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-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // UNSUPPORTED: no-threads 10 // UNSUPPORTED: c++03, c++11, c++14 11 12 // ALLOW_RETRIES: 2 13 14 // shared_mutex was introduced in macosx10.12 15 // UNSUPPORTED: use_system_cxx_lib && target={{.+}}-apple-macosx10.{{9|10|11}} 16 17 // <shared_mutex> 18 19 // class shared_mutex; 20 21 // void lock(); 22 23 #include <shared_mutex> 24 #include <thread> 25 #include <cstdlib> 26 #include <cassert> 27 28 #include "make_test_thread.h" 29 #include "test_macros.h" 30 31 std::shared_mutex m; 32 33 typedef std::chrono::system_clock Clock; 34 typedef Clock::time_point time_point; 35 typedef Clock::duration duration; 36 typedef std::chrono::milliseconds ms; 37 typedef std::chrono::nanoseconds ns; 38 39 ms WaitTime = ms(250); 40 41 // Thread sanitizer causes more overhead and will sometimes cause this test 42 // to fail. To prevent this we give Thread sanitizer more time to complete the 43 // test. 44 #if !defined(TEST_HAS_SANITIZERS) 45 ms Tolerance = ms(50); 46 #else 47 ms Tolerance = ms(50 * 5); 48 #endif 49 f()50void f() 51 { 52 time_point t0 = Clock::now(); 53 m.lock(); 54 time_point t1 = Clock::now(); 55 m.unlock(); 56 ns d = t1 - t0 - WaitTime; 57 assert(d < Tolerance); // within tolerance 58 } 59 main(int,char **)60int main(int, char**) 61 { 62 m.lock(); 63 std::thread t = support::make_test_thread(f); 64 std::this_thread::sleep_for(WaitTime); 65 m.unlock(); 66 t.join(); 67 68 return 0; 69 } 70