EntryPtr ret_entry_ptr) noexcept - { - assert(ret_entry_ptr->m_match == nullptr); - assert(!ret_entry_ptr->is_call()); - - ret_entry_ptr->m_match = this; - ret_entry_ptr->set_entry_id(m_entry_id); - - if (ret_entry_ptr->op().m_is_partitionable) - { - op().m_is_partitionable = ret_entry_ptr->op().m_is_partitionable; - op().m_partition = ret_entry_ptr->op().m_partition; - } - else - { - ret_entry_ptr->op().m_is_partitionable = op().m_is_partitionable; - ret_entry_ptr->op().m_partition = op().m_partition; - } - - m_match = ret_entry_ptr; - m_is_call = true; - - assert(is_call()); - assert(this == ret_entry_ptr->match()); - assert(match() == ret_entry_ptr); - assert(entry_id() == ret_entry_ptr->entry_id()); - assert(op().m_is_partitionable == ret_entry_ptr->op().m_is_partitionable); - assert(op().m_partition == ret_entry_ptr->op().m_partition); - } - - EntryPtr match() const noexcept - { - return m_match; - } - - bool is_call() const noexcept - { - return m_is_call; - } - }; +}; + +/// Fixed-size set of bits with persistence features +class Bitset +{ + public: + typedef std::size_t Pos; + + private: + friend struct BitsetHash; + friend class FlexibleBitset; + + typedef unsigned long Block; + typedef std::vector Blocks; + typedef Blocks::size_type BlockIndex; + + /// Accessible bits in a Block + typedef unsigned BlockWidth; + + static constexpr BlockWidth s_bits_per_block = + static_cast(sizeof(Block) * CHAR_BIT); + + static BlockIndex block_index(Pos pos) noexcept + { + return pos / s_bits_per_block; + } + + static BlockIndex blocks_size(Pos max_pos) noexcept + { + return block_index(max_pos) + 1U; + } + + static BlockWidth bit_index(Pos pos) noexcept + { + return static_cast(pos % s_bits_per_block); + } + + static Block bit_mask(Pos pos) noexcept + { + return Block(1U) << bit_index(pos); + } + + /// only resized by FlexibleBitset + Blocks m_blocks; + + std::size_t m_hash; + unsigned m_number_of_set_bits; + + Block& find_block(Pos pos) + { + BlockIndex i{ block_index(pos) }; + assert(i < m_blocks.size()); + return m_blocks[i]; + } + + // We exploit the fact that XOR forms an abelian group: + // first, clear hash of old block; then, hash new block. + void update_hash(Block old_block, Block new_block) + { + m_hash ^= old_block; + m_hash ^= new_block; + } + + public: + Bitset(Pos max_pos) + : m_blocks(blocks_size(max_pos)), + m_hash{ 0U }, + m_number_of_set_bits{ 0U } {} + + bool is_empty() const noexcept + { + return m_number_of_set_bits == 0U; + } + + bool set(Pos pos) + { + Block& block = find_block(pos); + const Block copy_block{ block }; + block |= bit_mask(pos); + + update_hash(copy_block, block); + + bool ok{ block != copy_block }; + m_number_of_set_bits += ok; + return ok; + } + + Bitset immutable_set(Pos pos) const + { + Bitset copy{ *this }; + copy.set(pos); + return copy; + } + + bool is_set(Pos pos) const + { + BlockIndex i{ block_index(pos) }; + if (i < m_blocks.size()) + return (m_blocks[i] & bit_mask(pos)) != 0U; + + return false; + } + + bool reset(Pos pos) + { + Block& block = find_block(pos); + const Block copy_block{ block }; + block &= ~bit_mask(pos); + + update_hash(copy_block, block); + + bool ok{ block != copy_block }; + m_number_of_set_bits -= ok; + return ok; + } + + Bitset immutable_reset(Pos pos) const + { + Bitset copy{ *this }; + copy.reset(pos); + return copy; + } + + // Same number of blocks && identical bits in all those blocks? + bool operator==(const Bitset& other) const noexcept + { + return m_number_of_set_bits == other.m_number_of_set_bits && + m_blocks == other.m_blocks; + } + + bool operator!=(const Bitset& other) const noexcept + { + return m_number_of_set_bits != other.m_number_of_set_bits || + m_blocks != other.m_blocks; + } +}; + +/// Constant-time, O(1), hash function +struct BitsetHash +{ + std::size_t operator()(const Bitset& bitset) const noexcept + { + return bitset.m_hash; + } +}; + +/// States of abstract data types +namespace state +{ + template + struct Hash + { + std::size_t operator()(const T&) const noexcept; + }; +} + +template +using OpPtr = std::unique_ptr>; + +/// Call/ret log entry + +/// S - sequential data type +template +class Entry +{ + private: + friend class Log; + friend class Slicer; + friend class LinearizabilityTester; + friend class LinearizabilityTester; + friend class LinearizabilityTester; + + // Ref counted pointer because we need to copy logs so that we + // can experimentally compare different linearizability testers + // + // However, this is an implementation detail and the strict type + // of OpPtr enforces at compile-time that we manage the + // ownership of these kind of pointers on the user's behalf. + Op* m_op_ptr; + unsigned m_entry_id; + std::thread::id m_thread_id; + EntryPtr m_match; + bool m_is_call; + + void inc_ref_counter() const noexcept + { + if (m_op_ptr != nullptr) + ++m_op_ptr->ref_counter; + } + + void dec_ref_counter() const + { + assert(m_op_ptr == nullptr || 0 < m_op_ptr->ref_counter); + + if (m_op_ptr != nullptr && --m_op_ptr->ref_counter == 0) + delete m_op_ptr; + } + + /// Log head + + /// \post: if _next is !nullptr, then _next->prev == this + Entry(EntryPtr _next) + : m_op_ptr{ nullptr }, + m_entry_id{}, + m_thread_id{}, + m_match{ nullptr }, + m_is_call{ false }, + prev{ nullptr }, + next{ _next } + { + if (_next != nullptr) + _next->prev = this; + } + + public: + ~Entry() + { + dec_ref_counter(); + } + + EntryPtr prev; + EntryPtr next; + + Entry() + : m_op_ptr{ nullptr }, + m_entry_id{}, + m_thread_id{}, + m_match{ nullptr }, + m_is_call{ false }, + prev{ nullptr }, + next{ nullptr } {} + + Entry(const Entry& entry) + : m_op_ptr{ entry.m_op_ptr }, + m_entry_id{ entry.m_entry_id }, + m_thread_id{ entry.m_thread_id }, + m_match{ entry.m_match }, + m_is_call{ entry.m_is_call }, + prev{ entry.prev }, + next{ entry.next } + { + inc_ref_counter(); + } + + Entry& operator=(const Entry& entry) + { + entry.inc_ref_counter(); + dec_ref_counter(); + + m_op_ptr = entry.m_op_ptr; + m_entry_id = entry.m_entry_id; + m_thread_id = entry.m_thread_id; + m_match = entry.m_match; + m_is_call = entry.m_is_call; + prev = entry.prev; + next = entry.next; + + return *this; + } + + Entry& operator=(Entry&& entry) + { + // only decrement required (due to move semantics) + dec_ref_counter(); + + m_op_ptr = entry.m_op_ptr; + m_entry_id = entry.m_entry_id; + m_thread_id = entry.m_thread_id; + m_match = entry.m_match; + m_is_call = entry.m_is_call; + prev = entry.prev; + next = entry.next; + + entry.m_op_ptr = nullptr; + entry.m_entry_id = 0; + entry.m_thread_id = 0; + entry.m_match = nullptr; + entry.m_is_call = false; + entry.prev = nullptr; + entry.next = nullptr; + + return *this; + } + + /// \pre: set_match && set_op have been called with non-null arguments + bool is_partitionable() const + { + assert(m_match != nullptr); + assert(m_match->m_op_ptr != nullptr); + assert(m_op_ptr->m_is_partitionable == m_match->m_op_ptr->m_is_partitionable); + assert(m_op_ptr->m_partition == m_match->m_op_ptr->m_partition); + + return m_op_ptr->m_is_partitionable; + } + + void set_op(OpPtr&& op_ptr) noexcept + { + m_op_ptr = op_ptr.release(); + inc_ref_counter(); + } + + Op& op() const + { + assert(m_op_ptr != nullptr); + return *m_op_ptr; + } + + const Op* const op_ptr() const noexcept + { + return m_op_ptr; + } + + void set_entry_id(unsigned entry_id) noexcept + { + m_entry_id = entry_id; + } + + unsigned entry_id() const noexcept + { + return m_entry_id; + } + + void set_thread_id(std::thread::id thread_id) noexcept + { + m_thread_id = thread_id; + } + + std::thread::id thread_id() const noexcept + { + return m_thread_id; + } + + /// \pre: ret_entry_ptr->match() == nullptr + /// \pre: !ret_entry_ptr->is_call() + /// + /// \post: this->is_call() + /// \post: this == ret_entry_ptr->match() + /// \post: this->match() == ret_entry_ptr + /// \post: this->entry_id() == ret_entry_ptr->entry_id() + /// \post: if this->is_partitionable() || ret_entry_ptr->is_partitionable(), + /// then this->op().partition() == ret_entry_ptr->op().partition() + void set_match(EntryPtr ret_entry_ptr) noexcept + { + assert(ret_entry_ptr->m_match == nullptr); + assert(!ret_entry_ptr->is_call()); + + ret_entry_ptr->m_match = this; + ret_entry_ptr->set_entry_id(m_entry_id); + + if (ret_entry_ptr->op().m_is_partitionable) + { + op().m_is_partitionable = ret_entry_ptr->op().m_is_partitionable; + op().m_partition = ret_entry_ptr->op().m_partition; + } + else + { + ret_entry_ptr->op().m_is_partitionable = op().m_is_partitionable; + ret_entry_ptr->op().m_partition = op().m_partition; + } + + m_match = ret_entry_ptr; + m_is_call = true; + + assert(is_call()); + assert(this == ret_entry_ptr->match()); + assert(match() == ret_entry_ptr); + assert(entry_id() == ret_entry_ptr->entry_id()); + assert(op().m_is_partitionable == ret_entry_ptr->op().m_is_partitionable); + assert(op().m_partition == ret_entry_ptr->op().m_partition); + } + + EntryPtr match() const noexcept + { + return m_match; + } + + bool is_call() const noexcept + { + return m_is_call; + } +}; #ifdef _LT_DEBUG_ - /// S - sequential data type - template - std::ostream& operator<<(std::ostream& os, EntryPtr entry_ptr) - { - if (entry_ptr == nullptr) - return os << "entry id: none, thread id: none [nullptr]"; - - const Entry& entry = *entry_ptr; - return os << - "entry id: " << entry.entry_id() << - ", thread id: " << entry.thread_id() << - ", " << (entry.is_call() ? "call: " : "return: ") << - entry.op(); - } +/// S - sequential data type +template +std::ostream& operator<<(std::ostream& os, EntryPtr entry_ptr) +{ + if (entry_ptr == nullptr) + return os << "entry id: none, thread id: none [nullptr]"; + + const Entry& entry = *entry_ptr; + return os << + "entry id: " << entry.entry_id() << + ", thread id: " << entry.thread_id() << + ", " << (entry.is_call() ? "call: " : "return: ") << + entry.op(); +} #endif - template - void Stack::push(EntryPtr ptr, S&& s) - { - assert(!is_full()); - assert(ptr != nullptr); - assert(ptr->is_call()); - - // no overflow - m_vector[m_top++] = std::make_pair(ptr, std::move(s)); - assert(0U != m_top); - } - - /// Input to linearizabilty testers - - /// S - sequential data type - template - class LogInfo - { - private: - friend class Slicer; - - EntryPtr m_log_head_ptr; - std::size_t m_number_of_entries; - - public: - /// \post: is_empty() - LogInfo() : m_log_head_ptr{ nullptr }, m_number_of_entries{ 0U } {} - - /// \pre: number_of_entries is positive && even - /// \pre: log_head_ptr is !nullptr - /// \post: !is_empty() - LogInfo(EntryPtr log_head_ptr, std::size_t number_of_entries) - : m_log_head_ptr{ log_head_ptr }, m_number_of_entries{ number_of_entries } - { - assert(log_head_ptr != nullptr); - assert(0U < m_number_of_entries); - assert((m_number_of_entries & 1U) == 0U); - } - - /// Ptr to the first entry in the log - EntryPtr log_head_ptr() const noexcept - { - return m_log_head_ptr; - } - - /// Total number of call entries plus return entries. - - /// Returns even number since every call is paired with a return - std::size_t number_of_entries() const noexcept - { - return m_number_of_entries; - } - - bool is_empty() const noexcept - { - return m_log_head_ptr == nullptr && m_number_of_entries == 0U; - } - }; +template +void Stack::push(EntryPtr ptr, S&& s) +{ + assert(!is_full()); + assert(ptr != nullptr); + assert(ptr->is_call()); + + // no overflow + m_vector[m_top++] = std::make_pair(ptr, std::move(s)); + assert(0U != m_top); +} + +/// Input to linearizabilty testers + +/// S - sequential data type +template +class LogInfo +{ + private: + friend class Slicer; + + EntryPtr m_log_head_ptr; + std::size_t m_number_of_entries; + + public: + /// \post: is_empty() + LogInfo() : m_log_head_ptr{ nullptr }, m_number_of_entries{ 0U } {} + + /// \pre: number_of_entries is positive && even + /// \pre: log_head_ptr is !nullptr + /// \post: !is_empty() + LogInfo(EntryPtr log_head_ptr, std::size_t number_of_entries) + : m_log_head_ptr{ log_head_ptr }, m_number_of_entries{ number_of_entries } + { + assert(log_head_ptr != nullptr); + assert(0U < m_number_of_entries); + assert((m_number_of_entries & 1U) == 0U); + } + + /// Ptr to the first entry in the log + EntryPtr log_head_ptr() const noexcept + { + return m_log_head_ptr; + } + + /// Total number of call entries plus return entries. + + /// Returns even number since every call is paired with a return + std::size_t number_of_entries() const noexcept + { + return m_number_of_entries; + } + + bool is_empty() const noexcept + { + return m_log_head_ptr == nullptr && m_number_of_entries == 0U; + } +}; #ifdef _LT_DEBUG_ - /// S - sequential data type - template - std::ostream& operator<<(std::ostream& os, const LogInfo& log_info) - { - EntryPtr entry_ptr{ log_info.log_head_ptr() }; - - os << "log info, number of entries: " << log_info.number_of_entries() << std::endl; - for (; entry_ptr != nullptr; entry_ptr = entry_ptr->next) - os << entry_ptr << std::endl; - - return os; - } +/// S - sequential data type +template +std::ostream& operator<<(std::ostream& os, const LogInfo& log_info) +{ + EntryPtr entry_ptr{ log_info.log_head_ptr() }; + + os << "log info, number of entries: " << log_info.number_of_entries() << std::endl; + for (; entry_ptr != nullptr; entry_ptr = entry_ptr->next) + os << entry_ptr << std::endl; + + return os; +} #endif - /// Bounded history log - - /// If you need thread-safety, use ConcurrentLog instead. - /// - /// S - sequential data type - template - class Log - { - private: - // fixed-size vector - typedef std::vector> Entries; - - public: - typedef typename Entries::size_type Size; - - private: - // we never resize the vector and so pointers into it are stable - Size m_entry_id, m_index; - Entries m_entries; - EntryPtr m_last_entry_ptr; - - void link(Entry& entry) noexcept - { - if (m_last_entry_ptr != nullptr) - m_last_entry_ptr->next = &entry; - - entry.prev = m_last_entry_ptr; - } - - public: - Log(const Log&) = delete; - - /// A history with at most capacity entries - Log(Size capacity) - : m_entry_id{ 0U }, - m_index{ 0U }, - m_entries(capacity), - m_last_entry_ptr{ nullptr } {} - - /// Copy entries - Log(LogInfo log_info) - : m_entry_id{ 0U }, - m_index{ 0U }, - m_entries(log_info.number_of_entries()), - m_last_entry_ptr{ nullptr } - { - EntryPtr entry_ptr{ log_info.log_head_ptr() }; - std::vector matches(log_info.number_of_entries() >> 1); - - while (entry_ptr != nullptr) - { - assert(m_index < m_entries.size()); - - Entry& new_entry = m_entries[m_index]; - new_entry = *entry_ptr; - new_entry.m_match = nullptr; - link(new_entry); - - if (new_entry.is_call()) - { - matches[new_entry.entry_id()] = m_index; - } - else - { - Entry& call_entry = m_entries[matches[new_entry.entry_id()]]; - call_entry.set_match(&new_entry); - } - - m_last_entry_ptr = &new_entry; - entry_ptr = entry_ptr->next; - ++m_index; - } - - assert(m_index == m_entries.size()); - assert(entry_ptr == nullptr); - } - - EntryPtr add_call(OpPtr&& op_ptr) - { - assert(m_index < m_entries.size()); - - Entry& entry = m_entries[m_index++]; - entry.set_op(std::move(op_ptr)); - entry.set_entry_id(m_entry_id++); - - link(entry); - m_last_entry_ptr = &entry; - return m_last_entry_ptr; - } - - /// \post: call_entry_ptr->is_call() - EntryPtr add_ret(EntryPtr call_entry_ptr, OpPtr&& op_ptr) - { - assert(m_index < m_entries.size()); - - Entry& entry = m_entries[m_index++]; - entry.set_op(std::move(op_ptr)); - link(entry); - - m_last_entry_ptr = &entry; - call_entry_ptr->set_match(m_last_entry_ptr); - - assert(call_entry_ptr->is_call()); - assert(m_entry_id <= m_index); - - return m_last_entry_ptr; - } - - EntryPtr log_head_ptr() - { - return &m_entries.front(); - } - - /// Total number of call entries plus return entries. - - /// Returns even number since every call is paired with a return - std::size_t number_of_entries() const noexcept - { - return m_index; - } - - LogInfo info() - { - return{ log_head_ptr(), number_of_entries() }; - } - }; - - /// Output of linearizability tester - - /// S - sequential data type - template - class Result - { - private: - friend class LinearizabilityTester; - friend class LinearizabilityTester; - friend class LinearizabilityTester; - typedef std::vector> EntryPtrs; - - bool m_is_linearizable; - EntryPtrs m_entry_ptrs; +/// Bounded history log + +/// If you need thread-safety, use ConcurrentLog instead. +/// +/// S - sequential data type +template +class Log +{ + private: + // fixed-size vector + typedef std::vector> Entries; + + public: + typedef typename Entries::size_type Size; + + private: + // we never resize the vector and so pointers into it are stable + Size m_entry_id, m_index; + Entries m_entries; + EntryPtr m_last_entry_ptr; + + void link(Entry& entry) noexcept + { + if (m_last_entry_ptr != nullptr) + m_last_entry_ptr->next = &entry; + + entry.prev = m_last_entry_ptr; + } + + public: + Log(const Log&) = delete; + + /// A history with at most capacity entries + Log(Size capacity) + : m_entry_id{ 0U }, + m_index{ 0U }, + m_entries(capacity), + m_last_entry_ptr{ nullptr } {} + + /// Copy entries + Log(LogInfo log_info) + : m_entry_id{ 0U }, + m_index{ 0U }, + m_entries(log_info.number_of_entries()), + m_last_entry_ptr{ nullptr } + { + EntryPtr entry_ptr{ log_info.log_head_ptr() }; + std::vector matches(log_info.number_of_entries() >> 1); + + while (entry_ptr != nullptr) + { + assert(m_index < m_entries.size()); + + Entry& new_entry = m_entries[m_index]; + new_entry = *entry_ptr; + new_entry.m_match = nullptr; + link(new_entry); + + if (new_entry.is_call()) + { + matches[new_entry.entry_id()] = m_index; + } + else + { + Entry& call_entry = m_entries[matches[new_entry.entry_id()]]; + call_entry.set_match(&new_entry); + } + + m_last_entry_ptr = &new_entry; + entry_ptr = entry_ptr->next; + ++m_index; + } + + assert(m_index == m_entries.size()); + assert(entry_ptr == nullptr); + } + + EntryPtr add_call(OpPtr&& op_ptr) + { + assert(m_index < m_entries.size()); + + Entry& entry = m_entries[m_index++]; + entry.set_op(std::move(op_ptr)); + entry.set_entry_id(m_entry_id++); + + link(entry); + m_last_entry_ptr = &entry; + return m_last_entry_ptr; + } + + /// \post: call_entry_ptr->is_call() + EntryPtr add_ret(EntryPtr call_entry_ptr, OpPtr&& op_ptr) + { + assert(m_index < m_entries.size()); + + Entry& entry = m_entries[m_index++]; + entry.set_op(std::move(op_ptr)); + link(entry); + + m_last_entry_ptr = &entry; + call_entry_ptr->set_match(m_last_entry_ptr); + + assert(call_entry_ptr->is_call()); + assert(m_entry_id <= m_index); + + return m_last_entry_ptr; + } + + EntryPtr log_head_ptr() + { + return &m_entries.front(); + } + + /// Total number of call entries plus return entries. + + /// Returns even number since every call is paired with a return + std::size_t number_of_entries() const noexcept + { + return m_index; + } + + LogInfo info() + { + return{ log_head_ptr(), number_of_entries() }; + } +}; + +/// Output of linearizability tester + +/// S - sequential data type +template +class Result +{ + private: + friend class LinearizabilityTester; + friend class LinearizabilityTester; + friend class LinearizabilityTester; + typedef std::vector> EntryPtrs; + + bool m_is_linearizable; + EntryPtrs m_entry_ptrs; #ifdef _LT_DEBUG_ - unsigned m_cutoff_entry_id; - EntryPtr m_log_head_ptr; + unsigned m_cutoff_entry_id; + EntryPtr m_log_head_ptr; #endif - bool m_is_timeout; + bool m_is_timeout; - double m_virtual_memory_usage; - double m_resident_set_size; + double m_virtual_memory_usage; + double m_resident_set_size; - void reset() - { - m_is_linearizable = true; - m_entry_ptrs.clear(); + void reset() + { + m_is_linearizable = true; + m_entry_ptrs.clear(); #ifdef _LT_DEBUG_ - m_cutoff_entry_id = 0U; - m_log_head_ptr = nullptr; + m_cutoff_entry_id = 0U; + m_log_head_ptr = nullptr; #endif - m_is_timeout = false; - m_virtual_memory_usage = 0.0; - m_resident_set_size = 0.0; - } - - public: - /// Initially linearizable - Result() - : m_is_linearizable{ true }, - m_entry_ptrs{}, + m_is_timeout = false; + m_virtual_memory_usage = 0.0; + m_resident_set_size = 0.0; + } + + public: + /// Initially linearizable + Result() + : m_is_linearizable{ true }, + m_entry_ptrs{}, #ifdef _LT_DEBUG_ - m_cutoff_entry_id{ 0U }, - m_log_head_ptr{ nullptr }, + m_cutoff_entry_id{ 0U }, + m_log_head_ptr{ nullptr }, #endif - m_is_timeout{ false }, - m_virtual_memory_usage{ 0.0 }, - m_resident_set_size{ 0.0 } {} - - /// \pre: !is_timeout() - bool is_linearizable() const noexcept - { - assert(!is_timeout()); - return m_is_linearizable; - } - - bool is_timeout() const noexcept - { - return m_is_timeout; - } - - /// Zero if unknown, unit: MiB - double virtual_memory_usage() const noexcept - { - return m_virtual_memory_usage; - } - - /// Zero if unknown, unit: MiB - double resident_set_size() const noexcept - { - return m_resident_set_size; - } + m_is_timeout{ false }, + m_virtual_memory_usage{ 0.0 }, + m_resident_set_size{ 0.0 } {} + + /// \pre: !is_timeout() + bool is_linearizable() const noexcept + { + assert(!is_timeout()); + return m_is_linearizable; + } + + bool is_timeout() const noexcept + { + return m_is_timeout; + } + + /// Zero if unknown, unit: MiB + double virtual_memory_usage() const noexcept + { + return m_virtual_memory_usage; + } + + /// Zero if unknown, unit: MiB + double resident_set_size() const noexcept + { + return m_resident_set_size; + } #ifdef _LT_DEBUG_ - void debug(std::ostream& os, bool verbose = false) - { - os << "Linearizable: "; - if (m_is_linearizable) - { - os << "Yes" << std::endl; - for (EntryPtr entry_ptr : m_entry_ptrs) - os << entry_ptr << " : " << entry_ptr->match() << std::endl; - - return; - } - - os << "No" << std::endl; - EntryPtr entry_ptr{ m_log_head_ptr }; - for (; entry_ptr != nullptr; entry_ptr = entry_ptr->next) - { - os << entry_ptr << std::endl; - if (entry_ptr->entry_id() == m_cutoff_entry_id) - { - os << "^ previous entries cannot be linearized" << std::endl; - - if (!(verbose || entry_ptr->is_call())) - return; - } - } - } + void debug(std::ostream& os, bool verbose = false) + { + os << "Linearizable: "; + if (m_is_linearizable) + { + os << "Yes" << std::endl; + for (EntryPtr entry_ptr : m_entry_ptrs) + os << entry_ptr << " : " << entry_ptr->match() << std::endl; + + return; + } + + os << "No" << std::endl; + EntryPtr entry_ptr{ m_log_head_ptr }; + for (; entry_ptr != nullptr; entry_ptr = entry_ptr->next) + { + os << entry_ptr << std::endl; + if (entry_ptr->entry_id() == m_cutoff_entry_id) + { + os << "^ previous entries cannot be linearized" << std::endl; + + if (!(verbose || entry_ptr->is_call())) + return; + } + } + } #endif - }; +}; #ifdef _LT_TIMEOUT_ - template - struct Timeout - { - const typename Clock::time_point start_time; - const typename Clock::duration max_duration; - - Timeout() - : start_time{ Clock::now() }, - max_duration{ Clock::duration::max() } {} - - Timeout(typename Clock::duration duration) - : start_time{ Clock::now() }, - max_duration{ duration } {} - - bool is_expired() const - { - return max_duration < (Clock::now() - start_time); - } - }; +template +struct Timeout +{ + const typename Clock::time_point start_time; + const typename Clock::duration max_duration; + + Timeout() + : start_time{ Clock::now() }, + max_duration{ Clock::duration::max() } {} + + Timeout(typename Clock::duration duration) + : start_time{ Clock::now() }, + max_duration{ duration } {} + + bool is_expired() const + { + return max_duration < (Clock::now() - start_time); + } +}; #endif - /// Least-recently used cache eviction - template> - class LruCache - { - private: - typedef std::list List; - typedef typename List::iterator ListIterator; - typedef std::unordered_map UnorderedMap; - typedef typename UnorderedMap::size_type Capacity; - - const Capacity m_capacity; - - UnorderedMap m_unordered_map; - List m_list; - - public: - typedef typename UnorderedMap::iterator Iterator; - - LruCache() - : m_capacity{ 4096 }, - m_unordered_map{ m_capacity } {} - - LruCache(Capacity capacity) - : m_capacity{ capacity }, - m_unordered_map{ m_capacity } {} - - bool insert(Key&& key) - { - std::pair pair{ m_unordered_map.insert( - std::make_pair(std::move(key), m_list.end())) }; - - if (pair.second) - pair.first->second = m_list.insert(m_list.end(), pair.first->first); - else - m_list.splice(m_list.end(), m_list, pair.first->second); - - if (m_unordered_map.size() == m_capacity) - { - auto iter = m_unordered_map.find(m_list.front()); - assert(iter != m_unordered_map.cend()); - m_unordered_map.erase(iter); - m_list.pop_front(); - } - - return pair.second; - } - }; - - namespace cache - { - // regardless of caching, we need to keep track of the current state of type S - template - using State = std::pair; - - // if caching is enabled, we use these hash functions - template - class StateHash - { - private: - // courtesy of Daniel Kroening, see CPROVER source file util/irep.cpp - static inline size_t hash_rotl(std::size_t value, unsigned shift) - { - return (value << shift) | (value >> ((sizeof(value) * 8U) - shift)); - } - - // courtesy of Daniel Kroening, see CPROVER source file util/irep.cpp - static inline size_t hash_combine(std::size_t h1, std::size_t h2) - { - return hash_rotl(h1, 7U) ^ h2; - } - - const BitsetHash m_bitset_hash; - const state::Hash