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 "condition_variable"
  11 #include "thread"
  12 #include "system_error"
  13 #include "cassert"
  14
  15 _LIBCPP_BEGIN_NAMESPACE_STD
  16
  17 condition_variable::~condition_variable()
  18 {
  19     pthread_cond_destroy(&__cv_);
  20 }
  21
  22 void
  23 condition_variable::notify_one() _NOEXCEPT
  24 {
  25     pthread_cond_signal(&__cv_);
  26 }
  27
  28 void
  29 condition_variable::notify_all() _NOEXCEPT
  30 {
  31     pthread_cond_broadcast(&__cv_);
  32 }
  33
  34 void
  35 condition_variable::wait(unique_lock<mutex>& lk)
  36 {
  37     if (!lk.owns_lock())
  38         __throw_system_error(EPERM,
  39                                   "condition_variable::wait: mutex not locked");
  40     int ec = pthread_cond_wait(&__cv_, lk.mutex()->native_handle());
  41     if (ec)
  42         __throw_system_error(ec, "condition_variable wait failed");
  43 }
  44
  45 void
  46 condition_variable::__do_timed_wait(unique_lock<mutex>& lk,
  47                chrono::time_point<chrono::system_clock, chrono::nanoseconds> tp)
  48 {
  49     using namespace chrono;
  50     if (!lk.owns_lock())
  51         __throw_system_error(EPERM,
  52                             "condition_variable::timed wait: mutex not locked");
  53     nanoseconds d = tp.time_since_epoch();
  54     if (d > nanoseconds(0x59682F000000E941))
  55         d = nanoseconds(0x59682F000000E941);
  56     timespec ts;
  57     seconds s = duration_cast<seconds>(d);
  58     typedef decltype(ts.tv_sec) ts_sec;
  59     _LIBCPP_CONSTEXPR ts_sec ts_sec_max = numeric_limits<ts_sec>::max();
  60     if (s.count() < ts_sec_max)
  61     {
  62         ts.tv_sec = static_cast<ts_sec>(s.count());
  63         ts.tv_nsec = static_cast<decltype(ts.tv_nsec)>((d - s).count());
  64     }
  65     else
  66     {
  67         ts.tv_sec = ts_sec_max;
  68         ts.tv_nsec = giga::num - 1;
  69     }
  70     int ec = pthread_cond_timedwait(&__cv_, lk.mutex()->native_handle(), &ts);
  71     if (ec != 0 && ec != ETIMEDOUT)
  72         __throw_system_error(ec, "condition_variable timed_wait failed");
  73 }
  74
  75 void
  76 notify_all_at_thread_exit(condition_variable& cond, unique_lock<mutex> lk)
  77 {
  78     __thread_local_data()->notify_all_at_thread_exit(&cond, lk.release());
  79 }
  80
  81 _LIBCPP_END_NAMESPACE_STD