1*38fd1498Szrj // mutex -*- C++ -*- 2*38fd1498Szrj 3*38fd1498Szrj // Copyright (C) 2008-2018 Free Software Foundation, Inc. 4*38fd1498Szrj // 5*38fd1498Szrj // This file is part of the GNU ISO C++ Library. This library is free 6*38fd1498Szrj // software; you can redistribute it and/or modify it under the 7*38fd1498Szrj // terms of the GNU General Public License as published by the 8*38fd1498Szrj // Free Software Foundation; either version 3, or (at your option) 9*38fd1498Szrj // any later version. 10*38fd1498Szrj 11*38fd1498Szrj // This library is distributed in the hope that it will be useful, 12*38fd1498Szrj // but WITHOUT ANY WARRANTY; without even the implied warranty of 13*38fd1498Szrj // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14*38fd1498Szrj // GNU General Public License for more details. 15*38fd1498Szrj 16*38fd1498Szrj // Under Section 7 of GPL version 3, you are granted additional 17*38fd1498Szrj // permissions described in the GCC Runtime Library Exception, version 18*38fd1498Szrj // 3.1, as published by the Free Software Foundation. 19*38fd1498Szrj 20*38fd1498Szrj // You should have received a copy of the GNU General Public License and 21*38fd1498Szrj // a copy of the GCC Runtime Library Exception along with this program; 22*38fd1498Szrj // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 23*38fd1498Szrj // <http://www.gnu.org/licenses/>. 24*38fd1498Szrj 25*38fd1498Szrj #include <mutex> 26*38fd1498Szrj 27*38fd1498Szrj #if defined(_GLIBCXX_HAS_GTHREADS) && defined(_GLIBCXX_USE_C99_STDINT_TR1) 28*38fd1498Szrj #ifndef _GLIBCXX_HAVE_TLS 29*38fd1498Szrj namespace 30*38fd1498Szrj { 31*38fd1498Szrj inline std::unique_lock<std::mutex>*& __get_once_functor_lock_ptr()32*38fd1498Szrj __get_once_functor_lock_ptr() 33*38fd1498Szrj { 34*38fd1498Szrj static std::unique_lock<std::mutex>* __once_functor_lock_ptr = 0; 35*38fd1498Szrj return __once_functor_lock_ptr; 36*38fd1498Szrj } 37*38fd1498Szrj } 38*38fd1498Szrj #endif 39*38fd1498Szrj 40*38fd1498Szrj namespace std _GLIBCXX_VISIBILITY(default) 41*38fd1498Szrj { 42*38fd1498Szrj _GLIBCXX_BEGIN_NAMESPACE_VERSION 43*38fd1498Szrj 44*38fd1498Szrj #ifdef _GLIBCXX_HAVE_TLS 45*38fd1498Szrj __thread void* __once_callable; 46*38fd1498Szrj __thread void (*__once_call)(); 47*38fd1498Szrj #else 48*38fd1498Szrj // Explicit instantiation due to -fno-implicit-instantiation. 49*38fd1498Szrj template class function<void()>; 50*38fd1498Szrj function<void()> __once_functor; 51*38fd1498Szrj 52*38fd1498Szrj mutex& 53*38fd1498Szrj __get_once_mutex() 54*38fd1498Szrj { 55*38fd1498Szrj static mutex once_mutex; 56*38fd1498Szrj return once_mutex; 57*38fd1498Szrj } 58*38fd1498Szrj 59*38fd1498Szrj // code linked against ABI 3.4.12 and later uses this 60*38fd1498Szrj void 61*38fd1498Szrj __set_once_functor_lock_ptr(unique_lock<mutex>* __ptr) 62*38fd1498Szrj { 63*38fd1498Szrj __get_once_functor_lock_ptr() = __ptr; 64*38fd1498Szrj } 65*38fd1498Szrj 66*38fd1498Szrj // unsafe - retained for compatibility with ABI 3.4.11 67*38fd1498Szrj unique_lock<mutex>& 68*38fd1498Szrj __get_once_functor_lock() 69*38fd1498Szrj { 70*38fd1498Szrj static unique_lock<mutex> once_functor_lock(__get_once_mutex(), defer_lock); 71*38fd1498Szrj return once_functor_lock; 72*38fd1498Szrj } 73*38fd1498Szrj #endif 74*38fd1498Szrj 75*38fd1498Szrj extern "C" 76*38fd1498Szrj { __once_proxy()77*38fd1498Szrj void __once_proxy() 78*38fd1498Szrj { 79*38fd1498Szrj #ifndef _GLIBCXX_HAVE_TLS 80*38fd1498Szrj function<void()> __once_call = std::move(__once_functor); 81*38fd1498Szrj if (unique_lock<mutex>* __lock = __get_once_functor_lock_ptr()) 82*38fd1498Szrj { 83*38fd1498Szrj // caller is using new ABI and provided lock ptr 84*38fd1498Szrj __get_once_functor_lock_ptr() = 0; 85*38fd1498Szrj __lock->unlock(); 86*38fd1498Szrj } 87*38fd1498Szrj else 88*38fd1498Szrj __get_once_functor_lock().unlock(); // global lock 89*38fd1498Szrj #endif 90*38fd1498Szrj __once_call(); 91*38fd1498Szrj } 92*38fd1498Szrj } 93*38fd1498Szrj 94*38fd1498Szrj _GLIBCXX_END_NAMESPACE_VERSION 95*38fd1498Szrj } // namespace std 96*38fd1498Szrj 97*38fd1498Szrj #endif // _GLIBCXX_HAS_GTHREADS && _GLIBCXX_USE_C99_STDINT_TR1 98