m_s_hash; - - public: - StateHash() : m_bitset_hash{}, m_s_hash{} {} - - std::size_t operator()(const State& state) const noexcept - { - return hash_combine(m_bitset_hash(state.first), m_s_hash(state.second)); - } - }; - - template - struct Switch - { - typedef std::nullptr_t Type; - - static bool try_insert(const S& s, const EntryPtr entry_ptr, - Type& cache, Bitset& bitset) - { - return true; - } - }; - - template - struct Switch - { - typedef LruCache, StateHash> Type; - - static bool try_insert(const S& s, const EntryPtr entry_ptr, - Type& cache, Bitset& bitset) - { - return cache.insert(std::make_pair(bitset.immutable_set(entry_ptr->entry_id()), s)); - } - }; - - template - struct Switch - { - typedef std::unordered_set, StateHash> Type; - - static bool try_insert(const S& s, const EntryPtr entry_ptr, - Type& cache, Bitset& bitset) - { - unsigned int pos = entry_ptr->entry_id(); - lt::Bitset bs = bitset.immutable_set(pos); - return std::get<1>(cache.emplace(bs, s)); - } - }; - } - - /// S - sequential data type - template - class LinearizabilityTester - { - private: - typedef cache::Switch Cache; - - // Maximum number of call/ret entries, i.e. half of the - // total number of entry pointers reachable in m_log_head - const std::size_t m_log_size; - - // History to linearize, every call is matched by a return - const Entry m_log_head; - - // Invariants: - // - // * for every EntryPtr `e` in `m_calls`, `e->is_call()` holds - // * for every EntryPtr `e`, if `e` in `m_calls`, then `e` is not reachable - // from `m_log_head` by following the next pointers. - Stack m_calls; +/// Least-recently used cache eviction +template> +class LruCache +{ + private: + typedef std::list List; + typedef typename List::iterator ListIterator; + typedef std::unordered_map UnorderedMap; + typedef typename UnorderedMap::size_type Capacity; + + const Capacity m_capacity; + + UnorderedMap m_unordered_map; + List m_list; + + public: + typedef typename UnorderedMap::iterator Iterator; + + LruCache() + : m_capacity{ 4096 }, + m_unordered_map{ m_capacity } {} + + LruCache(Capacity capacity) + : m_capacity{ capacity }, + m_unordered_map{ m_capacity } {} + + bool insert(Key&& key) + { + std::pair pair{ m_unordered_map.insert( + std::make_pair(std::move(key), m_list.end())) }; + + if (pair.second) + pair.first->second = m_list.insert(m_list.end(), pair.first->first); + else + m_list.splice(m_list.end(), m_list, pair.first->second); + + if (m_unordered_map.size() == m_capacity) + { + auto iter = m_unordered_map.find(m_list.front()); + assert(iter != m_unordered_map.cend()); + m_unordered_map.erase(iter); + m_list.pop_front(); + } + + return pair.second; + } +}; + +namespace cache +{ + // regardless of caching, we need to keep track of the current state of type S + template + using State = std::pair; + + // if caching is enabled, we use these hash functions + template + class StateHash + { + private: + // courtesy of Daniel Kroening, see CPROVER source file util/irep.cpp + static inline size_t hash_rotl(std::size_t value, unsigned shift) + { + return (value << shift) | (value >> ((sizeof(value) * 8U) - shift)); + } + + // courtesy of Daniel Kroening, see CPROVER source file util/irep.cpp + static inline size_t hash_combine(std::size_t h1, std::size_t h2) + { + return hash_rotl(h1, 7U) ^ h2; + } + + const BitsetHash m_bitset_hash; + const state::Hash m_s_hash; + + public: + StateHash() : m_bitset_hash{}, m_s_hash{} {} + + std::size_t operator()(const State& state) const noexcept + { + return hash_combine(m_bitset_hash(state.first), m_s_hash(state.second)); + } + }; + + template + struct Switch + { + typedef std::nullptr_t Type; + + static bool try_insert(const S& s, const EntryPtr entry_ptr, + Type& cache, Bitset& bitset) + { + return true; + } + }; + + template + struct Switch + { + typedef LruCache, StateHash> Type; + + static bool try_insert(const S& s, const EntryPtr entry_ptr, + Type& cache, Bitset& bitset) + { + return cache.insert(std::make_pair(bitset.immutable_set(entry_ptr->entry_id()), s)); + } + }; + + template + struct Switch + { + typedef std::unordered_set, StateHash> Type; + + static bool try_insert(const S& s, const EntryPtr entry_ptr, + Type& cache, Bitset& bitset) + { + unsigned int pos = entry_ptr->entry_id(); + lt::Bitset bs = bitset.immutable_set(pos); + return std::get<1>(cache.emplace(bs, s)); + } + }; +} + +/// S - sequential data type +template +class LinearizabilityTester +{ + private: + typedef cache::Switch Cache; + + // Maximum number of call/ret entries, i.e. half of the + // total number of entry pointers reachable in m_log_head + const std::size_t m_log_size; + + // History to linearize, every call is matched by a return + const Entry m_log_head; + + // Invariants: + // + // * for every EntryPtr `e` in `m_calls`, `e->is_call()` holds + // * for every EntryPtr `e`, if `e` in `m_calls`, then `e` is not reachable + // from `m_log_head` by following the next pointers. + Stack m_calls; #ifdef _LT_TIMEOUT_ - Timeout m_timeout; + Timeout m_timeout; #endif - // An approximation of the workload - unsigned long m_number_of_iterations; - - // see http://stackoverflow.com/questions/669438/how-to-get-memory-usage-at-run-time-in-c - // - // process_mem_usage(double &, double &) - takes two doubles by reference, - // attempts to read the system-dependent data for a process' virtual memory - // size && resident set size, && return the results in MiB. - // - // On failure, returns 0.0, 0.0 - static void process_mem_usage(double& vm_usage, double& resident_set) - { - vm_usage = resident_set = 0.0; - } - - // Temporarily remove call_entry_ptr and call_entry_ptr->match() from the log - - // \pre: call_entry_ptr->is_call() - static void lift(const EntryPtr call_entry_ptr) - { - const Entry& call = *call_entry_ptr; - assert(call.is_call()); - - Entry& match = *call.match(); - call.prev->next = call.next; - call.next->prev = call.prev; - match.prev->next = match.next; - - if (match.next != nullptr) - match.next->prev = match.prev; - } - - // Reinsert call_entry_ptr && call_entry_ptr->match() into the log - - // \pre: call_entry_ptr->is_call() - static void unlift(const EntryPtr call_entry_ptr) - { - const Entry& call = *call_entry_ptr; - assert(call.is_call()); - - Entry& match = *call.match(); - assert(match.prev->next == match.next); - match.prev->next = &match; - - if (match.next != nullptr) - match.next->prev = &match; - - assert(call.prev->next == call.next); - call.prev->next = call_entry_ptr; - call.next->prev = call_entry_ptr; - } - - void internal_check(Result& result, unsigned& global_linearized_entry_id) - { - S s, new_s; - bool is_entry_linearizable; - typename Cache::Type cache; - EntryPtr pop_entry_ptr, entry_ptr{ m_log_head.next }; - - double virtual_memory_usage; - double resident_set_size; - - // fixing the size is !merely an optimization but - // necessary for checking the equality of bitsets - Bitset linearized_entries(m_log_size); - - while (m_log_head.next != nullptr) - { - process_mem_usage(virtual_memory_usage, resident_set_size); - result.m_virtual_memory_usage = std::max(result.m_virtual_memory_usage, virtual_memory_usage); - result.m_resident_set_size = std::max(result.m_resident_set_size, resident_set_size); + // An approximation of the workload + unsigned long m_number_of_iterations; + + // see http://stackoverflow.com/questions/669438/how-to-get-memory-usage-at-run-time-in-c + // + // process_mem_usage(double &, double &) - takes two doubles by reference, + // attempts to read the system-dependent data for a process' virtual memory + // size && resident set size, && return the results in MiB. + // + // On failure, returns 0.0, 0.0 + static void process_mem_usage(double& vm_usage, double& resident_set) + { + vm_usage = resident_set = 0.0; + } + + // Temporarily remove call_entry_ptr and call_entry_ptr->match() from the log + + // \pre: call_entry_ptr->is_call() + static void lift(const EntryPtr call_entry_ptr) + { + const Entry& call = *call_entry_ptr; + assert(call.is_call()); + + Entry& match = *call.match(); + call.prev->next = call.next; + call.next->prev = call.prev; + match.prev->next = match.next; + + if (match.next != nullptr) + match.next->prev = match.prev; + } + + // Reinsert call_entry_ptr && call_entry_ptr->match() into the log + + // \pre: call_entry_ptr->is_call() + static void unlift(const EntryPtr call_entry_ptr) + { + const Entry& call = *call_entry_ptr; + assert(call.is_call()); + + Entry& match = *call.match(); + assert(match.prev->next == match.next); + match.prev->next = &match; + + if (match.next != nullptr) + match.next->prev = &match; + + assert(call.prev->next == call.next); + call.prev->next = call_entry_ptr; + call.next->prev = call_entry_ptr; + } + + void internal_check(Result& result, unsigned& global_linearized_entry_id) + { + S s, new_s; + bool is_entry_linearizable; + typename Cache::Type cache; + EntryPtr pop_entry_ptr, entry_ptr{ m_log_head.next }; + + double virtual_memory_usage; + double resident_set_size; + + // fixing the size is !merely an optimization but + // necessary for checking the equality of bitsets + Bitset linearized_entries(m_log_size); + + while (m_log_head.next != nullptr) + { + process_mem_usage(virtual_memory_usage, resident_set_size); + result.m_virtual_memory_usage = std::max(result.m_virtual_memory_usage, virtual_memory_usage); + result.m_resident_set_size = std::max(result.m_resident_set_size, resident_set_size); #ifdef _LT_TIMEOUT_ - if (m_timeout.is_expired()) - { - result.m_is_timeout = true; - break; - } + if (m_timeout.is_expired()) + { + result.m_is_timeout = true; + break; + } #endif - ++m_number_of_iterations; + ++m_number_of_iterations; - assert(entry_ptr != nullptr); - if (entry_ptr->is_call()) - { - assert(!m_calls.is_full()); - assert(entry_ptr->match() != nullptr); - assert(!linearized_entries.is_set(entry_ptr->entry_id())); + assert(entry_ptr != nullptr); + if (entry_ptr->is_call()) + { + assert(!m_calls.is_full()); + assert(entry_ptr->match() != nullptr); + assert(!linearized_entries.is_set(entry_ptr->entry_id())); - std::tie(is_entry_linearizable, new_s) = - entry_ptr->op().apply(s, entry_ptr->match()->op()); + std::tie(is_entry_linearizable, new_s) = + entry_ptr->op().apply(s, entry_ptr->match()->op()); - if (is_entry_linearizable && Cache::try_insert(new_s, entry_ptr, cache, linearized_entries)) - { - // call entry is always matched up with a return entry - assert(entry_ptr->next != nullptr); + if (is_entry_linearizable && Cache::try_insert(new_s, entry_ptr, cache, linearized_entries)) + { + // call entry is always matched up with a return entry + assert(entry_ptr->next != nullptr); - // provisionally linearize the call entry together with - // the associated state produced by the new linearization - m_calls.push(entry_ptr, std::move(s)); - s = std::move(new_s); - linearized_entries.set(entry_ptr->entry_id()); + // provisionally linearize the call entry together with + // the associated state produced by the new linearization + m_calls.push(entry_ptr, std::move(s)); + s = std::move(new_s); + linearized_entries.set(entry_ptr->entry_id()); - // provisionally remove the call && return entry from the history - lift(entry_ptr); + // provisionally remove the call && return entry from the history + lift(entry_ptr); - // restart from the beginning of the shortened history - entry_ptr = m_log_head.next; - } - else // cannot linearize call entry - { - // get the next entry in the unmodified history - entry_ptr = entry_ptr->next; + // restart from the beginning of the shortened history + entry_ptr = m_log_head.next; + } + else // cannot linearize call entry + { + // get the next entry in the unmodified history + entry_ptr = entry_ptr->next; #ifdef _LT_DEBUG_ - global_linearized_entry_id = std::max(global_linearized_entry_id, entry_ptr->entry_id()); + global_linearized_entry_id = std::max(global_linearized_entry_id, entry_ptr->entry_id()); #endif - } - } - else // handle "return" entry - { - if (m_calls.is_empty()) - break; - - assert(!m_calls.is_empty()); - - // revert state change - std::tie(pop_entry_ptr, s) = m_calls.top(); - assert(pop_entry_ptr != nullptr); - linearized_entries.reset(pop_entry_ptr->entry_id()); - - m_calls.pop(); - - // undo the provisional linearization - unlift(pop_entry_ptr); - - // continue after the entry to which we have just backtracked - entry_ptr = pop_entry_ptr->next; - } - } - - // all call entries linearized? - result.m_is_linearizable = m_calls.is_full(); - assert(result.m_is_linearizable == (m_log_head.next == nullptr)); - - // witness linearization - std::size_t pos{ 0 }; - result.m_entry_ptrs.resize(m_calls.size()); - for (EntryPtr& entry_ptr : result.m_entry_ptrs) - entry_ptr = m_calls.entry_ptr(pos++); - } - - public: - LinearizabilityTester(LogInfo log_info) - : m_log_size{ log_info.number_of_entries() >> 1 }, - m_log_head{ log_info.log_head_ptr() }, - m_calls{ m_log_size }, + } + } + else // handle "return" entry + { + if (m_calls.is_empty()) + break; + + assert(!m_calls.is_empty()); + + // revert state change + std::tie(pop_entry_ptr, s) = m_calls.top(); + assert(pop_entry_ptr != nullptr); + linearized_entries.reset(pop_entry_ptr->entry_id()); + + m_calls.pop(); + + // undo the provisional linearization + unlift(pop_entry_ptr); + + // continue after the entry to which we have just backtracked + entry_ptr = pop_entry_ptr->next; + } + } + + // all call entries linearized? + result.m_is_linearizable = m_calls.is_full(); + assert(result.m_is_linearizable == (m_log_head.next == nullptr)); + + // witness linearization + std::size_t pos{ 0 }; + result.m_entry_ptrs.resize(m_calls.size()); + for (EntryPtr& entry_ptr : result.m_entry_ptrs) + entry_ptr = m_calls.entry_ptr(pos++); + } + + public: + LinearizabilityTester(LogInfo log_info) + : m_log_size{ log_info.number_of_entries() >> 1 }, + m_log_head{ log_info.log_head_ptr() }, + m_calls{ m_log_size }, #ifdef _LT_TIMEOUT_ - m_timeout{}, + m_timeout{}, #endif - m_number_of_iterations{} {} + m_number_of_iterations{} {} #ifdef _LT_TIMEOUT_ - LinearizabilityTester(LogInfo log_info, - std::chrono::steady_clock::duration max_duration) - : m_log_size{ log_info.number_of_entries() >> 1 }, - m_log_head{ log_info.log_head_ptr() }, - m_calls{ m_log_size }, - m_timeout{ max_duration }, - m_number_of_iterations{} {} + LinearizabilityTester(LogInfo log_info, + std::chrono::steady_clock::duration max_duration) + : m_log_size{ log_info.number_of_entries() >> 1 }, + m_log_head{ log_info.log_head_ptr() }, + m_calls{ m_log_size }, + m_timeout{ max_duration }, + m_number_of_iterations{} {} #endif - /// A rough approximation of the workload - unsigned long number_of_iterations() const noexcept - { - return m_number_of_iterations; - } + /// A rough approximation of the workload + unsigned long number_of_iterations() const noexcept + { + return m_number_of_iterations; + } - /// Is history linearizable? + /// Is history linearizable? - /// Throws an exception on timeout - bool check() - { - Result result; - unsigned disregard_cutoff_entry_id; - internal_check(result, disregard_cutoff_entry_id); + /// Throws an exception on timeout + bool check() + { + Result result; + unsigned disregard_cutoff_entry_id; + internal_check(result, disregard_cutoff_entry_id); - if (result.is_timeout()) - throw std::runtime_error("Timeout!"); + if (result.is_timeout()) + throw std::runtime_error("Timeout!"); - return result.is_linearizable(); - } + return result.is_linearizable(); + } - void check(Result& result) - { - result.reset(); + void check(Result& result) + { + result.reset(); #ifdef _LT_DEBUG_ - internal_check(result, result.m_cutoff_entry_id); - result.m_log_head_ptr = m_log_head.next; + internal_check(result, result.m_cutoff_entry_id); + result.m_log_head_ptr = m_log_head.next; #else - unsigned disregard_cutoff_entry_id; - internal_check(result, disregard_cutoff_entry_id); + unsigned disregard_cutoff_entry_id; + internal_check(result, disregard_cutoff_entry_id); #endif - } - }; - - template - void compositional_check(Log& log, Result &result, - unsigned number_of_partitions, Duration max_duration) - { - Slicer slicer{ log.info(), number_of_partitions }; - for (unsigned partition = 0; partition < slicer.number_of_partitions; ++partition) - { - LinearizabilityTester tester{ slicer.sublog_info(partition), max_duration }; - tester.check(result); - if (!