ceph/src/boost/boost/asio/ssl/detail/openssl_init.hpp

   1 //
   2 // ssl/detail/openssl_init.hpp
   3 // ~~~~~~~~~~~~~~~~~~~~~~~~~~~
   4 //
   5 // Copyright (c) 2003-2017 Christopher M. Kohlhoff (chris at kohlhoff dot com)
   6 //
   7 // Distributed under the Boost Software License, Version 1.0. (See accompanying
   8 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   9 //
  10
  11 #ifndef BOOST_ASIO_SSL_DETAIL_OPENSSL_INIT_HPP
  12 #define BOOST_ASIO_SSL_DETAIL_OPENSSL_INIT_HPP
  13
  14 #if defined(_MSC_VER) && (_MSC_VER >= 1200)
  15 # pragma once
  16 #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
  17
  18 #include <boost/asio/detail/config.hpp>
  19 #include <cstring>
  20 #include <boost/asio/detail/memory.hpp>
  21 #include <boost/asio/detail/noncopyable.hpp>
  22 #include <boost/asio/ssl/detail/openssl_types.hpp>
  23
  24 #include <boost/asio/detail/push_options.hpp>
  25
  26 namespace boost {
  27 namespace asio {
  28 namespace ssl {
  29 namespace detail {
  30
  31 class openssl_init_base
  32   : private noncopyable
  33 {
  34 protected:
  35   // Class that performs the actual initialisation.
  36   class do_init;
  37
  38   // Helper function to manage a do_init singleton. The static instance of the
  39   // openssl_init object ensures that this function is always called before
  40   // main, and therefore before any other threads can get started. The do_init
  41   // instance must be static in this function to ensure that it gets
  42   // initialised before any other global objects try to use it.
  43   BOOST_ASIO_DECL static boost::asio::detail::shared_ptr<do_init> instance();
  44
  45 #if !defined(SSL_OP_NO_COMPRESSION) \
  46   && (OPENSSL_VERSION_NUMBER >= 0x00908000L)
  47   // Get an empty stack of compression methods, to be used when disabling
  48   // compression.
  49   BOOST_ASIO_DECL static STACK_OF(SSL_COMP)* get_null_compression_methods();
  50 #endif // !defined(SSL_OP_NO_COMPRESSION)
  51        // && (OPENSSL_VERSION_NUMBER >= 0x00908000L)
  52 };
  53
  54 template <bool Do_Init = true>
  55 class openssl_init : private openssl_init_base
  56 {
  57 public:
  58   // Constructor.
  59   openssl_init()
  60     : ref_(instance())
  61   {
  62     using namespace std; // For memmove.
  63
  64     // Ensure openssl_init::instance_ is linked in.
  65     openssl_init* tmp = &instance_;
  66     memmove(&tmp, &tmp, sizeof(openssl_init*));
  67   }
  68
  69   // Destructor.
  70   ~openssl_init()
  71   {
  72   }
  73
  74 #if !defined(SSL_OP_NO_COMPRESSION) \
  75   && (OPENSSL_VERSION_NUMBER >= 0x00908000L)
  76   using openssl_init_base::get_null_compression_methods;
  77 #endif // !defined(SSL_OP_NO_COMPRESSION)
  78        // && (OPENSSL_VERSION_NUMBER >= 0x00908000L)
  79
  80 private:
  81   // Instance to force initialisation of openssl at global scope.
  82   static openssl_init instance_;
  83
  84   // Reference to singleton do_init object to ensure that openssl does not get
  85   // cleaned up until the last user has finished with it.
  86   boost::asio::detail::shared_ptr<do_init> ref_;
  87 };
  88
  89 template <bool Do_Init>
  90 openssl_init<Do_Init> openssl_init<Do_Init>::instance_;
  91
  92 } // namespace detail
  93 } // namespace ssl
  94 } // namespace asio
  95 } // namespace boost
  96
  97 #include <boost/asio/detail/pop_options.hpp>
  98
  99 #if defined(BOOST_ASIO_HEADER_ONLY)
 100 # include <boost/asio/ssl/detail/impl/openssl_init.ipp>
 101 #endif // defined(BOOST_ASIO_HEADER_ONLY)
 102
 103 #endif // BOOST_ASIO_SSL_DETAIL_OPENSSL_INIT_HPP