1 #ifndef BOOST_SMART_PTR_DETAIL_ATOMIC_COUNT_GCC_HPP_INCLUDED 2 #define BOOST_SMART_PTR_DETAIL_ATOMIC_COUNT_GCC_HPP_INCLUDED 3 4 // 5 // boost/detail/atomic_count_gcc.hpp 6 // 7 // atomic_count for GNU libstdc++ v3 8 // 9 // http://gcc.gnu.org/onlinedocs/porting/Thread-safety.html 10 // 11 // Copyright (c) 2001, 2002 Peter Dimov and Multi Media Ltd. 12 // Copyright (c) 2002 Lars Gullik Bjønnes <larsbj@lyx.org> 13 // Copyright 2003-2005 Peter Dimov 14 // 15 // Distributed under the Boost Software License, Version 1.0. (See 16 // accompanying file LICENSE_1_0.txt or copy at 17 // http://www.boost.org/LICENSE_1_0.txt) 18 // 19 20 #if __GNUC__ * 100 + __GNUC_MINOR__ >= 402 21 # include <ext/atomicity.h> 22 #else 23 # include <bits/atomicity.h> 24 #endif 25 26 namespace boost 27 { 28 29 namespace detail 30 { 31 32 #if defined(__GLIBCXX__) // g++ 3.4+ 33 34 using __gnu_cxx::__atomic_add; 35 using __gnu_cxx::__exchange_and_add; 36 37 #endif 38 39 class atomic_count 40 { 41 public: 42 atomic_count(long v)43 explicit atomic_count( long v ) : value_( v ) {} 44 operator ++()45 long operator++() 46 { 47 return __exchange_and_add( &value_, +1 ) + 1; 48 } 49 operator --()50 long operator--() 51 { 52 return __exchange_and_add( &value_, -1 ) - 1; 53 } 54 operator long() const55 operator long() const 56 { 57 return __exchange_and_add( &value_, 0 ); 58 } 59 60 private: 61 62 atomic_count(atomic_count const &); 63 atomic_count & operator=(atomic_count const &); 64 65 mutable _Atomic_word value_; 66 }; 67 68 } // namespace detail 69 70 } // namespace boost 71 72 #endif // #ifndef BOOST_SMART_PTR_DETAIL_ATOMIC_COUNT_GCC_HPP_INCLUDED 73