mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-25 22:40:05 +00:00
44 lines
1.7 KiB
C
44 lines
1.7 KiB
C
/* Single thread optimization, Linux version.
|
|
Copyright (C) 2019-2024 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 _SINGLE_THREAD_H
|
|
#define _SINGLE_THREAD_H
|
|
|
|
#ifndef __ASSEMBLER__
|
|
# include <sys/single_threaded.h>
|
|
#endif
|
|
|
|
/* The default way to check if the process is single thread is by using the
|
|
pthread_t 'multiple_threads' field. However, for some architectures it is
|
|
faster to either use an extra field on TCB or global variables (the TCB
|
|
field is also used on x86 for some single-thread atomic optimizations).
|
|
|
|
The ABI might define SINGLE_THREAD_BY_GLOBAL to enable the single thread
|
|
check to use global variables instead of the pthread_t field. */
|
|
|
|
#if !defined SINGLE_THREAD_BY_GLOBAL || IS_IN (rtld)
|
|
# define SINGLE_THREAD_P \
|
|
(THREAD_GETMEM (THREAD_SELF, header.multiple_threads) == 0)
|
|
#else
|
|
# define SINGLE_THREAD_P (__libc_single_threaded_internal != 0)
|
|
#endif
|
|
|
|
#define RTLD_SINGLE_THREAD_P SINGLE_THREAD_P
|
|
|
|
#endif /* _SINGLE_THREAD_H */
|