llvm-project/libcxx/src/condition_variable.cpp

94 lines
2.7 KiB
C++

//===-------------------- condition_variable.cpp --------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "__config"
#ifndef _LIBCPP_HAS_NO_THREADS
#include "condition_variable"
#include "thread"
#include "system_error"
#include "__undef_macros"
#if defined(__ELF__) && defined(_LIBCPP_LINK_PTHREAD_LIB)
#pragma comment(lib, "pthread")
#endif
_LIBCPP_BEGIN_NAMESPACE_STD
// ~condition_variable is defined elsewhere.
void
condition_variable::notify_one() _NOEXCEPT
{
__libcpp_condvar_signal(&__cv_);
}
void
condition_variable::notify_all() _NOEXCEPT
{
__libcpp_condvar_broadcast(&__cv_);
}
void
condition_variable::wait(unique_lock<mutex>& lk) _NOEXCEPT
{
if (!lk.owns_lock())
__throw_system_error(EPERM,
"condition_variable::wait: mutex not locked");
int ec = __libcpp_condvar_wait(&__cv_, lk.mutex()->native_handle());
if (ec)
__throw_system_error(ec, "condition_variable wait failed");
}
void
condition_variable::__do_timed_wait(unique_lock<mutex>& lk,
chrono::time_point<chrono::system_clock, chrono::nanoseconds> tp) _NOEXCEPT
{
using namespace chrono;
if (!lk.owns_lock())
__throw_system_error(EPERM,
"condition_variable::timed wait: mutex not locked");
nanoseconds d = tp.time_since_epoch();
if (d > nanoseconds(0x59682F000000E941))
d = nanoseconds(0x59682F000000E941);
__libcpp_timespec_t ts;
seconds s = duration_cast<seconds>(d);
typedef decltype(ts.tv_sec) ts_sec;
_LIBCPP_CONSTEXPR ts_sec ts_sec_max = numeric_limits<ts_sec>::max();
if (s.count() < ts_sec_max)
{
ts.tv_sec = static_cast<ts_sec>(s.count());
ts.tv_nsec = static_cast<decltype(ts.tv_nsec)>((d - s).count());
}
else
{
ts.tv_sec = ts_sec_max;
ts.tv_nsec = giga::num - 1;
}
int ec = __libcpp_condvar_timedwait(&__cv_, lk.mutex()->native_handle(), &ts);
if (ec != 0 && ec != ETIMEDOUT)
__throw_system_error(ec, "condition_variable timed_wait failed");
}
void
notify_all_at_thread_exit(condition_variable& cond, unique_lock<mutex> lk)
{
auto& tl_ptr = __thread_local_data();
// If this thread was not created using std::thread then it will not have
// previously allocated.
if (tl_ptr.get() == nullptr) {
tl_ptr.set_pointer(new __thread_struct);
}
__thread_local_data()->notify_all_at_thread_exit(&cond, lk.release());
}
_LIBCPP_END_NAMESPACE_STD
#endif // !_LIBCPP_HAS_NO_THREADS