44 lines
1.6 KiB
C++
44 lines
1.6 KiB
C++
/* Copyright (C) 2011-2019 Free Software Foundation, Inc.
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Contributed by Richard Henderson <rth@redhat.com>.
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This file is part of the GNU Transactional Memory Library (libitm).
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Libitm is free software; you can redistribute it and/or modify it
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under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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Libitm is distributed in the hope that it will be useful, but WITHOUT ANY
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WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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more details.
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Under Section 7 of GPL version 3, you are granted additional
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permissions described in the GCC Runtime Library Exception, version
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3.1, as published by the Free Software Foundation.
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You should have received a copy of the GNU General Public License and
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a copy of the GCC Runtime Library Exception along with this program;
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see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
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<http://www.gnu.org/licenses/>. */
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/* Provide target-independant access to the futex system call. */
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/* Note for ARM:
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There are two styles of syscall, and in the eabi style the syscall
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number goes into the thumb frame pointer. We need to either write
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this in pure assembler or just defer entirely to libc. */
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#include <unistd.h>
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#include <sys/syscall.h>
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#include <errno.h>
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static inline long
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sys_futex0 (std::atomic<int> *addr, int op, int val)
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{
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long res = syscall (SYS_futex, (int*) addr, op, val, 0);
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if (__builtin_expect (res == -1, 0))
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return -errno;
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return res;
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}
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