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 // UNSUPPORTED: libcpp-has-no-threads 11 12 // <shared_mutex> 13 14 // template <class Mutex> class shared_lock; 15 16 // mutex_type* release() noexcept; 17 18 #include <shared_mutex> 19 #include <cassert> 20 21 #if _LIBCPP_STD_VER > 11 22 23 struct mutex 24 { 25 static int lock_count; 26 static int unlock_count; 27 void lock_shared() {++lock_count;} 28 void unlock_shared() {++unlock_count;} 29 }; 30 31 int mutex::lock_count = 0; 32 int mutex::unlock_count = 0; 33 34 mutex m; 35 36 #endif // _LIBCPP_STD_VER > 11 37 38 int main() 39 { 40 #if _LIBCPP_STD_VER > 11 41 std::shared_lock<mutex> lk(m); 42 assert(lk.mutex() == &m); 43 assert(lk.owns_lock() == true); 44 assert(mutex::lock_count == 1); 45 assert(mutex::unlock_count == 0); 46 assert(lk.release() == &m); 47 assert(lk.mutex() == nullptr); 48 assert(lk.owns_lock() == false); 49 assert(mutex::lock_count == 1); 50 assert(mutex::unlock_count == 0); 51 static_assert(noexcept(lk.release()), "release must be noexcept"); 52 #endif // _LIBCPP_STD_VER > 11 53 } 54
