[thirdparty/glibc.git] / sysdeps / unix / sysv / linux / clock_gettime.c

/* clock_gettime -- Get current time from a POSIX clockid_t.  Linux version.
   Copyright (C) 2003,2004,2005,2006,2007,2010,2011 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 <sysdep.h>
#include <errno.h>
#include <time.h>
#include "kernel-posix-cpu-timers.h"
#include <kernel-features.h>

#ifndef HAVE_CLOCK_GETTIME_VSYSCALL
# undef INTERNAL_VSYSCALL
# define INTERNAL_VSYSCALL INTERNAL_SYSCALL
# undef INLINE_VSYSCALL
# define INLINE_VSYSCALL INLINE_SYSCALL
#else
# include <bits/libc-vdso.h>
#endif

#ifndef SYSCALL_GETTIME
# define SYSCALL_GETTIME(id, tp) \
  INLINE_VSYSCALL (clock_gettime, 2, id, tp)
#endif
#ifndef INTERNAL_GETTIME
# define INTERNAL_GETTIME(id, tp) \
  INTERNAL_VSYSCALL (clock_gettime, err, 2, id, tp)
#endif

#ifdef __ASSUME_POSIX_TIMERS

/* This means the REALTIME and MONOTONIC clock are definitely
   supported in the kernel.  */
# define SYSDEP_GETTIME \
  SYSDEP_GETTIME_CPUTIME;						      \
  case CLOCK_REALTIME:							      \
  case CLOCK_MONOTONIC:							      \
    retval = SYSCALL_GETTIME (clock_id, tp);				      \
    break

# define __libc_missing_posix_timers 0
#elif defined __NR_clock_gettime
/* Is the syscall known to exist?  */
int __libc_missing_posix_timers attribute_hidden;

static inline int
maybe_syscall_gettime (clockid_t clock_id, struct timespec *tp)
{
  int e = EINVAL;

  if (!__libc_missing_posix_timers)
    {
      INTERNAL_SYSCALL_DECL (err);
      int r = INTERNAL_GETTIME (clock_id, tp);
      if (!INTERNAL_SYSCALL_ERROR_P (r, err))
	return 0;

      e = INTERNAL_SYSCALL_ERRNO (r, err);
      if (e == ENOSYS)
	{
	  __libc_missing_posix_timers = 1;
	  e = EINVAL;
	}
    }

  return e;
}

/* The REALTIME and MONOTONIC clock might be available.  Try the
   syscall first.  */
# define SYSDEP_GETTIME \
  SYSDEP_GETTIME_CPUTIME;						      \
  case CLOCK_REALTIME:							      \
  case CLOCK_MONOTONIC:							      \
  case CLOCK_MONOTONIC_RAW:						      \
  case CLOCK_REALTIME_COARSE:						      \
  case CLOCK_MONOTONIC_COARSE:						      \
    retval = maybe_syscall_gettime (clock_id, tp);			      \
    if (retval == 0)							      \
      break;								      \
    /* Fallback code.  */						      \
    if (retval == EINVAL && clock_id == CLOCK_REALTIME)			      \
      retval = realtime_gettime (tp);					      \
    else								      \
      {									      \
	__set_errno (retval);						      \
	retval = -1;							      \
      }									      \
    break
#endif

#ifdef __NR_clock_gettime
/* We handled the REALTIME clock here.  */
# define HANDLED_REALTIME	1
# define HANDLED_CPUTIME	1

# if __ASSUME_POSIX_CPU_TIMERS > 0

#  define SYSDEP_GETTIME_CPU(clock_id, tp) \
  retval = SYSCALL_GETTIME (clock_id, tp); \
  break
#  define SYSDEP_GETTIME_CPUTIME	/* Default catches them too.  */

