src/pulse/timeval.h

   1 #ifndef footimevalhfoo
   2 #define footimevalhfoo
   3
   4 /***
   5   This file is part of PulseAudio.
   6
   7   Copyright 2004-2006 Lennart Poettering
   8   Copyright 2006 Pierre Ossman <ossman@cendio.se> for Cendio AB
   9
  10   PulseAudio is free software; you can redistribute it and/or modify
  11   it under the terms of the GNU Lesser General Public License as
  12   published by the Free Software Foundation; either version 2.1 of the
  13   License, or (at your option) any later version.
  14
  15   PulseAudio is distributed in the hope that it will be useful, but
  16   WITHOUT ANY WARRANTY; without even the implied warranty of
  17   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  18   Lesser General Public License for more details.
  19
  20   You should have received a copy of the GNU Lesser General Public
  21   License along with PulseAudio; if not, write to the Free Software
  22   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  23   USA.
  24 ***/
  25
  26 #include <pulse/cdecl.h>
  27 #include <pulse/gccmacro.h>
  28 #include <pulse/sample.h>
  29 #include <pulse/version.h>
  30
  31 /** \file
  32  * Utility functions for handling timeval calculations */
  33
  34 PA_C_DECL_BEGIN
  35
  36 /** The number of milliseconds in a second */
  37 #define PA_MSEC_PER_SEC ((pa_usec_t) 1000ULL)
  38
  39 /** The number of microseconds in a second */
  40 #define PA_USEC_PER_SEC ((pa_usec_t) 1000000ULL)
  41
  42 /** The number of nanoseconds in a second */
  43 #define PA_NSEC_PER_SEC ((unsigned long long) 1000000000ULL)
  44
  45 /** The number of microseconds in a millisecond */
  46 #define PA_USEC_PER_MSEC ((pa_usec_t) 1000ULL)
  47
  48 /** The number of nanoseconds in a millisecond */
  49 #define PA_NSEC_PER_MSEC ((unsigned long long) 1000000ULL)
  50
  51 /** The number of nanoseconds in a microsecond */
  52 #define PA_NSEC_PER_USEC ((unsigned long long) 1000ULL)
  53
  54 /** Invalid time in usec. \since 0.9.15 */
  55 #define PA_USEC_INVALID ((pa_usec_t) -1)
  56
  57 /** Biggest time in usec. \since 0.9.18 */
  58 #define PA_USEC_MAX ((pa_usec_t) -2)
  59
  60 struct timeval;
  61
  62 /** Return the current wallclock timestamp, just like UNIX gettimeofday(). */
  63 struct timeval *pa_gettimeofday(struct timeval *tv);
  64
  65 /** Calculate the difference between the two specified timeval
  66  * structs. */
  67 pa_usec_t pa_timeval_diff(const struct timeval *a, const struct timeval *b) PA_GCC_PURE;
  68
  69 /** Compare the two timeval structs and return 0 when equal, negative when a < b, positive otherwise */
  70 int pa_timeval_cmp(const struct timeval *a, const struct timeval *b) PA_GCC_PURE;
  71
  72 /** Return the time difference between now and the specified timestamp */
  73 pa_usec_t pa_timeval_age(const struct timeval *tv);
  74
  75 /** Add the specified time in microseconds to the specified timeval structure */
  76 struct timeval* pa_timeval_add(struct timeval *tv, pa_usec_t v);
  77
  78 /** Subtract the specified time in microseconds to the specified timeval structure. \since 0.9.11 */
  79 struct timeval* pa_timeval_sub(struct timeval *tv, pa_usec_t v);
  80
  81 /** Store the specified uec value in the timeval struct. \since 0.9.7 */
  82 struct timeval* pa_timeval_store(struct timeval *tv, pa_usec_t v);
  83
  84 /** Load the specified tv value and return it in usec. \since 0.9.7 */
  85 pa_usec_t pa_timeval_load(const struct timeval *tv);
  86
  87 PA_C_DECL_END
  88
  89 #endif