1// Copyright (C) 2013 Vicente Botet
2//
3// Distributed under the Boost Software License, Version 1.0. (See accompanying
4// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
5
6////////////////////////////////////////////
7
8//#define BOOST_THREAD_PROVIDES_GENERIC_SHARED_MUTEX_ON_WIN
9#include <iostream>
10#include <boost/thread/thread_only.hpp>
11#include <boost/thread/shared_mutex.hpp>
12// shared_mutex_deadlock.cpp : Defines the entry point for the console application.
13//
14
15
16boost::shared_mutex mutex;
17
18void thread2_func()
19{
20 int i (0);
21 for (;;)
22 {
23 if (mutex.timed_lock(relative_time: boost::posix_time::milliseconds(500)))
24 {
25 std::cout << "Unique lock acquired" << std::endl
26 << "Test successful" << std::endl;
27 mutex.unlock();
28 break;
29 }
30 ++i;
31 if (i == 100)
32 {
33 std::cout << "Test failed. App is deadlocked" << std::endl;
34 break;
35 }
36 boost::this_thread::sleep(rel_time: boost::posix_time::seconds(1));
37 }
38}
39
40void thread3_func()
41{
42 boost::shared_lock<boost::shared_mutex> lock (mutex);
43 std::cout << "Shared lock acquired" << std::endl
44 << "Test successful" << std::endl;
45}
46
47void thread3_func_workaround()
48{
49 for (;;)
50 {
51 if (mutex.timed_lock_shared(relative_time: boost::posix_time::milliseconds(200)))
52 {
53 std::cout << "Shared lock acquired" << std::endl
54 << "Test successful" << std::endl;
55 mutex.unlock_shared();
56 break;
57 }
58 boost::this_thread::sleep(rel_time: boost::posix_time::milliseconds(100));
59 }
60}
61
62int main()
63{
64 std::cout << "Starting" << std::endl;
65
66 // 1 - lock the mutex
67 boost::shared_lock<boost::shared_mutex> lock (mutex);
68
69 // 2 - start thread#2
70 boost::thread thread2(&thread2_func);
71
72 // 3 - sleep
73 boost::this_thread::sleep(rel_time: boost::posix_time::milliseconds(10));
74
75 std::cout << "Thread#2 is waiting" << std::endl;
76
77 // - start thread3
78 boost::thread thread3(&thread3_func);
79 //boost::thread thread3(&thread3_func_workaround);
80
81 std::cout << "Thread#3 is started and blocked. It never will waked" << std::endl;
82
83 thread3.join(); // will never return
84
85 lock.unlock(); // release shared ownership. thread#2 will take unique ownership
86
87 thread2.join();
88
89 std::cout << "Finished" << std::endl;
90 return 0;
91}
92
93
94
95

source code of boost/libs/thread/test/test_7755.cpp