# else

int __libc_missing_posix_cpu_timers attribute_hidden;

static int
maybe_syscall_gettime_cpu (clockid_t clock_id, struct timespec *tp)
{
  int e = EINVAL;

  if (!__libc_missing_posix_cpu_timers)
    {
      INTERNAL_SYSCALL_DECL (err);
      int r = INTERNAL_GETTIME (clock_id, tp);
      if (!INTERNAL_SYSCALL_ERROR_P (r, err))
	return 0;

      e = INTERNAL_SYSCALL_ERRNO (r, err);
# ifndef __ASSUME_POSIX_TIMERS
      if (e == ENOSYS)
	{
	  __libc_missing_posix_timers = 1;
	  __libc_missing_posix_cpu_timers = 1;
	  e = EINVAL;
	}
      else
# endif
	{
	  if (e == EINVAL)
	    {
# ifdef HAVE_CLOCK_GETRES_VSYSCALL
	      /* Check whether the kernel supports CPU clocks at all.
		 If not, record it for the future.  */
	      r = INTERNAL_VSYSCALL (clock_getres, err, 2,
				     MAKE_PROCESS_CPUCLOCK (0, CPUCLOCK_SCHED),
				     NULL);
# else
	      /* Check whether the kernel supports CPU clocks at all.
		 If not, record it for the future.  */
	      r = INTERNAL_SYSCALL (clock_getres, err, 2,
				    MAKE_PROCESS_CPUCLOCK (0, CPUCLOCK_SCHED),
				    NULL);
# endif
	      if (INTERNAL_SYSCALL_ERROR_P (r, err))
		__libc_missing_posix_cpu_timers = 1;
	    }
	}
    }

  return e;
}

#  define SYSDEP_GETTIME_CPU(clock_id, tp) \
  retval = maybe_syscall_gettime_cpu (clock_id, tp);			      \
  if (retval == 0)							      \
    break;								      \
  if (retval != EINVAL || !__libc_missing_posix_cpu_timers)		      \
    {									      \
      __set_errno (retval);						      \
      retval = -1;							      \
      break;								      \
    }									      \
  retval = -1 /* Otherwise continue on to the HP_TIMING version.  */;

static inline int
maybe_syscall_gettime_cputime (clockid_t clock_id, struct timespec *tp)
{
  return maybe_syscall_gettime_cpu
    (clock_id == CLOCK_THREAD_CPUTIME_ID
     ? MAKE_THREAD_CPUCLOCK (0, CPUCLOCK_SCHED)
     : MAKE_PROCESS_CPUCLOCK (0, CPUCLOCK_SCHED),
     tp);
}

#  define SYSDEP_GETTIME_CPUTIME					      \
    case CLOCK_PROCESS_CPUTIME_ID:					      \
    case CLOCK_THREAD_CPUTIME_ID:					      \
      retval = maybe_syscall_gettime_cputime (clock_id, tp);		      \
      if (retval == 0)							      \
	break;								      \
      if (retval != EINVAL || !__libc_missing_posix_cpu_timers)		      \
	{								      \
	  __set_errno (retval);						      \
	  retval = -1;							      \
	  break;							      \
	}								      \
      retval = hp_timing_gettime (clock_id, tp);			      \
      break
#  if !HP_TIMING_AVAIL
#   define hp_timing_gettime(clock_id, tp) (__set_errno (EINVAL), -1)
#  endif

