src/systime.h

   1 /* systime.h - System-dependent definitions for time manipulations.
   2    Copyright (C) 1993-1994, 2002-2015 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
   9 (at 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 <http://www.gnu.org/licenses/>.  */
  18
  19 #ifndef EMACS_SYSTIME_H
  20 #define EMACS_SYSTIME_H
  21
  22 #include <timespec.h>
  23
  24 INLINE_HEADER_BEGIN
  25
  26 #ifdef emacs
  27 # ifdef HAVE_X_WINDOWS
  28 #  include <X11/X.h>
  29 # else
  30 typedef unsigned long Time;
  31 # endif
  32 #endif
  33
  34 /* On some configurations (hpux8.0, X11R4), sys/time.h and X11/Xos.h
  35    disagree about the name of the guard symbol.  */
  36 #ifdef HPUX
  37 #ifdef _STRUCT_TIMEVAL
  38 #ifndef __TIMEVAL__
  39 #define __TIMEVAL__
  40 #endif
  41 #endif
  42 #endif
  43
  44 #include <sys/time.h>   /* for 'struct timeval' */
  45 \f
  46 /* Emacs uses struct timespec to represent nonnegative temporal intervals.
  47
  48    WARNING: Since tv_sec might be an unsigned value, do not use struct
  49    timespec as a general-purpose data type for adding or subtracting
  50    arbitrary time values!  When computing A + B or A - B, typically A
  51    should be an absolute time since the epoch and B a nonnegative offset.  */
  52
  53 /* Return an invalid timespec.  */
  54 INLINE struct timespec
  55 invalid_timespec (void)
  56 {
  57   return make_timespec (0, -1);
  58 }
  59
  60 /* Return true if TIME is a valid timespec.  This currently doesn't worry
  61    about whether tv_nsec is less than TIMESPEC_RESOLUTION; leap seconds
  62    might cause a problem if it did.  */
  63 INLINE bool
  64 timespec_valid_p (struct timespec t)
  65 {
  66   return t.tv_nsec >= 0;
  67 }
  68
  69 /* Return current system time.  */
  70 INLINE struct timespec
  71 current_timespec (void)
  72 {
  73   struct timespec r;
  74   gettime (&r);
  75   return r;
  76 }
  77
  78 /* defined in sysdep.c */
  79 extern int set_file_times (int, const char *, struct timespec, struct timespec);
  80 extern struct timeval make_timeval (struct timespec) ATTRIBUTE_CONST;
  81
  82 /* defined in keyboard.c */
  83 extern void set_waiting_for_input (struct timespec *);
  84
  85 /* When lisp.h is not included Lisp_Object is not defined (this can
  86    happen when this files is used outside the src directory).
  87    Use GCPRO1 to determine if lisp.h was included.  */
  88 #ifdef GCPRO1
  89
  90 /* Emacs uses the integer list (HI LO US PS) to represent the time
  91    (HI << LO_TIME_BITS) + LO + US / 1e6 + PS / 1e12.  */
  92 enum { LO_TIME_BITS = 16 };
  93
  94 /* A Lisp time (HI LO US PS), sans the cons cells.  */
  95 struct lisp_time
  96 {
  97   EMACS_INT hi;
  98   int lo, us, ps;
  99 };
 100
 101 /* defined in editfns.c */
 102 extern Lisp_Object make_lisp_time (struct timespec);
 103 extern bool decode_time_components (Lisp_Object, Lisp_Object, Lisp_Object,
 104                                     Lisp_Object, struct lisp_time *, double *);
 105 extern struct timespec lisp_to_timespec (struct lisp_time);
 106 extern struct timespec lisp_time_argument (Lisp_Object);
 107 #endif
 108
 109 #ifndef HAVE_TZALLOC
 110 # undef mktime_z
 111 # undef timezone_t
 112 # undef tzalloc
 113 # undef tzfree
 114 # define mktime_z emacs_mktime_z
 115 # define timezone_t emacs_timezone_t
 116 # define tzalloc emacs_tzalloc
 117 # define tzfree emacs_tzfree
 118 typedef char const *timezone_t;
 119 INLINE timezone_t tzalloc (char const *name) { return name; }
 120 INLINE void tzfree (timezone_t tz) { }
 121 /* Defined in editfns.c.  */
 122 extern time_t mktime_z (timezone_t, struct tm *);
 123 #endif
 124
 125 INLINE_HEADER_END
 126
 127 #endif /* EMACS_SYSTIME_H */