glibc/sysdeps/unix/sysv/linux/clock_getres.c

77 lines
2.5 KiB
C

/* Copyright (C) 2003 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, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <sysdep.h>
#include "kernel-features.h"
#ifdef __ASSUME_POSIX_TIMERS
/* This means the REALTIME and MONOTONIC clock are definitely
supported in the kernel. */
# define SYSDEP_GETRES \
case CLOCK_REALTIME: \
case CLOCK_MONOTONIC: \
retval = INLINE_SYSCALL (clock_getres, 2, clock_id, res); \
break
#elif defined __NR_clock_getres
/* Is the syscall known to exist? */
extern int __libc_missing_posix_timers attribute_hidden;
/* The REALTIME and MONOTONIC clock might be available. Try the
syscall first. */
# define SYSDEP_GETRES \
case CLOCK_REALTIME: \
case CLOCK_MONOTONIC: \
{ \
int e = EINVAL; \
\
if (!__libc_missing_posix_timers) \
{ \
INTERNAL_SYSCALL_DECL (err); \
int r = INTERNAL_SYSCALL (clock_getres, err, 2, clock_id, res); \
if (!INTERNAL_SYSCALL_ERROR_P (r, err)) \
{ \
retval = 0; \
break; \
} \
\
e = INTERNAL_SYSCALL_ERRNO (r, err); \
if (e == ENOSYS) \
{ \
__libc_missing_posix_timers = 1; \
e = EINVAL; \
} \
} \
\
/* Fallback code. */ \
if (e == EINVAL && clock_id == CLOCK_REALTIME) \
HANDLE_REALTIME; \
else \
__set_errno (e); \
} \
break
#endif
#ifdef __NR_clock_getres
/* We handled the REALTIME clock here. */
# define HANDLED_REALTIME 1
#endif
#include <sysdeps/posix/clock_getres.c>