# endif
#endif

#include <sysdeps/unix/clock_gettime.c>
Commit	Line	Data
2f4f3bd4	1	/* clock_gettime -- Get current time from a POSIX clockid_t. Linux version.
a77d3c17	2	Copyright (C) 2003,2004,2005,2006,2007,2010,2011 Free Software Foundation, Inc.
ad0e8eb0 UD	3	This file is part of the GNU C Library.
	4
	5	The GNU C Library is free software; you can redistribute it and/or
	6	modify it under the terms of the GNU Lesser General Public
	7	License as published by the Free Software Foundation; either
	8	version 2.1 of the License, or (at your option) any later version.
	9
	10	The GNU C Library is distributed in the hope that it will be useful,
	11	but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	13	Lesser General Public License for more details.
	14
	15	You should have received a copy of the GNU Lesser General Public
59ba27a6 PE	16	License along with the GNU C Library; if not, see
59ba27a6 PE	17	<http://www.gnu.org/licenses/>. */
ad0e8eb0 UD	18
ad0e8eb0 UD	19	#include <sysdep.h>
2f4f3bd4	20	#include <errno.h>
6ba85a6d	21	#include <time.h>
2f4f3bd4	22	#include "kernel-posix-cpu-timers.h"
6ddd37a4	23	#include <kernel-features.h>
ad0e8eb0	24
8c2e201b UD	25	#ifndef HAVE_CLOCK_GETTIME_VSYSCALL
	26	# undef INTERNAL_VSYSCALL
	27	# define INTERNAL_VSYSCALL INTERNAL_SYSCALL
	28	# undef INLINE_VSYSCALL
	29	# define INLINE_VSYSCALL INLINE_SYSCALL
	30	#else
	31	# include <bits/libc-vdso.h>
	32	#endif
ad0e8eb0	33
a77d3c17 UD	34	#ifndef SYSCALL_GETTIME
	35	# define SYSCALL_GETTIME(id, tp) \
	36	INLINE_VSYSCALL (clock_gettime, 2, id, tp)
	37	#endif
	38	#ifndef INTERNAL_GETTIME
	39	# define INTERNAL_GETTIME(id, tp) \
	40	INTERNAL_VSYSCALL (clock_gettime, err, 2, id, tp)
	41	#endif
2f4f3bd4	42
ad0e8eb0	43	#ifdef __ASSUME_POSIX_TIMERS
2f4f3bd4	44
ad0e8eb0 UD	45	/* This means the REALTIME and MONOTONIC clock are definitely
ad0e8eb0 UD	46	supported in the kernel. */
7edb22ef UD	47	# define SYSDEP_GETTIME \
7edb22ef UD	48	SYSDEP_GETTIME_CPUTIME; \
ad0e8eb0 UD	49	case CLOCK_REALTIME: \
ad0e8eb0 UD	50	case CLOCK_MONOTONIC: \
a77d3c17 UD	51	retval = SYSCALL_GETTIME (clock_id, tp); \
a77d3c17 UD	52	break
2f4f3bd4 RM	53
2f4f3bd4 RM	54	# define __libc_missing_posix_timers 0
ad0e8eb0 UD	55	#elif defined __NR_clock_gettime
	56	/* Is the syscall known to exist? */
	57	int __libc_missing_posix_timers attribute_hidden;
	58
2f4f3bd4 RM	59	static inline int
	60	maybe_syscall_gettime (clockid_t clock_id, struct timespec *tp)
	61	{
	62	int e = EINVAL;
	63
	64	if (!__libc_missing_posix_timers)
	65	{
	66	INTERNAL_SYSCALL_DECL (err);
a77d3c17	67	int r = INTERNAL_GETTIME (clock_id, tp);
2f4f3bd4 RM	68	if (!INTERNAL_SYSCALL_ERROR_P (r, err))
	69	return 0;
	70
	71	e = INTERNAL_SYSCALL_ERRNO (r, err);
	72	if (e == ENOSYS)
	73	{
	74	__libc_missing_posix_timers = 1;
	75	e = EINVAL;
	76	}
	77	}
	78
	79	return e;
	80	}
	81
ad0e8eb0 UD	82	/* The REALTIME and MONOTONIC clock might be available. Try the
ad0e8eb0 UD	83	syscall first. */
7edb22ef UD	84	# define SYSDEP_GETTIME \
7edb22ef UD	85	SYSDEP_GETTIME_CPUTIME; \
ad0e8eb0 UD	86	case CLOCK_REALTIME: \
ad0e8eb0 UD	87	case CLOCK_MONOTONIC: \
89a4419c UD	88	case CLOCK_MONOTONIC_RAW: \
	89	case CLOCK_REALTIME_COARSE: \
	90	case CLOCK_MONOTONIC_COARSE: \
2f4f3bd4 RM	91	retval = maybe_syscall_gettime (clock_id, tp); \
	92	if (retval == 0) \
	93	break; \
	94	/* Fallback code. */ \
