1 //===-------------------- condition_variable.cpp --------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "__config"
10 
11 #ifndef _LIBCPP_HAS_NO_THREADS
12 
13 #include "condition_variable"
14 #include "thread"
15 #include "system_error"
16 #include "__undef_macros"
17 
18 #if defined(__unix__) &&  defined(__ELF__) && defined(_LIBCPP_HAS_COMMENT_LIB_PRAGMA)
19 #pragma comment(lib, "pthread")
20 #endif
21 
22 _LIBCPP_BEGIN_NAMESPACE_STD
23 
24 condition_variable::~condition_variable()
25 {
26     __libcpp_condvar_destroy(&__cv_);
27 }
28 
29 void
30 condition_variable::notify_one() _NOEXCEPT
31 {
32     __libcpp_condvar_signal(&__cv_);
33 }
34 
35 void
36 condition_variable::notify_all() _NOEXCEPT
37 {
38     __libcpp_condvar_broadcast(&__cv_);
39 }
40 
41 void
42 condition_variable::wait(unique_lock<mutex>& lk) _NOEXCEPT
43 {
44     if (!lk.owns_lock())
45         __throw_system_error(EPERM,
46                                   "condition_variable::wait: mutex not locked");
47     int ec = __libcpp_condvar_wait(&__cv_, lk.mutex()->native_handle());
48     if (ec)
49         __throw_system_error(ec, "condition_variable wait failed");
50 }
51 
52 void
53 condition_variable::__do_timed_wait(unique_lock<mutex>& lk,
54      chrono::time_point<chrono::system_clock, chrono::nanoseconds> tp) _NOEXCEPT
55 {
56     using namespace chrono;
57     if (!lk.owns_lock())
58         __throw_system_error(EPERM,
59                             "condition_variable::timed wait: mutex not locked");
60     nanoseconds d = tp.time_since_epoch();
61     if (d > nanoseconds(0x59682F000000E941))
62         d = nanoseconds(0x59682F000000E941);
63     __libcpp_timespec_t ts;
64     seconds s = duration_cast<seconds>(d);
65     typedef decltype(ts.tv_sec) ts_sec;
66     _LIBCPP_CONSTEXPR ts_sec ts_sec_max = numeric_limits<ts_sec>::max();
67     if (s.count() < ts_sec_max)
68     {
69         ts.tv_sec = static_cast<ts_sec>(s.count());
70         ts.tv_nsec = static_cast<decltype(ts.tv_nsec)>((d - s).count());
71     }
72     else
73     {
74         ts.tv_sec = ts_sec_max;
75         ts.tv_nsec = giga::num - 1;
76     }
77     int ec = __libcpp_condvar_timedwait(&__cv_, lk.mutex()->native_handle(), &ts);
78     if (ec != 0 && ec != ETIMEDOUT)
79         __throw_system_error(ec, "condition_variable timed_wait failed");
80 }
81 
82 void
83 notify_all_at_thread_exit(condition_variable& cond, unique_lock<mutex> lk)
84 {
85     auto& tl_ptr = __thread_local_data();
86     // If this thread was not created using std::thread then it will not have
87     // previously allocated.
88     if (tl_ptr.get() == nullptr) {
89         tl_ptr.set_pointer(new __thread_struct);
90     }
91     __thread_local_data()->notify_all_at_thread_exit(&cond, lk.release());
92 }
93 
94 _LIBCPP_END_NAMESPACE_STD
95 
96 #endif // !_LIBCPP_HAS_NO_THREADS
97