atomicity.h revision 117397
1254721Semaste/* Low-level functions for atomic operations. PA-RISC version. -*- C++ -*- 2254721Semaste Copyright 2002 Free Software Foundation, Inc. 3353358Sdim This file is part of the GNU C Library. 4353358Sdim 5353358Sdim The GNU C Library is free software; you can redistribute it and/or 6254721Semaste modify it under the terms of the GNU Library General Public License as 7254721Semaste published by the Free Software Foundation; either version 2 of the 8254721Semaste License, or (at your option) any later version. 9254721Semaste 10254721Semaste The GNU C Library is distributed in the hope that it will be useful, 11254721Semaste but WITHOUT ANY WARRANTY; without even the implied warranty of 12254721Semaste MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13254721Semaste Library General Public License for more details. 14254721Semaste 15314564Sdim You should have received a copy of the GNU Library General Public 16360784Sdim License along with the GNU C Library; see the file COPYING.LIB. If not, 17314564Sdim write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, 18314564Sdim Boston, MA 02111-1307, USA. */ 19314564Sdim 20254721Semaste#ifndef _BITS_ATOMICITY_H 21254721Semaste#define _BITS_ATOMICITY_H 1 22353358Sdim 23254721Semastetypedef int _Atomic_word; 24341825Sdim 25341825Sdimtemplate <int __inst> 26341825Sdimstruct __Atomicity_lock 27254721Semaste{ 28254721Semaste static volatile int _S_atomicity_lock; 29254721Semaste}; 30254721Semaste 31353358Sdimtemplate <int __inst> 32353358Sdimvolatile int 33360784Sdim__Atomicity_lock<__inst>::_S_atomicity_lock __attribute__ ((aligned (16))) = 1; 34360784Sdim 35254721Semaste/* Because of the lack of weak support when using the hpux 36314564Sdim som linker, we explicitly instantiate the atomicity lock 37341825Sdim in src/misc-inst.cc when _GLIBCPP_INST_ATOMICITY_LOCK 38254721Semaste is defined. */ 39314564Sdim#ifndef _GLIBCPP_INST_ATOMICITY_LOCK 40314564Sdimtemplate volatile int __Atomicity_lock<0>::_S_atomicity_lock; 41314564Sdim#endif 42254721Semaste 43314564Sdimstatic inline int 44276479Sdim__attribute__ ((__unused__)) 45314564Sdim__exchange_and_add (volatile _Atomic_word* __mem, int __val) 46314564Sdim{ 47321369Sdim _Atomic_word result; 48353358Sdim int tmp; 49353358Sdim volatile int& lock = __Atomicity_lock<0>::_S_atomicity_lock; 50353358Sdim 51276479Sdim __asm__ __volatile__ ("ldcw 0(%1),%0\n\t" 52360784Sdim "cmpib,<>,n 0,%0,.+20\n\t" 53360784Sdim "ldw 0(%1),%0\n\t" 54353358Sdim "cmpib,= 0,%0,.-4\n\t" 55321369Sdim "nop\n\t" 56321369Sdim "b,n .-20" 57321369Sdim : "=&r" (tmp) 58321369Sdim : "r" (&lock)); 59321369Sdim 60321369Sdim result = *__mem; 61353358Sdim *__mem = result + __val; 62321369Sdim /* Reset lock with PA 2.0 "ordered" store. */ 63321369Sdim __asm__ __volatile__ ("stw,ma %1,0(%0)" 64321369Sdim : : "r" (&lock), "r" (tmp) : "memory"); 65321369Sdim return result; 66321369Sdim} 67353358Sdim 68321369Sdimstatic inline void 69321369Sdim__attribute__ ((__unused__)) 70321369Sdim__atomic_add (_Atomic_word* __mem, int __val) 71321369Sdim{ 72353358Sdim int tmp; 73321369Sdim volatile int& lock = __Atomicity_lock<0>::_S_atomicity_lock; 74321369Sdim 75321369Sdim __asm__ __volatile__ ("ldcw 0(%1),%0\n\t" 76321369Sdim "cmpib,<>,n 0,%0,.+20\n\t" 77321369Sdim "ldw 0(%1),%0\n\t" 78321369Sdim "cmpib,= 0,%0,.-4\n\t" 79353358Sdim "nop\n\t" 80254721Semaste "b,n .-20" 81314564Sdim : "=&r" (tmp) 82254721Semaste : "r" (&lock)); 83254721Semaste 84314564Sdim *__mem += __val; 85314564Sdim /* Reset lock with PA 2.0 "ordered" store. */ 86321369Sdim __asm__ __volatile__ ("stw,ma %1,0(%0)" 87321369Sdim : : "r" (&lock), "r" (tmp) : "memory"); 88321369Sdim} 89321369Sdim 90360784Sdim#endif 91360784Sdim