/***************************************************************************** * vlc_mtime.h: high resolution time management functions ***************************************************************************** * This header provides portable high precision time management functions, * which should be the only ones used in other segments of the program, since * functions like gettimeofday() and ftime() are not always supported. * Most functions are declared as inline or as macros since they are only * interfaces to system calls and have to be called frequently. * 'm' stands for 'micro', since maximum resolution is the microsecond. * Functions prototyped are implemented in interface/mtime.c. ***************************************************************************** * Copyright (C) 1996, 1997, 1998, 1999, 2000 the VideoLAN team * $Id: f3bb895d42fdbde9294c2c60d378f5889ddaf684 $ * * Authors: Vincent Seguin <seguin@via.ecp.fr> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA. *****************************************************************************/#ifndef __VLC_MTIME_H# define __VLC_MTIME_H 1/***************************************************************************** * LAST_MDATE: date which will never happen ***************************************************************************** * This date can be used as a 'never' date, to mark missing events in a function * supposed to return a date, such as nothing to display in a function * returning the date of the first image to be displayed. It can be used in * comparaison with other values: all existing dates will be earlier. *****************************************************************************/#define LAST_MDATE ((mtime_t)((uint64_t)(-1)/2))/***************************************************************************** * MSTRTIME_MAX_SIZE: maximum possible size of mstrtime ***************************************************************************** * This values is the maximal possible size of the string returned by the * mstrtime() function, including '-' and the final '\0'. It should be used to * allocate the buffer. *****************************************************************************/#define MSTRTIME_MAX_SIZE 22/* Well, Duh? But it does clue us in that we are converting from   millisecond quantity to a second quantity or vice versa.*/#define MILLISECONDS_PER_SEC 1000#define msecstotimestr(psz_buffer, msecs) \  secstotimestr( psz_buffer, (msecs / (int) MILLISECONDS_PER_SEC) )/***************************************************************************** * Prototypes *****************************************************************************/VLC_EXPORT( char *,  mstrtime, ( char *psz_buffer, mtime_t date ) );VLC_EXPORT( mtime_t, mdate,    ( void ) );VLC_EXPORT( void,    mwait,    ( mtime_t date ) );VLC_EXPORT( void,    msleep,   ( mtime_t delay ) );VLC_EXPORT( char *,  secstotimestr, ( char *psz_buffer, int secs ) );#if defined (__GNUC__) && defined (__linux__)# define VLC_HARD_MIN_SLEEP 1000 /* Linux has 100, 250, 300 or 1000Hz */# define VLC_SOFT_MIN_SLEEP 9000000static__attribute__((unused))__attribute__((noinline))__attribute__((error("sorry, cannot sleep for such short a time")))mtime_t impossible_delay( mtime_t delay ){    (void) delay;    return VLC_HARD_MIN_SLEEP;}static__attribute__((unused))__attribute__((noinline))__attribute__((warning("use proper event handling instead of short delay")))mtime_t harmful_delay( mtime_t delay ){    return delay;}# define check_delay( d ) \    ((__builtin_constant_p(d < VLC_HARD_MIN_SLEEP) \   && (d < VLC_HARD_MIN_SLEEP)) \       ? impossible_delay(d) \       : ((__builtin_constant_p(d < VLC_SOFT_MIN_SLEEP) \       && (d < VLC_SOFT_MIN_SLEEP)) \           ? harmful_delay(d) \           : d))static__attribute__((unused))__attribute__((noinline))__attribute__((error("deadlines can not be constant")))mtime_t impossible_deadline( mtime_t deadline ){    return deadline;}# define check_deadline( d ) \    (__builtin_constant_p(d) ? impossible_deadline(d) : d)#else# define check_delay(d) (d)# define check_deadline(d) (d)#endif#define msleep(d) msleep(check_delay(d))#define mwait(d) mwait(check_deadline(d))/***************************************************************************** * date_t: date incrementation without long-term rounding errors *****************************************************************************/struct date_t{    mtime_t  date;    uint32_t i_divider_num;    uint32_t i_divider_den;    uint32_t i_remainder;};VLC_EXPORT( void,    date_Init,      ( date_t *, uint32_t, uint32_t ) );VLC_EXPORT( void,    date_Change,    ( date_t *, uint32_t, uint32_t ) );VLC_EXPORT( void,    date_Set,       ( date_t *, mtime_t ) );VLC_EXPORT( mtime_t, date_Get,       ( const date_t * ) );VLC_EXPORT( void,    date_Move,      ( date_t *, mtime_t ) );VLC_EXPORT( mtime_t, date_Increment, ( date_t *, uint32_t ) );VLC_EXPORT( uint64_t, NTPtime64,     ( void ) );#endif /* !__VLC_MTIME_ */