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// shared_lock(mutex_type& m, try_to_lock_t); 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 24std::shared_timed_mutex m; 25 26typedef std::chrono::system_clock Clock; 27typedef Clock::time_point time_point; 28typedef Clock::duration duration; 29typedef std::chrono::milliseconds ms; 30typedef std::chrono::nanoseconds ns; 31 32void f() 33{ 34 time_point t0 = Clock::now(); 35 { 36 std::shared_lock<std::shared_timed_mutex> lk(m, std::try_to_lock); 37 assert(lk.owns_lock() == false); 38 } 39 { 40 std::shared_lock<std::shared_timed_mutex> lk(m, std::try_to_lock); 41 assert(lk.owns_lock() == false); 42 } 43 { 44 std::shared_lock<std::shared_timed_mutex> lk(m, std::try_to_lock); 45 assert(lk.owns_lock() == false); 46 } 47 while (true) 48 { 49 std::shared_lock<std::shared_timed_mutex> lk(m, std::try_to_lock); 50 if (lk.owns_lock()) 51 break; 52 } 53 time_point t1 = Clock::now(); 54 ns d = t1 - t0 - ms(250); 55 assert(d < ms(200)); // within 200ms 56} 57 58#endif // _LIBCPP_STD_VER > 11 59 60int main() 61{ 62#if _LIBCPP_STD_VER > 11 63 m.lock(); 64 std::vector<std::thread> v; 65 for (int i = 0; i < 5; ++i) 66 v.push_back(std::thread(f)); 67 std::this_thread::sleep_for(ms(250)); 68 m.unlock(); 69 for (auto& t : v) 70 t.join(); 71#endif // _LIBCPP_STD_VER > 11 72} 73