1 // Implementation file for the -*- C++ -*- dynamic memory management header. 2 3 // Copyright (C) 1996-2018 Free Software Foundation, Inc. 4 // 5 // This file is part of GCC. 6 // 7 // GCC is free software; you can redistribute it and/or modify 8 // it under the terms of the GNU General Public License as published by 9 // the Free Software Foundation; either version 3, or (at your option) 10 // any later version. 11 // 12 // GCC is distributed in the hope that it will be useful, 13 // but WITHOUT ANY WARRANTY; without even the implied warranty of 14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 // GNU General Public License for more details. 16 // 17 // Under Section 7 of GPL version 3, you are granted additional 18 // permissions described in the GCC Runtime Library Exception, version 19 // 3.1, as published by the Free Software Foundation. 20 21 // You should have received a copy of the GNU General Public License and 22 // a copy of the GCC Runtime Library Exception along with this program; 23 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 24 // <http://www.gnu.org/licenses/>. 25 26 #include "new" 27 #include <bits/atomic_lockfree_defines.h> 28 29 #if ATOMIC_POINTER_LOCK_FREE < 2 30 #include <ext/concurrence.h> 31 namespace 32 { 33 __gnu_cxx::__mutex mx; 34 } 35 #endif 36 37 const std::nothrow_t std::nothrow = std::nothrow_t{ }; 38 39 using std::new_handler; 40 namespace 41 { 42 new_handler __new_handler; 43 } 44 45 new_handler 46 std::set_new_handler (new_handler handler) throw() 47 { 48 new_handler prev_handler; 49 #if ATOMIC_POINTER_LOCK_FREE > 1 50 __atomic_exchange (&__new_handler, &handler, &prev_handler, 51 __ATOMIC_ACQ_REL); 52 #else 53 __gnu_cxx::__scoped_lock l(mx); 54 prev_handler = __new_handler; 55 __new_handler = handler; 56 #endif 57 return prev_handler; 58 } 59 60 new_handler 61 std::get_new_handler () noexcept 62 { 63 new_handler handler; 64 #if ATOMIC_POINTER_LOCK_FREE > 1 65 __atomic_load (&__new_handler, &handler, __ATOMIC_ACQUIRE); 66 #else 67 __gnu_cxx::__scoped_lock l(mx); 68 handler = __new_handler; 69 #endif 70 return handler; 71 } 72