	95	if (retval == EINVAL && clock_id == CLOCK_REALTIME) \
	96	retval = realtime_gettime (tp); \
a77d3c17	97	else \
2f4f3bd4 RM	98	{ \
	99	__set_errno (retval); \
	100	retval = -1; \
	101	} \
7edb22ef	102	break
ad0e8eb0 UD	103	#endif
	104
	105	#ifdef __NR_clock_gettime
	106	/* We handled the REALTIME clock here. */
	107	# define HANDLED_REALTIME 1
2f4f3bd4 RM	108	# define HANDLED_CPUTIME 1
	109
	110	# if __ASSUME_POSIX_CPU_TIMERS > 0
	111
446514f9 AS	112	# define SYSDEP_GETTIME_CPU(clock_id, tp) \
	113	retval = SYSCALL_GETTIME (clock_id, tp); \
	114	break
2f4f3bd4 RM	115	# define SYSDEP_GETTIME_CPUTIME /* Default catches them too. */
	116
	117	# else
	118
	119	int __libc_missing_posix_cpu_timers attribute_hidden;
	120
	121	static int
	122	maybe_syscall_gettime_cpu (clockid_t clock_id, struct timespec *tp)
	123	{
	124	int e = EINVAL;
	125
	126	if (!__libc_missing_posix_cpu_timers)
	127	{
	128	INTERNAL_SYSCALL_DECL (err);
a77d3c17	129	int r = INTERNAL_GETTIME (clock_id, tp);
2f4f3bd4 RM	130	if (!INTERNAL_SYSCALL_ERROR_P (r, err))
	131	return 0;
	132
	133	e = INTERNAL_SYSCALL_ERRNO (r, err);
	134	# ifndef __ASSUME_POSIX_TIMERS
	135	if (e == ENOSYS)
	136	{
	137	__libc_missing_posix_timers = 1;
	138	__libc_missing_posix_cpu_timers = 1;
	139	e = EINVAL;
	140	}
	141	else
	142	# endif
	143	{
	144	if (e == EINVAL)
	145	{
4eb375fe	146	# ifdef HAVE_CLOCK_GETRES_VSYSCALL
2f4f3bd4 RM	147	/* Check whether the kernel supports CPU clocks at all.
2f4f3bd4 RM	148	If not, record it for the future. */
8c2e201b	149	r = INTERNAL_VSYSCALL (clock_getres, err, 2,
4eb375fe UD	150	MAKE_PROCESS_CPUCLOCK (0, CPUCLOCK_SCHED),
	151	NULL);
	152	# else
	153	/* Check whether the kernel supports CPU clocks at all.
	154	If not, record it for the future. */
	155	r = INTERNAL_SYSCALL (clock_getres, err, 2,
2f4f3bd4 RM	156	MAKE_PROCESS_CPUCLOCK (0, CPUCLOCK_SCHED),
2f4f3bd4 RM	157	NULL);
4eb375fe	158	# endif
2f4f3bd4 RM	159	if (INTERNAL_SYSCALL_ERROR_P (r, err))
	160	__libc_missing_posix_cpu_timers = 1;
	161	}
	162	}
	163	}
	164
	165	return e;
	166	}
	167
7edb22ef	168	# define SYSDEP_GETTIME_CPU(clock_id, tp) \
2f4f3bd4 RM	169	retval = maybe_syscall_gettime_cpu (clock_id, tp); \
	170	if (retval == 0) \
	171	break; \
	172	if (retval != EINVAL \|\| !__libc_missing_posix_cpu_timers) \
	173	{ \
	174	__set_errno (retval); \
	175	retval = -1; \
	176	break; \
	177	} \
	178	retval = -1 /* Otherwise continue on to the HP_TIMING version. */;
	179
	180	static inline int
	181	maybe_syscall_gettime_cputime (clockid_t clock_id, struct timespec *tp)
	182	{
	183	return maybe_syscall_gettime_cpu
	184	(clock_id == CLOCK_THREAD_CPUTIME_ID
	185	? MAKE_THREAD_CPUCLOCK (0, CPUCLOCK_SCHED)
	186	: MAKE_PROCESS_CPUCLOCK (0, CPUCLOCK_SCHED),
	187	tp);
	188	}
	189
	190	# define SYSDEP_GETTIME_CPUTIME \
	191	case CLOCK_PROCESS_CPUTIME_ID: \
	192	case CLOCK_THREAD_CPUTIME_ID: \
	193	retval = maybe_syscall_gettime_cputime (clock_id, tp); \
	194	if (retval == 0) \
	195	break; \
	196	if (retval != EINVAL \|\| !__libc_missing_posix_cpu_timers) \
	197	{ \
	198	__set_errno (retval); \
	199	retval = -1; \
	200	break; \
	201	} \
	202	retval = hp_timing_gettime (clock_id, tp); \
7edb22ef	203	break
2f4f3bd4 RM	204	# if !HP_TIMING_AVAIL
	205	# define hp_timing_gettime(clock_id, tp) (__set_errno (EINVAL), -1)
	206	# endif
	207
	208	# endif
ad0e8eb0 UD	209	#endif
	210
	211	#include <sysdeps/unix/clock_gettime.c>