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 // UNSUPPORTED: c++98, c++03, c++11 12 13 // <shared_mutex> 14 15 // template <class Mutex> class shared_lock; 16 17 // mutex_type* release() noexcept; 18 19 #include <shared_mutex> 20 #include <cassert> 21 22 struct mutex 23 { 24 static int lock_count; 25 static int unlock_count; 26 void lock_shared() {++lock_count;} 27 void unlock_shared() {++unlock_count;} 28 }; 29 30 int mutex::lock_count = 0; 31 int mutex::unlock_count = 0; 32 33 mutex m; 34 35 int main() 36 { 37 std::shared_lock<mutex> lk(m); 38 assert(lk.mutex() == &m); 39 assert(lk.owns_lock() == true); 40 assert(mutex::lock_count == 1); 41 assert(mutex::unlock_count == 0); 42 assert(lk.release() == &m); 43 assert(lk.mutex() == nullptr); 44 assert(lk.owns_lock() == false); 45 assert(mutex::lock_count == 1); 46 assert(mutex::unlock_count == 0); 47 static_assert(noexcept(lk.release()), "release must be noexcept"); 48 } 49
