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
93