1 /* systime.h - System-dependent definitions for time manipulations.
2 Copyright (C) 1993-1994, 2002-2023 Free Software Foundation, Inc.
3
4 This file is part of GNU Emacs.
5
6 GNU Emacs is free software: you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation, either version 3 of the License, or (at
9 your option) any later version.
10
11 GNU Emacs is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with GNU Emacs. If not, see <https://www.gnu.org/licenses/>. */
18
19 #ifndef EMACS_SYSTIME_H
20 #define EMACS_SYSTIME_H
21
22 #include "lisp.h"
23 #include <timespec.h>
24
25 INLINE_HEADER_BEGIN
26
27 #ifdef HAVE_X_WINDOWS
28 # include <X11/X.h>
29 #elif defined HAVE_HAIKU
30 # include <support/SupportDefs.h>
31 typedef int64 Time;
32 #else
33 typedef unsigned long Time;
34 #endif
35
36 /* On some configurations (hpux8.0, X11R4), sys/time.h and X11/Xos.h
37 disagree about the name of the guard symbol. */
38 #ifdef HPUX
39 #ifdef _STRUCT_TIMEVAL
40 #ifndef __TIMEVAL__
41 #define __TIMEVAL__
42 #endif
43 #endif
44 #endif
45
46 #include <sys/time.h> /* for 'struct timeval' */
47
48 #undef hz /* AIX <sys/param.h> #defines this. */
49
50 /* Emacs uses struct timespec to represent nonnegative temporal intervals.
51
52 WARNING: Since tv_sec might be an unsigned value, do not use struct
53 timespec as a general-purpose data type for adding or subtracting
54 arbitrary time values! When computing A + B or A - B, typically A
55 should be an absolute time since the epoch and B a nonnegative offset. */
56
57 /* Return an invalid timespec. */
58 INLINE struct timespec
59 invalid_timespec (void)
60 {
61 return make_timespec (0, -1);
62 }
63
64 /* Return true if TIME is a valid timespec. This currently doesn't worry
65 about whether tv_nsec is less than TIMESPEC_HZ; leap seconds might
66 cause a problem if it did. */
67 INLINE bool
68 timespec_valid_p (struct timespec t)
69 {
70 return t.tv_nsec >= 0;
71 }
72
73 /* defined in keyboard.c */
74 extern void set_waiting_for_input (struct timespec *);
75
76 /* Emacs uses the integer list (HI LO US PS) to represent the time
77 (HI << LO_TIME_BITS) + LO + US / 1e6 + PS / 1e12. */
78 enum { LO_TIME_BITS = 16 };
79
80 /* Components of a new-format Lisp timestamp. */
81 struct lisp_time
82 {
83 /* Clock count as a Lisp integer. */
84 Lisp_Object ticks;
85
86 /* Clock frequency (ticks per second) as a positive Lisp integer. */
87 Lisp_Object hz;
88 };
89
90 /* defined in timefns.c */
91 extern struct timeval make_timeval (struct timespec) ATTRIBUTE_CONST;
92 extern Lisp_Object make_lisp_time (struct timespec);
93 extern Lisp_Object timespec_to_lisp (struct timespec);
94 extern bool list4_to_timespec (Lisp_Object, Lisp_Object, Lisp_Object,
95 Lisp_Object, struct timespec *);
96 extern struct timespec lisp_time_argument (Lisp_Object);
97 extern double float_time (Lisp_Object);
98 extern void init_timefns (void);
99 extern void syms_of_timefns (void);
100
101 INLINE_HEADER_END
102
103 #endif /* EMACS_SYSTIME_H */