/*****************************************************************************
* mtime.c: high resolution time management functions
* Functions are prototyped in vlc_mtime.h.
*****************************************************************************
* Copyright (C) 1998-2007 the VideoLAN team
* Copyright © 2006-2007 Rémi Denis-Courmont
* $Id$
*
* Authors: Vincent Seguin <seguin@via.ecp.fr>
* Rémi Denis-Courmont <rem$videolan,org>
* Gisle Vanem
*
* 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.
*****************************************************************************/
/*****************************************************************************
* Preamble
*****************************************************************************/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include "vlc_common.h"
#include <time.h> /* clock_gettime(), clock_nanosleep() */
#include <assert.h>
#include <errno.h>
#ifdef HAVE_UNISTD_H
# include <unistd.h> /* select() */
#endif
#ifdef HAVE_KERNEL_OS_H
# include <kernel/OS.h>
#endif
#if defined( WIN32 ) || defined( UNDER_CE )
# include <windows.h>
# include <mmsystem.h>
#endif
#if defined( UNDER_CE )
# include <windows.h>
#endif
#if defined(HAVE_SYS_TIME_H)
# include <sys/time.h>
#endif
#if defined(HAVE_NANOSLEEP) && !defined(HAVE_DECL_NANOSLEEP)
int nanosleep(struct timespec *, struct timespec *);
#endif
#if !defined (_POSIX_CLOCK_SELECTION)
# define _POSIX_CLOCK_SELECTION (-1)
#endif
# if (_POSIX_CLOCK_SELECTION < 0)
/*
* We cannot use the monotonic clock is clock selection is not available,
* as it would screw vlc_cond_timedwait() completely. Instead, we have to
* stick to the realtime clock. Nevermind it screws everything when ntpdate
* warps the wall clock.
*/
# undef CLOCK_MONOTONIC
# define CLOCK_MONOTONIC CLOCK_REALTIME
#elif !defined (HAVE_CLOCK_NANOSLEEP)
/* Clock selection without clock in the first place, I don't think so. */
# error We have quite a situation here! Fix me if it ever happens.
#endif
/**
* Return a date in a readable format
*
* This function converts a mtime date into a string.
* psz_buffer should be a buffer long enough to store the formatted
* date.
* \param date to be converted
* \param psz_buffer should be a buffer at least MSTRTIME_MAX_SIZE characters
* \return psz_buffer is returned so this can be used as printf parameter.
*/
char *mstrtime( char *psz_buffer, mtime_t date )
{
static const mtime_t ll1000 = 1000, ll60 = 60, ll24 = 24;
snprintf( psz_buffer, MSTRTIME_MAX_SIZE, "%02d:%02d:%02d-%03d.%03d",
(int) (date / (ll1000 * ll1000 * ll60 * ll60) % ll24),
(int) (date / (ll1000 * ll1000 * ll60) % ll60),
(int) (date / (ll1000 * ll1000) % ll60),
(int) (date / ll1000 % ll1000),
(int) (date % ll1000) );
return( psz_buffer );
}
/**
* Convert seconds to a time in the format h:mm:ss.
*
* This function is provided for any interface function which need to print a
* time string in the format h:mm:ss
* date.
* \param secs the date to be converted
* \param psz_buffer should be a buffer at least MSTRTIME_MAX_SIZE characters
* \return psz_buffer is returned so this can be used as printf parameter.
*/
char *secstotimestr( char *psz_buffer, int i_seconds )
{
int i_hours, i_mins;
i_mins = i_seconds / 60;
i_hours = i_mins / 60 ;
if( i_hours )
{
snprintf( psz_buffer, MSTRTIME_MAX_SIZE, "%d:%2.2d:%2.2d",
(int) i_hours,
(int) (i_mins % 60),
(int) (i_seconds % 60) );
}
else
{
snprintf( psz_buffer, MSTRTIME_MAX_SIZE, "%2.2d:%2.2d",
(int) i_mins ,
(int) (i_seconds % 60) );
}
return( psz_buffer );
}
#if defined (HAVE_CLOCK_NANOSLEEP)
static unsigned prec = 0;
static void mprec_once( void )
{
struct timespec ts;
if( clock_getres( CLOCK_MONOTONIC, &ts ))
clock_getres( CLOCK_REALTIME, &ts );
prec = ts.tv_nsec / 1000;
}
#endif
/**
* Return a value that is no bigger than the clock precision
* (possibly zero).
