contrib/libc++/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 #include "cassert"
  18
  19 _LIBCPP_BEGIN_NAMESPACE_STD
  20
  21 condition_variable::~condition_variable()
  22 {
  23     pthread_cond_destroy(&__cv_);
  24 }
  25
  26 void
  27 condition_variable::notify_one() _NOEXCEPT
  28 {
  29     pthread_cond_signal(&__cv_);
  30 }
  31
  32 void
  33 condition_variable::notify_all() _NOEXCEPT
  34 {
  35     pthread_cond_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 = pthread_cond_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 = pthread_cond_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     __thread_local_data()->notify_all_at_thread_exit(&cond, lk.release());
  83 }
  84
  85 _LIBCPP_END_NAMESPACE_STD
  86
  87 #endif // !_LIBCPP_HAS_NO_THREADS