sys/src/cmd/rio/time.c

   1 #include <u.h>
   2 #include <libc.h>
   3 #include <draw.h>
   4 #include <thread.h>
   5 #include <cursor.h>
   6 #include <mouse.h>
   7 #include <keyboard.h>
   8 #include <frame.h>
   9 #include <fcall.h>
  10 #include "dat.h"
  11 #include "fns.h"
  12
  13 static Channel* ctimer; /* chan(Timer*)[100] */
  14 static Timer *timer;
  15
  16 static
  17 uint
  18 msec(void)
  19 {
  20         return nsec()/1000000;
  21 }
  22
  23 void
  24 timerstop(Timer *t)
  25 {
  26         t->next = timer;
  27         timer = t;
  28 }
  29
  30 void
  31 timercancel(Timer *t)
  32 {
  33         t->cancel = TRUE;
  34 }
  35
  36 static
  37 void
  38 timerproc(void*)
  39 {
  40         int i, nt, na, dt, del;
  41         Timer **t, *x;
  42         uint old, new;
  43
  44         rfork(RFFDG);
  45         threadsetname("TIMERPROC");
  46         t = nil;
  47         na = 0;
  48         nt = 0;
  49         old = msec();
  50         for(;;){
  51                 sleep(1);       /* will sleep minimum incr */
  52                 new = msec();
  53                 dt = new-old;
  54                 old = new;
  55                 if(dt < 0)      /* timer wrapped; go around, losing a tick */
  56                         continue;
  57                 for(i=0; i<nt; i++){
  58                         x = t[i];
  59                         x->dt -= dt;
  60                         del = 0;
  61                         if(x->cancel){
  62                                 timerstop(x);
  63                                 del = 1;
  64                         }else if(x->dt <= 0){
  65                                 /*
  66                                  * avoid possible deadlock if client is
  67                                  * now sending on ctimer
  68                                  */
  69                                 if(nbsendul(x->c, 0) > 0)
  70                                         del = 1;
  71                         }
  72                         if(del){
  73                                 memmove(&t[i], &t[i+1], (nt-i-1)*sizeof t[0]);
  74                                 --nt;
  75                                 --i;
  76                         }
  77                 }
  78                 if(nt == 0){
  79                         x = recvp(ctimer);
  80         gotit:
  81                         if(nt == na){
  82                                 na += 10;
  83                                 t = realloc(t, na*sizeof(Timer*));
  84                                 if(t == nil)
  85                                         abort();
  86                         }
  87                         t[nt++] = x;
  88                         old = msec();
  89                 }
  90                 if(nbrecv(ctimer, &x) > 0)
  91                         goto gotit;
  92         }
  93 }
  94
  95 void
  96 timerinit(void)
  97 {
  98         ctimer = chancreate(sizeof(Timer*), 100);
  99         proccreate(timerproc, nil, STACK);
 100 }
 101
 102 /*
 103  * timeralloc() and timerfree() don't lock, so can only be
 104  * called from the main proc.
 105  */
 106
 107 Timer*
 108 timerstart(int dt)
 109 {
 110         Timer *t;
 111
 112         t = timer;
 113         if(t)
 114                 timer = timer->next;
 115         else{
 116                 t = emalloc(sizeof(Timer));
 117                 t->c = chancreate(sizeof(int), 0);
 118         }
 119         t->next = nil;
 120         t->dt = dt;
 121         t->cancel = FALSE;
 122         sendp(ctimer, t);
 123         return t;
 124 }