libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/thread.sharedtimedmutex.class/try_lock_until.pass.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-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // UNSUPPORTED: no-threads
  10 // UNSUPPORTED: c++03, c++11
  11
  12 // ALLOW_RETRIES: 2
  13
  14 // <shared_mutex>
  15
  16 // class shared_timed_mutex;
  17
  18 // template <class Clock, class Duration>
  19 //     bool try_lock_until(const chrono::time_point<Clock, Duration>& abs_time);
  20
  21 #include <shared_mutex>
  22 #include <thread>
  23 #include <cstdlib>
  24 #include <cassert>
  25 #include <chrono>
  26
  27 #include "make_test_thread.h"
  28 #include "test_macros.h"
  29
  30 std::shared_timed_mutex m;
  31
  32 typedef std::chrono::steady_clock Clock;
  33 typedef Clock::time_point time_point;
  34 typedef Clock::duration duration;
  35 typedef std::chrono::milliseconds ms;
  36 typedef std::chrono::nanoseconds ns;
  37
  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_IS_EXECUTED_IN_A_SLOW_ENVIRONMENT)
  45 ms Tolerance = ms(50);
  46 #else
  47 ms Tolerance = ms(50 * 5);
  48 #endif
  49
  50 void f1()
  51 {
  52     time_point t0 = Clock::now();
  53     assert(m.try_lock_until(Clock::now() + WaitTime + Tolerance) == true);
  54     time_point t1 = Clock::now();
  55     m.unlock();
  56     ns d = t1 - t0 - WaitTime;
  57     assert(d < Tolerance);  // within tolerance
  58 }
  59
  60 void f2()
  61 {
  62     time_point t0 = Clock::now();
  63     assert(m.try_lock_until(Clock::now() + WaitTime) == false);
  64     time_point t1 = Clock::now();
  65     ns d = t1 - t0 - WaitTime;
  66     assert(d < Tolerance);  // within tolerance
  67 }
  68
  69 int main(int, char**)
  70 {
  71     {
  72         m.lock();
  73         std::thread t = support::make_test_thread(f1);
  74         std::this_thread::sleep_for(WaitTime);
  75         m.unlock();
  76         t.join();
  77     }
  78     {
  79         m.lock();
  80         std::thread t = support::make_test_thread(f2);
  81         std::this_thread::sleep_for(WaitTime + Tolerance);
  82         m.unlock();
  83         t.join();
  84     }
  85
  86   return 0;
  87 }