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: libcpp-has-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: with_system_cxx_lib=macosx10.11 16 // UNSUPPORTED: with_system_cxx_lib=macosx10.10 17 // UNSUPPORTED: with_system_cxx_lib=macosx10.9 18 19 // <shared_mutex> 20 21 // class shared_mutex; 22 23 // void lock(); 24 25 #include <shared_mutex> 26 #include <thread> 27 #include <cstdlib> 28 #include <cassert> 29 30 #include "test_macros.h" 31 32 std::shared_mutex m; 33 34 typedef std::chrono::system_clock Clock; 35 typedef Clock::time_point time_point; 36 typedef Clock::duration duration; 37 typedef std::chrono::milliseconds ms; 38 typedef std::chrono::nanoseconds ns; 39 40 #if !TEST_SLOW_HOST() 41 ms WaitTime = ms(250); 42 #else 43 ms WaitTime = ms(750); 44 #endif 45 46 // Thread sanitizer causes more overhead and will sometimes cause this test 47 // to fail. To prevent this we give Thread sanitizer more time to complete the 48 // test. 49 #if !defined(TEST_HAS_SANITIZERS) && !TEST_SLOW_HOST() 50 ms Tolerance = ms(50); 51 #else 52 ms Tolerance = ms(50 * 5); 53 #endif 54 f()55void f() 56 { 57 time_point t0 = Clock::now(); 58 m.lock(); 59 time_point t1 = Clock::now(); 60 m.unlock(); 61 ns d = t1 - t0 - WaitTime; 62 assert(d < Tolerance); // within tolerance 63 } 64 main(int,char **)65int main(int, char**) 66 { 67 m.lock(); 68 std::thread t(f); 69 std::this_thread::sleep_for(WaitTime); 70 m.unlock(); 71 t.join(); 72 73 return 0; 74 } 75