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