glibc/sysdeps/unix/sysv/linux/clock_nanosleep.c
2012-02-09 23:18:22 +00:00

96 lines
3.0 KiB
C

/* Copyright (C) 2003, 2004, 2005, 2006 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
<http://www.gnu.org/licenses/>. */
#include <time.h>
#include <errno.h>
#include <sysdep-cancel.h>
#include <kernel-features.h>
#include "kernel-posix-cpu-timers.h"
#ifdef __ASSUME_POSIX_TIMERS
/* We can simply use the syscall. The CPU clocks are not supported
with this function. */
int
clock_nanosleep (clockid_t clock_id, int flags, const struct timespec *req,
struct timespec *rem)
{
INTERNAL_SYSCALL_DECL (err);
int r;
if (clock_id == CLOCK_THREAD_CPUTIME_ID)
return EINVAL;
if (clock_id == CLOCK_PROCESS_CPUTIME_ID)
clock_id = MAKE_PROCESS_CPUCLOCK (0, CPUCLOCK_SCHED);
if (SINGLE_THREAD_P)
r = INTERNAL_SYSCALL (clock_nanosleep, err, 4, clock_id, flags, req, rem);
else
{
int oldstate = LIBC_CANCEL_ASYNC ();
r = INTERNAL_SYSCALL (clock_nanosleep, err, 4, clock_id, flags, req,
rem);
LIBC_CANCEL_RESET (oldstate);
}
return (INTERNAL_SYSCALL_ERROR_P (r, err)
? INTERNAL_SYSCALL_ERRNO (r, err) : 0);
}
#else
# ifdef __NR_clock_nanosleep
/* 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_NANOSLEEP \
if (!__libc_missing_posix_timers) \
{ \
clockid_t syscall_clockid; \
INTERNAL_SYSCALL_DECL (err); \
\
if (clock_id == CLOCK_THREAD_CPUTIME_ID) \
return EINVAL; \
if (clock_id == CLOCK_PROCESS_CPUTIME_ID) \
syscall_clockid = MAKE_PROCESS_CPUCLOCK (0, CPUCLOCK_SCHED); \
else \
syscall_clockid = clock_id; \
\
int oldstate = LIBC_CANCEL_ASYNC (); \
\
int r = INTERNAL_SYSCALL (clock_nanosleep, err, 4, \
syscall_clockid, flags, req, rem); \
\
LIBC_CANCEL_RESET (oldstate); \
\
if (!INTERNAL_SYSCALL_ERROR_P (r, err)) \
return 0; \
\
if (INTERNAL_SYSCALL_ERRNO (r, err) != ENOSYS) \
return INTERNAL_SYSCALL_ERRNO (r, err); \
\
__libc_missing_posix_timers = 1; \
}
# endif
# include <sysdeps/unix/clock_nanosleep.c>
#endif