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ab991a3d1b
Linux threads were removed about 12 years ago and the current
nptl implementation only requires 4-byte alignment for pthread
locks.
The 16-byte alignment causes various issues. For example in
building ignition-msgs, we have:
/usr/include/google/protobuf/map.h:124:37: error: static assertion failed
124 | static_assert(alignof(value_type) <= 8, "");
| ~~~~~~~~~~~~~~~~~~~~^~~~
This is caused by the 16-byte pthread lock alignment.
Signed-off-by: John David Anglin <dave.anglin@bell.net>
64 lines
2.3 KiB
C
64 lines
2.3 KiB
C
/* HPPA internal rwlock struct definitions.
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Copyright (C) 2019-2023 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#ifndef _RWLOCK_INTERNAL_H
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#define _RWLOCK_INTERNAL_H
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struct __pthread_rwlock_arch_t
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{
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/* In the old Linuxthreads pthread_rwlock_t, this is the
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start of the 4-word 16-byte aligned lock structure. The
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next four words are all set to 1 by the Linuxthreads
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PTHREAD_RWLOCK_INITIALIZER. We ignore them in NPTL.
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The 16-byte aligned lock stucture causes various pthread
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structures to be over aligned. This causes some builds
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to fail which assume a maximum alignment of 8 bytes.
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Linuxthreads has been removed for 12 years, so drop
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alignment of lock structure. */
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int __compat_padding[4];
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unsigned int __readers;
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unsigned int __writers;
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unsigned int __wrphase_futex;
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unsigned int __writers_futex;
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unsigned int __pad3;
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unsigned int __pad4;
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int __cur_writer;
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/* An unused word, reserved for future use. It was added
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to maintain the location of the flags from the Linuxthreads
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layout of this structure. */
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int __reserved1;
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/* FLAGS must stay at this position in the structure to maintain
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binary compatibility. */
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unsigned char __pad2;
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unsigned char __pad1;
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unsigned char __shared;
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unsigned char __flags;
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/* The NPTL pthread_rwlock_t is 4 words smaller than the
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Linuxthreads version. One word is in the middle of the
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structure, the other three are at the end. */
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int __reserved2;
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int __reserved3;
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int __reserved4;
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};
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#define __PTHREAD_RWLOCK_INITIALIZER(__flags) \
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{ 0, 0, 0, 0 }, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, __flags, 0, 0, 0
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#endif
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