mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-11 22:00:08 +00:00
2b778ceb40
I used these shell commands: ../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright (cd ../glibc && git commit -am"[this commit message]") and then ignored the output, which consisted lines saying "FOO: warning: copyright statement not found" for each of 6694 files FOO. I then removed trailing white space from benchtests/bench-pthread-locks.c and iconvdata/tst-iconv-big5-hkscs-to-2ucs4.c, to work around this diagnostic from Savannah: remote: *** pre-commit check failed ... remote: *** error: lines with trailing whitespace found remote: error: hook declined to update refs/heads/master
71 lines
2.1 KiB
C
71 lines
2.1 KiB
C
/* Auxiliary definitions for 64-bit time_t support.
|
|
Copyright (C) 2020-2021 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/>. */
|
|
|
|
#include <stdbool.h>
|
|
#include <atomic.h>
|
|
|
|
/* These helper functions are used to optimize the 64-bit time_t support on
|
|
configurations that requires support for 32-bit time_t fallback
|
|
(!__ASSUME_TIME64_SYSCALLS). The idea is once the kernel advertises that
|
|
it does not have 64-bit time_t support, glibc will stop to try issue the
|
|
64-bit time_t syscall altogether.
|
|
|
|
For instance:
|
|
|
|
#ifndef __NR_symbol_time64
|
|
# define __NR_symbol_time64 __NR_symbol
|
|
#endif
|
|
int r;
|
|
if (supports_time64 ())
|
|
{
|
|
r = INLINE_SYSCALL_CALL (symbol, ...);
|
|
if (r == 0 || errno != ENOSYS)
|
|
return r;
|
|
|
|
mark_time64_unsupported ();
|
|
}
|
|
#ifndef __ASSUME_TIME64_SYSCALLS
|
|
<32-bit fallback syscall>
|
|
#endif
|
|
return r;
|
|
|
|
On configuration with default 64-bit time_t this optimization should be
|
|
optimized away by the compiler resulting in no overhead. */
|
|
|
|
#ifndef __ASSUME_TIME64_SYSCALLS
|
|
extern int __time64_support attribute_hidden;
|
|
#endif
|
|
|
|
static inline bool
|
|
supports_time64 (void)
|
|
{
|
|
#ifdef __ASSUME_TIME64_SYSCALLS
|
|
return true;
|
|
#else
|
|
return atomic_load_relaxed (&__time64_support) != 0;
|
|
#endif
|
|
}
|
|
|
|
static inline void
|
|
mark_time64_unsupported (void)
|
|
{
|
|
#ifndef __ASSUME_TIME64_SYSCALLS
|
|
atomic_store_relaxed (&__time64_support, 0);
|
|
#endif
|
|
}
|