/*****************************************************************************
* mtime.c: high resolution time management functions
- * Functions are prototyped in mtime.h.
+ * Functions are prototyped in vlc_mtime.h.
*****************************************************************************
- * Copyright (C) 1998-2001, 2003 VideoLAN
- * $Id: mtime.c,v 1.39 2003/12/03 21:50:50 sigmunau Exp $
+ * 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
*
* 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., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
*****************************************************************************/
-/*
- * TODO:
- * see if using Linux real-time extensions is possible and profitable
- */
-
/*****************************************************************************
* Preamble
*****************************************************************************/
-#include <stdio.h> /* sprintf() */
-
-#include <vlc/vlc.h>
-#if defined( PTH_INIT_IN_PTH_H ) /* GNU Pth */
-# include <pth.h>
+#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
#if defined( WIN32 ) || defined( UNDER_CE )
# include <windows.h>
-#else
+# include <mmsystem.h>
+#endif
+
+#if defined(HAVE_SYS_TIME_H)
# include <sys/time.h>
#endif
-#if defined(HAVE_NANOSLEEP) && !defined(HAVE_STRUCT_TIMESPEC)
+#if defined(__APPLE__) && !defined(__powerpc__) && !defined(__ppc__) && !defined(__ppc64__)
+#define USE_APPLE_MACH 1
+# include <mach/mach.h>
+# include <mach/mach_time.h>
+#endif
+
+#if !defined(HAVE_STRUCT_TIMESPEC)
struct timespec
{
time_t tv_sec;
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 if 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 up 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.
+ * 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 mtime_t ll1000 = 1000, ll60 = 60, ll24 = 24;
+ 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),
* \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 )
+char *secstotimestr( char *psz_buffer, int32_t i_seconds )
{
- snprintf( psz_buffer, MSTRTIME_MAX_SIZE, "%d:%2.2d:%2.2d",
- (int) (i_seconds / (60 *60)),
- (int) ((i_seconds / 60) % 60),
- (int) (i_seconds % 60) );
- return( psz_buffer );
+ if( unlikely(i_seconds < 0) )
+ {
+ secstotimestr( psz_buffer + 1, -i_seconds );
+ *psz_buffer = '-';
+ return psz_buffer;
+ }
+
+ div_t d;
+
+ d = div( i_seconds, 60 );
+ i_seconds = d.rem;
+ d = div( d.quot, 60 );
+
+ if( d.quot )
+ snprintf( psz_buffer, MSTRTIME_MAX_SIZE, "%u:%02u:%02u",
+ d.quot, d.rem, i_seconds );
+ else
+ snprintf( psz_buffer, MSTRTIME_MAX_SIZE, "%02u:%02u",
+ d.rem, i_seconds );
+ 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
+}
+
+#ifdef USE_APPLE_MACH
+static mach_timebase_info_data_t mtime_timebase_info;
+static pthread_once_t mtime_timebase_info_once = PTHREAD_ONCE_INIT;
+static void mtime_init_timebase(void)
+{
+ mach_timebase_info(&mtime_timebase_info);
+}
+#endif
+
/**
* Return high precision date
*
- * Uses the gettimeofday() function when possible (1 MHz resolution) or the
- * ftime() function (1 kHz resolution).
+ * 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 )
{
-#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( USE_APPLE_MACH )
+ pthread_once(&mtime_timebase_info_once, mtime_init_timebase);
+ uint64_t date = mach_absolute_time();
+ mach_timebase_info_data_t tb = mtime_timebase_info;
+
+ /* tb.denom is uint32_t, switch to 64 bits to prevent overflow. */
+ uint64_t denom = tb.denom;
+
+ /* Switch to microsecs */
+ denom *= 1000LL;
+
+ /* Split the division to prevent overflow */
+ lldiv_t d = lldiv (tb.numer, denom);
+
+ res = (d.quot * date) + ((d.rem * date) / denom);
#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;
+ LARGE_INTEGER counter, freq;
+ if (!QueryPerformanceCounter (&counter)
+ || !QueryPerformanceFrequency (&freq))
+ abort();
- if( freq == I64C(-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.
