// <future> -*- C++ -*-
-// Copyright (C) 2009-2015 Free Software Foundation, Inc.
+// Copyright (C) 2009-2020 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 <functional>
#include <mutex>
#include <thread>
#include <condition_variable>
#include <atomic>
#include <bits/atomic_futex.h>
#include <bits/functexcept.h>
+#include <bits/invoke.h>
#include <bits/unique_ptr.h>
#include <bits/shared_ptr.h>
+#include <bits/std_function.h>
#include <bits/uses_allocator.h>
#include <bits/allocated_ptr.h>
#include <ext/aligned_buffer.h>
*/
class future_error : public logic_error
{
- error_code _M_code;
-
public:
- explicit future_error(error_code __ec)
- : logic_error("std::future_error: " + __ec.message()), _M_code(__ec)
+ explicit
+ future_error(future_errc __errc)
+ : future_error(std::make_error_code(__errc))
{ }
virtual ~future_error() noexcept;
const error_code&
code() const noexcept { return _M_code; }
+
+ private:
+ explicit
+ future_error(error_code __ec)
+ : logic_error("std::future_error: " + __ec.message()), _M_code(__ec)
+ { }
+
+ friend void __throw_future_error(int);
+
+ error_code _M_code;
};
// Forward declarations.
// _GLIBCXX_RESOLVE_LIB_DEFECTS
// 2021. Further incorrect usages of result_of
template<typename _Fn, typename... _Args>
- using __async_result_of = typename result_of<
- typename decay<_Fn>::type(typename decay<_Args>::type...)>::type;
+ using __async_result_of = typename __invoke_result<
+ typename decay<_Fn>::type, typename decay<_Args>::type...>::type;
template<typename _Fn, typename... _Args>
future<__async_result_of<_Fn, _Args...>>
future<__async_result_of<_Fn, _Args...>>
async(_Fn&& __fn, _Args&&... __args);
-#if defined(_GLIBCXX_HAS_GTHREADS) && defined(_GLIBCXX_USE_C99_STDINT_TR1) \
- && (ATOMIC_INT_LOCK_FREE > 1)
+#if defined(_GLIBCXX_HAS_GTHREADS)
/// Base class and enclosing scope.
struct __future_base
typedef _Res result_type;
_Result() noexcept : _M_initialized() { }
-
+
~_Result()
{
if (_M_initialized)
explicit
_Result_alloc(const _Alloc& __a) : _Result<_Res>(), _Alloc(__a)
{ }
-
+
private:
void _M_destroy()
{
{
if (static_cast<bool>(__res))
{
- error_code __ec(make_error_code(future_errc::broken_promise));
- __res->_M_error = make_exception_ptr(future_error(__ec));
+ __res->_M_error =
+ make_exception_ptr(future_error(future_errc::broken_promise));
// This function is only called when the last asynchronous result
// provider is abandoning this shared state, so noone can be
// trying to make the shared state ready at the same time, and
// Used by std::promise to copy construct the result.
typename promise<_Res>::_Ptr_type operator()() const
{
- _State_baseV2::_S_check(_M_promise->_M_future);
_M_promise->_M_storage->_M_set(*_M_arg);
return std::move(_M_promise->_M_storage);
}
// Used by std::promise to move construct the result.
typename promise<_Res>::_Ptr_type operator()() const
{
- _State_baseV2::_S_check(_M_promise->_M_future);
_M_promise->_M_storage->_M_set(std::move(*_M_arg));
return std::move(_M_promise->_M_storage);
}
_Res* _M_arg;
};
+ // set void
+ template<typename _Res>
+ struct _Setter<_Res, void>
+ {
+ static_assert(is_void<_Res>::value, "Only used for promise<void>");
+
+ typename promise<_Res>::_Ptr_type operator()() const
+ { return std::move(_M_promise->_M_storage); }
+
+ promise<_Res>* _M_promise;
+ };
+
struct __exception_ptr_tag { };
// set exceptions
// Used by std::promise to store an exception as the result.
