1 // future -*- C++ -*-
2 
3 // Copyright (C) 2009-2020 Free Software Foundation, Inc.
4 //
5 // This file is part of the GNU ISO C++ Library.  This library is free
6 // software; you can redistribute it and/or modify it under the
7 // terms of the GNU General Public License as published by the
8 // Free Software Foundation; either version 3, or (at your option)
9 // any later version.
10 
11 // This library is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 // GNU General Public License for more details.
15 
16 // Under Section 7 of GPL version 3, you are granted additional
17 // permissions described in the GCC Runtime Library Exception, version
18 // 3.1, as published by the Free Software Foundation.
19 
20 // You should have received a copy of the GNU General Public License and
21 // a copy of the GCC Runtime Library Exception along with this program;
22 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
23 // <http://www.gnu.org/licenses/>.
24 
25 #include <future>
26 #include <bits/functexcept.h>
27 
28 namespace
29 {
30   struct future_error_category : public std::error_category
31   {
32     virtual const char*
name__anon1e89eab30111::future_error_category33     name() const noexcept
34     { return "future"; }
35 
36     _GLIBCXX_DEFAULT_ABI_TAG
message__anon1e89eab30111::future_error_category37     virtual std::string message(int __ec) const
38     {
39       std::string __msg;
40       switch (std::future_errc(__ec))
41       {
42       case std::future_errc::broken_promise:
43           __msg = "Broken promise";
44           break;
45       case std::future_errc::future_already_retrieved:
46           __msg = "Future already retrieved";
47           break;
48       case std::future_errc::promise_already_satisfied:
49           __msg = "Promise already satisfied";
50           break;
51       case std::future_errc::no_state:
52           __msg = "No associated state";
53           break;
54       default:
55           __msg = "Unknown error";
56           break;
57       }
58       return __msg;
59     }
60   };
61 
62   const future_error_category&
__future_category_instance()63   __future_category_instance() noexcept
64   {
65     static const future_error_category __fec{};
66     return __fec;
67   }
68 }
69 
70 namespace std _GLIBCXX_VISIBILITY(default)
71 {
72 _GLIBCXX_BEGIN_NAMESPACE_VERSION
73 
74   void
__throw_future_error(int __i)75   __throw_future_error(int __i __attribute__((unused)))
76   { _GLIBCXX_THROW_OR_ABORT(future_error(make_error_code(future_errc(__i)))); }
77 
future_category()78   const error_category& future_category() noexcept
79   { return __future_category_instance(); }
80 
~future_error()81   future_error::~future_error() noexcept { }
82 
83   const char*
what() const84   future_error::what() const noexcept { return logic_error::what(); }
85 
86 #ifdef _GLIBCXX_HAS_GTHREADS
87   __future_base::_Result_base::_Result_base() = default;
88 
89   __future_base::_Result_base::~_Result_base() = default;
90 
91   void
_S_run(void * p)92   __future_base::_State_baseV2::_Make_ready::_S_run(void* p)
93   {
94     unique_ptr<_Make_ready> mr{static_cast<_Make_ready*>(p)};
95     if (auto state = mr->_M_shared_state.lock())
96       {
97 	// Use release MO to synchronize with observers of the ready state.
98 	state->_M_status._M_store_notify_all(_Status::__ready,
99 	    memory_order_release);
100       }
101   }
102 
103   // defined in src/c++11/condition_variable.cc
104   extern void
105   __at_thread_exit(__at_thread_exit_elt* elt);
106 
107   void
_M_set()108   __future_base::_State_baseV2::_Make_ready::_M_set()
109   {
110     _M_cb = &_Make_ready::_S_run;
111     __at_thread_exit(this);
112   }
113 #endif // _GLIBCXX_HAS_GTHREADS
114 
115 _GLIBCXX_END_NAMESPACE_VERSION
116 } // namespace std
117