freebsd-dev/games/larn/nap.c

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/* nap.c Larn is copyrighted 1986 by Noah Morgan. */
#include <signal.h>
#include <sys/types.h>
#ifdef SYSV
#include <sys/times.h>
#else
#ifdef BSD
#include <sys/timeb.h>
#endif BSD
#endif SYSV
/*
* routine to take a nap for n milliseconds
*/
nap(x)
register int x;
{
if (x<=0) return; /* eliminate chance for infinite loop */
lflush();
if (x > 999) sleep(x/1000); else napms(x);
}
#ifdef NONAP
napms(x) /* do nothing */
int x;
{
}
#else NONAP
#ifdef SYSV
/* napms - sleep for time milliseconds - uses times() */
/* this assumes that times returns a relative time in 60ths of a second */
/* this will do horrible things if your times() returns seconds! */
napms(time)
int time;
{
long matchclock, times();
struct tms stats;
if (time<=0) time=1; /* eliminate chance for infinite loop */
if ((matchclock = times(&stats)) == -1 || matchclock == 0)
return; /* error, or BSD style times() */
matchclock += (time / 17); /*17 ms/tic is 1000 ms/sec / 60 tics/sec */
while(matchclock < times(&stats))
;
}
#else not SYSV
#ifdef BSD
#ifdef SIGVTALRM
/* This must be BSD 4.2! */
#include <sys/time.h>
#define bit(_a) (1<<((_a)-1))
static nullf()
{
}
/* napms - sleep for time milliseconds - uses setitimer() */
napms(time)
int time;
{
struct itimerval timeout;
int (*oldhandler) ();
int oldsig;
if (time <= 0) return;
timerclear(&timeout.it_interval);
timeout.it_value.tv_sec = time / 1000;
timeout.it_value.tv_usec = (time % 1000) * 1000;
oldsig = sigblock(bit(SIGALRM));
setitimer(ITIMER_REAL, &timeout, (struct itimerval *)0);
oldhandler = signal(SIGALRM, nullf);
sigpause(oldsig);
signal(SIGALRM, oldhandler);
sigsetmask(oldsig);
}
#else
/* napms - sleep for time milliseconds - uses ftime() */
static napms(time)
int time;
{
/* assumed to be BSD UNIX */
struct timeb _gtime;
time_t matchtime;
unsigned short matchmilli;
register struct timeb *tp = & _gtime;
if (time <= 0) return;
ftime(tp);
matchmilli = tp->millitm + time;
matchtime = tp->time;
while (matchmilli >= 1000)
{
++matchtime;
matchmilli -= 1000;
}
while(1)
{
ftime(tp);
if ((tp->time > matchtime) ||
((tp->time == matchtime) && (tp->millitm >= matchmilli)))
break;
}
}
#endif
#else not BSD
static napms(time) int time; {} /* do nothing, forget it */
#endif BSD
#endif SYSV
#endif NONAP