mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-23 13:30:06 +00:00
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
112 lines
3.7 KiB
C
112 lines
3.7 KiB
C
/* Low-level lock implementation, x86 version.
|
|
Copyright (C) 2019 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Lesser General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2.1 of the License, or (at your option) any later version.
|
|
|
|
The GNU C 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
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
License along with the GNU C Library; if not, see
|
|
<https://www.gnu.org/licenses/>. */
|
|
|
|
#ifndef _X86_64_LOWLEVELLOCK_H
|
|
#define _X86_64_LOWLEVELLOCK_H 1
|
|
|
|
#ifndef __ASSEMBLER__
|
|
#include <sysdeps/nptl/lowlevellock.h>
|
|
#include <single-thread.h>
|
|
|
|
/* The lll_trylock, lll_lock, and lll_unlock implements a single-thread
|
|
optimization using the cmpxchgl instruction. It checks if the process
|
|
is single thread and avoid a more expensive atomic instruction. */
|
|
|
|
/* The single-thread optimization only works for libc itself, we need
|
|
atomicity for libpthread in case of shared futexes. */
|
|
#if !IS_IN(libc)
|
|
# define is_single_thread 0
|
|
#else
|
|
# define is_single_thread SINGLE_THREAD_P
|
|
#endif
|
|
|
|
/* In the __lllc_as we simply return the value in %eax after the cmpxchg
|
|
instruction. In case the operation succeeded this value is zero. In case
|
|
the operation failed, the cmpxchg instruction has loaded the current value
|
|
of the memory work which is guaranteed to be nonzero. */
|
|
static inline int
|
|
__attribute__ ((always_inline))
|
|
__lll_cas_lock (int *futex)
|
|
{
|
|
int ret;
|
|
asm volatile ("cmpxchgl %2, %1"
|
|
: "=a" (ret), "=m" (*futex)
|
|
: "r" (1), "m" (*futex), "0" (0)
|
|
: "memory");
|
|
return ret;
|
|
}
|
|
|
|
#undef lll_trylock
|
|
#define lll_trylock(lock) \
|
|
({ \
|
|
int __ret; \
|
|
if (is_single_thread) \
|
|
__ret = __lll_cas_lock (&(lock)); \
|
|
else \
|
|
__ret = __lll_trylock (&(lock)); \
|
|
__ret; \
|
|
})
|
|
|
|
#undef lll_lock
|
|
#define lll_lock(lock, private) \
|
|
((void) \
|
|
({ \
|
|
if (is_single_thread) \
|
|
__lll_cas_lock (&(lock)); \
|
|
else \
|
|
__lll_lock (&(lock), private); \
|
|
}))
|
|
|
|
#undef lll_unlock
|
|
#define lll_unlock(lock, private) \
|
|
((void) \
|
|
({ \
|
|
if (is_single_thread) \
|
|
(lock)--; \
|
|
else \
|
|
__lll_unlock (&(lock), private); \
|
|
}))
|
|
|
|
extern int __lll_clocklock_elision (int *futex, short *adapt_count,
|
|
clockid_t clockid,
|
|
const struct timespec *timeout,
|
|
int private) attribute_hidden;
|
|
|
|
#define lll_clocklock_elision(futex, adapt_count, clockid, timeout, private) \
|
|
__lll_clocklock_elision (&(futex), &(adapt_count), clockid, timeout, private)
|
|
|
|
extern int __lll_lock_elision (int *futex, short *adapt_count, int private)
|
|
attribute_hidden;
|
|
|
|
extern int __lll_unlock_elision (int *lock, int private)
|
|
attribute_hidden;
|
|
|
|
extern int __lll_trylock_elision (int *lock, short *adapt_count)
|
|
attribute_hidden;
|
|
|
|
#define lll_lock_elision(futex, adapt_count, private) \
|
|
__lll_lock_elision (&(futex), &(adapt_count), private)
|
|
#define lll_unlock_elision(futex, adapt_count, private) \
|
|
__lll_unlock_elision (&(futex), private)
|
|
#define lll_trylock_elision(futex, adapt_count) \
|
|
__lll_trylock_elision (&(futex), &(adapt_count))
|
|
|
|
#endif /* !__ASSEMBLER__ */
|
|
|
|
#endif /* lowlevellock.h */
|