| //===----------------------------------------------------------------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is dual licensed under the MIT and the University of Illinois Open |
| // Source Licenses. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // UNSUPPORTED: libcpp-has-no-threads |
| // UNSUPPORTED: c++03, c++98, c++11, c++14 |
| |
| // <shared_mutex> |
| |
| // class shared_mutex; |
| |
| // void lock_shared(); |
| |
| #include <shared_mutex> |
| #include <thread> |
| #include <vector> |
| #include <cstdlib> |
| #include <cassert> |
| |
| #include "test_macros.h" |
| |
| std::shared_mutex m; |
| |
| typedef std::chrono::system_clock Clock; |
| typedef Clock::time_point time_point; |
| typedef Clock::duration duration; |
| typedef std::chrono::milliseconds ms; |
| typedef std::chrono::nanoseconds ns; |
| |
| ms WaitTime = ms(250); |
| |
| // Thread sanitizer causes more overhead and will sometimes cause this test |
| // to fail. To prevent this we give Thread sanitizer more time to complete the |
| // test. |
| #if !defined(TEST_HAS_SANITIZERS) |
| ms Tolerance = ms(50); |
| #else |
| ms Tolerance = ms(50 * 5); |
| #endif |
| |
| void f() |
| { |
| time_point t0 = Clock::now(); |
| m.lock_shared(); |
| time_point t1 = Clock::now(); |
| m.unlock_shared(); |
| ns d = t1 - t0 - WaitTime; |
| assert(d < Tolerance); // within tolerance |
| } |
| |
| void g() |
| { |
| time_point t0 = Clock::now(); |
| m.lock_shared(); |
| time_point t1 = Clock::now(); |
| m.unlock_shared(); |
| ns d = t1 - t0; |
| assert(d < Tolerance); // within tolerance |
| } |
| |
| |
| int main() |
| { |
| m.lock(); |
| std::vector<std::thread> v; |
| for (int i = 0; i < 5; ++i) |
| v.push_back(std::thread(f)); |
| std::this_thread::sleep_for(WaitTime); |
| m.unlock(); |
| for (auto& t : v) |
| t.join(); |
| m.lock_shared(); |
| for (auto& t : v) |
| t = std::thread(g); |
| std::thread q(f); |
| std::this_thread::sleep_for(WaitTime); |
| m.unlock_shared(); |
| for (auto& t : v) |
| t.join(); |
| q.join(); |
| } |