*/
static inline unsigned mprec( void )
{
#if defined (HAVE_CLOCK_NANOSLEEP)
static pthread_once_t once = PTHREAD_ONCE_INIT;
pthread_once( &once, mprec_once );
return prec;
#else
return 0;
#endif
}
/**
* Return high precision date
*
* Use a 1 MHz clock when possible, or 1 kHz
*
* Beware ! It doesn't reflect the actual date (since epoch), but can be the machine's uptime or anything (when monotonic clock is used)
*/
mtime_t mdate( void )
{
mtime_t res;
#if defined (HAVE_CLOCK_NANOSLEEP)
struct timespec ts;
/* Try to use POSIX monotonic clock if available */
if( clock_gettime( CLOCK_MONOTONIC, &ts ) == EINVAL )
/* Run-time fallback to real-time clock (always available) */
(void)clock_gettime( CLOCK_REALTIME, &ts );
res = ((mtime_t)ts.tv_sec * (mtime_t)1000000)
+ (mtime_t)(ts.tv_nsec / 1000);
#elif defined( HAVE_KERNEL_OS_H )
res = real_time_clock_usecs();
#elif defined( WIN32 ) || defined( UNDER_CE )
/* We don't need the real date, just the value of a high precision timer */
static mtime_t freq = INT64_C(-1);
if( freq == INT64_C(-1) )
{
/* Extract from the Tcl source code:
* (http://www.cs.man.ac.uk/fellowsd-bin/TIP/7.html)
*
* Some hardware abstraction layers use the CPU clock
* in place of the real-time clock as a performance counter
* reference. This results in:
* - inconsistent results among the processors on
* multi-processor systems.
* - unpredictable changes in performance counter frequency
* on "gearshift" processors such as Transmeta and
* SpeedStep.
* There seems to be no way to test whether the performance
* counter is reliable, but a useful heuristic is that
* if its frequency is 1.193182 MHz or 3.579545 MHz, it's
* derived from a colorburst crystal and is therefore
* the RTC rather than the TSC. If it's anything else, we
* presume that the performance counter is unreliable.
*/
LARGE_INTEGER buf;
freq = ( QueryPerformanceFrequency( &buf ) &&
(buf.QuadPart == INT64_C(1193182) || buf.QuadPart == INT64_C(3579545) ) )
? buf.QuadPart : 0;
#if defined( WIN32 )
/* on windows 2000, XP and Vista detect if there are two
cores there - that makes QueryPerformanceFrequency in
any case not trustable?
(may also be true, for single cores with adaptive
CPU frequency and active power management?)
*/
HINSTANCE h_Kernel32 = LoadLibrary(_T("kernel32.dll"));
if(h_Kernel32)
{
void WINAPI (*pf_GetSystemInfo)(LPSYSTEM_INFO);
pf_GetSystemInfo = (void WINAPI (*)(LPSYSTEM_INFO))
GetProcAddress(h_Kernel32, _T("GetSystemInfo"));
if(pf_GetSystemInfo)
{
SYSTEM_INFO system_info;
pf_GetSystemInfo(&system_info);
if(system_info.dwNumberOfProcessors > 1)
freq = 0;
}
FreeLibrary(h_Kernel32);
}
#endif
}
if( freq != 0 )
{
LARGE_INTEGER counter;
QueryPerformanceCounter (&counter);
/* Convert to from (1/freq) to microsecond resolution */
/* We need to split the division to avoid 63-bits overflow */
lldiv_t d = lldiv (counter.QuadPart, freq);
res = (d.quot * 1000000) + ((d.rem * 1000000) / freq);
}
else
{
/* Fallback on timeGetTime() which has a milisecond resolution
* (actually, best case is about 5 ms resolution)
* timeGetTime() only returns a DWORD thus will wrap after
* about 49.7 days so we try to detect the wrapping. */
static CRITICAL_SECTION date_lock;
static mtime_t i_previous_time = INT64_C(-1);
static int i_wrap_counts = -1;
if( i_wrap_counts == -1 )
