1990/03091/gnot/clock.c (diff list | history)

gnot/clock.c on 1990/03091
1990/03091		#include "u.h" #include "lib.h" #include "mem.h" #include "dat.h" #include "fns.h" #include "io.h" #include "ureg.h" Alarm *alarmtab; Alarm* alarm(int ms, void (*f)(Alarm*), void *arg) { Alarm *a, *w, *pw; ulong s; if(ms < 0) ms = 0; a = newalarm(); a->dt = ms/MS2HZ; a->f = f; a->arg = arg; s = splhi(); lock(&m->alarmlock); pw = 0; for(w=m->alarm; w; pw=w, w=w->next){ if(w->dt <= a->dt){ a->dt -= w->dt; continue; } w->dt -= a->dt; break; } insert(&m->alarm, pw, a); unlock(&m->alarmlock); splx(s); return a; } void cancel(Alarm *a) { a->f = 0; } Alarm* newalarm(void) { int i; Alarm *a; for(i=0,a=alarmtab; i<conf.nalarm; i++,a++) if(a->busy==0 && a->f==0 && canlock(a)){ if(a->busy){ unlock(a); continue; } a->f = 0; a->arg = 0; a->busy = 1; unlock(a); return a; } panic("newalarm"); } void alarminit(void) { int i; alarmtab = ialloc(conf.nalarm*sizeof(Alarm), 0); for(i=0; i<conf.nalarm; i++){ lock(&alarmtab[i]); /* allocate locks, as they are used at interrupt time */ unlock(&alarmtab[i]); } } void delay(int ms) { ulong t, *p; int i; ms *= 1000; /* experimentally determined */ for(i=0; i<ms; i++) ; } void clock(Ureg *ur) { int i; Alarm *a; void (*f)(void*); Proc *p; SYNCREG[1] = 0x5F; /* clear interrupt */ m->ticks++; p = m->proc; if(p) p->time[p->insyscall]++; if(canlock(&m->alarmlock)){ if(m->alarm){ a = m->alarm; a->dt--; while(a && a->dt<=0){ f = a->f; /* avoid race with cancel */ if(f) (*f)(a); delete(&m->alarm, 0, a); a->busy = 0; a = m->alarm; } } unlock(&m->alarmlock); } if((ur->sr&SPL(7)) == 0){ spllo(); if(p && p->state==Running) sched(); } }