1 /*****************************************************************************
2 * mtime.c: high rezolution time management functions
3 * Functions are prototyped in mtime.h.
4 *****************************************************************************
5 * Copyright (C) 1998, 1999, 2000 VideoLAN
6 * $Id: mtime.c,v 1.24 2001/06/28 22:12:04 gbazin Exp $
8 * Authors: Vincent Seguin <seguin@via.ecp.fr>
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
23 *****************************************************************************/
27 * see if using Linux real-time extensions is possible and profitable
30 /*****************************************************************************
32 *****************************************************************************/
35 #include <stdio.h> /* sprintf() */
37 #if defined( PTH_INIT_IN_PTH_H ) /* GNU Pth */
42 # include <unistd.h> /* select() */
45 #ifdef HAVE_KERNEL_OS_H
46 # include <kernel/OS.h>
52 # include <sys/time.h>
59 /*****************************************************************************
60 * mstrtime: return a date in a readable format
61 *****************************************************************************
62 * This functions is provided for any interface function which need to print a
63 * date. psz_buffer should be a buffer long enough to store the formatted
65 *****************************************************************************/
66 char *mstrtime( char *psz_buffer, mtime_t date )
68 sprintf( psz_buffer, "%02d:%02d:%02d-%03d.%03d",
69 (int) (date / (I64C(1000) * I64C(1000) * I64C(60) * I64C(60)) % I64C(24)),
70 (int) (date / (I64C(1000) * I64C(1000) * I64C(60)) % I64C(60)),
71 (int) (date / (I64C(1000) * I64C(1000)) % I64C(60)),
72 (int) (date / I64C(1000) % I64C(1000)),
73 (int) (date % I64C(1000)) );
77 /*****************************************************************************
78 * mdate: return high precision date (inline function)
79 *****************************************************************************
80 * Uses the gettimeofday() function when possible (1 MHz resolution) or the
81 * ftime() function (1 kHz resolution).
82 *****************************************************************************/
85 #if defined( HAVE_KERNEL_OS_H )
86 return( real_time_clock_usecs() );
88 #elif defined( WIN32 )
89 /* We don't get the real date, just the value of a high precision timer.
90 * this is because the usual time functions have at best only a milisecond
92 mtime_t freq, usec_time;
94 if( QueryPerformanceFrequency( (LARGE_INTEGER *)&freq ) )
96 /* Microsecond resolution */
97 QueryPerformanceCounter( (LARGE_INTEGER *)&usec_time );
98 return ( usec_time * 1000000 ) / freq;
102 /* Milisecond resolution */
103 return 1000 * GetTickCount();
107 struct timeval tv_date;
109 /* gettimeofday() could return an error, and should be tested. However, the
110 * only possible error, according to 'man', is EFAULT, which can not happen
111 * here, since tv is a local variable. */
112 gettimeofday( &tv_date, NULL );
113 return( (mtime_t) tv_date.tv_sec * 1000000 + (mtime_t) tv_date.tv_usec );
118 /*****************************************************************************
119 * mwait: wait for a date (inline function)
120 *****************************************************************************
121 * This function uses select() and an system date function to wake up at a
122 * precise date. It should be used for process synchronization. If current date
123 * is posterior to wished date, the function returns immediately.
124 *****************************************************************************/
125 void mwait( mtime_t date )
127 #if defined( HAVE_KERNEL_OS_H )
130 delay = date - real_time_clock_usecs();
137 #elif defined( WIN32 )
138 mtime_t usec_time, delay;
141 delay = date - usec_time;
151 struct timeval tv_date;
153 struct timeval tv_date, tv_delay;
155 mtime_t delay; /* delay in msec, signed to detect errors */
157 /* see mdate() about gettimeofday() possible errors */
158 gettimeofday( &tv_date, NULL );
160 /* calculate delay and check if current date is before wished date */
161 delay = date - (mtime_t) tv_date.tv_sec * 1000000
162 - (mtime_t) tv_date.tv_usec
165 /* Linux/i386 has a granularity of 10 ms. It's better to be in advance
166 * than to be late. */
167 if( delay <= 0 ) /* wished date is now or already passed */
172 # if defined( PTH_INIT_IN_PTH_H )
175 # elif defined( HAVE_USLEEP )
179 tv_delay.tv_sec = delay / 1000000;
180 tv_delay.tv_usec = delay % 1000000;
181 /* see msleep() about select() errors */
182 select( 0, NULL, NULL, NULL, &tv_delay );
189 /*****************************************************************************
190 * msleep: more precise sleep() (inline function) (ok ?)
191 *****************************************************************************
192 * Portable usleep() function.
193 *****************************************************************************/
194 void msleep( mtime_t delay )
196 #if defined( HAVE_KERNEL_OS_H )
199 #elif defined( PTH_INIT_IN_PTH_H )
200 struct timeval tv_delay;
201 tv_delay.tv_sec = delay / 1000000;
202 tv_delay.tv_usec = delay % 1000000;
203 pth_select( 0, NULL, NULL, NULL, &tv_delay );
205 #elif defined( HAVE_USLEEP )
208 #elif defined( WIN32 )
209 Sleep( (int) (delay / 1000) );
212 struct timeval tv_delay;
214 tv_delay.tv_sec = delay / 1000000;
215 tv_delay.tv_usec = delay % 1000000;
216 /* select() return value should be tested, since several possible errors
217 * can occur. However, they should only happen in very particular occasions
218 * (i.e. when a signal is sent to the thread, or when memory is full), and
219 * can be ingnored. */
220 select( 0, NULL, NULL, NULL, &tv_delay );