{
/* Initialization */
#if defined( WIN32 )
i_previous_time = INT64_C(1000) * timeGetTime();
#else
i_previous_time = INT64_C(1000) * GetTickCount();
#endif
InitializeCriticalSection( &date_lock );
i_wrap_counts = 0;
}
EnterCriticalSection( &date_lock );
#if defined( WIN32 )
res = INT64_C(1000) *
(i_wrap_counts * INT64_C(0x100000000) + timeGetTime());
#else
res = INT64_C(1000) *
(i_wrap_counts * INT64_C(0x100000000) + GetTickCount());
#endif
if( i_previous_time > res )
{
/* Counter wrapped */
i_wrap_counts++;
res += INT64_C(0x100000000) * 1000;
}
i_previous_time = res;
LeaveCriticalSection( &date_lock );
}
#else
struct timeval tv_date;
/* gettimeofday() cannot fail given &tv_date is a valid address */
(void)gettimeofday( &tv_date, NULL );
res = (mtime_t) tv_date.tv_sec * 1000000 + (mtime_t) tv_date.tv_usec;
#endif
return res;
}
/**
* Wait for a date
*
* This function uses select() and an system date function to wake up at a
* precise date. It should be used for process synchronization. If current date
* is posterior to wished date, the function returns immediately.
* \param date The date to wake up at
*/
void mwait( mtime_t date )
{
/* If the deadline is already elapsed, or within the clock precision,
* do not even bother the system timer. */
date -= mprec();
#if defined (HAVE_CLOCK_NANOSLEEP)
lldiv_t d = lldiv( date, 1000000 );
struct timespec ts = { d.quot, d.rem * 1000 };
int val;
while( ( val = clock_nanosleep( CLOCK_MONOTONIC, TIMER_ABSTIME, &ts,
NULL ) ) == EINTR );
if( val == EINVAL )
{
ts.tv_sec = d.quot; ts.tv_nsec = d.rem * 1000;
while( clock_nanosleep( CLOCK_REALTIME, 0, &ts, NULL ) == EINTR );
}
#else
mtime_t delay = date - mdate();
if( delay > 0 )
msleep( delay );
#endif
}
/**
* More precise sleep()
*
* Portable usleep() function.
* \param delay the amount of time to sleep
*/
void msleep( mtime_t delay )
{
#if defined( HAVE_CLOCK_NANOSLEEP )
lldiv_t d = lldiv( delay, 1000000 );
struct timespec ts = { d.quot, d.rem * 1000 };
int val;
while( ( val = clock_nanosleep( CLOCK_MONOTONIC, 0, &ts, &ts ) ) == EINTR );
if( val == EINVAL )
{
ts.tv_sec = d.quot; ts.tv_nsec = d.rem * 1000;
while( clock_nanosleep( CLOCK_REALTIME, 0, &ts, &ts ) == EINTR );
}
#elif defined( HAVE_KERNEL_OS_H )
snooze( delay );
#elif defined( WIN32 ) || defined( UNDER_CE )
for (delay /= 1000; delay > 0x7fffffff; delay -= 0x7fffffff)
Sleep (0x7fffffff);
Sleep (delay);
#elif defined( HAVE_NANOSLEEP )
struct timespec ts_delay;
ts_delay.tv_sec = delay / 1000000;
ts_delay.tv_nsec = (delay % 1000000) * 1000;
while( nanosleep( &ts_delay, &ts_delay ) && ( errno == EINTR ) );
#else
struct timeval tv_delay;
tv_delay.tv_sec = delay / 1000000;
tv_delay.tv_usec = delay % 1000000;
/* If a signal is caught, you are screwed. Update your OS to nanosleep()
* or clock_nanosleep() if this is an issue. */
select( 0, NULL, NULL, NULL, &tv_delay );
#endif
}
/*
* Date management (internal and external)
*/
/**
* Initialize a date_t.
*
* \param date to initialize
* \param divider (sample rate) numerator
* \param divider (sample rate) denominator
*/
void date_Init( date_t *p_date, uint32_t i_divider_n, uint32_t i_divider_d )
{
p_date->date = 0;
p_date->i_divider_num = i_divider_n;
p_date->i_divider_den = i_divider_d;
p_date->i_remainder = 0;
}
/**
* Change a date_t.
