/*****************************************************************************
- * mtime.c: high rezolution time management functions
- * (c)1998 VideoLAN
+ * mtime.c: high resolution time management functions
+ * Functions are prototyped in vlc_mtime.h.
*****************************************************************************
- * Functions are prototyped in mtime.h.
- *****************************************************************************
- * to-do list:
- * see if using Linux real-time extensions is possible and profitable
+ * 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
*****************************************************************************/
-#include <stdio.h>
-#include <unistd.h>
-#include <sys/time.h>
-#include "common.h"
-#include "mtime.h"
+#include <vlc/vlc.h>
-/*****************************************************************************
- * mstrtime: return a date in a readable format
- *****************************************************************************
- * This functions is provided for any interface function which need to print a
- * date. psz_buffer should be a buffer long enough to store the formatted
+#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
+
+#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>
+#endif
+#if defined(HAVE_SYS_TIME_H)
+# include <sys/time.h>
+#endif
+
+#if !defined(HAVE_STRUCT_TIMESPEC)
+struct timespec
+{
+ time_t tv_sec;
+ int32_t tv_nsec;
+};
+#endif
+
+#if defined(HAVE_NANOSLEEP) && !defined(HAVE_DECL_NANOSLEEP)
+int nanosleep(struct timespec *, struct timespec *);
+#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 )
{
- sprintf( psz_buffer, "%02d:%02d:%02d-%03d.%03d",
- (int) (date / (1000LL * 1000LL * 60LL * 60LL) % 24LL),
- (int) (date / (1000LL * 1000LL * 60LL) % 60LL),
- (int) (date / (1000LL * 1000LL) % 60LL),
- (int) (date / 1000LL % 1000LL),
- (int) (date % 1000LL) );
+ static 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 );
}
-/*****************************************************************************
- * mdate: return high precision date (inline function)
- *****************************************************************************
+/**
+ * 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 )
+{
+ 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 );
+}
+
+/**
+ * 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
+ *
* Uses the gettimeofday() function when possible (1 MHz resolution) or the
* ftime() function (1 kHz resolution).
- *****************************************************************************/
+ */
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 = I64C(-1);
+
+ 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.
+ */
+ LARGE_INTEGER buf;
+
+ freq = ( QueryPerformanceFrequency( &buf ) &&
+ (buf.QuadPart == I64C(1193182) || buf.QuadPart == I64C(3579545) ) )
+ ? buf.QuadPart : 0;
+ }
+
+ 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 GetTickCount() which has a milisecond resolution
+ * (actually, best case is about 10 ms resolution)
+ * GetTickCount() 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 = I64C(-1);
+ static int i_wrap_counts = -1;
+
+ if( i_wrap_counts == -1 )
+ {
+ /* Initialization */
+ i_previous_time = I64C(1000) * GetTickCount();
+ InitializeCriticalSection( &date_lock );
+ i_wrap_counts = 0;
+ }
+
+ EnterCriticalSection( &date_lock );
+ res = I64C(1000) *
+ (i_wrap_counts * I64C(0x100000000) + GetTickCount());
+ if( i_previous_time > res )
+ {
+ /* Counter wrapped */
+ i_wrap_counts++;
+ res += I64C(0x100000000) * 1000;
+ }
+ i_previous_time = res;
+ LeaveCriticalSection( &date_lock );
+ }
+#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 cached_time = res;
}
-/*****************************************************************************
- * mwait: wait for a date (inline function)
- *****************************************************************************
+/**
+ * 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 )
{
- struct timeval tv_date, tv_delay;
- mtime_t delay; /* delay in msec, signed to detect errors */
+ if( prec == 0 )
+ prec = mprec();
+
+ /* 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;
- /* see mdate() about gettimeofday() possible errors */
- gettimeofday( &tv_date, NULL );
+#if 0 && defined (HAVE_CLOCK_NANOSLEEP)
+ lldiv_t d = lldiv( date, 1000000 );
+ struct timespec ts = { d.quot, d.rem * 1000 };
- /* 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;
- if( delay <= 0 ) /* wished date is now or already passed */
+ 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 );
}
-#ifndef usleep
- tv_delay.tv_sec = delay / 1000000;
- tv_delay.tv_usec = delay % 1000000;
-
- /* see msleep() about select() errors */
- select( 0, NULL, NULL, NULL, &tv_delay );
#else
- usleep( delay );
+
+ mtime_t delay = date - mdate();
+ if( delay > 0 )
+ msleep( delay );
+
#endif
}
-/*****************************************************************************
- * msleep: more precise sleep() (inline function) (ok ?)
- *****************************************************************************
+/**
+ * More precise sleep()
+ *
* Portable usleep() function.
- *****************************************************************************/
+ * \param delay the amount of time to sleep
+ */
void msleep( mtime_t delay )
{
-#ifndef usleep
+ 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 )
+ pth_usleep( delay );
+
+#elif defined( ST_INIT_IN_ST_H )
+ st_usleep( delay );
+
+#elif defined( WIN32 ) || defined( UNDER_CE )
+ Sleep( (int) (delay / 1000) );
+
+#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;
- /* 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 ingnored. */
+
+ /* 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;
+}
+
+/*
+ * 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 )
+{
+ 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->date += i_dividend / p_date->i_divider_num * p_date->i_divider_den;
+ 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. */
+ p_date->date += p_date->i_divider_den;
+ 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
- usleep( delay );
+# 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