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 <libsec.h>
12 #include "dat.h"
13 #include "fns.h"
14 
15 static Channel*	ctimer;	/* chan(Timer*)[100] */
16 static Timer *timer;
17 
18 static
19 uint
20 msec(void)
21 {
22 	return nsec()/1000000;
23 }
24 
25 void
26 timerstop(Timer *t)
27 {
28 	t->next = timer;
29 	timer = t;
30 }
31 
32 void
33 timercancel(Timer *t)
34 {
35 	t->cancel = TRUE;
36 }
37 
38 static
39 void
40 timerproc(void *v)
41 {
42 	int i, nt, na, dt, del;
43 	Timer **t, *x;
44 	uint old, new;
45 
46 	USED(v);
47 	threadsetname("timerproc");
48 	rfork(RFFDG);
49 	t = nil;
50 	na = 0;
51 	nt = 0;
52 	old = msec();
53 	for(;;){
54 		sleep(10);	/* longer sleeps here delay recv on ctimer, but 10ms should not be noticeable */
55 		new = msec();
56 		dt = new-old;
57 		old = new;
58 		if(dt < 0)	/* timer wrapped; go around, losing a tick */
59 			continue;
60 		for(i=0; i<nt; i++){
61 			x = t[i];
62 			x->dt -= dt;
63 			del = FALSE;
64 			if(x->cancel){
65 				timerstop(x);
66 				del = TRUE;
67 			}else if(x->dt <= 0){
68 				/*
69 				 * avoid possible deadlock if client is
70 				 * now sending on ctimer
71 				 */
72 				if(nbsendul(x->c, 0) > 0)
73 					del = TRUE;
74 			}
75 			if(del){
76 				memmove(&t[i], &t[i+1], (nt-i-1)*sizeof t[0]);
77 				--nt;
78 				--i;
79 			}
80 		}
81 		if(nt == 0){
82 			x = recvp(ctimer);
83 	gotit:
84 			if(nt == na){
85 				na += 10;
86 				t = realloc(t, na*sizeof(Timer*));
87 				if(t == nil)
88 					error("timer realloc failed");
89 			}
90 			t[nt++] = x;
91 			old = msec();
92 		}
93 		if(nbrecv(ctimer, &x) > 0)
94 			goto gotit;
95 	}
96 }
97 
98 void
99 timerinit(void)
100 {
101 	ctimer = chancreate(sizeof(Timer*), 100);
102 	chansetname(ctimer, "ctimer");
103 	proccreate(timerproc, nil, STACK);
104 }
105 
106 Timer*
107 timerstart(int dt)
108 {
109 	Timer *t;
110 
111 	t = timer;
112 	if(t)
113 		timer = timer->next;
114 	else{
115 		t = emalloc(sizeof(Timer));
116 		t->c = chancreate(sizeof(int), 0);
117 		chansetname(t->c, "tc%p", t->c);
118 	}
119 	t->next = nil;
120 	t->dt = dt;
121 	t->cancel = FALSE;
122 	sendp(ctimer, t);
123 	return t;
124 }