// <thread> -*- C++ -*-
-// Copyright (C) 2008, 2009 Free Software Foundation, Inc.
+// Copyright (C) 2008-2021 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 2, or (at your option)
+// 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,
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
-// You should have received a copy of the GNU General Public License
-// along with this library; see the file COPYING. If not, write to
-// the Free Software Foundation, 51 Franklin Street, Fifth Floor,
-// Boston, MA 02110-1301, USA.
-
-// As a special exception, you may use this file as part of a free software
-// library without restriction. Specifically, if other files instantiate
-// templates or use macros or inline functions from this file, or you compile
-// this file and link it with other files to produce an executable, this
-// file does not by itself cause the resulting executable to be covered by
-// the GNU General Public License. This exception does not however
-// invalidate any other reasons why the executable file might be covered by
-// the GNU General Public License.
-
-/** @file thread
+// 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/>.
+
+/** @file include/thread
* This is a Standard C++ Library header.
*/
#pragma GCC system_header
-#ifndef __GXX_EXPERIMENTAL_CXX0X__
-# include <c++0x_warning.h>
+#if __cplusplus < 201103L
+# include <bits/c++0x_warning.h>
#else
-#include <chrono>
-#include <exception>
-#include <functional>
-#include <memory>
-#include <mutex>
-#include <condition_variable>
-#include <type_traits>
-#include <cstddef>
-#include <bits/functexcept.h>
-#include <bits/gthr.h>
-
-#if defined(_GLIBCXX_HAS_GTHREADS) && defined(_GLIBCXX_USE_C99_STDINT_TR1)
-
-namespace std
-{
- class __thread_data_base;
+#include <chrono> // std::chrono::*
- typedef shared_ptr<__thread_data_base> __thread_data_ptr;
+#if __cplusplus > 201703L
+# include <compare> // std::strong_ordering
+# include <stop_token> // std::stop_source, std::stop_token, std::nostopstate
+#endif
- class __thread_data_base : public enable_shared_from_this<__thread_data_base>
- {
- public:
- __thread_data_base() = default;
- virtual ~__thread_data_base() = default;
-
- virtual void __run() = 0;
-
- __gthread_t _M_thread_handle;
- __thread_data_ptr _M_this_ptr;
- mutex _M_data_mutex;
- };
-
- template<typename _Callable>
- class __thread_data : public __thread_data_base
- {
- public:
- __thread_data(_Callable&& __f)
- : _M_func(std::forward<_Callable>(__f))
- { }
+#include <bits/std_thread.h> // std::thread, get_id, yield
- void __run()
- { _M_func(); }
+#ifdef _GLIBCXX_USE_NANOSLEEP
+# include <cerrno> // errno, EINTR
+# include <time.h> // nanosleep
+#endif
- private:
- _Callable _M_func;
- };
+namespace std _GLIBCXX_VISIBILITY(default)
+{
+_GLIBCXX_BEGIN_NAMESPACE_VERSION
+
+ /**
+ * @defgroup threads Threads
+ * @ingroup concurrency
+ *
+ * Classes for thread support.
+ * @{
+ */
+
+ // std::thread is defined in <bits/std_thread.h>
+
+#if __cpp_lib_three_way_comparison
+ inline strong_ordering
+ operator<=>(thread::id __x, thread::id __y) noexcept
+ { return __x._M_thread <=> __y._M_thread; }
+#else
+ inline bool
+ operator!=(thread::id __x, thread::id __y) noexcept
+ { return !(__x == __y); }
- /// thread
- class thread
+ inline bool
+ operator<(thread::id __x, thread::id __y) noexcept
{
- public:
- // types
- class id;
- typedef __gthread_t native_handle_type;
-
- // cons
- thread() = default;
-
- template<typename _Callable>
- explicit thread(_Callable __f)
- : _M_thread_data(__make_thread_data(__f))
- { __start_thread(); }
-
- template<typename _Callable, typename... _Args>
- thread(_Callable&& __f, _Args&&... __args)
- : _M_thread_data(__make_thread_data(std::bind(__f, __args...)))
- { __start_thread(); }
-
- ~thread()
- { detach(); }
-
- thread(const thread&) = delete;
- thread(thread&&);
- thread& operator=(const thread&) = delete;
- thread& operator=(thread&&);
-
- // members
- void
- swap(thread&& __t)
- { std::swap(_M_thread_data, __t._M_thread_data); }
-
- bool
- joinable() const;
-
- void
- join();
-
- void
- detach();
+ // Pthreads doesn't define any way to do this, so we just have to
+ // assume native_handle_type is LessThanComparable.
