Millisecond-based alarm

[hyc@hanauma.jpl.nasa.gov (Howard Chu)]

I found Talarm to be pretty reliable, but I needed finer resolution, so I've
added a Tmalarm that doesn't convert to seconds, etc. Talarm just calls
Tmalarm now. It seems like a useful addition, what do you folks think?
*** 1.1	1994/01/30 14:11:23
--- dos.c	1994/01/30 14:29:10
***************
*** 360,363 ****
--- 360,378 ----
  {
  	long oldalarm;
+ 	oldalarm = t_malarm(x*1000);
+ 	oldalarm = (oldalarm+999) / 1000;	/* convert to seconds */
+ 	return oldalarm;
+ }
+ 
+ /*
+  * t_malarm(x): set the alarm clock to go off in "x" milliseconds. returns
+  * the old value ofthe alarm clock
+  */
+ 
+ long ARGS_ON_STACK
+ t_malarm(x)
+ 	long x;
+ {
+ 	long oldalarm;
  	TIMEOUT *t;
  
***************
*** 378,383 ****
  	}
  
- 	oldalarm = (oldalarm+999) / 1000;	/* convert to seconds */
- 
  /* we were just querying the alarm */
  	if (x < 0)
--- 393,396 ----
***************
*** 388,394 ****
  		canceltimeout(curproc->alarmtim);
  
! /* add a new alarm, to occur in 1000*x milliseconds */
  	if (x)
! 		curproc->alarmtim = addtimeout(1000*x, alarmme);
  	else
  		curproc->alarmtim = 0;
--- 401,407 ----
  		canceltimeout(curproc->alarmtim);
  
! /* add a new alarm, to occur in x milliseconds */
  	if (x)
! 		curproc->alarmtim = addtimeout(x, alarmme);
  	else
  		curproc->alarmtim = 0;
***************
*** 589,591 ****
--- 602,605 ----
  	dos_tab[0x13b] = d_getcwd;
  	dos_tab[0x13c] = s_alert;
+ 	dos_tab[0x13d] = t_malarm;
  }
*** 1.3	1994/01/30 13:04:54
--- proto.h	1994/01/30 14:22:44
***************
*** 86,89 ****
--- 86,90 ----
  long ARGS_ON_STACK p_pause P_((void));
  long ARGS_ON_STACK t_alarm P_((long x));
+ long ARGS_ON_STACK t_malarm P_((long x));
  long ARGS_ON_STACK s_ysconf P_((int which));
  long ARGS_ON_STACK s_alert P_((char *msg));