src/pulse/timeval.c

   1 /***
   2   This file is part of PulseAudio.
   3
   4   Copyright 2004-2006 Lennart Poettering
   5   Copyright 2006 Pierre Ossman <ossman@cendio.se> for Cendio AB
   6
   7   PulseAudio is free software; you can redistribute it and/or modify
   8   it under the terms of the GNU Lesser General Public License as
   9   published by the Free Software Foundation; either version 2.1 of the
  10   License, or (at your option) any later version.
  11
  12   PulseAudio is distributed in the hope that it will be useful, but
  13   WITHOUT ANY WARRANTY; without even the implied warranty of
  14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  15   Lesser General Public License for more details.
  16
  17   You should have received a copy of the GNU Lesser General Public
  18   License along with PulseAudio; if not, write to the Free Software
  19   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  20   USA.
  21 ***/
  22
  23 #ifdef HAVE_CONFIG_H
  24 #include <config.h>
  25 #endif
  26
  27 #include <stddef.h>
  28 #include <sys/time.h>
  29
  30 #ifdef HAVE_WINDOWS_H
  31 #include <windows.h>
  32 #endif
  33
  34 #include <pulsecore/macro.h>
  35 #include <pulsecore/core-util.h>
  36
  37 #include "timeval.h"
  38
  39 struct timeval *pa_gettimeofday(struct timeval *tv) {
  40     pa_assert(tv);
  41
  42 #if defined(OS_IS_WIN32)
  43     /*
  44      * Copied from implementation by Steven Edwards (LGPL).
  45      * Found on wine mailing list.
  46      */
  47 #if defined(_MSC_VER) || defined(__BORLANDC__)
  48 #define EPOCHFILETIME (116444736000000000i64)
  49 #else
  50 #define EPOCHFILETIME (116444736000000000LL)
  51 #endif
  52     FILETIME ft;
  53     LARGE_INTEGER li;
  54     int64_t t;
  55
  56     GetSystemTimeAsFileTime(&ft);
  57     li.LowPart  = ft.dwLowDateTime;
  58     li.HighPart = ft.dwHighDateTime;
  59     t  = li.QuadPart;       /* In 100-nanosecond intervals */
  60     t -= EPOCHFILETIME;     /* Offset to the Epoch time */
  61     t /= 10;                /* In microseconds */
  62     tv->tv_sec  = (time_t) (t / PA_USEC_PER_SEC);
  63     tv->tv_usec = (suseconds_t) (t % PA_USEC_PER_SEC);
  64 #elif defined(HAVE_GETTIMEOFDAY)
  65     pa_assert_se(gettimeofday(tv, NULL) == 0);
  66 #else
  67 #error "Platform lacks gettimeofday() or equivalent function."
  68 #endif
  69
  70     return tv;
  71 }
  72
  73 pa_usec_t pa_timeval_diff(const struct timeval *a, const struct timeval *b) {
  74     pa_usec_t r;
  75
  76     pa_assert(a);
  77     pa_assert(b);
  78
  79     /* Check which whan is the earlier time and swap the two arguments if required. */
  80     if (PA_UNLIKELY(pa_timeval_cmp(a, b) < 0)) {
  81         const struct timeval *c;
  82         c = a;
  83         a = b;
  84         b = c;
  85     }
  86
  87     /* Calculate the second difference*/
  88     r = ((pa_usec_t) a->tv_sec - (pa_usec_t) b->tv_sec) * PA_USEC_PER_SEC;
  89
  90     /* Calculate the microsecond difference */
  91     if (a->tv_usec > b->tv_usec)
  92         r += (pa_usec_t) a->tv_usec - (pa_usec_t) b->tv_usec;
