src/systime.h

   1 /* systime.h - System-dependent definitions for time manipulations.
   2    Copyright (C) 1993 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 1, or (at your option)
   9 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; see the file COPYING.  If not, write to
  18 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
  19
  20 #ifdef TIME_WITH_SYS_TIME
  21 #include <sys/time.h>
  22 #include <time.h>
  23 #else
  24 #ifdef HAVE_SYS_TIME_H
  25 #include <sys/time.h>
  26 #else
  27 #include <time.h>
  28 #endif
  29 #endif
  30
  31 #ifdef HAVE_TZNAME
  32 #ifndef tzname          /* For SGI.  */
  33 extern char *tzname[];  /* RS6000 and others want it this way.  */
  34 #endif
  35 #endif
  36
  37 /* SVr4 doesn't actually declare this in its #include files.  */
  38 #ifdef USG5_4
  39 extern long timezone;
  40 #endif
  41
  42 #ifdef VMS
  43 #ifdef VAXC
  44 #include "vmstime.h"
  45 #endif
  46 #endif
  47
  48 \f
  49 /* EMACS_TIME is the type to use to represent temporal intervals -
  50    struct timeval on some systems, int on others.  It can be passed as
  51    the timeout argument to the select  system call.
  52
  53    EMACS_SECS (TIME) is an rvalue for the seconds component of TIME.
  54    EMACS_SET_SECS (TIME, SECONDS) sets that to SECONDS.
  55
  56    EMACS_HAS_USECS is defined iff EMACS_TIME has a usecs component.
  57    EMACS_USECS (TIME) is an rvalue for the microseconds component of TIME.
  58         This returns zero if EMACS_TIME doesn't have a microseconds component.
  59    EMACS_SET_USECS (TIME, MICROSECONDS) sets that to MICROSECONDS.
  60         This does nothing if EMACS_TIME doesn't have a microseconds component.
  61
  62    EMACS_SET_SECS_USECS (TIME, SECS, USECS) sets both components of TIME.
  63
  64    EMACS_GET_TIME (TIME) stores the current system time in TIME, which
  65         should be an lvalue.
  66    EMACS_SET_UTIMES (PATH, ATIME, MTIME) changes the last-access and
  67         last-modification times of the file named PATH to ATIME and
  68         MTIME, which are EMACS_TIMEs.
  69
  70    EMACS_ADD_TIME (DEST, SRC1, SRC2) adds SRC1 to SRC2 and stores the
  71         result in DEST.  SRC should not be negative.
  72
  73    EMACS_SUB_TIME (DEST, SRC1, SRC2) subtracts SRC2 from SRC1 and
  74         stores the result in DEST.  SRC should not be negative.
  75    EMACS_TIME_NEG_P (TIME) is true iff TIME is negative.
  76
  77 */
  78
  79 #ifdef HAVE_TIMEVAL
  80
  81 #define EMACS_HAS_USECS
  82
  83 #define EMACS_TIME struct timeval
  84 #define EMACS_SECS(time)                    ((time).tv_sec  + 0)
  85 #define EMACS_USECS(time)                   ((time).tv_usec + 0)
  86 #define EMACS_SET_SECS(time, seconds)       ((time).tv_sec  = (seconds))
  87 #define EMACS_SET_USECS(time, microseconds) ((time).tv_usec = (microseconds))
  88
  89 #define EMACS_GET_TIME(time)                                    \
  90 {                                                               \
  91   struct timezone dummy;                                        \
  92   gettimeofday (&(time), &dummy);                               \
  93 }
  94
  95 #define EMACS_ADD_TIME(dest, src1, src2)                        \
  96 {                                                               \
  97   (dest).tv_sec  = (src1).tv_sec  + (src2).tv_sec;              \
  98   (dest).tv_usec = (src1).tv_usec + (src2).tv_usec;             \
  99   if ((dest).tv_usec > 1000000)                                 \
 100     (dest).tv_usec -= 1000000, (dest).tv_sec++;                 \
 101 }
 102
 103 #define EMACS_SUB_TIME(dest, src1, src2)                        \
 104 {                                                               \
 105   (dest).tv_sec  = (src1).tv_sec  - (src2).tv_sec;              \
 106   (dest).tv_usec = (src1).tv_usec - (src2).tv_usec;             \
 107   if ((dest).tv_usec < 0)                                       \
 108     (dest).tv_usec += 1000000, (dest).tv_sec--;                 \
 109 }
 110
 111 #define EMACS_TIME_NEG_P(time)                                  \
 112   ((time).tv_sec < 0                                            \
 113    || ((time).tv_sec == 0                                       \
 114        && (time).tv_usec < 0))
 115
 116 #else /* ! defined (HAVE_TIMEVAL) */
 117
 118 #define EMACS_TIME int
 119 #define EMACS_SECS(time)                    (time)
 120 #define EMACS_USECS(time)                   0
 121 #define EMACS_SET_SECS(time, seconds)       ((time) = (seconds))
 122 #define EMACS_SET_USECS(time, usecs)        0
 123
 124 #define EMACS_GET_TIME(t) ((t) = time ((long *) 0))
 125 #define EMACS_ADD_TIME(dest, src1, src2) ((dest) = (src1) + (src2))
 126 #define EMACS_SUB_TIME(dest, src1, src2) ((dest) = (src1) - (src2))
 127 #define EMACS_TIME_NEG_P(t) ((t) < 0)
 128
 129 #endif /* ! defined (HAVE_TIMEVAL) */
 130
 131 #define EMACS_SET_SECS_USECS(time, secs, usecs)                 \
 132   (EMACS_SET_SECS (time, secs), EMACS_SET_USECS (time, usecs))
 133
 134 #ifdef USE_UTIME
 135
 136 #define EMACS_SET_UTIMES(path, atime, mtime)                    \
 137   {                                                             \
 138     time_t tv[2];                                               \
 139     tv[0] = EMACS_SECS (atime);                                 \
 140     tv[1] = EMACS_SECS (mtime);                                 \
 141     utime ((path), tv);                                         \
 142   }
 143
 144 #else /* ! defined (USE_UTIME) */
 145
 146 #define EMACS_SET_UTIMES(path, atime, mtime)                    \
 147   {                                                             \
 148     EMACS_TIME tv[2];                                           \
 149     tv[0] = atime;                                              \
 150     tv[1] = mtime;                                              \
 151     utimes ((path), tv);                                        \
 152   }
 153
 154 #endif /* ! defined (USE_UTIME) */