65 lines · cpp
1//===----------------------------------------------------------------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9// UNSUPPORTED: no-threads10// UNSUPPORTED: c++03, c++1111 12// <shared_mutex>13 14// class shared_timed_mutex;15 16// bool try_lock();17 18#include <shared_mutex>19#include <atomic>20#include <cassert>21#include <chrono>22#include <thread>23 24#include "make_test_thread.h"25 26int main(int, char**) {27 // Try to exclusive-lock a mutex that is not locked yet. This should succeed.28 {29 std::shared_timed_mutex m;30 bool succeeded = m.try_lock();31 assert(succeeded);32 m.unlock();33 }34 35 // Try to exclusive-lock a mutex that is already locked exclusively. This should fail.36 {37 std::shared_timed_mutex m;38 m.lock();39 40 std::thread t = support::make_test_thread([&] {41 bool succeeded = m.try_lock();42 assert(!succeeded);43 });44 t.join();45 46 m.unlock();47 }48 49 // Try to exclusive-lock a mutex that is already share-locked. This should fail.50 {51 std::shared_timed_mutex m;52 m.lock_shared();53 54 std::thread t = support::make_test_thread([&] {55 bool succeeded = m.try_lock();56 assert(!succeeded);57 });58 t.join();59 60 m.unlock_shared();61 }62 63 return 0;64}65