(result.is_timeout() || result.is_linearizable())) - break; - } - } - - /// RAII class to ensure a thread becomes unjoinable on all paths - class Thread - { - private: - std::thread m_thread; - - public: - Thread() - : m_thread{} {} - - Thread(std::thread&& thread) - : m_thread(std::move(thread)) {} - - template - Thread(F&& f, Args&&... args) - : m_thread(std::forward(f), std::forward(args)...) {} - - ~Thread() - { - if (m_thread.joinable()) - m_thread.join(); - } - - /// \pre: joinable() - /// \post: not joinable() - - /// Throws std::system_error if an error occurs. - void join() - { - m_thread.join(); - } - - bool joinable() const noexcept - { - return m_thread.joinable(); - } - - Thread& operator=(Thread&& thread) - { - m_thread = std::move(thread.m_thread); - return *this; - } - }; - - /// Partition history into sub-histories - - /// A slicer partitions the history into independent sub-histories. - /// Our partitioning scheme hinges on Theorem 3.6.1 in "The Art of - /// Multiprocessor Programming" (Revised Ed.) by Herlihy && Shavit. - /// - /// Typically only associative concurrent abstract data types (ADTs) - /// such as sets && hash tables are suitable for this partitioning - /// scheme. && !all operations on such ADTs are always supported. - /// For example, the partitioning scheme is incompatible with 0-arg - /// operations such as "empty?" on sets. But it is very effective if - /// we want to only check linearizability of say "insert", "remove" - /// && "contains". - /// - /// S - sequential data type - template - class Slicer - { - private: - typedef std::vector> Sublogs; - - static void slice(const Entry& log_head, Sublogs& sublogs) - { - const typename Sublogs::size_type n = sublogs.size(); - - EntryPtr entry_ptr{ log_head.next }, next_entry_ptr; - std::vector> last_entry_ptrs(sublogs.size()); - std::vector entry_ids(sublogs.size()); - typename Sublogs::size_type i; - unsigned new_entry_id; - - while (entry_ptr != nullptr) - { - i = entry_ptr->op().partition() % n; - - LogInfo& log_info = sublogs[i]; - EntryPtr& last_entry_ptr = last_entry_ptrs[i]; - - if (log_info.log_head_ptr() == nullptr) - { - // initialize sub-log - assert(entry_ptr->is_call()); - assert(last_entry_ptr == nullptr); - - log_info.m_log_head_ptr = entry_ptr; - log_info.m_number_of_entries = 1U; - } - else - { - // size of the sub-log increases - ++log_info.m_number_of_entries; - - assert(last_entry_ptr != nullptr); - last_entry_ptr->next = entry_ptr; - } - - if (entry_ptr->is_call()) - { - new_entry_id = entry_ids[i]++; - entry_ptr->set_entry_id(new_entry_id); - entry_ptr->match()->set_entry_id(new_entry_id); - } - - next_entry_ptr = entry_ptr->next; - entry_ptr->prev = last_entry_ptr; - entry_ptr->next = nullptr; - last_entry_ptr = entry_ptr; - entry_ptr = next_entry_ptr; - } - } - - Sublogs m_sublogs; - unsigned m_current_partition; - - public: - const Entry log_head; - const unsigned number_of_partitions; - - Slicer(LogInfo log_info, unsigned _number_of_partitions) - : m_sublogs(_number_of_partitions), - m_current_partition{ 0U }, - log_head{ log_info.log_head_ptr() }, - number_of_partitions{ _number_of_partitions } - { - slice(log_head, m_sublogs); - } - - const LogInfo& sublog_info(unsigned partition) const - { - return m_sublogs[partition]; - } - - const LogInfo& next_sublog_info() - { - static LogInfo s_empty_log; - - unsigned partition = m_current_partition; - ++m_current_partition; - - if (partition < number_of_partitions) - return m_sublogs[partition]; - - return s_empty_log; - } - }; - - /// S - sequential data type - template - class ConcurrentLog - { - private: - typedef std::vector> Entries; - typedef typename Entries::size_type Size; - - Entries m_entries; - std::atomic m_index; - - static void link(EntryPtr last_entry_ptr, Entry& entry) - { - if (last_entry_ptr != nullptr) - last_entry_ptr->next = &entry; - - entry.prev = last_entry_ptr; - } - - public: - ConcurrentLog(Size capacity) - : m_entries(capacity), - m_index{ 0U } {} - - /// \remark thread-safe - - /// \pre: enough capacity - EntryPtr push_back(OpPtr&& op_ptr) - { - // we use the relaxed memory || der tag because we - // do !need to read any other memory locations - Size index = m_index.fetch_add(1U, std::memory_order_relaxed); - - assert(index < m_entries.size()); - - // There is no data race, see [container.requirements.dataraces] - // in Section 23.2.2, paragraph 2, p. 734 in the C++11 language - // specification. Since the index was incremented atomically, - // each thread accesses a different element in the vector. - Entry& entry = m_entries[index]; - entry.set_op(std::move(op_ptr)); - entry.set_thread_id(std::this_thread::get_id()); - - return &entry; - } - - /// \remark thread-safe - - /// \pre: enough capacity - /// \post: call_entry_ptr->is_call() - EntryPtr push_back(EntryPtr call_entry_ptr, OpPtr&& op_ptr) - { - EntryPtr entry_ptr = push_back(std::move(op_ptr)); - call_entry_ptr->set_match(entry_ptr); - assert(call_entry_ptr->is_call()); - - return entry_ptr; - } - - /// \warning !thread-safe - EntryPtr log_head_ptr() - { - if (m_entries.front().next == nullptr) - { - unsigned entry_id{ 0U }; - Size index{ 0U }; - - EntryPtr last_entry_ptr{ nullptr }; - for (Entry& entry : m_entries) - { - if (index == m_index) - break; - - ++index; - - if (entry.is_call()) - { - entry.set_entry_id(entry_id); - entry.match()->set_entry_id(entry_id); - - ++entry_id; - } - - link(last_entry_ptr, entry); - last_entry_ptr = &entry; - } - } - - return &m_entries.front(); - } - - /// Total number of call entries plus return entries. - - /// Returns even number since every call is paired with a return - /// - /// \warning !thread-safe - std::size_t number_of_entries() const noexcept - { - return m_index.load(); - } - - /// \warning !thread-safe - LogInfo info() - { - return{ log_head_ptr(), number_of_entries() }; - } - }; - - /************* Models for sequential abstract data types *************/ - - class FlexibleBitset - { - public: - typedef Bitset::Pos Pos; - - private: - Bitset m_bitset; - - void allocate_blocks_if_neccessary(Pos pos) noexcept - { - if (pos < Bitset::s_bits_per_block) - return; - - assert(0U < pos); - Bitset::BlockIndex new_size{ Bitset::blocks_size(pos) }; - if (m_bitset.m_blocks.size() < new_size) { - m_bitset.m_blocks.resize(new_size); - } - } - - public: - FlexibleBitset() - : m_bitset{ 1U } {} - - FlexibleBitset(Pos max_pos) - : m_bitset{ max_pos } {} - - bool is_empty() const noexcept - { - return m_bitset.is_empty(); - } - - bool set(Pos pos) - { - allocate_blocks_if_neccessary(pos); - return m_bitset.set(pos); - } - - bool is_set(Pos pos) const - { - return m_bitset.is_set(pos); - } - - bool reset(Pos pos) - { - allocate_blocks_if_neccessary(pos); - return m_bitset.reset(pos); - } - - /// Same size && bits? - bool operator==(const FlexibleBitset& other) const noexcept - { - return m_bitset == other.m_bitset; - } - - bool operator!=(const FlexibleBitset& other) const noexcept - { - return m_bitset != other.m_bitset; - } - - std::size_t hash_code() const noexcept - { - return m_bitset.m_hash; - } - }; - - namespace state - { - namespace internal - { - template - struct RetOp : public Op - { - typedef RetOp Base; - - const Ret ret; - - RetOp(Ret r) - : Op(), ret{ r } {} - - RetOp(Ret r, unsigned partition) - : Op(partition), ret{ r } {} + } +}; + +template +void compositional_check(Log& log, Result &result, + unsigned number_of_partitions, Duration max_duration) +{ + Slicer slicer{ log.info(), number_of_partitions }; + for (unsigned partition = 0; partition < slicer.number_of_partitions; ++partition) + { + LinearizabilityTester tester{ slicer.sublog_info(partition), max_duration }; + tester.check(result); + if (!