120 lines
2.9 KiB
C++
120 lines
2.9 KiB
C++
// fg_timer.cxx -- time handling routines
|
|
//
|
|
// Written by Curtis Olson, started June 1997.
|
|
//
|
|
// Copyright (C) 1997 Curtis L. Olson - http://www.flightgear.org/~curt
|
|
//
|
|
// 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., 675 Mass Ave, Cambridge, MA 02139, USA.
|
|
//
|
|
// $Id$
|
|
|
|
|
|
#ifdef HAVE_CONFIG_H
|
|
# include <config.h>
|
|
#endif
|
|
|
|
#include <signal.h> // for timer routines
|
|
#include <stdio.h> // for printf()
|
|
|
|
#ifdef HAVE_STDLIB_H
|
|
# include <stdlib.h>
|
|
#endif
|
|
|
|
#ifdef HAVE_SYS_TIME_H
|
|
# include <sys/time.h> // for get/setitimer, gettimeofday, struct timeval
|
|
#endif
|
|
|
|
#include <simgear/timing/timestamp.hxx>
|
|
|
|
#include "fg_timer.hxx"
|
|
|
|
|
|
unsigned long int fgSimTime;
|
|
|
|
#ifdef HAVE_SETITIMER
|
|
static struct itimerval t, ot;
|
|
static void (*callbackfunc)(int multi_loop);
|
|
|
|
|
|
// This routine catches the SIGALRM
|
|
void fgTimerCatch( int dummy ) {
|
|
int warning_avoider;
|
|
|
|
// get past a compiler warning
|
|
warning_avoider = dummy;
|
|
|
|
// ignore any SIGALRM's until we come back from our EOM iteration
|
|
signal(SIGALRM, SIG_IGN);
|
|
|
|
// printf("In fgTimerCatch()\n");
|
|
|
|
// -1 tells the routine to use default interval rather than
|
|
// something dynamically calculated based on frame rate
|
|
callbackfunc(-1);
|
|
|
|
signal(SIGALRM, fgTimerCatch);
|
|
}
|
|
|
|
|
|
// this routine initializes the interval timer to generate a SIGALRM
|
|
// after the specified interval (dt)
|
|
void fgTimerInit(float dt, void (*f)( int )) {
|
|
int terr;
|
|
int isec;
|
|
int usec;
|
|
|
|
callbackfunc = f;
|
|
|
|
isec = (int) dt;
|
|
usec = 1000000 * ((int)dt - isec);
|
|
|
|
t.it_interval.tv_sec = isec;
|
|
t.it_interval.tv_usec = usec;
|
|
t.it_value.tv_sec = isec;
|
|
t.it_value.tv_usec = usec;
|
|
// printf("fgTimerInit() called\n");
|
|
fgTimerCatch(0); // set up for SIGALRM signal catch
|
|
terr = setitimer( ITIMER_REAL, &t, &ot );
|
|
if (terr) {
|
|
printf("Error returned from setitimer");
|
|
exit(0);
|
|
}
|
|
}
|
|
#endif // HAVE_SETITIMER
|
|
|
|
|
|
// This function returns the number of microseconds since the last
|
|
// time it was called.
|
|
int fgGetTimeInterval( void ) {
|
|
int interval;
|
|
static int inited = 0;
|
|
static SGTimeStamp last;
|
|
SGTimeStamp current;
|
|
|
|
|
|
if ( ! inited ) {
|
|
inited = 1;
|
|
last.stamp();
|
|
interval = 0;
|
|
} else {
|
|
current.stamp();
|
|
interval = current - last;
|
|
last = current;
|
|
}
|
|
|
|
return interval;
|
|
}
|
|
|
|
|