Chris@16: //
Chris@16: // detail/thread_info_base.hpp
Chris@16: // ~~~~~~~~~~~~~~~~~~~~~~~~~~~
Chris@16: //
Chris@101: // Copyright (c) 2003-2015 Christopher M. Kohlhoff (chris at kohlhoff dot com)
Chris@16: //
Chris@16: // Distributed under the Boost Software License, Version 1.0. (See accompanying
Chris@16: // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
Chris@16: //
Chris@16: 
Chris@16: #ifndef BOOST_ASIO_DETAIL_THREAD_INFO_BASE_HPP
Chris@16: #define BOOST_ASIO_DETAIL_THREAD_INFO_BASE_HPP
Chris@16: 
Chris@16: #if defined(_MSC_VER) && (_MSC_VER >= 1200)
Chris@16: # pragma once
Chris@16: #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
Chris@16: 
Chris@16: #include <climits>
Chris@16: #include <cstddef>
Chris@16: #include <boost/asio/detail/noncopyable.hpp>
Chris@16: 
Chris@16: #include <boost/asio/detail/push_options.hpp>
Chris@16: 
Chris@16: namespace boost {
Chris@16: namespace asio {
Chris@16: namespace detail {
Chris@16: 
Chris@16: class thread_info_base
Chris@16:   : private noncopyable
Chris@16: {
Chris@16: public:
Chris@16:   thread_info_base()
Chris@16:     : reusable_memory_(0)
Chris@16:   {
Chris@16:   }
Chris@16: 
Chris@16:   ~thread_info_base()
Chris@16:   {
Chris@16:     if (reusable_memory_)
Chris@16:       ::operator delete(reusable_memory_);
Chris@16:   }
Chris@16: 
Chris@16:   static void* allocate(thread_info_base* this_thread, std::size_t size)
Chris@16:   {
Chris@16:     if (this_thread && this_thread->reusable_memory_)
Chris@16:     {
Chris@16:       void* const pointer = this_thread->reusable_memory_;
Chris@16:       this_thread->reusable_memory_ = 0;
Chris@16: 
Chris@16:       unsigned char* const mem = static_cast<unsigned char*>(pointer);
Chris@16:       if (static_cast<std::size_t>(mem[0]) >= size)
Chris@16:       {
Chris@16:         mem[size] = mem[0];
Chris@16:         return pointer;
Chris@16:       }
Chris@16: 
Chris@16:       ::operator delete(pointer);
Chris@16:     }
Chris@16: 
Chris@16:     void* const pointer = ::operator new(size + 1);
Chris@16:     unsigned char* const mem = static_cast<unsigned char*>(pointer);
Chris@16:     mem[size] = (size <= UCHAR_MAX) ? static_cast<unsigned char>(size) : 0;
Chris@16:     return pointer;
Chris@16:   }
Chris@16: 
Chris@16:   static void deallocate(thread_info_base* this_thread,
Chris@16:       void* pointer, std::size_t size)
Chris@16:   {
Chris@16:     if (size <= UCHAR_MAX)
Chris@16:     {
Chris@16:       if (this_thread && this_thread->reusable_memory_ == 0)
Chris@16:       {
Chris@16:         unsigned char* const mem = static_cast<unsigned char*>(pointer);
Chris@16:         mem[0] = mem[size];
Chris@16:         this_thread->reusable_memory_ = pointer;
Chris@16:         return;
Chris@16:       }
Chris@16:     }
Chris@16: 
Chris@16:     ::operator delete(pointer);
Chris@16:   }
Chris@16: 
Chris@16: private:
Chris@16:   void* reusable_memory_;
Chris@16: };
Chris@16: 
Chris@16: } // namespace detail
Chris@16: } // namespace asio
Chris@16: } // namespace boost
Chris@16: 
Chris@16: #include <boost/asio/detail/pop_options.hpp>
Chris@16: 
Chris@16: #endif // BOOST_ASIO_DETAIL_THREAD_INFO_BASE_HPP