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author | Joel Sherrill <joel.sherrill@oarcorp.com> | 2003-04-29 21:57:39 +0000 |
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committer | Loren J. Rittle <ljrittle@gcc.gnu.org> | 2003-04-29 21:57:39 +0000 |
commit | 51dc3d74f84691bda6b24b495ec8cd0f9e52460d (patch) | |
tree | 169fda86022dd5d6db7f97c1065d6c6496576092 /libstdc++-v3/config/cpu | |
parent | 0219237c53194d1820ab8b00c6af19f68c7862c8 (diff) | |
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atomicity.h: New file.
2003-04-29 Joel Sherrill <joel.sherrill@OARcorp.com>
Loren J. Rittle <ljrittle@acm.org>
Martin v. Loewis <martin@v.loewis.de>
* config/cpu/i386/atomicity.h: New file.
Co-Authored-By: Loren J. Rittle <ljrittle@acm.org>
Co-Authored-By: Martin v. Loewis <martin@v.loewis.de>
From-SVN: r66261
Diffstat (limited to 'libstdc++-v3/config/cpu')
-rw-r--r-- | libstdc++-v3/config/cpu/i386/atomicity.h | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/libstdc++-v3/config/cpu/i386/atomicity.h b/libstdc++-v3/config/cpu/i386/atomicity.h new file mode 100644 index 0000000..ac9f770 --- /dev/null +++ b/libstdc++-v3/config/cpu/i386/atomicity.h @@ -0,0 +1,75 @@ +// Low-level functions for atomic operations: x86, x >= 3 version -*- C++ -*- + +// Copyright (C) 2003 Free Software Foundation, Inc. +// +// This file is part of the GNU ISO C++ Library. This library is free +// software; you can redistribute it and/or modify it under the +// terms of the GNU General Public License as published by the +// Free Software Foundation; either version 2, or (at your option) +// any later version. + +// This library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU General Public License for more details. + +// You should have received a copy of the GNU General Public License along +// with this library; see the file COPYING. If not, write to the Free +// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, +// USA. + +// As a special exception, you may use this file as part of a free software +// library without restriction. Specifically, if other files instantiate +// templates or use macros or inline functions from this file, or you compile +// this file and link it with other files to produce an executable, this +// file does not by itself cause the resulting executable to be covered by +// the GNU General Public License. This exception does not however +// invalidate any other reasons why the executable file might be covered by +// the GNU General Public License. + +#ifndef _BITS_ATOMICITY_H +#define _BITS_ATOMICITY_H 1 + +typedef int _Atomic_word; + +template <int __inst> +struct __Atomicity_lock +{ + static volatile _Atomic_word _S_atomicity_lock; +}; + +template <int __inst> +volatile _Atomic_word __Atomicity_lock<__inst>::_S_atomicity_lock = 0; + +template volatile _Atomic_word __Atomicity_lock<0>::_S_atomicity_lock; + +static inline _Atomic_word +__attribute__ ((__unused__)) +__exchange_and_add (volatile _Atomic_word *__mem, int __val) +{ + register _Atomic_word __result, __tmp = 1; + + /* obtain the atomic exchange/add spin lock */ + do { + __asm__ __volatile__ ("xchgl %0,%1" + : "+m" (__Atomicity_lock<0>::_S_atomicity_lock), + "+r" (__tmp)); + } while (__tmp); + + __result = *__mem; + *__mem += __val; + + /* release spin lock */ + __Atomicity_lock<0>::_S_atomicity_lock = 0; + + return __result; +} + +static inline void +__attribute__ ((__unused__)) +__atomic_add (volatile _Atomic_word* __mem, int __val) +{ + __exchange_and_add (__mem, __val); +} + +#endif /* atomicity.h */ |