src/systime.h

   1 /* systime.h - System-dependent definitions for time manipulations.
   2    Copyright (C) 1993-1994, 2002-2013 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;
  71   r.tv_sec = s;
  72   r.tv_nsec = ns;
  73   return r;
  74 }
  75
  76 /* Return an invalid Emacs time.  */
  77 SYSTIME_INLINE EMACS_TIME
  78 invalid_emacs_time (void)
  79 {
  80   EMACS_TIME r;
  81   r.tv_sec = 0;
  82   r.tv_nsec = -1;
  83   return r;
  84 }
  85
  86 /* Return current system time.  */
  87 SYSTIME_INLINE EMACS_TIME
  88 current_emacs_time (void)
  89 {
  90   EMACS_TIME r;
  91   gettime (&r);
  92   return r;
  93 }
  94
  95 /* Return the result of adding A to B, or of subtracting B from A.
  96    On overflow, store an extremal value: ergo, if time_t is unsigned,
  97    return 0 if the true answer would be negative.
  98
  99    WARNING: These are NOT general-purpose macros for adding or
 100    subtracting arbitrary time values!  They are generally intended to
 101    be used with their first argument an absolute time since the epoch
 102    and the second argument a non-negative offset.  Do NOT use them for
 103    anything else.  */
 104 SYSTIME_INLINE EMACS_TIME
 105 add_emacs_time (EMACS_TIME a, EMACS_TIME b)
 106 {
 107   return timespec_add (a, b);
 108 }
 109 SYSTIME_INLINE EMACS_TIME
 110 sub_emacs_time (EMACS_TIME a, EMACS_TIME b)
 111 {
 112   return timespec_sub (a, b);
 113 }
 114
 115 /* Return the sign of the valid time stamp TIME, either -1, 0, or 1.
 116    Note: this can only return a negative value if time_t is a signed
 117    data type.  */
 118 SYSTIME_INLINE int
 119 EMACS_TIME_SIGN (EMACS_TIME t)
 120 {
 121   return timespec_sign (t);
 122 }
 123
 124 /* Return 1 if TIME is a valid time stamp.  */
 125 SYSTIME_INLINE int
 126 EMACS_TIME_VALID_P (EMACS_TIME t)
 127 {
 128   return t.tv_nsec >= 0;
 129 }
 130
 131 /* Convert the double D to the greatest EMACS_TIME not greater than D.
 132    On overflow, return an extremal value; in particular, if time_t is
 133    an unsigned data type and D is negative, return zero.  Return the
 134    minimum EMACS_TIME if D is not a number.  */
 135 SYSTIME_INLINE EMACS_TIME
 136 EMACS_TIME_FROM_DOUBLE (double d)
 137 {
 138   return dtotimespec (d);
 139 }
 140
 141 /* Convert the Emacs time T to an approximate double value D.  */
 142 SYSTIME_INLINE double
 143 EMACS_TIME_TO_DOUBLE (EMACS_TIME t)
 144 {
 145   return timespectod (t);
 146 }
 147
 148 /* defined in sysdep.c */
 149 extern int set_file_times (int, const char *, EMACS_TIME, EMACS_TIME);
 150 extern struct timeval make_timeval (EMACS_TIME) ATTRIBUTE_CONST;
 151
 152 /* defined in keyboard.c */
 153 extern void set_waiting_for_input (EMACS_TIME *);
 154
 155 /* When lisp.h is not included Lisp_Object is not defined (this can
 156    happen when this files is used outside the src directory).
 157    Use GCPRO1 to determine if lisp.h was included.  */
 158 #ifdef GCPRO1
 159 /* defined in editfns.c */
 160 extern Lisp_Object make_lisp_time (EMACS_TIME);
 161 extern bool decode_time_components (Lisp_Object, Lisp_Object, Lisp_Object,
 162                                     Lisp_Object, EMACS_TIME *, double *);
 163 extern EMACS_TIME lisp_time_argument (Lisp_Object);
 164 #endif
 165
 166 /* Compare times T1 and T2 for equality, inequality etc.  */
 167 SYSTIME_INLINE int
 168 EMACS_TIME_EQ (EMACS_TIME t1, EMACS_TIME t2)
 169 {
 170   return timespec_cmp (t1, t2) == 0;
 171 }
 172 SYSTIME_INLINE int
 173 EMACS_TIME_LT (EMACS_TIME t1, EMACS_TIME t2)
 174 {
 175   return timespec_cmp (t1, t2) < 0;
 176 }
 177 SYSTIME_INLINE int
 178 EMACS_TIME_LE (EMACS_TIME t1, EMACS_TIME t2)
 179 {
 180   return timespec_cmp (t1, t2) <= 0;
 181 }
 182
 183 INLINE_HEADER_END
 184
 185 #endif /* EMACS_SYSTIME_H */