  93     else if (a->tv_usec < b->tv_usec)
  94         r -= (pa_usec_t) b->tv_usec - (pa_usec_t) a->tv_usec;
  95
  96     return r;
  97 }
  98
  99 int pa_timeval_cmp(const struct timeval *a, const struct timeval *b) {
 100     pa_assert(a);
 101     pa_assert(b);
 102
 103     if (a->tv_sec < b->tv_sec)
 104         return -1;
 105
 106     if (a->tv_sec > b->tv_sec)
 107         return 1;
 108
 109     if (a->tv_usec < b->tv_usec)
 110         return -1;
 111
 112     if (a->tv_usec > b->tv_usec)
 113         return 1;
 114
 115     return 0;
 116 }
 117
 118 pa_usec_t pa_timeval_age(const struct timeval *tv) {
 119     struct timeval now;
 120     pa_assert(tv);
 121
 122     return pa_timeval_diff(pa_gettimeofday(&now), tv);
 123 }
 124
 125 struct timeval* pa_timeval_add(struct timeval *tv, pa_usec_t v) {
 126     time_t secs;
 127     pa_assert(tv);
 128
 129     secs = (time_t) (v/PA_USEC_PER_SEC);
 130
 131     if (PA_UNLIKELY(tv->tv_sec > PA_INT_TYPE_MAX(time_t) - secs))
 132         goto overflow;
 133
 134     tv->tv_sec += secs;
 135     v -= (pa_usec_t) secs * PA_USEC_PER_SEC;
 136     tv->tv_usec += (suseconds_t) v;
 137
 138     /* Normalize */
 139     while ((pa_usec_t) tv->tv_usec >= PA_USEC_PER_SEC) {
 140
 141         if (PA_UNLIKELY(tv->tv_sec >= PA_INT_TYPE_MAX(time_t)))
 142             goto overflow;
 143
 144         tv->tv_sec++;
 145         tv->tv_usec -= (suseconds_t) PA_USEC_PER_SEC;
 146     }
 147
 148     return tv;
 149
 150 overflow:
 151     tv->tv_sec = PA_INT_TYPE_MAX(time_t);
 152     tv->tv_usec = (suseconds_t) (PA_USEC_PER_SEC-1);
 153     return tv;
 154 }
 155
 156 struct timeval* pa_timeval_sub(struct timeval *tv, pa_usec_t v) {
 157     time_t secs;
 158     pa_assert(tv);
 159
 160     secs = (time_t) (v/PA_USEC_PER_SEC);
 161
 162     if (PA_UNLIKELY(tv->tv_sec < secs))
 163         goto underflow;
 164
 165     tv->tv_sec -= secs;
 166     v -= (pa_usec_t) secs * PA_USEC_PER_SEC;
 167
 168     if (tv->tv_usec >= (suseconds_t) v)
 169         tv->tv_usec -= (suseconds_t) v;
 170     else {
 171
 172         if (PA_UNLIKELY(tv->tv_sec <= 0))
 173             goto underflow;
 174
 175         tv->tv_sec --;
 176         tv->tv_usec += (suseconds_t) (PA_USEC_PER_SEC - v);
 177     }
 178
 179     return tv;
 180
 181 underflow:
 182     tv->tv_sec = 0;
 183     tv->tv_usec = 0;
 184     return tv;
 185 }
 186
 187 struct timeval* pa_timeval_store(struct timeval *tv, pa_usec_t v) {
 188     pa_assert(tv);
 189
 190     if (PA_UNLIKELY(v == PA_USEC_INVALID)) {
 191         tv->tv_sec = PA_INT_TYPE_MAX(time_t);
 192         tv->tv_usec = (suseconds_t) (PA_USEC_PER_SEC-1);
 193
 194         return tv;
 195     }
 196
 197     tv->tv_sec = (time_t) (v / PA_USEC_PER_SEC);
 198     tv->tv_usec = (suseconds_t) (v % PA_USEC_PER_SEC);
 199
 200     return tv;
 201 }
 202
 203 pa_usec_t pa_timeval_load(const struct timeval *tv) {
 204
 205     if (PA_UNLIKELY(!tv))
 206         return PA_USEC_INVALID;
 207
 208     return
 209         (pa_usec_t) tv->tv_sec * PA_USEC_PER_SEC +
 210         (pa_usec_t) tv->tv_usec;
 211 }