src/systime.h

   1 /* systime.h - System-dependent definitions for time manipulations.
   2    Copyright (C) 1993-1994, 2002-2012 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 #ifndef SYSTIME_INLINE
  26 # define SYSTIME_INLINE INLINE
  27 #endif
  28
  29 #ifdef emacs
  30 # ifdef HAVE_X_WINDOWS
  31 #  include <X11/X.h>
  32 # else
  33 typedef unsigned long Time;
  34 # endif
  35 #endif
  36
  37 /* On some configurations (hpux8.0, X11R4), sys/time.h and X11/Xos.h
  38    disagree about the name of the guard symbol.  */
  39 #ifdef HPUX
  40 #ifdef _STRUCT_TIMEVAL
  41 #ifndef __TIMEVAL__
  42 #define __TIMEVAL__
  43 #endif
  44 #endif
  45 #endif
  46
  47 #include <sys/time.h>   /* for 'struct timeval' */
  48 \f
  49 /* The type to use to represent non-negative temporal intervals.  Its
  50    address can be passed as the timeout argument to the pselect system
  51    call.  */
  52 typedef struct timespec EMACS_TIME;
  53
  54 /* Resolution of EMACS_TIME time stamps (in units per second), and log
  55    base 10 of the resolution.  The log must be a positive integer.  */
  56 enum { EMACS_TIME_RESOLUTION = 1000000000 };
  57 enum { LOG10_EMACS_TIME_RESOLUTION = 9 };
  58
  59 /* EMACS_SECS (TIME) is the seconds component of TIME.
  60    EMACS_NSECS (TIME) is the nanoseconds component of TIME.
  61    emacs_secs_addr (PTIME) is the address of *PTIME's seconds component.  */
  62 SYSTIME_INLINE time_t EMACS_SECS (EMACS_TIME t) { return t.tv_sec; }
  63 SYSTIME_INLINE int EMACS_NSECS (EMACS_TIME t) { return t.tv_nsec; }
  64 SYSTIME_INLINE time_t *emacs_secs_addr (EMACS_TIME *t) { return &t->tv_sec; }
  65
  66 /* Return an Emacs time with seconds S and nanoseconds NS.  */
  67 SYSTIME_INLINE EMACS_TIME
  68 make_emacs_time (time_t s, int ns)
  69 {
  70   EMACS_TIME r = { s, ns };
  71   return r;
  72 }
  73
  74 /* Return an invalid Emacs time.  */
  75 SYSTIME_INLINE EMACS_TIME
  76 invalid_emacs_time (void)
  77 {
  78   EMACS_TIME r = { 0, -1 };
  79   return r;
  80 }
  81
  82 /* Return current system time.  */
  83 SYSTIME_INLINE EMACS_TIME
  84 current_emacs_time (void)
  85 {
  86   EMACS_TIME r;
  87   gettime (&r);
  88   return r;
  89 }
  90
  91 /* Return the result of adding A to B, or of subtracting B from A.
  92    On overflow, store an extremal value: ergo, if time_t is unsigned,
  93    return 0 if the true answer would be negative.
  94
  95    WARNING: These are NOT general-purpose macros for adding or
  96    subtracting arbitrary time values!  They are generally intended to
  97    be used with their first argument an absolute time since the epoch
  98    and the second argument a non-negative offset.  Do NOT use them for
  99    anything else.  */
 100 SYSTIME_INLINE EMACS_TIME
 101 add_emacs_time (EMACS_TIME a, EMACS_TIME b)
 102 {
 103   return timespec_add (a, b);
 104 }
 105 SYSTIME_INLINE EMACS_TIME
 106 sub_emacs_time (EMACS_TIME a, EMACS_TIME b)
 107 {
 108   return timespec_sub (a, b);
 109 }
 110
 111 /* Return the sign of the valid time stamp TIME, either -1, 0, or 1.
 112    Note: this can only return a negative value if time_t is a signed
 113    data type.  */
 114 SYSTIME_INLINE int
 115 EMACS_TIME_SIGN (EMACS_TIME t)
 116 {
 117   return timespec_sign (t);
 118 }
 119
 120 /* Return 1 if TIME is a valid time stamp.  */
 121 SYSTIME_INLINE int
 122 EMACS_TIME_VALID_P (EMACS_TIME t)
 123 {
 124   return 0 <= t.tv_nsec;
 125 }
 126
 127 /* Convert the double D to the greatest EMACS_TIME not greater than D.
 128    On overflow, return an extremal value; in particular, if time_t is
 129    an unsigned data type and D is negative, return zero.  Return the
 130    minimum EMACS_TIME if D is not a number.  */
 131 SYSTIME_INLINE EMACS_TIME
 132 EMACS_TIME_FROM_DOUBLE (double d)
 133 {
 134   return dtotimespec (d);
 135 }
 136
 137 /* Convert the Emacs time T to an approximate double value D.  */
 138 SYSTIME_INLINE double
 139 EMACS_TIME_TO_DOUBLE (EMACS_TIME t)
 140 {
 141   return timespectod (t);
 142 }
 143
 144 /* defined in sysdep.c */
 145 extern int set_file_times (int, const char *, EMACS_TIME, EMACS_TIME);
 146 extern struct timeval make_timeval (EMACS_TIME);
 147
 148 /* defined in keyboard.c */
 149 extern void set_waiting_for_input (EMACS_TIME *);
 150
 151 /* When lisp.h is not included Lisp_Object is not defined (this can
 152    happen when this files is used outside the src directory).
 153    Use GCPRO1 to determine if lisp.h was included.  */
 154 #ifdef GCPRO1
 155 /* defined in editfns.c */
 156 extern Lisp_Object make_lisp_time (EMACS_TIME);
 157 extern int decode_time_components (Lisp_Object, Lisp_Object, Lisp_Object,
 158                                    Lisp_Object, EMACS_TIME *, double *);
 159 extern EMACS_TIME lisp_time_argument (Lisp_Object);
 160 #endif
 161
 162 /* Compare times T1 and T2 for equality, inequality etc.  */
 163 SYSTIME_INLINE int
 164 EMACS_TIME_EQ (EMACS_TIME t1, EMACS_TIME t2)
 165 {
 166   return timespec_cmp (t1, t2) == 0;
 167 }
 168 SYSTIME_INLINE int
 169 EMACS_TIME_NE (EMACS_TIME t1, EMACS_TIME t2)
 170 {
 171   return timespec_cmp (t1, t2) != 0;
 172 }
 173 SYSTIME_INLINE int
 174 EMACS_TIME_GT (EMACS_TIME t1, EMACS_TIME t2)
 175 {
 176   return timespec_cmp (t1, t2) > 0;
 177 }
 178 SYSTIME_INLINE int
 179 EMACS_TIME_GE (EMACS_TIME t1, EMACS_TIME t2)
 180 {
 181   return timespec_cmp (t1, t2) >= 0;
 182 }
 183 SYSTIME_INLINE int
 184 EMACS_TIME_LT (EMACS_TIME t1, EMACS_TIME t2)
 185 {
 186   return timespec_cmp (t1, t2) < 0;
 187 }
 188 SYSTIME_INLINE int
 189 EMACS_TIME_LE (EMACS_TIME t1, EMACS_TIME t2)
 190 {
 191   return timespec_cmp (t1, t2) <= 0;
 192 }
 193
 194 INLINE_HEADER_END
 195
 196 #endif /* EMACS_SYSTIME_H */