(result.is_timeout() || result.is_linearizable())) + break; + } +} + +/// RAII class to ensure a thread becomes unjoinable on all paths +class Thread +{ + private: + std::thread m_thread; + + public: + Thread() + : m_thread{} {} + + Thread(std::thread&& thread) + : m_thread(std::move(thread)) {} + + template + Thread(F&& f, Args&&... args) + : m_thread(std::forward(f), std::forward(args)...) {} + + ~Thread() + { + if (m_thread.joinable()) + m_thread.join(); + } + + /// \pre: joinable() + /// \post: not joinable() + + /// Throws std::system_error if an error occurs. + void join() + { + m_thread.join(); + } + + bool joinable() const noexcept + { + return m_thread.joinable(); + } + + Thread& operator=(Thread&& thread) + { + m_thread = std::move(thread.m_thread); + return *this; + } +}; + +/// Partition history into sub-histories + +/// A slicer partitions the history into independent sub-histories. +/// Our partitioning scheme hinges on Theorem 3.6.1 in "The Art of +/// Multiprocessor Programming" (Revised Ed.) by Herlihy && Shavit. +/// +/// Typically only associative concurrent abstract data types (ADTs) +/// such as sets && hash tables are suitable for this partitioning +/// scheme. && !all operations on such ADTs are always supported. +/// For example, the partitioning scheme is incompatible with 0-arg +/// operations such as "empty?" on sets. But it is very effective if +/// we want to only check linearizability of say "insert", "remove" +/// && "contains". +/// +/// S - sequential data type +template +class Slicer +{ + private: + typedef std::vector> Sublogs; + + static void slice(const Entry& log_head, Sublogs& sublogs) + { + const typename Sublogs::size_type n = sublogs.size(); + + EntryPtr entry_ptr{ log_head.next }, next_entry_ptr; + std::vector> last_entry_ptrs(sublogs.size()); + std::vector entry_ids(sublogs.size()); + typename Sublogs::size_type i; + unsigned new_entry_id; + + while (entry_ptr != nullptr) + { + i = entry_ptr->op().partition() % n; + + LogInfo& log_info = sublogs[i]; + EntryPtr& last_entry_ptr = last_entry_ptrs[i]; + + if (log_info.log_head_ptr() == nullptr) + { + // initialize sub-log + assert(entry_ptr->is_call()); + assert(last_entry_ptr == nullptr); + + log_info.m_log_head_ptr = entry_ptr; + log_info.m_number_of_entries = 1U; + } + else + { + // size of the sub-log increases + ++log_info.m_number_of_entries; + + assert(last_entry_ptr != nullptr); + last_entry_ptr->next = entry_ptr; + } + + if (entry_ptr->is_call()) + { + new_entry_id = entry_ids[i]++; + entry_ptr->set_entry_id(new_entry_id); + entry_ptr->match()->set_entry_id(new_entry_id); + } + + next_entry_ptr = entry_ptr->next; + entry_ptr->prev = last_entry_ptr; + entry_ptr->next = nullptr; + last_entry_ptr = entry_ptr; + entry_ptr = next_entry_ptr; + } + } + + Sublogs m_sublogs; + unsigned m_current_partition; + + public: + const Entry log_head; + const unsigned number_of_partitions; + + Slicer(LogInfo log_info, unsigned _number_of_partitions) + : m_sublogs(_number_of_partitions), + m_current_partition{ 0U }, + log_head{ log_info.log_head_ptr() }, + number_of_partitions{ _number_of_partitions } + { + slice(log_head, m_sublogs); + } + + const LogInfo& sublog_info(unsigned partition) const + { + return m_sublogs[partition]; + } + + const LogInfo& next_sublog_info() + { + static LogInfo s_empty_log; + + unsigned partition = m_current_partition; + ++m_current_partition; + + if (partition < number_of_partitions) + return m_sublogs[partition]; + + return s_empty_log; + } +}; + +/// S - sequential data type +template +class ConcurrentLog +{ + private: + typedef std::vector> Entries; + typedef typename Entries::size_type Size; + + Entries m_entries; + std::atomic m_index; + + static void link(EntryPtr last_entry_ptr, Entry& entry) + { + if (last_entry_ptr != nullptr) + last_entry_ptr->next = &entry; + + entry.prev = last_entry_ptr; + } + + public: + ConcurrentLog(Size capacity) + : m_entries(capacity), + m_index{ 0U } {} + + /// \remark thread-safe + + /// \pre: enough capacity + EntryPtr push_back(OpPtr&& op_ptr) + { + // we use the relaxed memory || der tag because we + // do !need to read any other memory locations + Size index = m_index.fetch_add(1U, std::memory_order_relaxed); + + assert(index < m_entries.size()); + + // There is no data race, see [container.requirements.dataraces] + // in Section 23.2.2, paragraph 2, p. 734 in the C++11 language + // specification. Since the index was incremented atomically, + // each thread accesses a different element in the vector. + Entry& entry = m_entries[index]; + entry.set_op(std::move(op_ptr)); + entry.set_thread_id(std::this_thread::get_id()); + + return &entry; + } + + /// \remark thread-safe + + /// \pre: enough capacity + /// \post: call_entry_ptr->is_call() + EntryPtr push_back(EntryPtr call_entry_ptr, OpPtr&& op_ptr) + { + EntryPtr entry_ptr = push_back(std::move(op_ptr)); + call_entry_ptr->set_match(entry_ptr); + assert(call_entry_ptr->is_call()); + + return entry_ptr; + } + + /// \warning !thread-safe + EntryPtr log_head_ptr() + { + if (m_entries.front().next == nullptr) + { + unsigned entry_id{ 0U }; + Size index{ 0U }; + + EntryPtr last_entry_ptr{ nullptr }; + for (Entry& entry : m_entries) + { + if (index == m_index) + break; + + ++index; + + if (entry.is_call()) + { + entry.set_entry_id(entry_id); + entry.match()->set_entry_id(entry_id); + + ++entry_id; + } + + link(last_entry_ptr, entry); + last_entry_ptr = &entry; + } + } + + return &m_entries.front(); + } + + /// Total number of call entries plus return entries. + + /// Returns even number since every call is paired with a return + /// + /// \warning !thread-safe + std::size_t number_of_entries() const noexcept + { + return m_index.load(); + } + + /// \warning !thread-safe + LogInfo info() + { + return{ log_head_ptr(), number_of_entries() }; + } +}; + +/************* Models for sequential abstract data types *************/ + +class FlexibleBitset +{ + public: + typedef Bitset::Pos Pos; + + private: + Bitset m_bitset; + + void allocate_blocks_if_neccessary(Pos pos) noexcept + { + if (pos < Bitset::s_bits_per_block) + return; + + assert(0U < pos); + Bitset::BlockIndex new_size{ Bitset::blocks_size(pos) }; + if (m_bitset.m_blocks.size() < new_size) { + m_bitset.m_blocks.resize(new_size); + } + } + + public: + FlexibleBitset() + : m_bitset{ 1U } {} + + FlexibleBitset(Pos max_pos) + : m_bitset{ max_pos } {} + + bool is_empty() const noexcept + { + return m_bitset.is_empty(); + } + + bool set(Pos pos) + { + allocate_blocks_if_neccessary(pos); + return m_bitset.set(pos); + } + + bool is_set(Pos pos) const + { + return m_bitset.is_set(pos); + } + + bool reset(Pos pos) + { + allocate_blocks_if_neccessary(pos); + return m_bitset.reset(pos); + } + + /// Same size && bits? + bool operator==(const FlexibleBitset& other) const noexcept + { + return m_bitset == other.m_bitset; + } + + bool operator!=(const FlexibleBitset& other) const noexcept + { + return m_bitset != other.m_bitset; + } + + std::size_t hash_code() const noexcept + { + return m_bitset.m_hash; + } +}; + +namespace state +{ +namespace internal +{ +template +struct RetOp : public Op +{ + typedef RetOp Base; + + const Ret ret; + + RetOp(Ret r) + : Op(), ret{ r } {} + + RetOp(Ret r, unsigned partition) + : Op(partition), ret{ r } {} #ifdef _LT_DEBUG_ - std::ostream& print(std::ostream& os) const override - { - return os << "ret: " << ret; - } + std::ostream& print(std::ostream& os) const override + { + return os << "ret: " << ret; + } #endif - }; +}; - template - struct ZeroArgOp : public Op - { - typedef ZeroArgOp Base; +template +struct ZeroArgOp : public Op +{ + typedef ZeroArgOp Base; - ZeroArgOp() - : Op() {} + ZeroArgOp() + : Op() {} #ifdef _LT_DEBUG_ - std::ostream& print(std::ostream& os) const override - { - return os << op_name << "()"; - } + std::ostream& print(std::ostream& os) const override + { + return os << op_name << "()"; + } #endif - }; +}; - template - struct ArgOp : public Op - { - typedef ArgOp Base; +template +struct ArgOp : public Op +{ + typedef ArgOp Base; - const Value value; + const Value value; - ArgOp(Value v) - : Op(v), value{ v } {} + ArgOp(Value v) + : Op(v), value{ v } {} - ArgOp(bool is_partitionable, Value v) - : Op(is_partitionable, v), value{ v } {} + ArgOp(bool is_partitionable, Value v) + : Op(is_partitionable, v), value{ v } {} #ifdef _LT_DEBUG_ - std::ostream& print(std::ostream& os) const override - { - return os << op_name << "(" << std::to_string(value) << ")"; - } + std::ostream& print(std::ostream& os) const override + { + return os << op_name << "(" << std::to_string(value) << ")"; + } #endif - }; - } - - /// Byte read-write register with CAS - class Atomic - { - public: - typedef signed char Value; - - private: - static constexpr char s_read_op_name[5] = "read"; - static constexpr char s_write_op_name[6] = "write"; - - struct ReadRetOp : public Op - { - private: - const bool m_is_pending; - const Value m_value; - - public: - ReadRetOp(bool is_pending, Value value) - : Op(), - m_is_pending(is_pending), - m_value{ value } {} - - bool is_pending() const noexcept - { - return m_is_pending; - } - - /// \pre: !is_pending() - Value value() const - { - assert(!m_is_pending); - return m_value; - } +}; +} + +/// Byte read-write register with CAS +class Atomic +{ + public: + typedef signed char Value; + + private: + static constexpr char s_read_op_name[5] = "read"; + static constexpr char s_write_op_name[6] = "write"; + + struct ReadRetOp : public Op + { + private: + const bool m_is_pending; + const Value m_value; + + public: + ReadRetOp(bool