condition_variable.cpp revision 360784 
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
26void
27condition_variable::notify_one() _NOEXCEPT
28{
29    __libcpp_condvar_signal(&__cv_);
30}
31
32void
33condition_variable::notify_all() _NOEXCEPT
34{
35    __libcpp_condvar_broadcast(&__cv_);
36}
37
38void
39condition_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
49void
50condition_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
79void
80notify_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