1//===----------------------------------------------------------------------===//
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 <condition_variable>
10#include <thread>
11
12#if defined(__ELF__) && defined(_LIBCPP_LINK_PTHREAD_LIB)
13# pragma comment(lib, "pthread")
14#endif
15
16_LIBCPP_PUSH_MACROS
17#include <__undef_macros>
18
19_LIBCPP_BEGIN_NAMESPACE_STD
20
21// ~condition_variable is defined elsewhere.
22
23void condition_variable::notify_one() noexcept { __libcpp_condvar_signal(&__cv_); }
24
25void condition_variable::notify_all() noexcept { __libcpp_condvar_broadcast(&__cv_); }
26
27void condition_variable::wait(unique_lock<mutex>& lk) noexcept {
28 if (!lk.owns_lock())
29 __throw_system_error(EPERM, "condition_variable::wait: mutex not locked");
30 int ec = __libcpp_condvar_wait(&__cv_, lk.mutex()->native_handle());
31 if (ec)
32 __throw_system_error(ec, "condition_variable wait failed");
33}
34
35void condition_variable::__do_timed_wait(unique_lock<mutex>& lk,
36 chrono::time_point<chrono::system_clock, chrono::nanoseconds> tp) noexcept {
37 using namespace chrono;
38 if (!lk.owns_lock())
39 __throw_system_error(EPERM, "condition_variable::timed wait: mutex not locked");
40 nanoseconds d = tp.time_since_epoch();
41 if (d > nanoseconds(0x59682F000000E941))
42 d = nanoseconds(0x59682F000000E941);
43 __libcpp_timespec_t ts;
44 seconds s = duration_cast<seconds>(d: d);
45 typedef decltype(ts.tv_sec) ts_sec;
46 constexpr ts_sec ts_sec_max = numeric_limits<ts_sec>::max();
47 if (s.count() < ts_sec_max) {
48 ts.tv_sec = static_cast<ts_sec>(s.count());
49 ts.tv_nsec = static_cast<decltype(ts.tv_nsec)>((d - s).count());
50 } else {
51 ts.tv_sec = ts_sec_max;
52 ts.tv_nsec = giga::num - 1;
53 }
54 int ec = __libcpp_condvar_timedwait(&__cv_, lk.mutex()->native_handle(), &ts);
55 if (ec != 0 && ec != ETIMEDOUT)
56 __throw_system_error(ec, "condition_variable timed_wait failed");
57}
58
59void notify_all_at_thread_exit(condition_variable& cond, unique_lock<mutex> lk) {
60 auto& tl_ptr = __thread_local_data();
61 // If this thread was not created using std::thread then it will not have
62 // previously allocated.
63 if (tl_ptr.get() == nullptr) {
64 tl_ptr.set_pointer(new __thread_struct);
65 }
66 __thread_local_data()->notify_all_at_thread_exit(&cond, lk.release());
67}
68
69_LIBCPP_END_NAMESPACE_STD
70
71_LIBCPP_POP_MACROS
72

source code of libcxx/src/condition_variable.cpp