implement Timerm; include "common.m"; sys : Sys;acme : Acme;utils : Utils;dat : Dat; millisec : import sys;Timer : import dat; init(mods : ref Dat->Mods){	sys = mods.sys;	acme = mods.acme;	utils = mods.utils;	dat = mods.dat;} ctimer : chan of ref Timer; timeproc(){	i, nt, na, dt : int;	x : ref Timer;	t : array of ref Timer;	old, new : int; 	acme->timerpid = sys->pctl(0, nil);	sys->pctl(Sys->FORKFD, nil);	t = array[10] of ref Timer;	na = 10;	nt = 0;	old = millisec();	for(;;){		if (nt == 0) {	# don't waste cpu time			x = <-ctimer;			t[nt++] = x;			old = millisec();		}		sys->sleep(1);	# will sleep minimum incr 		new = millisec();		dt = new-old;		old = new;		if(dt < 0)	# timer wrapped; go around, losing a tick 			continue;		for(i=0; i<nt; i++){			x = t[i];			x.dt -= dt;			if(x.dt <= 0){				#				# avoid possible deadlock if client is				# now sending on ctimer				#				 				alt {					x.c <-= 0 =>						t[i:] = t[i+1:nt];						t[nt-1] = nil;						nt--;						i--;					* =>						;				}			}		}		gotone := 1;		while (gotone) {			alt {				x = <-ctimer =>					if (nt == na) {						ot := t;						t = array[na+10] of ref Timer;						t[0:] = ot[0:na];						ot = nil;						na += 10;					}					t[nt++] = x;					old = millisec();				* =>					gotone = 0;			}		}	}} timerinit(){	ctimer = chan of ref Timer;	spawn timeproc();} ## timeralloc() and timerfree() don't lock, so can only be# called from the main proc.#  timer : ref Timer; timerstart(dt : int) : ref Timer{	t : ref Timer; 	t = timer;	if(t != nil)		timer = timer.next;	else{		t = ref Timer;		t.c = chan of int;	}	t.next = nil;	t.dt = dt;	ctimer <-= t;	return t;} timerstop(t : ref Timer){	t.next = timer;	timer = t;} timerwaittask(timer : ref Timer){	<-(timer.c);	timerstop(timer);}