typename promise<_Res>::_Ptr_type operator()() const
{
- _State_baseV2::_S_check(_M_promise->_M_future);
_M_promise->_M_storage->_M_error = *_M_ex;
return std::move(_M_promise->_M_storage);
}
static _Setter<_Res, _Arg&&>
__setter(promise<_Res>* __prom, _Arg&& __arg)
{
- return _Setter<_Res, _Arg&&>{ __prom, &__arg };
+ _S_check(__prom->_M_future);
+ return _Setter<_Res, _Arg&&>{ __prom, std::__addressof(__arg) };
}
template<typename _Res>
static _Setter<_Res, __exception_ptr_tag>
__setter(exception_ptr& __ex, promise<_Res>* __prom)
{
+ _S_check(__prom->_M_future);
return _Setter<_Res, __exception_ptr_tag>{ __prom, &__ex };
}
+ template<typename _Res>
+ static _Setter<_Res, void>
+ __setter(promise<_Res>* __prom)
+ {
+ _S_check(__prom->_M_future);
+ return _Setter<_Res, void>{ __prom };
+ }
+
template<typename _Tp>
static void
_S_check(const shared_ptr<_Tp>& __p)
class _Async_state_commonV2;
#endif
- template<typename _BoundFn, typename = typename _BoundFn::result_type>
+ template<typename _BoundFn,
+ typename _Res = decltype(std::declval<_BoundFn&>()())>
class _Deferred_state;
- template<typename _BoundFn, typename = typename _BoundFn::result_type>
+ template<typename _BoundFn,
+ typename _Res = decltype(std::declval<_BoundFn&>()())>
class _Async_state_impl;
template<typename _Signature>
return std::move(this->_M_get_result()._M_value());
}
- shared_future<_Res> share();
+ shared_future<_Res> share() noexcept;
};
/// Partial specialization for future<R&>
return this->_M_get_result()._M_get();
}
- shared_future<_Res&> share();
+ shared_future<_Res&> share() noexcept;
};
/// Explicit specialization for future<void>
this->_M_get_result();
}
- shared_future<void> share();
+ shared_future<void> share() noexcept;
};
constexpr shared_future() noexcept : _Base_type() { }
/// Copy constructor
- shared_future(const shared_future& __sf) : _Base_type(__sf) { }
+ shared_future(const shared_future& __sf) noexcept : _Base_type(__sf) { }
/// Construct from a future rvalue
shared_future(future<_Res>&& __uf) noexcept
: _Base_type(std::move(__sf))
{ }
- shared_future& operator=(const shared_future& __sf)
+ shared_future& operator=(const shared_future& __sf) noexcept
{
shared_future(__sf)._M_swap(*this);
return *this;
: _M_state(std::move(__uf._M_state))
{ }
+ // _GLIBCXX_RESOLVE_LIB_DEFECTS
+ // 2556. Wide contract for future::share()
template<typename _Res>
inline shared_future<_Res>
- future<_Res>::share()
+ future<_Res>::share() noexcept
{ return shared_future<_Res>(std::move(*this)); }
template<typename _Res>
inline shared_future<_Res&>
- future<_Res&>::share()
+ future<_Res&>::share() noexcept
{ return shared_future<_Res&>(std::move(*this)); }
inline shared_future<void>
- future<void>::share()
+ future<void>::share() noexcept
{ return shared_future<void>(std::move(*this)); }
/// Primary template for promise
typedef __future_base::_Result<_Res> _Res_type;
typedef __future_base::_Ptr<_Res_type> _Ptr_type;
template<typename, typename> friend class _State::_Setter;
+ friend _State;
shared_ptr<_State> _M_future;
_Ptr_type _M_storage;
typedef __future_base::_Result<_Res&> _Res_type;
typedef __future_base::_Ptr<_Res_type> _Ptr_type;
template<typename, typename> friend class _State::_Setter;
+ friend _State;
shared_ptr<_State> _M_future;
_Ptr_type _M_storage;
typedef __future_base::_Result<void> _Res_type;
typedef __future_base::_Ptr<_Res_type> _Ptr_type;
template<typename, typename> friend class _State::_Setter;
+ friend _State;
shared_ptr<_State> _M_future;
_Ptr_type _M_storage;
{ return future<void>(_M_future); }
// Setting the result
- void set_value();
+ void
+ set_value()
+ { _M_future->_M_set_result(_State::__setter(this)); }
void
set_exception(exception_ptr __p)
{ _M_future->_M_set_result(_State::__setter(__p, this)); }
void
- set_value_at_thread_exit();
+ set_value_at_thread_exit()
+ { _M_future->_M_set_delayed_result(_State::__setter(this), _M_future); }
void
set_exception_at_thread_exit(exception_ptr __p)
}
};
- // set void
- template<>
