ceph/src/boost/libs/dll/example/tutorial6/on_unload_lib.cpp

   1 // Copyright 2014 Renato Tegon Forti, Antony Polukhin.
   2 // Copyright 2015 Antony Polukhin.
   3 //
   4 // Distributed under the Boost Software License, Version 1.0.
   5 // (See accompanying file LICENSE_1_0.txt
   6 // or copy at http://www.boost.org/LICENSE_1_0.txt)
   7
   8 // MinGW related workaround
   9 #define BOOST_DLL_FORCE_ALIAS_INSTANTIATION
  10
  11 //[plugcpp_on_unload
  12 #include <boost/dll/alias.hpp> // for BOOST_DLL_ALIAS
  13 #include <boost/function.hpp>
  14 #include <vector>
  15
  16 namespace my_namespace {
  17
  18 struct on_unload {
  19     typedef boost::function<void()> callback_t;
  20     typedef on_unload this_type;
  21
  22     ~on_unload() {
  23         for (std::size_t i = 0; i < callbacks_.size(); ++i) {
  24             callback_t& function = callbacks_[i];
  25             function(); // calling the callback
  26         }
  27     }
  28
  29     // not thread safe
  30     static void add(const callback_t& function) {
  31         static this_type instance;
  32         instance.callbacks_.push_back(function);
  33     }
  34
  35 private:
  36     std::vector<callback_t> callbacks_;
  37     on_unload() {} // prohibit construction outside of the `add` function
  38 };
  39
  40 // Exporting the static "add" function with name "on_unload"
  41 BOOST_DLL_ALIAS(my_namespace::on_unload::add, on_unload)
  42
  43 } // namespace my_namespace
  44
  45 //]
  46
  47
  48