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 *v)
40 {
41 	int i, nt, na, dt, del;
42 	Timer **t, *x;
43 	uint old, new;
44 
45 	USED(v);
46 	threadsetname("timerproc");
47 	rfork(RFFDG);
48 	t = nil;
49 	na = 0;
50 	nt = 0;
51 	old = msec();
52 	for(;;){
53 		sleep(1);	/* will sleep minimum incr */
54 		new = msec();
55 		dt = new-old;
56 		old = new;
57 		if(dt < 0)	/* timer wrapped; go around, losing a tick */
58 			continue;
59 		for(i=0; i<nt; i++){
60 			x = t[i];
61 			x->dt -= dt;
62 			del = FALSE;
63 			if(x->cancel){
64 				timerstop(x);
65 				del = TRUE;
66 			}else if(x->dt <= 0){
67 				/*
68 				 * avoid possible deadlock if client is
69 				 * now sending on ctimer
70 				 */
71 				if(nbsendul(x->c, 0) > 0)
72 					del = TRUE;
73 			}
74 			if(del){
75 				memmove(&t[i], &t[i+1], (nt-i-1)*sizeof t[0]);
76 				--nt;
77 				--i;
78 			}
79 		}
80 		if(nt == 0){
81 			x = recvp(ctimer);
82 	gotit:
83 			if(nt == na){
84 				na += 10;
85 				t = realloc(t, na*sizeof(Timer*));
86 				if(t == nil)
87 					error("timer realloc failed");
88 			}
89 			t[nt++] = x;
90 			old = msec();
91 		}
92 		if(nbrecv(ctimer, &x) > 0)
93 			goto gotit;
94 	}
95 }
96 
97 void
98 timerinit(void)
99 {
100 	ctimer = chancreate(sizeof(Timer*), 100);
101 	chansetname(ctimer, "ctimer");
102 	proccreate(timerproc, nil, STACK);
103 }
104 
105 Timer*
106 timerstart(int dt)
107 {
108 	Timer *t;
109 
110 	t = timer;
111 	if(t)
112 		timer = timer->next;
113 	else{
114 		t = emalloc(sizeof(Timer));
115 		t->c = chancreate(sizeof(int), 0);
116 		chansetname(t->c, "tc%p", t->c);
117 	}
118 	t->next = nil;
119 	t->dt = dt;
120 	t->cancel = FALSE;
121 	sendp(ctimer, t);
122 	return t;
123 }