Insane_DNS/libraries/asio-1.28.1/include/asio/ssl/detail/openssl_init.hpp

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2023-10-24 21:59:30 -04:00
//
// ssl/detail/openssl_init.hpp
// ~~~~~~~~~~~~~~~~~~~~~~~~~~~
//
// Copyright (c) 2003-2023 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_SSL_DETAIL_OPENSSL_INIT_HPP
#define ASIO_SSL_DETAIL_OPENSSL_INIT_HPP
#if defined(_MSC_VER) && (_MSC_VER >= 1200)
# pragma once
#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
#include "asio/detail/config.hpp"
#include <cstring>
#include "asio/detail/memory.hpp"
#include "asio/detail/noncopyable.hpp"
#include "asio/ssl/detail/openssl_types.hpp"
#include "asio/detail/push_options.hpp"
namespace asio {
namespace ssl {
namespace detail {
class openssl_init_base
: private noncopyable
{
protected:
// Class that performs the actual initialisation.
class do_init;
// Helper function to manage a do_init singleton. The static instance of the
// openssl_init object ensures that this function is always called before
// main, and therefore before any other threads can get started. The do_init
// instance must be static in this function to ensure that it gets
// initialised before any other global objects try to use it.
ASIO_DECL static asio::detail::shared_ptr<do_init> instance();
#if !defined(SSL_OP_NO_COMPRESSION) \
&& (OPENSSL_VERSION_NUMBER >= 0x00908000L)
// Get an empty stack of compression methods, to be used when disabling
// compression.
ASIO_DECL static STACK_OF(SSL_COMP)* get_null_compression_methods();
#endif // !defined(SSL_OP_NO_COMPRESSION)
// && (OPENSSL_VERSION_NUMBER >= 0x00908000L)
};
template <bool Do_Init = true>
class openssl_init : private openssl_init_base
{
public:
// Constructor.
openssl_init()
: ref_(instance())
{
using namespace std; // For memmove.
// Ensure openssl_init::instance_ is linked in.
openssl_init* tmp = &instance_;
memmove(&tmp, &tmp, sizeof(openssl_init*));
}
// Destructor.
~openssl_init()
{
}
#if !defined(SSL_OP_NO_COMPRESSION) \
&& (OPENSSL_VERSION_NUMBER >= 0x00908000L)
using openssl_init_base::get_null_compression_methods;
#endif // !defined(SSL_OP_NO_COMPRESSION)
// && (OPENSSL_VERSION_NUMBER >= 0x00908000L)
private:
// Instance to force initialisation of openssl at global scope.
static openssl_init instance_;
// Reference to singleton do_init object to ensure that openssl does not get
// cleaned up until the last user has finished with it.
asio::detail::shared_ptr<do_init> ref_;
};
template <bool Do_Init>
openssl_init<Do_Init> openssl_init<Do_Init>::instance_;
} // namespace detail
} // namespace ssl
} // namespace asio
#include "asio/detail/pop_options.hpp"
#if defined(ASIO_HEADER_ONLY)
# include "asio/ssl/detail/impl/openssl_init.ipp"
#endif // defined(ASIO_HEADER_ONLY)
#endif // ASIO_SSL_DETAIL_OPENSSL_INIT_HPP