- struct __future_base::_State_base::_Setter<void, void>
- {
- promise<void>::_Ptr_type operator()() const
- {
- _State_base::_S_check(_M_promise->_M_future);
- return std::move(_M_promise->_M_storage);
- }
-
- promise<void>* _M_promise;
- };
-
- inline void
- promise<void>::set_value()
- { _M_future->_M_set_result(_State::_Setter<void, void>{ this }); }
-
- inline void
- promise<void>::set_value_at_thread_exit()
- {
- _M_future->_M_set_delayed_result(_State::_Setter<void, void>{this},
- _M_future);
- }
-
template<typename _Ptr_type, typename _Fn, typename _Res>
struct __future_base::_Task_setter
{
virtual void
_M_run(_Args&&... __args)
{
- // bound arguments decay so wrap lvalue references
- auto __boundfn = std::__bind_simple(std::ref(_M_impl._M_fn),
- _S_maybe_wrap_ref(std::forward<_Args>(__args))...);
+ auto __boundfn = [&] () -> _Res {
+ return std::__invoke_r<_Res>(_M_impl._M_fn,
+ std::forward<_Args>(__args)...);
+ };
this->_M_set_result(_S_task_setter(this->_M_result, __boundfn));
}
virtual void
_M_run_delayed(_Args&&... __args, weak_ptr<_State_base> __self)
{
- // bound arguments decay so wrap lvalue references
- auto __boundfn = std::__bind_simple(std::ref(_M_impl._M_fn),
- _S_maybe_wrap_ref(std::forward<_Args>(__args))...);
+ auto __boundfn = [&] () -> _Res {
+ return std::__invoke_r<_Res>(_M_impl._M_fn,
+ std::forward<_Args>(__args)...);
+ };
this->_M_set_delayed_result(_S_task_setter(this->_M_result, __boundfn),
std::move(__self));
}
virtual shared_ptr<_Task_state_base<_Res(_Args...)>>
_M_reset();
- template<typename _Tp>
- static reference_wrapper<_Tp>
- _S_maybe_wrap_ref(_Tp& __t)
- { return std::ref(__t); }
-
- template<typename _Tp>
- static
- typename enable_if<!is_lvalue_reference<_Tp>::value, _Tp>::type&&
- _S_maybe_wrap_ref(_Tp&& __t)
- { return std::forward<_Tp>(__t); }
-
struct _Impl : _Alloc
{
template<typename _Fn2>
} _M_impl;
};
- template<typename _Signature, typename _Fn, typename _Alloc>
+ template<typename _Signature, typename _Fn,
+ typename _Alloc = std::allocator<int>>
static shared_ptr<__future_base::_Task_state_base<_Signature>>
- __create_task_state(_Fn&& __fn, const _Alloc& __a)
+ __create_task_state(_Fn&& __fn, const _Alloc& __a = _Alloc())
{
typedef typename decay<_Fn>::type _Fn2;
typedef __future_base::_Task_state<_Fn2, _Alloc, _Signature> _State;
static_cast<_Alloc&>(_M_impl));
}
- template<typename _Task, typename _Fn, bool
- = is_same<_Task, typename decay<_Fn>::type>::value>
- struct __constrain_pkgdtask
- { typedef void __type; };
-
- template<typename _Task, typename _Fn>
- struct __constrain_pkgdtask<_Task, _Fn, true>
- { };
-
/// packaged_task
template<typename _Res, typename... _ArgTypes>
class packaged_task<_Res(_ArgTypes...)>
typedef __future_base::_Task_state_base<_Res(_ArgTypes...)> _State_type;
shared_ptr<_State_type> _M_state;
+ // _GLIBCXX_RESOLVE_LIB_DEFECTS
+ // 3039. Unnecessary decay in thread and packaged_task
+ template<typename _Fn, typename _Fn2 = __remove_cvref_t<_Fn>>
+ using __not_same
+ = typename enable_if<!is_same<packaged_task, _Fn2>::value>::type;
+
public:
// Construction and destruction
packaged_task() noexcept { }
- // _GLIBCXX_RESOLVE_LIB_DEFECTS
- // 2095. missing constructors needed for uses-allocator construction
- template<typename _Allocator>
- packaged_task(allocator_arg_t, const _Allocator& __a) noexcept
- { }
-
- template<typename _Fn, typename = typename
- __constrain_pkgdtask<packaged_task, _Fn>::__type>
+ template<typename _Fn, typename = __not_same<_Fn>>
explicit
packaged_task(_Fn&& __fn)
- : packaged_task(allocator_arg, std::allocator<int>(),
- std::forward<_Fn>(__fn))
+ : _M_state(
+ __create_task_state<_Res(_ArgTypes...)>(std::forward<_Fn>(__fn)))
{ }
+#if __cplusplus < 201703L
// _GLIBCXX_RESOLVE_LIB_DEFECTS
- // 2097. packaged_task constructors should be constrained
+ // 2097. packaged_task constructors should be constrained
// 2407. [this constructor should not be] explicit
- template<typename _Fn, typename _Alloc, typename = typename
