// <thread> -*- C++ -*-
-// Copyright (C) 2008-2016 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
# include <bits/c++0x_warning.h>
#else
-#include <chrono>
-#include <memory>
-#include <tuple>
-#include <cerrno>
-#include <bits/functexcept.h>
-#include <bits/functional_hash.h>
-#include <bits/invoke.h>
-#include <bits/gthr.h>
+#include <chrono> // std::chrono::*
-#if defined(_GLIBCXX_HAS_GTHREADS) && defined(_GLIBCXX_USE_C99_STDINT_TR1)
+#if __cplusplus > 201703L
+# include <compare> // std::strong_ordering
+# include <stop_token> // std::stop_source, std::stop_token, std::nostopstate
+#endif
+
+#include <bits/std_thread.h> // std::thread, get_id, yield
+
+#ifdef _GLIBCXX_USE_NANOSLEEP
+# include <cerrno> // errno, EINTR
+# include <time.h> // nanosleep
+#endif
namespace std _GLIBCXX_VISIBILITY(default)
{
* @{
*/
- /// thread
- class thread
- {
- public:
- // Abstract base class for types that wrap arbitrary functors to be
- // invoked in the new thread of execution.
- struct _State
- {
- virtual ~_State();
- virtual void _M_run() = 0;
- };
- using _State_ptr = unique_ptr<_State>;
-
- typedef __gthread_t native_handle_type;
-
- /// thread::id
- class id
- {
- native_handle_type _M_thread;
-
- public:
- id() noexcept : _M_thread() { }
-
- explicit
- id(native_handle_type __id) : _M_thread(__id) { }
-
- private:
- friend class thread;
- friend class hash<thread::id>;
-
- friend bool
- operator==(thread::id __x, thread::id __y) noexcept;
-
- friend bool
- operator<(thread::id __x, thread::id __y) noexcept;
-
- template<class _CharT, class _Traits>
- friend basic_ostream<_CharT, _Traits>&
- operator<<(basic_ostream<_CharT, _Traits>& __out, thread::id __id);
- };
-
- private:
- id _M_id;
-
- public:
- thread() noexcept = default;
- // _GLIBCXX_RESOLVE_LIB_DEFECTS
- // 2097. packaged_task constructors should be constrained
- thread(thread&) = delete;
- thread(const thread&) = delete;
-
- thread(thread&& __t) noexcept
- { swap(__t); }
+ // std::thread is defined in <bits/std_thread.h>
- template<typename _Callable, typename... _Args>
- explicit
- thread(_Callable&& __f, _Args&&... __args)
- {
-#ifdef GTHR_ACTIVE_PROXY
- // Create a reference to pthread_create, not just the gthr weak symbol.
- auto __depend = reinterpret_cast<void(*)()>(&pthread_create);
+#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
- auto __depend = nullptr;
-#endif
- _M_start_thread(_S_make_state(
- __make_invoker(std::forward<_Callable>(__f),
- std::forward<_Args>(__args)...)),
- __depend);
- }
-
- ~thread()
- {
- if (joinable())
- std::terminate();
- }
-
- thread& operator=(const thread&) = delete;
-
- thread& operator=(thread&& __t) noexcept
- {
- if (joinable())
- std::terminate();
- swap(__t);
- return *this;
- }
-
- void
- swap(thread& __t) noexcept
- { std::swap(_M_id, __t._M_id); }
-
- bool
- joinable() const noexcept
- { return !(_M_id == id()); }
-
- void
- join();
-
- void
- detach();
-
- thread::id
- get_id() const noexcept
- { return _M_id; }
-
- /** @pre thread is joinable
- */
- native_handle_type
- native_handle()
- { return _M_id._M_thread; }
-
- // Returns a value that hints at the number of hardware thread contexts.
- static unsigned int
- hardware_concurrency() noexcept;
-
- private:
- template<typename _Callable>
- struct _State_impl : public _State
- {
- _Callable _M_func;
-
- _State_impl(_Callable&& __f) : _M_func(std::forward<_Callable>(__f))
- { }
-
- void
- _M_run() { _M_func(); }
- };
-
- void
- _M_start_thread(_State_ptr, void (*)());
-
- template<typename _Callable>
- static _State_ptr
- _S_make_state(_Callable&& __f)
- {
- using _Impl = _State_impl<_Callable>;
- return _State_ptr{new _Impl{std::forward<_Callable>(__f)}};
- }
-#if _GLIBCXX_THREAD_ABI_COMPAT
- public:
- struct _Impl_base;
- typedef shared_ptr<_Impl_base> __shared_base_type;
- struct _Impl_base
- {
- __shared_base_type _M_this_ptr;
- virtual ~_Impl_base() = default;
- virtual void _M_run() = 0;
- };
-
- private:
- void
- _M_start_thread(__shared_base_type, void (*)());
-
- void
- _M_start_thread(__shared_base_type);
-#endif
-
- private:
- // A call wrapper that does INVOKE(forwarded tuple elements...)
- template<typename _Tuple>
- struct _Invoker
- {
- _Tuple _M_t;
-
- template<size_t _Index>
- static __tuple_element_t<_Index, _Tuple>&&
- _S_declval();
-
- template<size_t... _Ind>
- auto
- _M_invoke(_Index_tuple<_Ind...>)
- noexcept(noexcept(std::__invoke(_S_declval<_Ind>()...)))
- -> decltype(std::__invoke(_S_declval<_Ind>()...))
