1 | /////////1/////////2/////////3/////////4/////////5/////////6/////////7/////////8 |
2 | // test_singleton_inherited.cpp: |
3 | // Test the singleton class for a "inherited" singleton (used as Foo:public singleton<Foo>) |
4 | // This can be uses as singleton<Foo>::get_const_instance() OR Foo::get_const_instance() |
5 | // |
6 | // - is_destroyed returns false when singleton is active or uninitialized |
7 | // - is_destroyed returns true when singleton is destructed |
8 | // - the singleton is eventually destructed (no memory leak) |
9 | |
10 | // (C) Copyright 2018 Alexander Grund |
11 | // Use, modification and distribution is subject to the Boost Software |
12 | // License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at |
13 | // http://www.boost.org/LICENSE_1_0.txt) |
14 | |
15 | #include "test_tools.hpp" |
16 | #include <boost/serialization/singleton.hpp> |
17 | #include <boost/preprocessor/stringize.hpp> |
18 | #include <stdexcept> |
19 | |
20 | // Can't use BOOST_TEST because: |
21 | // a) destructors are called after program exit |
22 | // b) This is intended to be used by shared libraries too which would then need their own report_errors call |
23 | // We halso have to disable the Wterminate warning as we call this from dtors |
24 | // C++ will terminate the program in such cases which is OK here |
25 | #pragma GCC diagnostic push |
26 | #pragma GCC diagnostic ignored "-Wterminate" |
27 | #define THROW_ON_FALSE(cond) if(!(cond)) throw std::runtime_error(__FILE__ "(" BOOST_PP_STRINGIZE(__LINE__) ") Assertion failed: " #cond) |
28 | |
29 | // Enum to designate the state of the singletonized instances |
30 | enum ConstructionState{CS_UNINIT, CS_INIT, CS_DESTROYED}; |
31 | |
32 | // We need another singleton to check for the destruction of the singletons at program exit |
33 | // We don't need all the magic for shared library anti-optimization and can keep it very simple |
34 | struct controller{ |
35 | static controller& getInstance(){ |
36 | static controller instance; |
37 | return instance; |
38 | } |
39 | ConstructionState state; |
40 | private: |
41 | controller() { |
42 | state = CS_UNINIT; |
43 | } |
44 | ~controller(); |
45 | }; |
46 | |
47 | // A simple class that sets its construction state in the controller singleton |
48 | struct Foo: boost::serialization::singleton<Foo>{ |
49 | Foo(): i(42) { |
50 | // access controller singleton. Therefore controller will be constructed before this |
51 | THROW_ON_FALSE(controller::getInstance().state == CS_UNINIT); |
52 | controller::getInstance().state = CS_INIT; |
53 | } |
54 | ~Foo() { |
55 | // Because controller is constructed before this, it will be destructed AFTER this. Hence controller is still valid |
56 | THROW_ON_FALSE(controller::getInstance().state == CS_INIT); |
57 | controller::getInstance().state = CS_DESTROYED; |
58 | } |
59 | // Volatile to prevent compiler optimization from removing this |
60 | volatile int i; |
61 | }; |
62 | |
63 | controller::~controller() { |
64 | // If this fails, the singletons were not freed and memory is leaked |
65 | THROW_ON_FALSE(state == CS_DESTROYED); |
66 | // If this fails, then the destroyed flag is not set and one may use a deleted instance if relying on this flag |
67 | THROW_ON_FALSE(boost::serialization::singleton<Foo>::is_destroyed()); |
68 | THROW_ON_FALSE(Foo::is_destroyed()); |
69 | } |
70 | |
71 | int |
72 | test_main( int /* argc */, char* /* argv */[] ) |
73 | { |
74 | // Check if the singleton is alive and use it |
75 | BOOST_CHECK(!boost::serialization::singleton<Foo>::is_destroyed()); |
76 | BOOST_CHECK(!Foo::is_destroyed()); |
77 | |
78 | BOOST_CHECK(boost::serialization::singleton<Foo>::get_const_instance().i == 42); |
79 | BOOST_CHECK(Foo::get_const_instance().i == 42); |
80 | return EXIT_SUCCESS; |
81 | } |
82 | |