- */
-
- freq = ( QueryPerformanceFrequency( (LARGE_INTEGER *)&freq ) &&
- (freq == I64C(1193182) || freq == I64C(3579545) ) )
- ? freq : 0;
- }
+ /* 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.QuadPart);
- if( freq != 0 )
- {
- /* Microsecond resolution */
- QueryPerformanceCounter( (LARGE_INTEGER *)&usec_time );
- return ( usec_time * 1000000 ) / freq;
- }
-
- /* Milisecond resolution (actually, best case is about 10 ms resolution) */
- return 1000 * GetTickCount();
+ res = (d.quot * 1000000) + ((d.rem * 1000000) / freq.QuadPart);
#else
struct timeval tv_date;
- /* gettimeofday() could return an error, and should be tested. However, the
- * only possible error, according to 'man', is EFAULT, which can not happen
- * here, since tv is a local variable. */
- gettimeofday( &tv_date, NULL );
- return( (mtime_t) tv_date.tv_sec * 1000000 + (mtime_t) tv_date.tv_usec );
-
+ /* 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;
}
+#undef mwait
/**
* Wait for a date
*
*/
void mwait( mtime_t date )
{
-#if defined( HAVE_KERNEL_OS_H )
- mtime_t delay;
-
- 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 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 )
{
- return;
+ ts.tv_sec = d.quot; ts.tv_nsec = d.rem * 1000;
+ while( clock_nanosleep( CLOCK_REALTIME, 0, &ts, NULL ) == EINTR );
}
- snooze( delay );
-#elif defined( WIN32 ) || defined( UNDER_CE )
- mtime_t usec_time, delay;
+#elif defined (WIN32)
+ mtime_t i_total;
- usec_time = mdate();
- delay = date - usec_time;
- if( delay <= 0 )
+ while( (i_total = (date - mdate())) > 0 )
{
- return;
+ const mtime_t i_sleep = i_total / 1000;
+ DWORD i_delay = (i_sleep > 0x7fffffff) ? 0x7fffffff : i_sleep;
+ vlc_testcancel();
+ SleepEx( i_delay, TRUE );
}
- msleep( delay );
+ vlc_testcancel();
#else
+ mtime_t delay = date - mdate();
+ if( delay > 0 )
+ msleep( delay );
- struct timeval tv_date;
- mtime_t delay; /* delay in msec, signed to detect errors */
+#endif
+}
- /* 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;
+#include "libvlc.h" /* vlc_backtrace() */
+#undef msleep
- /* 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 */
+/**
+ * Portable usleep(). Cancellation point.
+ *
+ * \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 )
{
- return;
+ ts.tv_sec = d.quot; ts.tv_nsec = d.rem * 1000;
+ while( clock_nanosleep( CLOCK_REALTIME, 0, &ts, &ts ) == EINTR );
}
-# if defined( PTH_INIT_IN_PTH_H )
- pth_usleep( delay );
+#elif defined( HAVE_KERNEL_OS_H )
+ snooze( delay );
-# elif defined( ST_INIT_IN_ST_H )
- st_usleep( delay );
+#elif defined( WIN32 ) || defined( UNDER_CE )
+ mwait (mdate () + delay);
-# else
+#elif defined( HAVE_NANOSLEEP )
+ struct timespec ts_delay;
-# if defined( HAVE_NANOSLEEP )
- {
- struct timespec ts_delay;
- ts_delay.tv_sec = delay / 1000000;
- ts_delay.tv_nsec = (delay % 1000000) * 1000;
+ 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
- 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
+#elif defined (USE_APPLE_MACH)
+ /* The version that should be used, if it was cancelable */
+ pthread_once(&mtime_timebase_info_once, mtime_init_timebase);
+ uint64_t mach_time = delay * 1000 * mtime_timebase_info.denom / mtime_timebase_info.numer;
+ mach_wait_until(mach_time + mach_absolute_time());
-# endif
+#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)
+ */
+
/**
- * More precise sleep()
+ * Initialize a date_t.
*
- * Portable usleep() function.
- * \param delay the amount of time to sleep
+ * \param date to initialize
+ * \param divider (sample rate) numerator
+ * \param divider (sample rate) denominator
*/
-void msleep( mtime_t delay )
+
+void date_Init( date_t *p_date, uint32_t i_divider_n, uint32_t i_divider_d )
{
-#if defined( HAVE_KERNEL_OS_H )
- snooze( delay );
+ 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;
+}
-#elif defined( PTH_INIT_IN_PTH_H )
- pth_usleep( delay );
+/**
+ * Change a date_t.
+ *
+ * \param date to change
+ * \param divider (sample rate) numerator
+ * \param divider (sample rate) denominator
+ */
-#elif defined( ST_INIT_IN_ST_H )
- st_usleep( delay );
+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;
+}
-#elif defined( WIN32 ) || defined( UNDER_CE )
- Sleep( (int) (delay / 1000) );
+/**
+ * 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;
+}
-#elif defined( HAVE_NANOSLEEP )
- struct timespec ts_delay;
+/**
+ * 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;
+}
- ts_delay.tv_sec = delay / 1000000;
- ts_delay.tv_nsec = (delay % 1000000) * 1000;
+/**
+ * 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;
+ }
- nanosleep( &ts_delay, NULL );
+ return p_date->date;
+}
+
+/**
+ * Decrement the date and return the result, taking into account
+ * rounding errors.
+ *
+ * \param date to decrement
+ * \param decrementation in number of samples
+ * \return date value
+ */
+mtime_t date_Decrement( 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;
+ unsigned i_rem_adjust = i_dividend % p_date->i_divider_num;
+ if( p_date->i_remainder < i_rem_adjust )
+ {
+ /* This is Bresenham algorithm. */
+ assert( p_date->i_remainder > -p_date->i_divider_num);
+ p_date->date -= 1;
+ p_date->i_remainder += p_date->i_divider_num;
+ }
+
+ p_date->i_remainder -= i_rem_adjust;
+
+ 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
- struct timeval tv_delay;
+# define DELTA_EPOCH_IN_USEC 11644473600000000ULL
+#endif
- tv_delay.tv_sec = delay / 1000000;
- tv_delay.tv_usec = delay % 1000000;
+static uint64_t filetime_to_unix_epoch (const FILETIME *ft)
+{
+ uint64_t res = (uint64_t) ft->dwHighDateTime << 32;
- /* 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. */
- select( 0, NULL, NULL, NULL, &tv_delay );
+ 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