+ return __x._M_thread < __y._M_thread;
+ }
- thread::id
- get_id() const;
+ inline bool
+ operator<=(thread::id __x, thread::id __y) noexcept
+ { return !(__y < __x); }
- native_handle_type
- native_handle()
- { return _M_thread_data->_M_thread_handle; }
+ inline bool
+ operator>(thread::id __x, thread::id __y) noexcept
+ { return __y < __x; }
- // static members
- static unsigned hardware_concurrency();
+ inline bool
+ operator>=(thread::id __x, thread::id __y) noexcept
+ { return !(__x < __y); }
+#endif // __cpp_lib_three_way_comparison
- __thread_data_ptr
- _M_get_thread_data() const
+ template<class _CharT, class _Traits>
+ inline basic_ostream<_CharT, _Traits>&
+ operator<<(basic_ostream<_CharT, _Traits>& __out, thread::id __id)
{
- lock_guard<mutex> __l(_M_thread_data_mutex);
- return _M_thread_data;
+ if (__id == thread::id())
+ return __out << "thread::id of a non-executing thread";
+ else
+ return __out << __id._M_thread;
}
- private:
- template<typename _Callable>
- __thread_data_ptr
- __make_thread_data(_Callable&& __f)
- {
- return __thread_data_ptr(
- new __thread_data<_Callable>(std::forward<_Callable>(__f)));
- }
-
- __thread_data_ptr
- __make_thread_data(void(*__f)())
- { return __thread_data_ptr(new __thread_data<void(*)()>(__f)); }
-
- void __start_thread();
-
- __thread_data_ptr _M_thread_data;
- mutable mutex _M_thread_data_mutex;
- };
-
- inline void
- swap(thread& __x, thread& __y)
- { __x.swap(__y); }
-
- inline void
- swap(thread&& __x, thread& __y)
- { __x.swap(__y); }
-
- inline void
- swap(thread& __x, thread&& __y)
- { __x.swap(__y); }
-
+ /** @namespace std::this_thread
+ * @brief ISO C++ 2011 namespace for interacting with the current thread
+ *
+ * C++11 30.3.2 [thread.thread.this] Namespace this_thread.
+ */
namespace this_thread
{
- thread::id
- get_id();
+#ifndef _GLIBCXX_NO_SLEEP
-#ifdef _GLIBCXX_USE_SCHED_YIELD
- inline void
- yield()
- { __gthread_yield(); }
+#ifndef _GLIBCXX_USE_NANOSLEEP
+ void
+ __sleep_for(chrono::seconds, chrono::nanoseconds);
#endif
-#ifdef _GLIBCXX_USE_NANOSLEEP
- template<typename _Clock, typename _Duration>
- inline void
- sleep_until(const chrono::time_point<_Clock, _Duration>& __atime)
- { sleep_for(__atime - _Clock::now()); }
-
+ /// this_thread::sleep_for
template<typename _Rep, typename _Period>
inline void
sleep_for(const chrono::duration<_Rep, _Period>& __rtime)
{
- chrono::seconds __s =
- chrono::duration_cast<chrono::seconds>(__rtime);
-
- chrono::nanoseconds __ns =
- chrono::duration_cast<chrono::nanoseconds>(__rtime - __s);
-
- __gthread_time_t __ts =
+ if (__rtime <= __rtime.zero())
+ return;
+ auto __s = chrono::duration_cast<chrono::seconds>(__rtime);
+ auto __ns = chrono::duration_cast<chrono::nanoseconds>(__rtime - __s);
+#ifdef _GLIBCXX_USE_NANOSLEEP
+ struct ::timespec __ts =
{
static_cast<std::time_t>(__s.count()),
static_cast<long>(__ns.count())
};
-
- ::nanosleep(&__ts, 0);
+ while (::nanosleep(&__ts, &__ts) == -1 && errno == EINTR)
+ { }
+#else
+ __sleep_for(__s, __ns);
+#endif
}
+
+ /// this_thread::sleep_until
+ template<typename _Clock, typename _Duration>
+ inline void
+ sleep_until(const chrono::time_point<_Clock, _Duration>& __atime)
+ {
+#if __cplusplus > 201703L
+ static_assert(chrono::is_clock_v<_Clock>);
#endif
- }
+ auto __now = _Clock::now();
+ if (_Clock::is_steady)
+ {
+ if (__now < __atime)
+ sleep_for(__atime - __now);
+ return;
+ }
+ while (__now < __atime)
+ {
+ sleep_for(__atime - __now);
+ __now = _Clock::now();
+ }
+ }
+ } // namespace this_thread
+#endif // ! NO_SLEEP
- /// thread::id
- class thread::id
+#ifdef __cpp_lib_jthread
+
+ /// A thread that can be requested to stop and automatically joined.
