| // |
| // detail/gcc_arm_fenced_block.hpp |
| // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
| // |
| // Copyright (c) 2003-2016 Christopher M. Kohlhoff (chris at kohlhoff dot com) |
| // |
| // Distributed under the Boost Software License, Version 1.0. (See accompanying |
| // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) |
| // |
| |
| #ifndef ASIO_DETAIL_GCC_ARM_FENCED_BLOCK_HPP |
| #define ASIO_DETAIL_GCC_ARM_FENCED_BLOCK_HPP |
| |
| #if defined(_MSC_VER) && (_MSC_VER >= 1200) |
| # pragma once |
| #endif // defined(_MSC_VER) && (_MSC_VER >= 1200) |
| |
| #include "asio/detail/config.hpp" |
| |
| #if defined(__GNUC__) && defined(__arm__) |
| |
| #include "asio/detail/noncopyable.hpp" |
| |
| #include "asio/detail/push_options.hpp" |
| |
| namespace asio { |
| namespace detail { |
| |
| class gcc_arm_fenced_block |
| : private noncopyable |
| { |
| public: |
| enum half_t { half }; |
| enum full_t { full }; |
| |
| // Constructor for a half fenced block. |
| explicit gcc_arm_fenced_block(half_t) |
| { |
| } |
| |
| // Constructor for a full fenced block. |
| explicit gcc_arm_fenced_block(full_t) |
| { |
| barrier(); |
| } |
| |
| // Destructor. |
| ~gcc_arm_fenced_block() |
| { |
| barrier(); |
| } |
| |
| private: |
| static void barrier() |
| { |
| #if defined(__ARM_ARCH_4__) \ |
| || defined(__ARM_ARCH_4T__) \ |
| || defined(__ARM_ARCH_5__) \ |
| || defined(__ARM_ARCH_5E__) \ |
| || defined(__ARM_ARCH_5T__) \ |
| || defined(__ARM_ARCH_5TE__) \ |
| || defined(__ARM_ARCH_5TEJ__) \ |
| || defined(__ARM_ARCH_6__) \ |
| || defined(__ARM_ARCH_6J__) \ |
| || defined(__ARM_ARCH_6K__) \ |
| || defined(__ARM_ARCH_6Z__) \ |
| || defined(__ARM_ARCH_6ZK__) \ |
| || defined(__ARM_ARCH_6T2__) |
| # if defined(__thumb__) |
| // This is just a placeholder and almost certainly not sufficient. |
| __asm__ __volatile__ ("" : : : "memory"); |
| # else // defined(__thumb__) |
| int a = 0, b = 0; |
| __asm__ __volatile__ ("swp %0, %1, [%2]" |
| : "=&r"(a) : "r"(1), "r"(&b) : "memory", "cc"); |
| # endif // defined(__thumb__) |
| #else |
| // ARMv7 and later. |
| __asm__ __volatile__ ("dmb" : : : "memory"); |
| #endif |
| } |
| }; |
| |
| } // namespace detail |
| } // namespace asio |
| |
| #include "asio/detail/pop_options.hpp" |
| |
| #endif // defined(__GNUC__) && defined(__arm__) |
| |
| #endif // ASIO_DETAIL_GCC_ARM_FENCED_BLOCK_HPP |