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      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 #include "__undef_macros"
     18 
     19 _LIBCPP_BEGIN_NAMESPACE_STD
     20 
     21 condition_variable::~condition_variable()
     22 {
     23     __libcpp_condvar_destroy(&__cv_);
     24 }
     25 
     26 void
     27 condition_variable::notify_one() _NOEXCEPT
     28 {
     29     __libcpp_condvar_signal(&__cv_);
     30 }
     31 
     32 void
     33 condition_variable::notify_all() _NOEXCEPT
     34 {
     35     __libcpp_condvar_broadcast(&__cv_);
     36 }
     37 
     38 void
     39 condition_variable::wait(unique_lock<mutex>& lk) _NOEXCEPT
     40 {
     41     if (!lk.owns_lock())
     42         __throw_system_error(EPERM,
     43                                   "condition_variable::wait: mutex not locked");
     44     int ec = __libcpp_condvar_wait(&__cv_, lk.mutex()->native_handle());
     45     if (ec)
     46         __throw_system_error(ec, "condition_variable wait failed");
     47 }
     48 
     49 void
     50 condition_variable::__do_timed_wait(unique_lock<mutex>& lk,
     51      chrono::time_point<chrono::system_clock, chrono::nanoseconds> tp) _NOEXCEPT
     52 {
     53     using namespace chrono;
     54     if (!lk.owns_lock())
     55         __throw_system_error(EPERM,
     56                             "condition_variable::timed wait: mutex not locked");
     57     nanoseconds d = tp.time_since_epoch();
     58     if (d > nanoseconds(0x59682F000000E941))
     59         d = nanoseconds(0x59682F000000E941);
     60     timespec ts;
     61     seconds s = duration_cast<seconds>(d);
     62     typedef decltype(ts.tv_sec) ts_sec;
     63     _LIBCPP_CONSTEXPR ts_sec ts_sec_max = numeric_limits<ts_sec>::max();
     64     if (s.count() < ts_sec_max)
     65     {
     66         ts.tv_sec = static_cast<ts_sec>(s.count());
     67         ts.tv_nsec = static_cast<decltype(ts.tv_nsec)>((d - s).count());
     68     }
     69     else
     70     {
     71         ts.tv_sec = ts_sec_max;
     72         ts.tv_nsec = giga::num - 1;
     73     }
     74     int ec = __libcpp_condvar_timedwait(&__cv_, lk.mutex()->native_handle(), &ts);
     75     if (ec != 0 && ec != ETIMEDOUT)
     76         __throw_system_error(ec, "condition_variable timed_wait failed");
     77 }
     78 
     79 void
     80 notify_all_at_thread_exit(condition_variable& cond, unique_lock<mutex> lk)
     81 {
     82     auto& tl_ptr = __thread_local_data();
     83     // If this thread was not created using std::thread then it will not have
     84     // previously allocated.
     85     if (tl_ptr.get() == nullptr) {
     86         tl_ptr.set_pointer(new __thread_struct);
     87     }
     88     __thread_local_data()->notify_all_at_thread_exit(&cond, lk.release());
     89 }
     90 
     91 _LIBCPP_END_NAMESPACE_STD
     92 
     93 #endif // !_LIBCPP_HAS_NO_THREADS
     94