sys/src/cmd/acme/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 <plumb.h>
  11 #include "dat.h"
  12 #include "fns.h"
  13
  14 static Channel* ctimer; /* chan(Timer*)[100] */
  15 static Timer *timer;
  16
  17 static
  18 uint
  19 msec(void)
  20 {
  21         return nsec()/1000000;
  22 }
  23
  24 void
  25 timerstop(Timer *t)
  26 {
  27         t->next = timer;
  28         timer = t;
  29 }
  30
  31 void
  32 timercancel(Timer *t)
  33 {
  34         t->cancel = TRUE;
  35 }
  36
  37 static
  38 void
  39 timerproc(void*)
  40 {
  41         int i, nt, na, dt, del;
  42         Timer **t, *x;
  43         uint old, new;
  44
  45         threadsetname("timerproc");
  46         rfork(RFFDG);
  47         t = nil;
  48         na = 0;
  49         nt = 0;
  50         old = msec();
  51         for(;;){
  52                 sleep(1);       /* will sleep minimum incr */
  53                 new = msec();
  54                 dt = new-old;
  55                 old = new;
  56                 if(dt < 0)      /* timer wrapped; go around, losing a tick */
  57                         continue;
  58                 for(i=0; i<nt; i++){
  59                         x = t[i];
  60                         x->dt -= dt;
  61                         del = FALSE;
  62                         if(x->cancel){
  63                                 timerstop(x);
  64                                 del = TRUE;
  65                         }else if(x->dt <= 0){
  66                                 /*
  67                                  * avoid possible deadlock if client is
  68                                  * now sending on ctimer
  69                                  */
  70                                 if(nbsendul(x->c, 0) > 0)
  71                                         del = TRUE;
  72                         }
  73                         if(del){
  74                                 memmove(&t[i], &t[i+1], (nt-i-1)*sizeof t[0]);
  75                                 --nt;
  76                                 --i;
  77                         }
  78                 }
  79                 if(nt == 0){
  80                         x = recvp(ctimer);
  81         gotit:
  82                         if(nt == na){
  83                                 na += 10;
  84                                 t = realloc(t, na*sizeof(Timer*));
  85                                 if(t == nil)
  86                                         error("timer realloc failed");
  87                         }
  88                         t[nt++] = x;
  89                         old = msec();
  90                 }
  91                 if(nbrecv(ctimer, &x) > 0)
  92                         goto gotit;
  93         }
  94 }
  95
  96 void
  97 timerinit(void)
  98 {
  99         ctimer = chancreate(sizeof(Timer*), 100);
 100         proccreate(timerproc, nil, STACK);
 101 }
 102
 103 Timer*
 104 timerstart(int dt)
 105 {
 106         Timer *t;
 107
 108         t = timer;
 109         if(t)
 110                 timer = timer->next;
 111         else{
 112                 t = emalloc(sizeof(Timer));
 113                 t->c = chancreate(sizeof(int), 0);
 114         }
 115         t->next = nil;
 116         t->dt = dt;
 117         t->cancel = FALSE;
 118         sendp(ctimer, t);
 119         return t;
 120 }