- { return std::__invoke(std::get<_Ind>(std::move(_M_t))...); }
-
- using _Indices
- = typename _Build_index_tuple<tuple_size<_Tuple>::value>::__type;
-
- auto
- operator()()
- noexcept(noexcept(std::declval<_Invoker&>()._M_invoke(_Indices())))
- -> decltype(std::declval<_Invoker&>()._M_invoke(_Indices()))
- { return _M_invoke(_Indices()); }
- };
-
- // Alias for _Invoker<tuple<DECAY_COPY(_Tp)...>>
- template<typename... _Tp>
- using __invoker_type
- = _Invoker<decltype(std::make_tuple(std::declval<_Tp>()...))>;
-
- public:
- // Returns a call wrapper that does
- // INVOKE(DECAY_COPY(__callable), DECAY_COPY(__args)).
- template<typename _Callable, typename... _Args>
- static __invoker_type<_Callable, _Args...>
- __make_invoker(_Callable&& __callable, _Args&&... __args)
- {
- return { {
- std::make_tuple(std::forward<_Callable>(__callable),
- std::forward<_Args>(__args)...)
- } };
- }
- };
-
- inline void
- swap(thread& __x, thread& __y) noexcept
- { __x.swap(__y); }
-
- inline bool
- operator==(thread::id __x, thread::id __y) noexcept
- {
- // pthread_equal is undefined if either thread ID is not valid, so we
- // can't safely use __gthread_equal on default-constructed values (nor
- // the non-zero value returned by this_thread::get_id() for
- // single-threaded programs using GNU libc). Assume EqualityComparable.
- return __x._M_thread == __y._M_thread;
- }
-
inline bool
operator!=(thread::id __x, thread::id __y) noexcept
{ return !(__x == __y); }
inline bool
operator>=(thread::id __x, thread::id __y) noexcept
{ return !(__x < __y); }
-
- // DR 889.
- /// std::hash specialization for thread::id.
- template<>
- struct hash<thread::id>
- : public __hash_base<size_t, thread::id>
- {
- size_t
- operator()(const thread::id& __id) const noexcept
- { return std::_Hash_impl::hash(__id._M_thread); }
- };
+#endif // __cpp_lib_three_way_comparison
template<class _CharT, class _Traits>
inline basic_ostream<_CharT, _Traits>&
return __out << __id._M_thread;
}
-_GLIBCXX_END_NAMESPACE_VERSION
-
/** @namespace std::this_thread
- * @brief ISO C++ 2011 entities sub-namespace for thread.
- * 30.3.2 Namespace 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
{
- _GLIBCXX_BEGIN_NAMESPACE_VERSION
-
- /// get_id
- inline thread::id
- get_id() noexcept
- {
-#ifdef __GLIBC__
- // For the GNU C library pthread_self() is usable without linking to
- // libpthread.so but returns 0, so we cannot use it in single-threaded
- // programs, because this_thread::get_id() != thread::id{} must be true.
- // We know that pthread_t is an integral type in the GNU C library.
- if (!__gthread_active_p())
- return thread::id(1);
-#endif
- return thread::id(__gthread_self());
- }
-
- /// yield
- inline void
- yield() noexcept
- {
-#ifdef _GLIBCXX_USE_SCHED_YIELD
- __gthread_yield();
-#endif
- }
+#ifndef _GLIBCXX_NO_SLEEP
+#ifndef _GLIBCXX_USE_NANOSLEEP
void
__sleep_for(chrono::seconds, chrono::nanoseconds);
+#endif
- /// sleep_for
+ /// this_thread::sleep_for
template<typename _Rep, typename _Period>
inline void
sleep_for(const chrono::duration<_Rep, _Period>& __rtime)
auto __s = chrono::duration_cast<chrono::seconds>(__rtime);
auto __ns = chrono::duration_cast<chrono::nanoseconds>(__rtime - __s);
#ifdef _GLIBCXX_USE_NANOSLEEP
- __gthread_time_t __ts =
+ struct ::timespec __ts =
{
static_cast<std::time_t>(__s.count()),
static_cast<long>(__ns.count())
#endif
}
- /// sleep_until
+ /// 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)
{
__now = _Clock::now();
}
}
+ } // namespace this_thread
+#endif // ! NO_SLEEP
- _GLIBCXX_END_NAMESPACE_VERSION
- }
+#ifdef __cpp_lib_jthread
- // @} group threads
+ /// A thread that can be requested to stop and automatically joined.
+ class jthread
+ {
+ public:
+ using id = thread::id;
+ using native_handle_type = thread::native_handle_type;
-} // namespace
+ jthread() noexcept
+ : _M_stop_source{nostopstate}
+ { }
+
+ 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)...)}
+ { }
-#endif // _GLIBCXX_HAS_GTHREADS && _GLIBCXX_USE_C99_STDINT_TR1
+ jthread(const jthread&) = delete;
+ jthread(jthread&&) noexcept = default;
-#endif // C++11
+ ~jthread()
+ {
+ if (joinable())
+ {
+ request_stop();
+ join();
+ }
+ }
+
+ jthread&
+ operator=(const jthread&) = delete;
+
+ jthread&
+ operator=(jthread&& __other) noexcept
+ {
+ std::jthread(std::move(__other)).swap(*this);
+ return *this;
+ }
+
+ void
+ swap(jthread& __other) noexcept
+ {
+ std::swap(_M_stop_source, __other._M_stop_source);
+ std::swap(_M_thread, __other._M_thread);
+ }
+
+ [[nodiscard]] bool
+ joinable() const noexcept
+ {
+ return _M_thread.joinable();
+ }
+
+ void
+ join()
+ {
+ _M_thread.join();
+ }
+
+ 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();
+ }
+
+ [[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
+
+ // @} group threads
+
+_GLIBCXX_END_NAMESPACE_VERSION
+} // namespace
+#endif // C++11
#endif // _GLIBCXX_THREAD