libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/thread.sharedtimedmutex.class/try_lock.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: libcpp-has-no-threads
  10 // UNSUPPORTED: c++03, c++11
  11
  12 // ALLOW_RETRIES: 2
  13
  14 // shared_timed_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_timed_mutex;
  22
  23 // bool try_lock();
  24
  25 #include <shared_mutex>
  26 #include <thread>
  27 #include <cstdlib>
  28 #include <cassert>
  29
  30 #include "make_test_thread.h"
  31 #include "test_macros.h"
  32
  33 std::shared_timed_mutex m;
  34
  35 typedef std::chrono::system_clock Clock;
  36 typedef Clock::time_point time_point;
  37 typedef Clock::duration duration;
  38 typedef std::chrono::milliseconds ms;
  39 typedef std::chrono::nanoseconds ns;
  40
  41 void f()
  42 {
  43     time_point t0 = Clock::now();
  44     assert(!m.try_lock());
  45     assert(!m.try_lock());
  46     assert(!m.try_lock());
  47     while(!m.try_lock())
  48         ;
  49     time_point t1 = Clock::now();
  50     m.unlock();
  51     ns d = t1 - t0 - ms(250);
  52     assert(d < ms(200));  // within 200ms
  53 }
  54
  55 int main(int, char**)
  56 {
  57     m.lock();
  58     std::thread t = support::make_test_thread(f);
  59     std::this_thread::sleep_for(ms(250));
  60     m.unlock();
  61     t.join();
  62
  63   return 0;
  64 }