1*38fd1498Szrj // Exception Handling support header for -*- C++ -*- 2*38fd1498Szrj 3*38fd1498Szrj // Copyright (C) 2016-2018 Free Software Foundation, Inc. 4*38fd1498Szrj // 5*38fd1498Szrj // This file is part of GCC. 6*38fd1498Szrj // 7*38fd1498Szrj // GCC is free software; you can redistribute it and/or modify 8*38fd1498Szrj // it under the terms of the GNU General Public License as published by 9*38fd1498Szrj // the Free Software Foundation; either version 3, or (at your option) 10*38fd1498Szrj // any later version. 11*38fd1498Szrj // 12*38fd1498Szrj // GCC is distributed in the hope that it will be useful, 13*38fd1498Szrj // but WITHOUT ANY WARRANTY; without even the implied warranty of 14*38fd1498Szrj // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15*38fd1498Szrj // GNU General Public License for more details. 16*38fd1498Szrj // 17*38fd1498Szrj // Under Section 7 of GPL version 3, you are granted additional 18*38fd1498Szrj // permissions described in the GCC Runtime Library Exception, version 19*38fd1498Szrj // 3.1, as published by the Free Software Foundation. 20*38fd1498Szrj 21*38fd1498Szrj // You should have received a copy of the GNU General Public License and 22*38fd1498Szrj // a copy of the GCC Runtime Library Exception along with this program; 23*38fd1498Szrj // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 24*38fd1498Szrj // <http://www.gnu.org/licenses/>. 25*38fd1498Szrj 26*38fd1498Szrj /** @file eh_atomics.h 27*38fd1498Szrj * This is an internal header file, included by library source files. 28*38fd1498Szrj * Do not attempt to use it directly. 29*38fd1498Szrj */ 30*38fd1498Szrj 31*38fd1498Szrj #ifndef _EH_ATOMICS_H 32*38fd1498Szrj #define _EH_ATOMICS_H 1 33*38fd1498Szrj 34*38fd1498Szrj #include <bits/c++config.h> 35*38fd1498Szrj #include <bits/atomic_word.h> 36*38fd1498Szrj #include <bits/atomic_lockfree_defines.h> 37*38fd1498Szrj #if ATOMIC_INT_LOCK_FREE <= 1 38*38fd1498Szrj # include <ext/atomicity.h> 39*38fd1498Szrj #endif 40*38fd1498Szrj 41*38fd1498Szrj #pragma GCC visibility push(default) 42*38fd1498Szrj extern "C++" { 43*38fd1498Szrj namespace __gnu_cxx 44*38fd1498Szrj { 45*38fd1498Szrj void 46*38fd1498Szrj __eh_atomic_inc (_Atomic_word* __count) __attribute__((always_inline)); 47*38fd1498Szrj 48*38fd1498Szrj bool 49*38fd1498Szrj __eh_atomic_dec (_Atomic_word* __count) __attribute__((always_inline)); 50*38fd1498Szrj 51*38fd1498Szrj // Increments the count. 52*38fd1498Szrj inline void __eh_atomic_inc(_Atomic_word * __count)53*38fd1498Szrj __eh_atomic_inc (_Atomic_word* __count) 54*38fd1498Szrj { 55*38fd1498Szrj #if ATOMIC_INT_LOCK_FREE > 1 56*38fd1498Szrj __atomic_add_fetch (__count, 1, __ATOMIC_ACQ_REL); 57*38fd1498Szrj #else 58*38fd1498Szrj _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE (__count); 59*38fd1498Szrj __gnu_cxx::__atomic_add_dispatch (__count, 1); 60*38fd1498Szrj _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER (__count); 61*38fd1498Szrj #endif 62*38fd1498Szrj } 63*38fd1498Szrj 64*38fd1498Szrj // Decrements the count and returns true if it reached zero. 65*38fd1498Szrj inline bool __eh_atomic_dec(_Atomic_word * __count)66*38fd1498Szrj __eh_atomic_dec (_Atomic_word* __count) 67*38fd1498Szrj { 68*38fd1498Szrj #if ATOMIC_INT_LOCK_FREE > 1 69*38fd1498Szrj return __atomic_sub_fetch (__count, 1, __ATOMIC_ACQ_REL) == 0; 70*38fd1498Szrj #else 71*38fd1498Szrj _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE (__count); 72*38fd1498Szrj if (__gnu_cxx::__exchange_and_add_dispatch (__count, -1) == 1) 73*38fd1498Szrj { 74*38fd1498Szrj _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER (__count); 75*38fd1498Szrj return true; 76*38fd1498Szrj } 77*38fd1498Szrj return false; 78*38fd1498Szrj #endif 79*38fd1498Szrj } 80*38fd1498Szrj } // namespace __gnu_cxx 81*38fd1498Szrj } 82*38fd1498Szrj #pragma GCC visibility pop 83*38fd1498Szrj 84*38fd1498Szrj #endif // _EH_ATOMICS_H 85