is_pending, Value value) + : Op(), + m_is_pending(is_pending), + m_value{ value } {} + + bool is_pending() const noexcept + { + return m_is_pending; + } + + /// \pre: !is_pending() + Value value() const + { + assert(!m_is_pending); + return m_value; + } #ifdef _LT_DEBUG_ - std::ostream& print(std::ostream& os) const override - { - if (m_is_pending) - return os << "read() : pending"; + std::ostream& print(std::ostream& os) const override + { + if (m_is_pending) + return os << "read() : pending"; - return os << "read() : " << std::to_string(m_value); - } + return os << "read() : " << std::to_string(m_value); + } #endif - }; - - struct ReadCallOp : public internal::ZeroArgOp - { - ReadCallOp() : Base() {} - - std::pair internal_apply(const Atomic& atomic, const Op& op) override - { - const ReadRetOp& read_ret = dynamic_cast(op); - - if (read_ret.is_pending()) - return{ true, atomic }; - - return{ atomic.get() == read_ret.value(), atomic }; - } - }; - - struct CASRetOp : public Op - { - private: - // 0: pending, 1: failed, 2: ok - const unsigned m_status; - - public: - CASRetOp(unsigned status) - : Op(), - m_status(status) {} - - bool is_pending() const noexcept - { - return m_status == 0U; - } - - /// \pre: !is_pending() - bool is_ok() const - { - assert(0U < m_status); - return m_status == 2U; - } + }; + + struct ReadCallOp : public internal::ZeroArgOp + { + ReadCallOp() : Base() {} + + std::pair internal_apply(const Atomic& atomic, const Op& op) override + { + const ReadRetOp& read_ret = dynamic_cast(op); + + if (read_ret.is_pending()) + return{ true, atomic }; + + return{ atomic.get() == read_ret.value(), atomic }; + } + }; + + struct CASRetOp : public Op + { + private: + // 0: pending, 1: failed, 2: ok + const unsigned m_status; + + public: + CASRetOp(unsigned status) + : Op(), + m_status(status) {} + + bool is_pending() const noexcept + { + return m_status == 0U; + } + + /// \pre: !is_pending() + bool is_ok() const + { + assert(0U < m_status); + return m_status == 2U; + } #ifdef _LT_DEBUG_ - std::ostream& print(std::ostream& os) const override - { - os << "cas() : "; + std::ostream& print(std::ostream& os) const override + { + os << "cas() : "; - if (is_pending()) - return os << "pending"; + if (is_pending()) + return os << "pending"; - if (is_ok()) - return os << "succeeded"; + if (is_ok()) + return os << "succeeded"; - return os << "failed"; - } + return os << "failed"; + } #endif - }; + }; - struct CASCallOp : public Op - { - const Value current_value, new_value; + struct CASCallOp : public Op + { + const Value current_value, new_value; - CASCallOp(Value current_v, Value new_v) - : Op(), - current_value{ current_v }, - new_value{ new_v } {} + CASCallOp(Value current_v, Value new_v) + : Op(), + current_value{ current_v }, + new_value{ new_v } {} #ifdef _LT_DEBUG_ - std::ostream& print(std::ostream& os) const override - { - return os << "cas(" << std::to_string(current_value) << ", " << std::to_string(new_value) << ")"; - } + std::ostream& print(std::ostream& os) const override + { + return os << "cas(" << std::to_string(current_value) << ", " << std::to_string(new_value) << ")"; + } #endif - std::pair internal_apply(const Atomic& atomic, const Op& op) override - { - const CASRetOp& cas_ret = dynamic_cast(op); + std::pair internal_apply(const Atomic& atomic, const Op& op) override + { + const CASRetOp& cas_ret = dynamic_cast(op); - if (cas_ret.is_pending()) - { - if (atomic.get() == current_value) - return{ true, atomic.set(new_value) }; + if (cas_ret.is_pending()) + { + if (atomic.get() == current_value) + return{ true, atomic.set(new_value) }; - return{ true, atomic }; - } + return{ true, atomic }; + } - if (atomic.get() == current_value) - return{ cas_ret.is_ok(), atomic.set(new_value) }; + if (atomic.get() == current_value) + return{ cas_ret.is_ok(), atomic.set(new_value) }; - return{ !cas_ret.is_ok(), atomic }; - } - }; + return{ !cas_ret.is_ok(), atomic }; + } + }; - struct WriteRetOp : public Op - { - const bool is_pending; + struct WriteRetOp : public Op + { + const bool is_pending; - WriteRetOp(bool pending) - : Op(), - is_pending(pending) {} + WriteRetOp(bool pending) + : Op(), + is_pending(pending) {} #ifdef _LT_DEBUG_ - std::ostream& print(std::ostream& os) const override - { - if (is_pending) - return os << "write() : pending"; + std::ostream& print(std::ostream& os) const override + { + if (is_pending) + return os << "write() : pending"; - return os << "write() : succeeded"; - } + return os << "write() : succeeded"; + } #endif - }; - - struct WriteCallOp : public internal::ArgOp - { - typedef internal::ArgOp Base; - - WriteCallOp(Value new_value) - : Base(false, new_value) {} - - std::pair internal_apply(const Atomic& atomic, const Op& op) override - { - const WriteRetOp& write_ret = dynamic_cast(op); - - // we don't need to check write_ret.is_pending because if the - // write is pending then it could be still linearized last - return{ true, atomic.set(Base::value) }; - } - }; - - Value m_value; - - Atomic(Value value) : m_value{ value } {} - - public: - typedef std::unique_ptr> AtomicOpPtr; - - static AtomicOpPtr make_read_call() - { - return make_unique(); - } - - static AtomicOpPtr make_read_ret(Value v) - { - return make_unique(false, v); - } - - static AtomicOpPtr make_read_pending() - { - return make_unique(true, '\0'); - } - - static AtomicOpPtr make_write_call(Value v) - { - return make_unique(v); - } - - static AtomicOpPtr make_write_ret() - { - return make_unique(false); - } - - static AtomicOpPtr make_write_pending() - { - return make_unique(true); - } - - static AtomicOpPtr make_cas_call(Value curr_value, Value new_value) - { - return make_unique(curr_value, new_value); - } - - static AtomicOpPtr make_cas_ret(bool ok) - { - return make_unique(1U + ok); - } - - static AtomicOpPtr make_cas_pending() - { - return make_unique(0U); - } - - /// Initially, register is negative - Atomic() : m_value{ -1 } {} - - Value get() const noexcept - { - return m_value; - } - - Atomic set(Value v) const noexcept - { - return{ v }; - } - - bool operator==(const Atomic& atomic) const - { - return m_value == atomic.m_value; - } - - bool operator!=(const Atomic& atomic) const - { - return m_value != atomic.m_value; - } - }; - - constexpr char Atomic::s_read_op_name[]; - constexpr char Atomic::s_write_op_name[]; - - template<> - struct Hash - { - std::size_t operator()(const Atomic& atomic) const noexcept - { - return atomic.get() * 193U; - } - }; - } + }; + + struct WriteCallOp : public internal::ArgOp + { + typedef internal::ArgOp Base; + + WriteCallOp(Value new_value) + : Base(false, new_value) {} + + std::pair internal_apply(const Atomic& atomic, const Op& op) override + { + const WriteRetOp& write_ret = dynamic_cast(op); + + // we don't need to check write_ret.is_pending because if the + // write is pending then it could be still linearized last + return{ true, atomic.set(Base::value) }; + } + }; + + Value m_value; + + Atomic(Value value) : m_value{ value } {} + + public: + typedef std::unique_ptr> AtomicOpPtr; + + static AtomicOpPtr make_read_call() + { + return make_unique(); + } + + static AtomicOpPtr make_read_ret(Value v) + { + return make_unique(false, v); + } + + static AtomicOpPtr make_read_pending() + { + return make_unique(true, '\0'); + } + + static AtomicOpPtr make_write_call(Value v) + { + return make_unique(v); + } + + static AtomicOpPtr make_write_ret() + { + return make_unique(false); + } + + static AtomicOpPtr make_write_pending() + { + return make_unique(true); + } + + static AtomicOpPtr make_cas_call(Value curr_value, Value new_value) + { + return make_unique(curr_value, new_value); + } + + static AtomicOpPtr make_cas_ret(bool ok) + { + return make_unique(1U + ok); + } + + static AtomicOpPtr make_cas_pending() + { + return make_unique(0U); + } + + /// Initially, register is negative + Atomic() : m_value{ -1 } {} + + Value get() const noexcept + { + return m_value; + } + + Atomic set(Value v) const noexcept + { + return{ v }; + } + + bool operator==(const Atomic& atomic) const + { + return m_value == atomic.m_value; + } + + bool operator!=(const Atomic& atomic) const + { + return m_value != atomic.m_value; + } +}; + +constexpr char Atomic::s_read_op_name[]; +constexpr char Atomic::s_write_op_name[]; + +template<> +struct Hash +{ + std::size_t operator()(const Atomic& atomic) const noexcept + { + return atomic.get() * 193U; + } +}; +} } #endif