+ class jthread
{
public:
- id() : _M_thread_id() { }
+ using id = thread::id;
+ using native_handle_type = thread::native_handle_type;
- private:
- friend class thread;
+ jthread() noexcept
+ : _M_stop_source{nostopstate}
+ { }
- friend thread::id this_thread::get_id();
+ template<typename _Callable, typename... _Args,
+ typename = enable_if_t<!is_same_v<remove_cvref_t<_Callable>,
+ jthread>>>
+ explicit
+ jthread(_Callable&& __f, _Args&&... __args)
+ : _M_thread{_S_create(_M_stop_source, std::forward<_Callable>(__f),
+ std::forward<_Args>(__args)...)}
+ { }
- friend bool
- operator==(thread::id __x, thread::id __y)
- { return static_cast<bool>(__gthread_equal(__x._M_thread_id,
- __y._M_thread_id)); }
+ jthread(const jthread&) = delete;
+ jthread(jthread&&) noexcept = default;
- friend bool
- operator<(thread::id __x, thread::id __y)
- { return __x._M_thread_id < __y._M_thread_id; }
+ ~jthread()
+ {
+ if (joinable())
+ {
+ request_stop();
+ join();
+ }
+ }
- template<class _CharT, class _Traits>
- friend basic_ostream<_CharT, _Traits>&
- operator<<(basic_ostream<_CharT, _Traits>&& __out, thread::id __id);
+ jthread&
+ operator=(const jthread&) = delete;
- id(__gthread_t __id)
- : _M_thread_id(__id)
- { }
-
- __gthread_t _M_thread_id;
- };
+ jthread&
+ operator=(jthread&& __other) noexcept
+ {
+ std::jthread(std::move(__other)).swap(*this);
+ return *this;
+ }
- inline bool
- operator!=(thread::id __x, thread::id __y)
- { return !(__x == __y); }
-
- inline bool
- operator<=(thread::id __x, thread::id __y)
- { return !(__y < __x); }
-
- inline bool
- operator>(thread::id __x, thread::id __y)
- { return __y < __x; }
-
- inline bool
- operator>=(thread::id __x, thread::id __y)
- { return !(__x < __y); }
-
- template<class _CharT, class _Traits>
- inline basic_ostream<_CharT, _Traits>&
- operator<<(basic_ostream<_CharT, _Traits>&& __out, thread::id __id)
+ void
+ swap(jthread& __other) noexcept
{
- if(__id == thread::id())
- return __out << "non-executing thread";
- else
- return __out << __id._M_thread_id;
- }
+ std::swap(_M_stop_source, __other._M_stop_source);
+ std::swap(_M_thread, __other._M_thread);
+ }
- inline bool
- thread::joinable() const
- { return get_id() != thread::id(); }
+ [[nodiscard]] bool
+ joinable() const noexcept
+ {
+ return _M_thread.joinable();
+ }
- inline thread::id
- thread::get_id() const
- {
- if(_M_thread_data)
- return thread::id(_M_thread_data->_M_thread_handle);
- else
- return thread::id();
- }
+ void
+ join()
+ {
+ _M_thread.join();
+ }
- namespace this_thread
- {
- inline thread::id
- get_id()
- { return thread::id(__gthread_self()); }
- }
-}
+ void
+ detach()
+ {
+ _M_thread.detach();
+ }
+
+ [[nodiscard]] id
+ get_id() const noexcept
+ {
+ return _M_thread.get_id();
+ }
+
+ [[nodiscard]] native_handle_type
+ native_handle()
+ {
+ return _M_thread.native_handle();
+ }
+
+ [[nodiscard]] static unsigned
+ hardware_concurrency() noexcept
+ {
+ return thread::hardware_concurrency();
+ }
-#endif // _GLIBCXX_HAS_GTHREADS && _GLIBCXX_USE_C99_STDINT_TR1
+ [[nodiscard]] stop_source
+ get_stop_source() noexcept
+ {
+ return _M_stop_source;
+ }
+
+ [[nodiscard]] stop_token
+ get_stop_token() const noexcept
+ {
+ return _M_stop_source.get_token();
+ }
+
+ bool request_stop() noexcept
+ {
+ return _M_stop_source.request_stop();
+ }
+
+ friend void swap(jthread& __lhs, jthread& __rhs) noexcept
+ {
+ __lhs.swap(__rhs);
+ }
+
+ private:
+ template<typename _Callable, typename... _Args>
+ static thread
+ _S_create(stop_source& __ssrc, _Callable&& __f, _Args&&... __args)
+ {
+ if constexpr(is_invocable_v<decay_t<_Callable>, stop_token,
+ decay_t<_Args>...>)
+ return thread{std::forward<_Callable>(__f), __ssrc.get_token(),
+ std::forward<_Args>(__args)...};
+ else
+ {
+ static_assert(is_invocable_v<decay_t<_Callable>,
+ decay_t<_Args>...>,
+ "std::thread arguments must be invocable after"
+ " conversion to rvalues");
+ return thread{std::forward<_Callable>(__f),
+ std::forward<_Args>(__args)...};
+ }
+ }
+
+ stop_source _M_stop_source;
+ thread _M_thread;
+ };
+#endif // __cpp_lib_jthread
-#endif // __GXX_EXPERIMENTAL_CXX0X__
+ // @} group threads
+_GLIBCXX_END_NAMESPACE_VERSION
+} // namespace
+#endif // C++11
#endif // _GLIBCXX_THREAD