--- /dev/null
+/*
+ This file is a part of libcds - Concurrent Data Structures library
+
+ (C) Copyright Maxim Khizhinsky (libcds.dev@gmail.com) 2006-2017
+
+ Source code repo: http://github.com/khizmax/libcds/
+ Download: http://sourceforge.net/projects/libcds/files/
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions are met:
+
+ * Redistributions of source code must retain the above copyright notice, this
+ list of conditions and the following disclaimer.
+
+ * Redistributions in binary form must reproduce the above copyright notice,
+ this list of conditions and the following disclaimer in the documentation
+ and/or other materials provided with the distribution.
+
+ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#ifndef CDSLIB_GC_DETAILS_HP_COMMON_H
+#define CDSLIB_GC_DETAILS_HP_COMMON_H
+
+#include <cds/algo/atomic.h>
+#include <cds/gc/details/retired_ptr.h>
+
+#ifdef CDS_ENABLE_HPSTAT
+# define CDS_HPSTAT( expr ) expr
+#else
+# define CDS_HPSTAT( expr )
+#endif
+
+//@cond
+namespace cds { namespace gc { namespace hp { namespace common {
+
+ /// Hazard pointer type
+ typedef void* hazard_ptr;
+
+ /// Retired pointer
+ using cds::gc::details::retired_ptr;
+ using cds::gc::make_retired_ptr;
+
+ /// Hazard pointer guard
+ class guard
+ {
+ public:
+ guard() noexcept
+ : hp_( nullptr )
+ , next_( nullptr )
+ {}
+
+ template <typename T>
+ T* operator=( T* ptr ) noexcept
+ {
+ set( ptr );
+ return ptr;
+ }
+
+ std::nullptr_t operator=( std::nullptr_t ) noexcept
+ {
+ clear();
+ return nullptr;
+ }
+
+ hazard_ptr get() const noexcept
+ {
+ return hp_.load( atomics::memory_order_acquire );
+ }
+
+ hazard_ptr get( atomics::memory_order order ) const noexcept
+ {
+ return hp_.load( order );
+ }
+
+ template <typename T>
+ T* get_as() const noexcept
+ {
+ return reinterpret_cast<T*>( get());
+ }
+
+ template <typename T>
+ void set( T* ptr ) noexcept
+ {
+ hp_.store( reinterpret_cast<hazard_ptr>( ptr ), atomics::memory_order_release );
+ }
+
+ void clear( atomics::memory_order order ) noexcept
+ {
+ hp_.store( nullptr, order );
+ }
+
+ void clear() noexcept
+ {
+ clear( atomics::memory_order_release );
+ }
+
+ private:
+ atomics::atomic<hazard_ptr> hp_;
+
+ public:
+ guard* next_; // free guard list
+ };
+
+ /// Array of guards
+ template <size_t Capacity>
+ class guard_array
+ {
+ public:
+ static size_t const c_nCapacity = Capacity;
+
+ public:
+ guard_array()
+ : arr_{ nullptr }
+ {}
+
+ static constexpr size_t capacity()
+ {
+ return c_nCapacity;
+ }
+
+ guard* operator[]( size_t idx ) const noexcept
+ {
+ assert( idx < capacity());
+ return arr_[idx];
+ }
+
+ template <typename T>
+ void set( size_t idx, T* ptr ) noexcept
+ {
+ assert( idx < capacity());
+ assert( arr_[idx] != nullptr );
+
+ arr_[idx]->set( ptr );
+ }
+
+ void clear( size_t idx ) noexcept
+ {
+ assert( idx < capacity());
+ assert( arr_[idx] != nullptr );
+
+ arr_[idx]->clear();
+ }
+
+ guard* release( size_t idx ) noexcept
+ {
+ assert( idx < capacity());
+
+ guard* g = arr_[idx];
+ arr_[idx] = nullptr;
+ return g;
+ }
+
+ void reset( size_t idx, guard* g ) noexcept
+ {
+ assert( idx < capacity());
+ assert( arr_[idx] == nullptr );
+
+ arr_[idx] = g;
+ }
+
+ private:
+ guard* arr_[c_nCapacity];
+ };
+
+
+ /// Retired pointer disposer
+ typedef void ( *disposer_func )( void* );
+
+}}}} // namespace cds::gc::hp::common
+//@endcond
+
+#endif // #ifndef CDSLIB_GC_DETAILS_HP_COMMON_H
+
+