*
* \param date to change
* \param divider (sample rate) numerator
* \param divider (sample rate) denominator
*/
void date_Change( date_t *p_date, uint32_t i_divider_n, uint32_t i_divider_d )
{
/* change time scale of remainder */
p_date->i_remainder = p_date->i_remainder * i_divider_n / p_date->i_divider_num;
p_date->i_divider_num = i_divider_n;
p_date->i_divider_den = i_divider_d;
}
/**
* Set the date value of a date_t.
*
* \param date to set
* \param date value
*/
void date_Set( date_t *p_date, mtime_t i_new_date )
{
p_date->date = i_new_date;
p_date->i_remainder = 0;
}
/**
* Get the date of a date_t
*
* \param date to get
* \return date value
*/
mtime_t date_Get( const date_t *p_date )
{
return p_date->date;
}
/**
* Move forwards or backwards the date of a date_t.
*
* \param date to move
* \param difference value
*/
void date_Move( date_t *p_date, mtime_t i_difference )
{
p_date->date += i_difference;
}
/**
* Increment the date and return the result, taking into account
* rounding errors.
*
* \param date to increment
* \param incrementation in number of samples
* \return date value
*/
mtime_t date_Increment( date_t *p_date, uint32_t i_nb_samples )
{
mtime_t i_dividend = (mtime_t)i_nb_samples * 1000000 * p_date->i_divider_den;
p_date->date += i_dividend / p_date->i_divider_num;
p_date->i_remainder += (int)(i_dividend % p_date->i_divider_num);
if( p_date->i_remainder >= p_date->i_divider_num )
{
/* This is Bresenham algorithm. */
assert( p_date->i_remainder < 2*p_date->i_divider_num);
p_date->date += 1;
p_date->i_remainder -= p_date->i_divider_num;
}
return p_date->date;
}
#ifndef HAVE_GETTIMEOFDAY
#ifdef WIN32
/*
* Number of micro-seconds between the beginning of the Windows epoch
* (Jan. 1, 1601) and the Unix epoch (Jan. 1, 1970).
*
* This assumes all Win32 compilers have 64-bit support.
*/
#if defined(_MSC_VER) || defined(_MSC_EXTENSIONS) || defined(__WATCOMC__)
# define DELTA_EPOCH_IN_USEC 11644473600000000Ui64
#else
# define DELTA_EPOCH_IN_USEC 11644473600000000ULL
#endif
static uint64_t filetime_to_unix_epoch (const FILETIME *ft)
{
uint64_t res = (uint64_t) ft->dwHighDateTime << 32;
res |= ft->dwLowDateTime;
res /= 10; /* from 100 nano-sec periods to usec */
res -= DELTA_EPOCH_IN_USEC; /* from Win epoch to Unix epoch */
return (res);
}
static int gettimeofday (struct timeval *tv, void *tz )
{
FILETIME ft;
uint64_t tim;
if (!tv) {
return VLC_EGENERIC;
}
GetSystemTimeAsFileTime (&ft);
tim = filetime_to_unix_epoch (&ft);
tv->tv_sec = (long) (tim / 1000000L);
tv->tv_usec = (long) (tim % 1000000L);
return (0);
}
#endif
#endif
/**
* @return NTP 64-bits timestamp in host byte order.
*/
uint64_t NTPtime64 (void)
{
struct timespec ts;
#if defined (CLOCK_REALTIME)
clock_gettime (CLOCK_REALTIME, &ts);
#else
{
struct timeval tv;
gettimeofday (&tv, NULL);
ts.tv_sec = tv.tv_sec;
ts.tv_nsec = tv.tv_usec * 1000;
}
#endif
/* Convert nanoseconds to 32-bits fraction (232 picosecond units) */
uint64_t t = (uint64_t)(ts.tv_nsec) << 32;
t /= 1000000000;
/* There is 70 years (incl. 17 leap ones) offset to the Unix Epoch.
* No leap seconds during that period since they were not invented yet.
*/
assert (t < 0x100000000);
t |= ((70LL * 365 + 17) * 24 * 60 * 60 + ts.tv_sec) << 32;
return t;
}
