| 1 | // Signals2 library |
|---|---|
| 2 | // |
| 3 | // Regression test based on bug report from Arian Alin Radu. |
| 4 | // The problem was that tracked objects could be released |
| 5 | // while holding the signal mutex during signal invocation. |
| 6 | // This could result in a recursive |
| 7 | // lock attempt if the tracked object manipulates the signal |
| 8 | // in its destructor. |
| 9 | |
| 10 | // Copyright Frank Mori Hess 2019 |
| 11 | // Use, modification and |
| 12 | // distribution is subject to the Boost Software License, Version |
| 13 | // 1.0. (See accompanying file LICENSE_1_0.txt or copy at |
| 14 | // http://www.boost.org/LICENSE_1_0.txt) |
| 15 | |
| 16 | // For more information, see http://www.boost.org |
| 17 | |
| 18 | #define BOOST_TEST_MODULE signals2 deadlock regression test |
| 19 | #include <boost/test/included/unit_test.hpp> |
| 20 | #include <boost/shared_ptr.hpp> |
| 21 | #include <boost/make_shared.hpp> |
| 22 | #include <boost/signals2/signal.hpp> |
| 23 | #include <boost/signals2/signal_type.hpp> |
| 24 | |
| 25 | namespace bs2 = boost::signals2; |
| 26 | |
| 27 | |
| 28 | // dummy mutex that detects attempts to recursively lock |
| 29 | class test_mutex |
| 30 | { |
| 31 | public: |
| 32 | test_mutex(): m_locked(false) {} |
| 33 | void lock() |
| 34 | { |
| 35 | BOOST_CHECK(m_locked == false); |
| 36 | m_locked = true; |
| 37 | } |
| 38 | bool try_lock() |
| 39 | { |
| 40 | if(m_locked) return false; |
| 41 | lock(); |
| 42 | return true; |
| 43 | } |
| 44 | void unlock() |
| 45 | { |
| 46 | m_locked = false; |
| 47 | } |
| 48 | private: |
| 49 | bool m_locked; |
| 50 | }; |
| 51 | |
| 52 | using namespace bs2::keywords; |
| 53 | typedef bs2::signal_type<void(), mutex_type<test_mutex> >::type Signal; |
| 54 | |
| 55 | class SelfReference: private boost::noncopyable |
| 56 | { |
| 57 | public: |
| 58 | boost::shared_ptr<SelfReference> m_self; |
| 59 | boost::shared_ptr<Signal> m_signal; |
| 60 | |
| 61 | boost::signals2::connection m_conReleaseSelf; |
| 62 | boost::signals2::connection m_conDoNothing; |
| 63 | |
| 64 | SelfReference() |
| 65 | { |
| 66 | m_signal = boost::make_shared<Signal>(); |
| 67 | } |
| 68 | |
| 69 | ~SelfReference() |
| 70 | { |
| 71 | // the first slot (ReleaseSelf) has been called; now the trackable object (this) |
| 72 | // was released, while the second slot is locked |
| 73 | BOOST_CHECK(!m_conReleaseSelf.connected()); |
| 74 | // the second slot is locked, and we enter a recursive (pthread: dead) lock |
| 75 | BOOST_CHECK(m_conDoNothing.connected()); |
| 76 | m_conReleaseSelf.disconnect(); |
| 77 | m_conDoNothing.disconnect(); |
| 78 | // enter recursive (pthread: dead) lock again: |
| 79 | BOOST_CHECK(m_signal->empty()); |
| 80 | } |
| 81 | |
| 82 | void ReleaseSelf() |
| 83 | { |
| 84 | m_self.reset(); |
| 85 | } |
| 86 | |
| 87 | static void DoNothing() |
| 88 | { |
| 89 | } |
| 90 | |
| 91 | static void Run() |
| 92 | { |
| 93 | boost::shared_ptr<Signal> signal; |
| 94 | { |
| 95 | boost::shared_ptr<SelfReference> obj = boost::make_shared<SelfReference>(); |
| 96 | obj->m_self = obj; |
| 97 | signal = obj->m_signal; |
| 98 | |
| 99 | obj->m_conReleaseSelf = signal->connect(slot: Signal::slot_type(&SelfReference::ReleaseSelf, obj.get()).track(tracked: obj)); |
| 100 | obj->m_conDoNothing = signal->connect(slot: Signal::slot_type(&SelfReference::DoNothing)); |
| 101 | } |
| 102 | (*signal)(); |
| 103 | } |
| 104 | }; |
| 105 | |
| 106 | BOOST_AUTO_TEST_CASE(test_main) |
| 107 | { |
| 108 | SelfReference::Run(); |
| 109 | } |
| 110 |