ceph/src/Beast/include/beast/core/handler_helpers.hpp

   1 //
   2 // Copyright (c) 2013-2017 Vinnie Falco (vinnie dot falco at gmail dot com)
   3 //
   4 // Distributed under the Boost Software License, Version 1.0. (See accompanying
   5 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   6 //
   7
   8 #ifndef BEAST_HANDLER_HELPERS_HPP
   9 #define BEAST_HANDLER_HELPERS_HPP
  10
  11 #include <beast/config.hpp>
  12 #include <boost/asio/handler_alloc_hook.hpp>
  13 #include <boost/asio/handler_continuation_hook.hpp>
  14 #include <boost/asio/handler_invoke_hook.hpp>
  15 #include <memory>
  16
  17 /*  Calls to:
  18
  19     * asio_handler_allocate
  20     * asio_handler_deallocate
  21     * asio_handler_invoke
  22     * asio_handler_is_continuation
  23
  24     must be made from a namespace that does not
  25     contain overloads of this function. The beast_asio_helpers
  26     namespace is defined here for that purpose.
  27 */
  28
  29 namespace beast_asio_helpers {
  30
  31 /// Allocation function for handlers.
  32 template <class Handler>
  33 inline
  34 void*
  35 allocate(std::size_t s, Handler& handler)
  36 {
  37 #if !defined(BOOST_ASIO_HAS_HANDLER_HOOKS)
  38     return ::operator new(s);
  39 #else
  40     using boost::asio::asio_handler_allocate;
  41     return asio_handler_allocate(s, std::addressof(handler));
  42 #endif
  43 }
  44
  45 /// Deallocation function for handlers.
  46 template<class Handler>
  47 inline
  48 void
  49 deallocate(void* p, std::size_t s, Handler& handler)
  50 {
  51 #if !defined(BOOST_ASIO_HAS_HANDLER_HOOKS)
  52     ::operator delete(p);
  53 #else
  54     using boost::asio::asio_handler_deallocate;
  55     asio_handler_deallocate(p, s, std::addressof(handler));
  56 #endif
  57 }
  58
  59 /// Invoke function for handlers.
  60 template<class Function, class Handler>
  61 inline
  62 void
  63 invoke(Function& function, Handler& handler)
  64 {
  65 #if !defined(BOOST_ASIO_HAS_HANDLER_HOOKS)
  66     Function tmp(function);
  67     tmp();
  68 #else
  69     using boost::asio::asio_handler_invoke;
  70     asio_handler_invoke(function, std::addressof(handler));
  71 #endif
  72 }
  73
  74 /// Invoke function for handlers.
  75 template<class Function, class Handler>
  76 inline
  77 void
  78 invoke(Function const& function, Handler& handler)
  79 {
  80 #if !defined(BOOST_ASIO_HAS_HANDLER_HOOKS)
  81     Function tmp(function);
  82     tmp();
  83 #else
  84     using boost::asio::asio_handler_invoke;
  85     asio_handler_invoke(function, std::addressof(handler));
  86 #endif
  87 }
  88
  89 /// Returns true if handler represents a continuation of the asynchronous operation
  90 template<class Handler>
  91 inline
  92 bool
  93 is_continuation(Handler& handler)
  94 {
  95 #if !defined(BOOST_ASIO_HAS_HANDLER_HOOKS)
  96     return false;
  97 #else
  98     using boost::asio::asio_handler_is_continuation;
  99     return asio_handler_is_continuation(std::addressof(handler));
 100 #endif
 101 }
 102
 103 } // beast_asio_helpers
 104
 105 #endif