ceph/src/rgw/rgw_boost_asio_coroutine.h

   1 //
   2 // copy of needed class and macors from coroutine.hpp
   3 //
   4 // Copyright (c) 2003-2013 Christopher M. Kohlhoff (chris at kohlhoff dot com)
   5 //
   6 // Distributed under the Boost Software License, Version 1.0. (See accompanying
   7 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   8 //
   9
  10 #ifndef RGW_BOOST_ASIO_COROUTINE_H
  11 #define RGW_BOOST_ASIO_COROUTINE_H
  12
  13 #ifndef HAVE_BOOST_ASIO_COROUTINE
  14
  15 namespace boost {
  16 namespace asio {
  17 namespace detail {
  18
  19 class coroutine_ref;
  20
  21 } // namespace detail
  22
  23 class coroutine
  24 {
  25 public:
  26   /// Constructs a coroutine in its initial state.
  27   coroutine() : value_(0) {}
  28
  29   /// Returns true if the coroutine is the child of a fork.
  30   bool is_child() const { return value_ < 0; }
  31
  32   /// Returns true if the coroutine is the parent of a fork.
  33   bool is_parent() const { return !is_child(); }
  34
  35   /// Returns true if the coroutine has reached its terminal state.
  36   bool is_complete() const { return value_ == -1; }
  37
  38 private:
  39   friend class detail::coroutine_ref;
  40   int value_;
  41 };
  42
  43
  44 namespace detail {
  45
  46 class coroutine_ref
  47 {
  48 public:
  49   coroutine_ref(coroutine& c) : value_(c.value_), modified_(false) {}
  50   coroutine_ref(coroutine* c) : value_(c->value_), modified_(false) {}
  51   ~coroutine_ref() { if (!modified_) value_ = -1; }
  52   operator int() const { return value_; }
  53   int& operator=(int v) { modified_ = true; return value_ = v; }
  54 private:
  55   void operator=(const coroutine_ref&);
  56   int& value_;
  57   bool modified_;
  58 };
  59
  60 } // namespace detail
  61 } // namespace asio
  62 } // namespace boost
  63
  64 #endif // HAVE_BOOST_ASIO_COROUTINE
  65
  66 #endif // RGW_BOOST_ASIO_COROUTINE_H
  67