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 // template <class Mutex> class shared_lock; 13 14 // bool try_lock(); 15 16 #include <shared_mutex> 17 #include <cassert> 18 19 #if _LIBCPP_STD_VER > 11 20 21 bool try_lock_called = false; 22 23 struct mutex 24 { 25 bool try_lock_shared() 26 { 27 try_lock_called = !try_lock_called; 28 return try_lock_called; 29 } 30 void unlock_shared() {} 31 }; 32 33 mutex m; 34 35 #endif // _LIBCPP_STD_VER > 11 36 37 int main() 38 { 39 #if _LIBCPP_STD_VER > 11 40 std::shared_lock<mutex> lk(m, std::defer_lock); 41 assert(lk.try_lock() == true); 42 assert(try_lock_called == true); 43 assert(lk.owns_lock() == true); 44 try 45 { 46 lk.try_lock(); 47 assert(false); 48 } 49 catch (std::system_error& e) 50 { 51 assert(e.code().value() == EDEADLK); 52 } 53 lk.unlock(); 54 assert(lk.try_lock() == false); 55 assert(try_lock_called == false); 56 assert(lk.owns_lock() == false); 57 lk.release(); 58 try 59 { 60 lk.try_lock(); 61 assert(false); 62 } 63 catch (std::system_error& e) 64 { 65 assert(e.code().value() == EPERM); 66 } 67 #endif // _LIBCPP_STD_VER > 11 68 } 69
