105 lines
3.3 KiB
C
105 lines
3.3 KiB
C
/*
|
|
===========================================================================
|
|
|
|
Doom 3 GPL Source Code
|
|
Copyright (C) 1999-2011 id Software LLC, a ZeniMax Media company.
|
|
|
|
This file is part of the Doom 3 GPL Source Code (?Doom 3 Source Code?).
|
|
|
|
Doom 3 Source Code 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 3 of the License, or
|
|
(at your option) any later version.
|
|
|
|
Doom 3 Source Code 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 Doom 3 Source Code. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
In addition, the Doom 3 Source Code is also subject to certain additional terms. You should have received a copy of these additional terms immediately following the terms and conditions of the GNU General Public License which accompanied the Doom 3 Source Code. If not, please request a copy in writing from id Software at the address below.
|
|
|
|
If you have questions concerning this license or the applicable additional terms, you may contact in writing id Software LLC, c/o ZeniMax Media Inc., Suite 120, Rockville, Maryland 20850 USA.
|
|
|
|
===========================================================================
|
|
*/
|
|
|
|
#include <stdio.h>
|
|
#include <sys/time.h>
|
|
#include <sched.h>
|
|
#include <errno.h>
|
|
|
|
/*
|
|
================
|
|
Sys_Milliseconds
|
|
================
|
|
*/
|
|
/* base time in seconds, that's our origin
|
|
timeval:tv_sec is an int:
|
|
assuming this wraps every 0x7fffffff - ~68 years since the Epoch (1970) - we're safe till 2038
|
|
using unsigned long data type to work right with Sys_XTimeToSysTime */
|
|
unsigned long sys_timeBase = 0;
|
|
/* current time in ms, using sys_timeBase as origin
|
|
NOTE: sys_timeBase*1000 + curtime -> ms since the Epoch
|
|
0x7fffffff ms - ~24 days
|
|
or is it 48 days? the specs say int, but maybe it's casted from unsigned int?
|
|
*/
|
|
int Sys_Milliseconds(void)
|
|
{
|
|
int curtime;
|
|
struct timeval tp;
|
|
|
|
gettimeofday(&tp, NULL);
|
|
|
|
if (!sys_timeBase) {
|
|
sys_timeBase = tp.tv_sec;
|
|
return tp.tv_usec / 1000;
|
|
}
|
|
|
|
curtime = (tp.tv_sec - sys_timeBase) * 1000 + tp.tv_usec / 1000;
|
|
|
|
return curtime;
|
|
}
|
|
|
|
#define STAT_BUF 100
|
|
|
|
int main(int argc, void *argv[]) {
|
|
int start = 30; // start waiting with 30 ms
|
|
int dec = 2; // decrement by 2 ms
|
|
int min = 4; // min wait test
|
|
int i, j, now, next;
|
|
int stats[STAT_BUF];
|
|
|
|
struct sched_param parm;
|
|
|
|
Sys_Milliseconds(); // init
|
|
|
|
// set schedule policy to see if that affects usleep
|
|
// (root rights required for that)
|
|
parm.sched_priority = 99;
|
|
if ( sched_setscheduler(0, SCHED_RR, &parm) != 0 ) {
|
|
printf("sched_setscheduler SCHED_RR failed: %s\n", strerror(errno) );
|
|
} else {
|
|
printf("sched_setscheduler SCHED_RR ok\n");
|
|
}
|
|
|
|
// now run the test
|
|
for( i = start ; i >= min ; i -= dec ) {
|
|
printf( "sleep %d ms", i );
|
|
for( j = 0 ; j < STAT_BUF ; j++ ) {
|
|
now = Sys_Milliseconds();
|
|
usleep(i*1000);
|
|
stats[j] = Sys_Milliseconds() - now;
|
|
}
|
|
for( j = 0; j < STAT_BUF; j++) {
|
|
if ( ! (j & 0xf) ) {
|
|
printf("\n");
|
|
}
|
|
printf( "%d ", stats[j] );
|
|
}
|
|
printf("\n");
|
|
}
|
|
return 0;
|
|
}
|