- __constrain_pkgdtask<packaged_task, _Fn>::__type>
+ // 2921. packaged_task and type-erased allocators
+ template<typename _Fn, typename _Alloc, typename = __not_same<_Fn>>
packaged_task(allocator_arg_t, const _Alloc& __a, _Fn&& __fn)
: _M_state(__create_task_state<_Res(_ArgTypes...)>(
- std::forward<_Fn>(__fn), __a))
+ std::forward<_Fn>(__fn), __a))
{ }
+ // _GLIBCXX_RESOLVE_LIB_DEFECTS
+ // 2095. missing constructors needed for uses-allocator construction
+ template<typename _Allocator>
+ packaged_task(allocator_arg_t, const _Allocator& __a) noexcept
+ { }
+
+ template<typename _Allocator>
+ packaged_task(allocator_arg_t, const _Allocator&,
+ const packaged_task&) = delete;
+
+ template<typename _Allocator>
+ packaged_task(allocator_arg_t, const _Allocator&,
+ packaged_task&& __other) noexcept
+ { this->swap(__other); }
+#endif
+
~packaged_task()
{
if (static_cast<bool>(_M_state) && !_M_state.unique())
packaged_task(const packaged_task&) = delete;
packaged_task& operator=(const packaged_task&) = delete;
- template<typename _Allocator>
- packaged_task(allocator_arg_t, const _Allocator&,
- const packaged_task&) = delete;
-
// Move support
packaged_task(packaged_task&& __other) noexcept
{ this->swap(__other); }
- template<typename _Allocator>
- packaged_task(allocator_arg_t, const _Allocator&,
- packaged_task&& __other) noexcept
- { this->swap(__other); }
-
packaged_task& operator=(packaged_task&& __other) noexcept
{
packaged_task(std::move(__other)).swap(*this);
packaged_task<_Res(_ArgTypes...)>& __y) noexcept
{ __x.swap(__y); }
+#if __cplusplus < 201703L
+ // _GLIBCXX_RESOLVE_LIB_DEFECTS
+ // 2976. Dangling uses_allocator specialization for packaged_task
template<typename _Res, typename _Alloc>
struct uses_allocator<packaged_task<_Res>, _Alloc>
: public true_type { };
-
+#endif
// Shared state created by std::async().
// Holds a deferred function and storage for its result.
//
// [futures.async]:
//
- // — a call to a waiting function on an asynchronous return object that
+ // - a call to a waiting function on an asynchronous return object that
// shares the shared state created by this async call shall block until
// the associated thread has completed, as if joined, or else time out.
//
- // — the associated thread completion synchronizes with the return from
+ // - the associated thread completion synchronizes with the return from
// the first function that successfully detects the ready status of the
// shared state or with the return from the last function that releases
// the shared state, whichever happens first.
/// async
template<typename _Fn, typename... _Args>
- future<__async_result_of<_Fn, _Args...>>
+ _GLIBCXX_NODISCARD future<__async_result_of<_Fn, _Args...>>
async(launch __policy, _Fn&& __fn, _Args&&... __args)
{
std::shared_ptr<__future_base::_State_base> __state;
{
__try
{
- __state = __future_base::_S_make_async_state(std::__bind_simple(
- std::forward<_Fn>(__fn), std::forward<_Args>(__args)...));
+ __state = __future_base::_S_make_async_state(
+ std::thread::__make_invoker(std::forward<_Fn>(__fn),
+ std::forward<_Args>(__args)...)
+ );
}
#if __cpp_exceptions
catch(const system_error& __e)
}
if (!__state)
{
- __state = __future_base::_S_make_deferred_state(std::__bind_simple(
- std::forward<_Fn>(__fn), std::forward<_Args>(__args)...));
+ __state = __future_base::_S_make_deferred_state(
+ std::thread::__make_invoker(std::forward<_Fn>(__fn),
+ std::forward<_Args>(__args)...));
}
return future<__async_result_of<_Fn, _Args...>>(__state);
}
/// async, potential overload
template<typename _Fn, typename... _Args>
- inline future<__async_result_of<_Fn, _Args...>>
+ _GLIBCXX_NODISCARD inline future<__async_result_of<_Fn, _Args...>>
async(_Fn&& __fn, _Args&&... __args)
{
return std::async(launch::async|launch::deferred,
}
#endif // _GLIBCXX_ASYNC_ABI_COMPAT
-#endif // _GLIBCXX_HAS_GTHREADS && _GLIBCXX_USE_C99_STDINT_TR1
- // && ATOMIC_INT_LOCK_FREE
+#endif // _GLIBCXX_HAS_GTHREADS
// @} group futures
_GLIBCXX_END_NAMESPACE_VERSION