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// thread -*- C++ -*-
// Copyright (C) 2008-2022 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.
// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
// <http://www.gnu.org/licenses/>.
#define _GLIBCXX_THREAD_ABI_COMPAT 1
#define _GLIBCXX_THREAD_IMPL 1
#include <memory> // include this first so <thread> can use shared_ptr
#include <thread>
#include <system_error>
#include <cerrno>
#include <cxxabi_forced.h>
#ifndef _GLIBCXX_USE_NANOSLEEP
# ifdef _GLIBCXX_HAVE_SLEEP
# include <unistd.h>
# elif defined(_GLIBCXX_HAVE_WIN32_SLEEP)
# include <windows.h>
# elif defined _GLIBCXX_NO_SLEEP && defined _GLIBCXX_HAS_GTHREADS
// We expect to be able to sleep for targets that support multiple threads:
# error "No sleep function known for this target"
# endif
#endif
#ifdef _GLIBCXX_HAS_GTHREADS
#if defined(_GLIBCXX_USE_GET_NPROCS)
# include <sys/sysinfo.h>
# define _GLIBCXX_NPROCS get_nprocs()
#elif defined(_GLIBCXX_USE_PTHREADS_NUM_PROCESSORS_NP)
# define _GLIBCXX_NPROCS pthread_num_processors_np()
#elif defined(_GLIBCXX_USE_SYSCTL_HW_NCPU)
# include <stddef.h>
# include <sys/sysctl.h>
static inline int get_nprocs()
{
int count;
size_t size = sizeof(count);
int mib[] = { CTL_HW, HW_NCPU };
if (!sysctl(mib, 2, &count, &size, NULL, 0))
return count;
return 0;
}
# define _GLIBCXX_NPROCS get_nprocs()
#elif defined(_GLIBCXX_USE_SC_NPROCESSORS_ONLN)
# include <unistd.h>
# define _GLIBCXX_NPROCS sysconf(_SC_NPROCESSORS_ONLN)
#elif defined(_GLIBCXX_USE_SC_NPROC_ONLN)
# include <unistd.h>
# define _GLIBCXX_NPROCS sysconf(_SC_NPROC_ONLN)
#elif defined(_WIN32)
# include <windows.h>
static inline int get_nprocs()
{
SYSTEM_INFO sysinfo;
GetSystemInfo(&sysinfo);
return (int) sysinfo.dwNumberOfProcessors;
}
# define _GLIBCXX_NPROCS get_nprocs()
#else
# define _GLIBCXX_NPROCS 0
#endif
namespace std _GLIBCXX_VISIBILITY(default)
{
extern "C"
{
static void*
execute_native_thread_routine(void* __p)
{
thread::_State_ptr __t{ static_cast<thread::_State*>(__p) };
__t->_M_run();
return nullptr;
}
#if _GLIBCXX_THREAD_ABI_COMPAT
static void*
execute_native_thread_routine_compat(void* __p)
{
thread::_Impl_base* __t = static_cast<thread::_Impl_base*>(__p);
thread::__shared_base_type __local;
// Now that a new thread has been created we can transfer ownership of
// the thread state to a local object, breaking the reference cycle
// created in thread::_M_start_thread.
__local.swap(__t->_M_this_ptr);
__t->_M_run();
return nullptr;
}
#endif
} // extern "C"
_GLIBCXX_BEGIN_NAMESPACE_VERSION
thread::_State::~_State() = default;
void
thread::join()
{
int __e = EINVAL;
if (_M_id != id())
__e = __gthread_join(_M_id._M_thread, 0);
if (__e)
__throw_system_error(__e);
_M_id = id();
}
void
thread::detach()
{
int __e = EINVAL;
if (_M_id != id())
__e = __gthread_detach(_M_id._M_thread);
if (__e)
__throw_system_error(__e);
_M_id = id();
}
void
thread::_M_start_thread(_State_ptr state, void (*)())
{
if (!__gthread_active_p())
{
#if __cpp_exceptions
throw system_error(make_error_code(errc::operation_not_permitted),
"Enable multithreading to use std::thread");
#else
__builtin_abort();
#endif
}
const int err = __gthread_create(&_M_id._M_thread,
&execute_native_thread_routine,
state.get());
if (err)
__throw_system_error(err);
state.release();
}
#if _GLIBCXX_THREAD_ABI_COMPAT
void
thread::_M_start_thread(__shared_base_type __b)
{
if (!__gthread_active_p())
#if __cpp_exceptions
throw system_error(make_error_code(errc::operation_not_permitted),
"Enable multithreading to use std::thread");
#else
__throw_system_error(int(errc::operation_not_permitted));
#endif
_M_start_thread(std::move(__b), nullptr);
}
void
thread::_M_start_thread(__shared_base_type __b, void (*)())
{
auto ptr = __b.get();
// Create a reference cycle that will be broken in the new thread.
ptr->_M_this_ptr = std::move(__b);
int __e = __gthread_create(&_M_id._M_thread,
&execute_native_thread_routine_compat, ptr);
if (__e)
{
ptr->_M_this_ptr.reset(); // break reference cycle, destroying *ptr.
__throw_system_error(__e);
}
}
#endif
unsigned int
thread::hardware_concurrency() noexcept
{
int __n = _GLIBCXX_NPROCS;
if (__n < 0)
__n = 0;
return __n;
}
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace std
#endif // _GLIBCXX_HAS_GTHREADS
#ifndef _GLIBCXX_NO_SLEEP
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
namespace this_thread
{
void
__sleep_for(chrono::seconds __s, chrono::nanoseconds __ns)
{
#ifdef _GLIBCXX_USE_NANOSLEEP
struct ::timespec __ts =
{
static_cast<std::time_t>(__s.count()),
static_cast<long>(__ns.count())
};
while (::nanosleep(&__ts, &__ts) == -1 && errno == EINTR)
{ }
#elif defined(_GLIBCXX_HAVE_SLEEP)
const auto target = chrono::steady_clock::now() + __s + __ns;
while (true)
{
unsigned secs = __s.count();
if (__ns.count() > 0)
{
# ifdef _GLIBCXX_HAVE_USLEEP
long us = __ns.count() / 1000;
if (us == 0)
us = 1;
::usleep(us);
# else
if (__ns.count() > 1000000 || secs == 0)
++secs; // No sub-second sleep function, so round up.
# endif
}
if (secs > 0)
{
// Sleep in a loop to handle interruption by signals:
while ((secs = ::sleep(secs)))
{ }
}
const auto now = chrono::steady_clock::now();
if (now >= target)
break;
__s = chrono::duration_cast<chrono::seconds>(target - now);
__ns = chrono::duration_cast<chrono::nanoseconds>(target - (now + __s));
}
#elif defined(_GLIBCXX_HAVE_WIN32_SLEEP)
unsigned long ms = __ns.count() / 1000000;
if (__ns.count() > 0 && ms == 0)
ms = 1;
::Sleep(chrono::milliseconds(__s).count() + ms);
#endif
}
}
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace std
#endif // ! NO_SLEEP