1 /* Implementation of the SYSTEM_CLOCK intrinsic.
2 Copyright (C) 2004, 2005, 2007, 2009, 2010, 2011 Free Software
5 This file is part of the GNU Fortran runtime library (libgfortran).
7 Libgfortran is free software; you can redistribute it and/or
8 modify it under the terms of the GNU General Public
9 License as published by the Free Software Foundation; either
10 version 3 of the License, or (at your option) any later version.
12 Libgfortran is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 Under Section 7 of GPL version 3, you are granted additional
18 permissions described in the GCC Runtime Library Exception, version
19 3.1, as published by the Free Software Foundation.
21 You should have received a copy of the GNU General Public License and
22 a copy of the GCC Runtime Library Exception along with this program;
23 see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
24 <http://www.gnu.org/licenses/>. */
26 #include "libgfortran.h"
33 /* POSIX states that CLOCK_REALTIME must be present if clock_gettime
34 is available, others are optional. */
35 #if defined(HAVE_CLOCK_GETTIME) || defined(HAVE_CLOCK_GETTIME_LIBRT)
36 #ifdef CLOCK_MONOTONIC
37 #define GF_CLOCK_MONOTONIC CLOCK_MONOTONIC
39 #define GF_CLOCK_MONOTONIC CLOCK_REALTIME
43 /* Weakref trickery for clock_gettime(). On Glibc, clock_gettime()
44 requires us to link in librt, which also pulls in libpthread. In
45 order to avoid this by default, only call clock_gettime() through a
48 Some targets don't support weak undefined references; on these
49 GTHREAD_USE_WEAK is 0. So we need to define it to 1 on other
51 #ifndef GTHREAD_USE_WEAK
52 #define GTHREAD_USE_WEAK 1
55 #if SUPPORTS_WEAK && GTHREAD_USE_WEAK && defined(HAVE_CLOCK_GETTIME_LIBRT)
56 static int weak_gettime (clockid_t
, struct timespec
*)
57 __attribute__((__weakref__("clock_gettime")));
61 /* High resolution monotonic clock, falling back to the realtime clock
62 if the target does not support such a clock.
65 secs - OUTPUT, seconds
66 nanosecs - OUTPUT, nanoseconds
68 If the target supports a monotonic clock, the OUTPUT arguments
69 represent a monotonically incrementing clock starting from some
70 unspecified time in the past.
72 If a monotonic clock is not available, falls back to the realtime
73 clock which is not monotonic.
75 Return value: 0 for success, -1 for error. In case of error, errno
79 gf_gettime_mono (time_t * secs
, long * nanosecs
)
82 #ifdef HAVE_CLOCK_GETTIME
84 err
= clock_gettime (GF_CLOCK_MONOTONIC
, &ts
);
86 *nanosecs
= ts
.tv_nsec
;
89 #if defined(HAVE_CLOCK_GETTIME_LIBRT) && SUPPORTS_WEAK && GTHREAD_USE_WEAK
93 err
= weak_gettime (GF_CLOCK_MONOTONIC
, &ts
);
95 *nanosecs
= ts
.tv_nsec
;
99 err
= gf_gettime (secs
, nanosecs
);
105 extern void system_clock_4 (GFC_INTEGER_4
*, GFC_INTEGER_4
*, GFC_INTEGER_4
*);
106 export_proto(system_clock_4
);
108 extern void system_clock_8 (GFC_INTEGER_8
*, GFC_INTEGER_8
*, GFC_INTEGER_8
*);
109 export_proto(system_clock_8
);
112 /* prefix(system_clock_4) is the INTEGER(4) version of the SYSTEM_CLOCK
113 intrinsic subroutine. It returns the number of clock ticks for the current
114 system time, the number of ticks per second, and the maximum possible value
115 for COUNT. On the first call to SYSTEM_CLOCK, COUNT is set to zero. */
118 system_clock_4(GFC_INTEGER_4
*count
, GFC_INTEGER_4
*count_rate
,
119 GFC_INTEGER_4
*count_max
)
129 if (sizeof (secs
) < sizeof (GFC_INTEGER_4
))
130 internal_error (NULL
, "secs too small");
132 if (gf_gettime_mono (&secs
, &nanosecs
) == 0)
134 GFC_UINTEGER_4 ucnt
= (GFC_UINTEGER_4
) secs
* TCK
;
135 ucnt
+= (nanosecs
+ 500000000 / TCK
) / (1000000000 / TCK
);
136 if (ucnt
> GFC_INTEGER_4_HUGE
)
137 cnt
= ucnt
- GFC_INTEGER_4_HUGE
- 1;
140 mx
= GFC_INTEGER_4_HUGE
;
145 *count
= - GFC_INTEGER_4_HUGE
;
146 if (count_rate
!= NULL
)
148 if (count_max
!= NULL
)
155 if (count_rate
!= NULL
)
157 if (count_max
!= NULL
)
162 /* INTEGER(8) version of the above routine. */
165 system_clock_8 (GFC_INTEGER_8
*count
, GFC_INTEGER_8
*count_rate
,
166 GFC_INTEGER_8
*count_max
)
169 #define TCK 1000000000
176 if (sizeof (secs
) < sizeof (GFC_INTEGER_4
))
177 internal_error (NULL
, "secs too small");
179 if (gf_gettime_mono (&secs
, &nanosecs
) == 0)
181 GFC_UINTEGER_8 ucnt
= (GFC_UINTEGER_8
) secs
* TCK
;
182 ucnt
+= (nanosecs
+ 500000000 / TCK
) / (1000000000 / TCK
);
183 if (ucnt
> GFC_INTEGER_8_HUGE
)
184 cnt
= ucnt
- GFC_INTEGER_8_HUGE
- 1;
187 mx
= GFC_INTEGER_8_HUGE
;
192 *count
= - GFC_INTEGER_8_HUGE
;
193 if (count_rate
!= NULL
)
195 if (count_max
!= NULL
)
203 if (count_rate
!= NULL
)
205 if (count_max
!= NULL
)