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5a82c74822
Also, change sources.redhat.com to sourceware.org.
This patch was automatically generated by running the following shell
script, which uses GNU sed, and which avoids modifying files imported
from upstream:
sed -ri '
s,(http|ftp)(://(.*\.)?(gnu|fsf|sourceware)\.org($|[^.]|\.[^a-z])),https\2,g
s,(http|ftp)(://(.*\.)?)sources\.redhat\.com($|[^.]|\.[^a-z]),https\2sourceware.org\4,g
' \
$(find $(git ls-files) -prune -type f \
! -name '*.po' \
! -name 'ChangeLog*' \
! -path COPYING ! -path COPYING.LIB \
! -path manual/fdl-1.3.texi ! -path manual/lgpl-2.1.texi \
! -path manual/texinfo.tex ! -path scripts/config.guess \
! -path scripts/config.sub ! -path scripts/install-sh \
! -path scripts/mkinstalldirs ! -path scripts/move-if-change \
! -path INSTALL ! -path locale/programs/charmap-kw.h \
! -path po/libc.pot ! -path sysdeps/gnu/errlist.c \
! '(' -name configure \
-execdir test -f configure.ac -o -f configure.in ';' ')' \
! '(' -name preconfigure \
-execdir test -f preconfigure.ac ';' ')' \
-print)
and then by running 'make dist-prepare' to regenerate files built
from the altered files, and then executing the following to cleanup:
chmod a+x sysdeps/unix/sysv/linux/riscv/configure
# Omit irrelevant whitespace and comment-only changes,
# perhaps from a slightly-different Autoconf version.
git checkout -f \
sysdeps/csky/configure \
sysdeps/hppa/configure \
sysdeps/riscv/configure \
sysdeps/unix/sysv/linux/csky/configure
# Omit changes that caused a pre-commit check to fail like this:
# remote: *** error: sysdeps/powerpc/powerpc64/ppc-mcount.S: trailing lines
git checkout -f \
sysdeps/powerpc/powerpc64/ppc-mcount.S \
sysdeps/unix/sysv/linux/s390/s390-64/syscall.S
# Omit change that caused a pre-commit check to fail like this:
# remote: *** error: sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S: last line does not end in newline
git checkout -f sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S
76 lines
2.5 KiB
C
76 lines
2.5 KiB
C
/* elision-trylock.c: Lock eliding trylock for pthreads.
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Copyright (C) 2013-2019 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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<https://www.gnu.org/licenses/>. */
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#include <pthread.h>
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#include <pthreadP.h>
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#include <lowlevellock.h>
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#include "hle.h"
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#include <elision-conf.h>
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#define aconf __elision_aconf
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/* Try to elide a futex trylock. FUTEX is the futex variable. ADAPT_COUNT is
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the adaptation counter in the mutex. */
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int
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__lll_trylock_elision (int *futex, short *adapt_count)
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{
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/* Implement POSIX semantics by forbiding nesting
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trylock. Sorry. After the abort the code is re-executed
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non transactional and if the lock was already locked
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return an error. */
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_xabort (_ABORT_NESTED_TRYLOCK);
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/* Only try a transaction if it's worth it. See __lll_lock_elision for
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why we need atomic accesses. Relaxed MO is sufficient because this is
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just a hint. */
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if (atomic_load_relaxed (adapt_count) <= 0)
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{
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unsigned status;
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if ((status = _xbegin()) == _XBEGIN_STARTED)
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{
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if (*futex == 0)
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return 0;
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/* Lock was busy. Fall back to normal locking.
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Could also _xend here but xabort with 0xff code
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is more visible in the profiler. */
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_xabort (_ABORT_LOCK_BUSY);
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}
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if (!(status & _XABORT_RETRY))
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{
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/* Internal abort. No chance for retry. For future
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locks don't try speculation for some time. See above for MO. */
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if (atomic_load_relaxed (adapt_count)
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!= aconf.skip_lock_internal_abort)
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atomic_store_relaxed (adapt_count, aconf.skip_lock_internal_abort);
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}
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/* Could do some retries here. */
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}
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else
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{
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/* Lost updates are possible but harmless (see above). */
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atomic_store_relaxed (adapt_count,
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atomic_load_relaxed (adapt_count) - 1);
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}
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return lll_trylock (*futex);
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}
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