src/condition_variable.cpp

   1 //===-------------------- condition_variable.cpp --------------------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is dual licensed under the MIT and the University of Illinois Open
   6 // Source Licenses. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 #include "__config"
  11
  12 #ifndef _LIBCPP_HAS_NO_THREADS
  13
  14 #include "condition_variable"
  15 #include "thread"
  16 #include "system_error"
  17
  18 _LIBCPP_BEGIN_NAMESPACE_STD
  19
  20 condition_variable::~condition_variable()
  21 {
  22     __libcpp_condvar_destroy(&__cv_);
  23 }
  24
  25 void
  26 condition_variable::notify_one() _NOEXCEPT
  27 {
  28     __libcpp_condvar_signal(&__cv_);
  29 }
  30
  31 void
  32 condition_variable::notify_all() _NOEXCEPT
  33 {
  34     __libcpp_condvar_broadcast(&__cv_);
  35 }
  36
  37 void
  38 condition_variable::wait(unique_lock<mutex>& lk) _NOEXCEPT
  39 {
  40     if (!lk.owns_lock())
  41         __throw_system_error(EPERM,
  42                                   "condition_variable::wait: mutex not locked");
  43     int ec = __libcpp_condvar_wait(&__cv_, lk.mutex()->native_handle());
  44     if (ec)
  45         __throw_system_error(ec, "condition_variable wait failed");
  46 }
  47
  48 void
  49 condition_variable::__do_timed_wait(unique_lock<mutex>& lk,
  50      chrono::time_point<chrono::system_clock, chrono::nanoseconds> tp) _NOEXCEPT
  51 {
  52     using namespace chrono;
  53     if (!lk.owns_lock())
  54         __throw_system_error(EPERM,
  55                             "condition_variable::timed wait: mutex not locked");
  56     nanoseconds d = tp.time_since_epoch();
  57     if (d > nanoseconds(0x59682F000000E941))
  58         d = nanoseconds(0x59682F000000E941);
  59     timespec ts;
  60     seconds s = duration_cast<seconds>(d);
  61     typedef decltype(ts.tv_sec) ts_sec;
  62     _LIBCPP_CONSTEXPR ts_sec ts_sec_max = numeric_limits<ts_sec>::max();
  63     if (s.count() < ts_sec_max)
  64     {
  65         ts.tv_sec = static_cast<ts_sec>(s.count());
  66         ts.tv_nsec = static_cast<decltype(ts.tv_nsec)>((d - s).count());
  67     }
  68     else
  69     {
  70         ts.tv_sec = ts_sec_max;
  71         ts.tv_nsec = giga::num - 1;
  72     }
  73     int ec = __libcpp_condvar_timedwait(&__cv_, lk.mutex()->native_handle(), &ts);
  74     if (ec != 0 && ec != ETIMEDOUT)
  75         __throw_system_error(ec, "condition_variable timed_wait failed");
  76 }
  77
  78 void
  79 notify_all_at_thread_exit(condition_variable& cond, unique_lock<mutex> lk)
  80 {
  81     auto& tl_ptr = __thread_local_data();
  82     // If this thread was not created using std::thread then it will not have
  83     // previously allocated.
  84     if (tl_ptr.get() == nullptr) {
  85         tl_ptr.set_pointer(new __thread_struct);
  86     }
  87     __thread_local_data()->notify_all_at_thread_exit(&cond, lk.release());
  88 }
  89
  90 _LIBCPP_END_NAMESPACE_STD
  91
  92 #endif // !_LIBCPP_HAS_NO_THREADS