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// future -*- C++ -*-
// Copyright (C) 2009-2022 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/>.
#include <future>
#include <bits/functexcept.h>
#if __has_cpp_attribute(clang::require_constant_initialization)
# define __constinit [[clang::require_constant_initialization]]
#endif
namespace
{
struct future_error_category final : public std::error_category
{
const char*
name() const noexcept final
{ return "future"; }
_GLIBCXX_DEFAULT_ABI_TAG
std::string
message(int __ec) const final
{
std::string __msg;
switch (std::future_errc(__ec))
{
case std::future_errc::broken_promise:
__msg = "Broken promise";
break;
case std::future_errc::future_already_retrieved:
__msg = "Future already retrieved";
break;
case std::future_errc::promise_already_satisfied:
__msg = "Promise already satisfied";
break;
case std::future_errc::no_state:
__msg = "No associated state";
break;
default:
__msg = "Unknown error";
break;
}
return __msg;
}
};
struct constant_init
{
union {
unsigned char unused;
future_error_category cat;
};
constexpr constant_init() : cat() { }
~constant_init() { /* do nothing, union member is not destroyed */ }
};
__constinit constant_init future_category_instance{};
}
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
void
__throw_future_error(int __i __attribute__((unused)))
{ _GLIBCXX_THROW_OR_ABORT(future_error(make_error_code(future_errc(__i)))); }
const error_category& future_category() noexcept
{ return future_category_instance.cat; }
future_error::~future_error() noexcept { }
const char*
future_error::what() const noexcept { return logic_error::what(); }
#ifdef _GLIBCXX_HAS_GTHREADS
__future_base::_Result_base::_Result_base() = default;
__future_base::_Result_base::~_Result_base() = default;
void
__future_base::_State_baseV2::_Make_ready::_S_run(void* p)
{
unique_ptr<_Make_ready> mr{static_cast<_Make_ready*>(p)};
if (auto state = mr->_M_shared_state.lock())
{
// Use release MO to synchronize with observers of the ready state.
state->_M_status._M_store_notify_all(_Status::__ready,
memory_order_release);
}
}
// defined in src/c++11/condition_variable.cc
extern void
__at_thread_exit(__at_thread_exit_elt* elt);
void
__future_base::_State_baseV2::_Make_ready::_M_set()
{
_M_cb = &_Make_ready::_S_run;
__at_thread_exit(this);
}
#endif // _GLIBCXX_HAS_GTHREADS
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace std