/*****************************************************************************
* mtime.c: high resolution time management functions
- * Functions are prototyped in mtime.h.
+ * Functions are prototyped in vlc_mtime.h.
*****************************************************************************
- * Copyright (C) 1998-2004 the VideoLAN team
+ * 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
/*****************************************************************************
* Preamble
*****************************************************************************/
-#include <stdio.h> /* sprintf() */
-#include <time.h> /* clock_gettime(), clock_nanosleep() */
-#include <stdlib.h> /* ldiv() */
#include <vlc/vlc.h>
+#include <time.h> /* clock_gettime(), clock_nanosleep() */
+#include <assert.h>
+#include <errno.h>
+
+
#if defined( PTH_INIT_IN_PTH_H ) /* GNU Pth */
# include <pth.h>
#endif
#if defined( WIN32 ) || defined( UNDER_CE )
# include <windows.h>
-#else
+#endif
+#if defined(HAVE_SYS_TIME_H)
# include <sys/time.h>
#endif
-#if defined(HAVE_NANOSLEEP) && !defined(HAVE_STRUCT_TIMESPEC)
+#if !defined(HAVE_STRUCT_TIMESPEC)
struct timespec
{
time_t tv_sec;
return( psz_buffer );
}
+/**
+ * Return a value that is no bigger than the clock precision
+ * (possibly zero).
+ */
+static inline unsigned mprec( void )
+{
+#if defined (HAVE_CLOCK_NANOSLEEP)
+ struct timespec ts;
+ if( clock_getres( CLOCK_MONOTONIC, &ts ))
+ clock_getres( CLOCK_REALTIME, &ts );
+
+ return ts.tv_nsec / 1000;
+#endif
+ return 0;
+}
+
+static unsigned prec = 0;
+static volatile mtime_t cached_time = 0;
+#if defined( HAVE_CLOCK_NANOSLEEP )
+# if (_POSIX_MONOTONIC_CLOCK - 0 < 0)
+# define CLOCK_MONOTONIC CLOCK_REALTIME
+# endif
+#endif
/**
* Return high precision date
*/
mtime_t mdate( void )
{
-#if defined( HAVE_KERNEL_OS_H )
- return( real_time_clock_usecs() );
+ 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 = I64C(-1);
- mtime_t usec_time;
if( freq == I64C(-1) )
{
* the RTC rather than the TSC. If it's anything else, we
* presume that the performance counter is unreliable.
*/
+ LARGE_INTEGER buf;
- freq = ( QueryPerformanceFrequency( (LARGE_INTEGER *)&freq ) &&
- (freq == I64C(1193182) || freq == I64C(3579545) ) )
- ? freq : 0;
+ freq = ( QueryPerformanceFrequency( &buf ) &&
+ (buf.QuadPart == I64C(1193182) || buf.QuadPart == I64C(3579545) ) )
+ ? buf.QuadPart : 0;
}
if( freq != 0 )
{
- /* Microsecond resolution */
- QueryPerformanceCounter( (LARGE_INTEGER *)&usec_time );
- return ( usec_time * 1000000 ) / freq;
+ 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
{
}
EnterCriticalSection( &date_lock );
- usec_time = I64C(1000) *
+ res = I64C(1000) *
(i_wrap_counts * I64C(0x100000000) + GetTickCount());
- if( i_previous_time > usec_time )
+ if( i_previous_time > res )
{
/* Counter wrapped */
i_wrap_counts++;
- usec_time += I64C(0x100000000000);
+ res += I64C(0x100000000) * 1000;
}
- i_previous_time = usec_time;
+ i_previous_time = res;
LeaveCriticalSection( &date_lock );
-
- return usec_time;
}
-
-#elif defined (HAVE_CLOCK_GETTIME)
- struct timespec ts;
-
-# ifdef _POSIX_MONOTONIC_CLOCK
- /* Try to use POSIX monotonic clock if available */
- if( clock_gettime( CLOCK_MONOTONIC, &ts ) )
-# endif
- /* Run-time fallback to real-time clock (always available) */
- (void)clock_gettime( CLOCK_REALTIME, &ts );
-
- return (ts.tv_sec * 1000000) + (ts.tv_nsec / 1000);
#else
struct timeval tv_date;
/* gettimeofday() cannot fail given &tv_date is a valid address */
(void)gettimeofday( &tv_date, NULL );
- return( (mtime_t) tv_date.tv_sec * 1000000 + (mtime_t) tv_date.tv_usec );
+ res = (mtime_t) tv_date.tv_sec * 1000000 + (mtime_t) tv_date.tv_usec;
#endif
+
+ return cached_time = res;
}
/**
*/
void mwait( mtime_t date )
{
-#if defined( HAVE_KERNEL_OS_H )
- mtime_t delay;
+ if( prec == 0 )
+ prec = mprec();
- delay = date - real_time_clock_usecs();
- if( delay <= 0 )
- {
+ /* If the deadline is already elapsed, or within the clock precision,
+ * do not even bother the clock. */
+ if( ( date - cached_time ) < (mtime_t)prec ) // OK: mtime_t is signed
return;
- }
- snooze( delay );
-#elif defined( WIN32 ) || defined( UNDER_CE )
- mtime_t usec_time, delay;
+#if 0 && defined (HAVE_CLOCK_NANOSLEEP)
+ lldiv_t d = lldiv( date, 1000000 );
+ struct timespec ts = { d.quot, d.rem * 1000 };
- usec_time = mdate();
- delay = date - usec_time;
- if( delay <= 0 )
+ int val;
+ while( ( val = clock_nanosleep( CLOCK_MONOTONIC, TIMER_ABSTIME, &ts,
+ NULL ) ) == EINTR );
+ if( val == EINVAL )
{
- return;
+ ts.tv_sec = d.quot; ts.tv_nsec = d.rem * 1000;
+ while( clock_nanosleep( CLOCK_REALTIME, 0, &ts, NULL ) == EINTR );
}
- msleep( delay );
-
-#elif defined (HAVE_CLOCK_GETTIME)
- struct timespec ts;
- ldiv_t d;
-
-# if 1
- /*
- * Ideally, we'd use absolute time (TIMER_ABSTIME), instead of
- * computing the time difference... but VLC mtime_t type seems to
- * overflow way too quickly for this to work properly, or maybe it's a
- * signedness problem (??).
- */
- date -= mdate();
- if( date <= 0 )
- return;
-# endif
- d = ldiv( date, 1000000 );
- ts.tv_sec = d.quot;
- ts.tv_nsec = d.rem * 1000;
-
-# ifdef _POSIX_MONOTONIC_CLOCK
- if( clock_nanosleep( CLOCK_MONOTONIC, 0 /*TIMER_ABSTIME*/, &ts, NULL ) )
-# endif
- (void)clock_nanosleep( CLOCK_REALTIME, 0, &ts, NULL );
#else
- struct timeval tv_date;
- mtime_t delay; /* delay in msec, signed to detect errors */
-
- /* see mdate() about gettimeofday() possible errors */
- gettimeofday( &tv_date, NULL );
-
- /* calculate delay and check if current date is before wished date */
- delay = date - (mtime_t) tv_date.tv_sec * 1000000
- - (mtime_t) tv_date.tv_usec
- - 10000;
-
- /* Linux/i386 has a granularity of 10 ms. It's better to be in advance
- * than to be late. */
- if( delay <= 0 ) /* wished date is now or already passed */
- {
- return;
- }
-
-# if defined( PTH_INIT_IN_PTH_H )
- pth_usleep( delay );
-
-# elif defined( ST_INIT_IN_ST_H )
- st_usleep( delay );
-
-# else
-
-# if defined( HAVE_NANOSLEEP )
- {
- struct timespec ts_delay;
- ts_delay.tv_sec = delay / 1000000;
- ts_delay.tv_nsec = (delay % 1000000) * 1000;
-
- nanosleep( &ts_delay, NULL );
- }
-
-# else
- tv_date.tv_sec = delay / 1000000;
- tv_date.tv_usec = delay % 1000000;
- /* see msleep() about select() errors */
- select( 0, NULL, NULL, NULL, &tv_date );
-# endif
-
-# endif
+ mtime_t delay = date - mdate();
+ if( delay > 0 )
+ msleep( delay );
#endif
}
*/
void msleep( mtime_t delay )
{
-#if defined( HAVE_KERNEL_OS_H )
+ mtime_t earlier = cached_time;
+
+#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( PTH_INIT_IN_PTH_H )
ts_delay.tv_sec = delay / 1000000;
ts_delay.tv_nsec = (delay % 1000000) * 1000;
- nanosleep( &ts_delay, NULL );
+ 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;
- /* select() return value should be tested, since several possible errors
- * can occur. However, they should only happen in very particular occasions
- * (i.e. when a signal is sent to the thread, or when memory is full), and
- * can be ignored. */
+ /* 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
+
+ earlier += delay;
+ if( cached_time < earlier )
+ cached_time = earlier;
}
/*
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;
+}
+
projects / vlc / blobdiff