/***************************************************************************** * mtime.c: high rezolution time management functions * Functions are prototyped in mtime.h. ***************************************************************************** * Copyright (C) 1998-2001 VideoLAN * $Id: mtime.c,v 1.32 2002/06/01 12:32:01 sam Exp $ * * Authors: Vincent Seguin <seguin@via.ecp.fr> * * 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., 59 Temple Place - Suite 330, Boston, MA 02111, 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> #endif #ifdef HAVE_UNISTD_H # include <unistd.h> /* select() */ #endif #ifdef HAVE_KERNEL_OS_H # include <kernel/OS.h> #endif #if defined( WIN32 ) # include <windows.h> #else # include <sys/time.h> #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 *); #endif /***************************************************************************** * 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 * date. *****************************************************************************/ char *mstrtime( char *psz_buffer, mtime_t date ) { sprintf( psz_buffer, "%02d:%02d:%02d-%03d.%03d", (int) (date / (I64C(1000) * I64C(1000) * I64C(60) * I64C(60)) % I64C(24)), (int) (date / (I64C(1000) * I64C(1000) * I64C(60)) % I64C(60)), (int) (date / (I64C(1000) * I64C(1000)) % I64C(60)), (int) (date / I64C(1000) % I64C(1000)), (int) (date % I64C(1000)) ); return( psz_buffer ); } /***************************************************************************** * mdate: return high precision date (inline function) ***************************************************************************** * Uses the gettimeofday() function when possible (1 MHz resolution) or the * ftime() function (1 kHz resolution). *****************************************************************************/ mtime_t mdate( void ) { #if defined( HAVE_KERNEL_OS_H ) return( real_time_clock_usecs() ); #elif defined( WIN32 ) /* We don't get the real date, just the value of a high precision timer. * this is because the usual time functions have at best only a milisecond * resolution */ mtime_t freq, usec_time; if( QueryPerformanceFrequency( (LARGE_INTEGER *)&freq ) ) { /* Microsecond resolution */ QueryPerformanceCounter( (LARGE_INTEGER *)&usec_time ); return ( usec_time * 1000000 ) / freq; } /* Milisecond resolution */ return 1000 * GetTickCount(); #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 ); #endif } /***************************************************************************** * mwait: wait for a date (inline function) ***************************************************************************** * 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. *****************************************************************************/ 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 ) mtime_t usec_time, delay; usec_time = mdate(); delay = date - usec_time; if( delay <= 0 ) { return; } msleep( delay ); #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 #endif } /***************************************************************************** * msleep: more precise sleep() (inline function) (ok ?) ***************************************************************************** * Portable usleep() function. *****************************************************************************/ void msleep( mtime_t delay ) { #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 ) 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 ); #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. */ select( 0, NULL, NULL, NULL, &tv_delay ); #endif }