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(__ELF__) && defined(_LIBCPP_LINK_PTHREAD_LIB)
19 #pragma comment(lib, "pthread")
20 #endif
21
22 _LIBCPP_BEGIN_NAMESPACE_STD
23
24 // ~condition_variable is defined elsewhere.
25
26 void
notify_one()27 condition_variable::notify_one() noexcept
28 {
29 __libcpp_condvar_signal(&__cv_);
30 }
31
32 void
notify_all()33 condition_variable::notify_all() noexcept
34 {
35 __libcpp_condvar_broadcast(&__cv_);
36 }
37
38 void
wait(unique_lock<mutex> & lk)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
__do_timed_wait(unique_lock<mutex> & lk,chrono::time_point<chrono::system_clock,chrono::nanoseconds> tp)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 __libcpp_timespec_t 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
notify_all_at_thread_exit(condition_variable & cond,unique_lock<mutex> lk)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