1 //===----------------------------------------------------------------------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is dual licensed under the MIT and the University of Illinois Open 6 // Source Licenses. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 10 // <shared_mutex> 11 12 // class shared_timed_mutex; 13 14 // bool try_lock_shared(); 15 16 #include <shared_mutex> 17 #include <thread> 18 #include <vector> 19 #include <cstdlib> 20 #include <cassert> 21 22 #if _LIBCPP_STD_VER > 11 23 24 std::shared_timed_mutex m; 25 26 typedef std::chrono::system_clock Clock; 27 typedef Clock::time_point time_point; 28 typedef Clock::duration duration; 29 typedef std::chrono::milliseconds ms; 30 typedef std::chrono::nanoseconds ns; 31 f()32void f() 33 { 34 time_point t0 = Clock::now(); 35 assert(!m.try_lock_shared()); 36 assert(!m.try_lock_shared()); 37 assert(!m.try_lock_shared()); 38 while(!m.try_lock_shared()) 39 ; 40 time_point t1 = Clock::now(); 41 m.unlock_shared(); 42 ns d = t1 - t0 - ms(250); 43 assert(d < ms(200)); // within 200ms 44 } 45 46 #endif // _LIBCPP_STD_VER > 11 47 main()48int main() 49 { 50 #if _LIBCPP_STD_VER > 11 51 m.lock(); 52 std::vector<std::thread> v; 53 for (int i = 0; i < 5; ++i) 54 v.push_back(std::thread(f)); 55 std::this_thread::sleep_for(ms(250)); 56 m.unlock(); 57 for (auto& t : v) 58 t.join(); 59 #endif // _LIBCPP_STD_VER > 11 60 } 61