ref: b502a62da2ec6058923db94f87ecc2d29db2fa77
dir: /os/boot.original/puma/alarm.c/
#include "u.h" #include "lib.h" #include "mem.h" #include "dat.h" #include "fns.h" #include "io.h" #define MAXALARM 10 Alarm alarmtab[MAXALARM]; /* * Insert new into list after where */ void insert(List **head, List *where, List *new) { if(where == 0){ new->next = *head; *head = new; }else{ new->next = where->next; where->next = new; } } /* * Delete old from list. where->next is known to be old. */ void delete(List **head, List *where, List *old) { if(where == 0){ *head = old->next; return; } where->next = old->next; } Alarm* newalarm(void) { int i; Alarm *a; for(i=0,a=alarmtab; i < nelem(alarmtab); i++,a++) if(a->busy==0 && a->f==0){ a->f = 0; a->arg = 0; a->busy = 1; return a; } panic("newalarm"); return 0; /* not reached */ } Alarm* alarm(int ms, void (*f)(Alarm*), void *arg) { Alarm *a, *w, *pw; ulong s; if(ms < 0) ms = 0; s = splhi(); a = newalarm(); a->dt = MS2TK(ms); a->f = f; a->arg = arg; 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); splx(s); return a; } void cancel(Alarm *a) { a->f = 0; } void alarminit(void) { } #define NA 10 /* alarms per clock tick */ void checkalarms(void) { int i, n, s; Alarm *a; void (*f)(void*); Alarm *alist[NA]; s = splhi(); a = m->alarm; if(a){ for(n=0; a && a->dt<=0 && n<NA; n++){ alist[n] = a; delete(&m->alarm, 0, a); a = m->alarm; } if(a) a->dt--; for(i = 0; i < n; i++){ f = alist[i]->f; /* avoid race with cancel */ if(f) (*f)(alist[i]); alist[i]->busy = 0; } } splx(s); }