Chris@16: //
Chris@16: // detail/gcc_arm_fenced_block.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_GCC_ARM_FENCED_BLOCK_HPP
Chris@16: #define BOOST_ASIO_DETAIL_GCC_ARM_FENCED_BLOCK_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 <boost/asio/detail/config.hpp>
Chris@16: 
Chris@16: #if defined(__GNUC__) && defined(__arm__)
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 gcc_arm_fenced_block
Chris@16:   : private noncopyable
Chris@16: {
Chris@16: public:
Chris@16:   enum half_t { half };
Chris@16:   enum full_t { full };
Chris@16: 
Chris@16:   // Constructor for a half fenced block.
Chris@16:   explicit gcc_arm_fenced_block(half_t)
Chris@16:   {
Chris@16:   }
Chris@16: 
Chris@16:   // Constructor for a full fenced block.
Chris@16:   explicit gcc_arm_fenced_block(full_t)
Chris@16:   {
Chris@16:     barrier();
Chris@16:   }
Chris@16: 
Chris@16:   // Destructor.
Chris@16:   ~gcc_arm_fenced_block()
Chris@16:   {
Chris@16:     barrier();
Chris@16:   }
Chris@16: 
Chris@16: private:
Chris@16:   static void barrier()
Chris@16:   {
Chris@16: #if defined(__ARM_ARCH_4__) \
Chris@16:     || defined(__ARM_ARCH_4T__) \
Chris@16:     || defined(__ARM_ARCH_5__) \
Chris@16:     || defined(__ARM_ARCH_5E__) \
Chris@16:     || defined(__ARM_ARCH_5T__) \
Chris@16:     || defined(__ARM_ARCH_5TE__) \
Chris@16:     || defined(__ARM_ARCH_5TEJ__) \
Chris@16:     || defined(__ARM_ARCH_6__) \
Chris@16:     || defined(__ARM_ARCH_6J__) \
Chris@16:     || defined(__ARM_ARCH_6K__) \
Chris@16:     || defined(__ARM_ARCH_6Z__) \
Chris@16:     || defined(__ARM_ARCH_6ZK__) \
Chris@16:     || defined(__ARM_ARCH_6T2__)
Chris@16: # if defined(__thumb__)
Chris@16:     // This is just a placeholder and almost certainly not sufficient.
Chris@16:     __asm__ __volatile__ ("" : : : "memory");
Chris@16: # else // defined(__thumb__)
Chris@16:     int a = 0, b = 0;
Chris@16:     __asm__ __volatile__ ("swp %0, %1, [%2]"
Chris@16:         : "=&r"(a) : "r"(1), "r"(&b) : "memory", "cc");
Chris@16: # endif // defined(__thumb__)
Chris@16: #else
Chris@16:     // ARMv7 and later.
Chris@16:     __asm__ __volatile__ ("dmb" : : : "memory");
Chris@16: #endif
Chris@16:   }
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 // defined(__GNUC__) && defined(__arm__)
Chris@16: 
Chris@16: #endif // BOOST_ASIO_DETAIL_GCC_ARM_FENCED_BLOCK_HPP