X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fmisc%2Fmtime.c;h=dd95a61a665aec6e71ee8129cc973d8d0a58558b;hb=ccc3af5d2f49174bd214cd579d6af827b5685b3e;hp=324feea0705357fca0840a1b4d3ce7779881ac95;hpb=a04423daf678b33f451c5d24d7129d95957e4318;p=vlc diff --git a/src/misc/mtime.c b/src/misc/mtime.c index 324feea070..dd95a61a66 100644 --- a/src/misc/mtime.c +++ b/src/misc/mtime.c @@ -1,67 +1,51 @@ /***************************************************************************** * 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 VLC authors and VideoLAN + * Copyright © 2006-2007 Rémi Denis-Courmont + * $Id$ * * Authors: Vincent Seguin + * Rémi Denis-Courmont + * 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 + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU Lesser General Public License as published by + * the Free Software Foundation; either version 2.1 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. + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU Lesser 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., 59 Temple Place - Suite 330, Boston, MA 02111, USA. + * You should have received a copy of the GNU Lesser 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. *****************************************************************************/ -/* - * TODO: - * see if using Linux real-time extensions is possible and profitable - */ - /***************************************************************************** * Preamble *****************************************************************************/ -#include /* sprintf() */ - -#include -#if defined( PTH_INIT_IN_PTH_H ) /* GNU Pth */ -# include +#ifdef HAVE_CONFIG_H +# include "config.h" #endif +#include +#include + #ifdef HAVE_UNISTD_H -# include /* select() */ +# include #endif - -#ifdef HAVE_KERNEL_OS_H -# include +#if !defined (_POSIX_TIMERS) +# define _POSIX_TIMERS (-1) #endif - -#if defined( WIN32 ) || defined( UNDER_CE ) -# include +#if (_POSIX_TIMERS > 0) +# include /* clock_gettime() */ #else -# include -#endif - -#if defined(HAVE_NANOSLEEP) && !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 *); +# include #endif /** @@ -69,14 +53,14 @@ int nanosleep(struct timespec *, struct timespec *); * * 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), @@ -97,199 +81,186 @@ char *mstrtime( char *psz_buffer, mtime_t date ) * \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 high precision date - * - * Uses the gettimeofday() function when possible (1 MHz resolution) or the - * ftime() function (1 kHz resolution). - */ -mtime_t mdate( void ) +char *secstotimestr( char *psz_buffer, int32_t i_seconds ) { -#if defined( HAVE_KERNEL_OS_H ) - return( 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) ) + if( unlikely(i_seconds < 0) ) { - /* 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; + secstotimestr( psz_buffer + 1, -i_seconds ); + *psz_buffer = '-'; + return psz_buffer; } - if( freq != 0 ) - { - /* Microsecond resolution */ - QueryPerformanceCounter( (LARGE_INTEGER *)&usec_time ); - return ( usec_time * 1000000 ) / freq; - } + div_t d; - /* Milisecond resolution (actually, best case is about 10 ms resolution) */ - return 1000 * GetTickCount(); + d = div( i_seconds, 60 ); + i_seconds = d.rem; + d = div( d.quot, 60 ); -#else - struct timeval tv_date; + 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; +} - /* 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 ); +/* + * Date management (internal and external) + */ -#endif +/** + * 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; } /** - * Wait for a date + * Change a date_t. * - * 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 + * \param date to change + * \param divider (sample rate) numerator + * \param divider (sample rate) denominator */ -void mwait( mtime_t date ) -{ -#if defined( HAVE_KERNEL_OS_H ) - mtime_t delay; - - delay = date - real_time_clock_usecs(); - if( delay <= 0 ) - { - return; - } - snooze( delay ); -#elif defined( WIN32 ) || defined( UNDER_CE ) - mtime_t usec_time, 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; +} - usec_time = mdate(); - delay = date - usec_time; - if( delay <= 0 ) - { - return; - } - msleep( delay ); +/** + * 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; +} -#else +/** + * 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; +} - struct timeval tv_date; - mtime_t delay; /* delay in msec, signed to detect errors */ +/** + * 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; +} - /* see mdate() about gettimeofday() possible errors */ - gettimeofday( &tv_date, NULL ); +/** + * 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 = i_nb_samples * CLOCK_FREQ * p_date->i_divider_den; + lldiv_t d = lldiv( i_dividend, p_date->i_divider_num ); - /* 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; + p_date->date += d.quot; + p_date->i_remainder += (int)d.rem; - /* 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 */ + if( p_date->i_remainder >= p_date->i_divider_num ) { - return; + /* 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; } -# if defined( PTH_INIT_IN_PTH_H ) - pth_usleep( delay ); - -# elif defined( ST_INIT_IN_ST_H ) - st_usleep( delay ); + return p_date->date; +} -# else +/** + * 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 defined( HAVE_NANOSLEEP ) + if( p_date->i_remainder < i_rem_adjust ) { - struct timespec ts_delay; - ts_delay.tv_sec = delay / 1000000; - ts_delay.tv_nsec = (delay % 1000000) * 1000; - - nanosleep( &ts_delay, NULL ); + /* 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; } -# 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 + p_date->i_remainder -= i_rem_adjust; -#endif + return p_date->date; } /** - * More precise sleep() - * - * Portable usleep() function. - * \param delay the amount of time to sleep + * @return NTP 64-bits timestamp in host byte order. */ -void msleep( mtime_t delay ) +uint64_t NTPtime64 (void) { -#if 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; - - nanosleep( &ts_delay, NULL ); +#if (_POSIX_TIMERS > 0) + struct timespec ts; + clock_gettime (CLOCK_REALTIME, &ts); #else - struct timeval tv_delay; + struct timeval tv; + struct + { + uint32_t tv_sec; + uint32_t tv_nsec; + } ts; - tv_delay.tv_sec = delay / 1000000; - tv_delay.tv_usec = delay % 1000000; + gettimeofday (&tv, NULL); + ts.tv_sec = tv.tv_sec; + ts.tv_nsec = tv.tv_usec * 1000; +#endif - /* 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 ); + /* Convert nanoseconds to 32-bits fraction (232 picosecond units) */ + uint64_t t = (uint64_t)(ts.tv_nsec) << 32; + t /= 1000000000; -#endif + + /* 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; }