geometry/srs/shared_grids_std.hpp

0001 // Boost.Geometry
0002
0003 // Copyright (c) 2018-2019, Oracle and/or its affiliates.
0004 // Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle
0005
0006 // Use, modification and distribution is subject to the Boost Software License,
0007 // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
0008 // http://www.boost.org/LICENSE_1_0.txt)
0009
0010 #ifndef BOOST_GEOMETRY_SRS_SHARED_GRIDS_STD_HPP
0011 #define BOOST_GEOMETRY_SRS_SHARED_GRIDS_STD_HPP
0012
0013
0014 #include <boost/config.hpp>
0015
0016 #ifdef BOOST_NO_CXX14_HDR_SHARED_MUTEX
0017 #error "C++14 <shared_mutex> header required."
0018 #endif
0019
0020 #include <boost/geometry/srs/projections/grids.hpp>
0021
0022 #include <mutex>
0023 #include <shared_mutex>
0024
0025
0026 namespace boost { namespace geometry
0027 {
0028
0029 namespace srs
0030 {
0031
0032 class shared_grids_std
0033 {
0034
0035 // VS 2015 Update 2
0036 #if defined(_MSC_FULL_VER) && (_MSC_FULL_VER >= 190023918)
0037     typedef std::shared_mutex mutex_type;
0038 // Other C++17
0039 #elif !defined(BOOST_NO_CXX14_HDR_SHARED_MUTEX) && (__cplusplus > 201402L)
0040     typedef std::shared_mutex mutex_type;
0041 #else
0042     typedef std::shared_timed_mutex mutex_type;
0043 #endif
0044
0045 public:
0046     std::size_t size() const
0047     {
0048         std::shared_lock<mutex_type> lock(mutex);
0049         return gridinfo.size();
0050     }
0051
0052     bool empty() const
0053     {
0054         std::shared_lock<mutex_type> lock(mutex);
0055         return gridinfo.empty();
0056     }
0057
0058     typedef projections::detail::shared_grids_tag tag;
0059
0060     struct read_locked
0061     {
0062         read_locked(shared_grids_std & g)
0063             : gridinfo(g.gridinfo)
0064             , lock(g.mutex)
0065         {}
0066
0067         // should be const&
0068         projections::detail::pj_gridinfo & gridinfo;
0069
0070     private:
0071         std::shared_lock<mutex_type> lock;
0072     };
0073
0074     struct write_locked
0075     {
0076         write_locked(shared_grids_std & g)
0077             : gridinfo(g.gridinfo)
0078             , lock(g.mutex)
0079         {}
0080
0081         projections::detail::pj_gridinfo & gridinfo;
0082
0083     private:
0084         std::unique_lock<mutex_type> lock;
0085     };
0086
0087 private:
0088     projections::detail::pj_gridinfo gridinfo;
0089     mutable mutex_type mutex;
0090 };
0091
0092
0093 } // namespace srs
0094
0095
0096 }} // namespace boost::geometry
0097
0098
0099 #endif // BOOST_GEOMETRY_SRS_SHARED_GRIDS_STD_HPP