1 6f4d00ee 2013-09-23 0intro #include "stdinc.h"
 2 6f4d00ee 2013-09-23 0intro #include "dat.h"
 3 6f4d00ee 2013-09-23 0intro #include "fns.h"
 4 6f4d00ee 2013-09-23 0intro #include "error.h"
 5 6f4d00ee 2013-09-23 0intro 
 6 6f4d00ee 2013-09-23 0intro struct Periodic {
 7 4b576658 2013-09-23 0intro 	QLock lk;
 8 6f4d00ee 2013-09-23 0intro 	int die;		/* flag: quit if set */
 9 6f4d00ee 2013-09-23 0intro 	void (*f)(void*);	/* call this each period */
10 6f4d00ee 2013-09-23 0intro 	void *a;		/* argument to f */
11 6f4d00ee 2013-09-23 0intro 	int msec;		/* period */
12 6f4d00ee 2013-09-23 0intro };
13 6f4d00ee 2013-09-23 0intro 
14 6f4d00ee 2013-09-23 0intro static void periodicThread(void *a);
15 6f4d00ee 2013-09-23 0intro 
16 6f4d00ee 2013-09-23 0intro Periodic *
17 6f4d00ee 2013-09-23 0intro periodicAlloc(void (*f)(void*), void *a, int msec)
18 6f4d00ee 2013-09-23 0intro {
19 6f4d00ee 2013-09-23 0intro 	Periodic *p;
20 6f4d00ee 2013-09-23 0intro 
21 4b576658 2013-09-23 0intro 	p = vtmallocz(sizeof(Periodic));
22 6f4d00ee 2013-09-23 0intro 	p->f = f;
23 6f4d00ee 2013-09-23 0intro 	p->a = a;
24 6f4d00ee 2013-09-23 0intro 	p->msec = msec;
25 6f4d00ee 2013-09-23 0intro 	if(p->msec < 10)
26 6f4d00ee 2013-09-23 0intro 		p->msec = 10;
27 6f4d00ee 2013-09-23 0intro 
28 4b576658 2013-09-23 0intro 	proccreate(periodicThread, p, STACK);
29 6f4d00ee 2013-09-23 0intro 	return p;
30 6f4d00ee 2013-09-23 0intro }
31 6f4d00ee 2013-09-23 0intro 
32 6f4d00ee 2013-09-23 0intro void
33 6f4d00ee 2013-09-23 0intro periodicKill(Periodic *p)
34 6f4d00ee 2013-09-23 0intro {
35 6f4d00ee 2013-09-23 0intro 	if(p == nil)
36 6f4d00ee 2013-09-23 0intro 		return;
37 4b576658 2013-09-23 0intro 	qlock(&p->lk);
38 6f4d00ee 2013-09-23 0intro 	p->die = 1;
39 4b576658 2013-09-23 0intro 	qunlock(&p->lk);
40 6f4d00ee 2013-09-23 0intro }
41 6f4d00ee 2013-09-23 0intro 
42 6f4d00ee 2013-09-23 0intro static void
43 6f4d00ee 2013-09-23 0intro periodicFree(Periodic *p)
44 6f4d00ee 2013-09-23 0intro {
45 4b576658 2013-09-23 0intro 	vtfree(p);
46 6f4d00ee 2013-09-23 0intro }
47 6f4d00ee 2013-09-23 0intro 
48 6f4d00ee 2013-09-23 0intro static void
49 6f4d00ee 2013-09-23 0intro periodicThread(void *a)
50 6f4d00ee 2013-09-23 0intro {
51 6f4d00ee 2013-09-23 0intro 	Periodic *p = a;
52 6f4d00ee 2013-09-23 0intro 	vlong t, ct, ts;		/* times in ms. */
53 6f4d00ee 2013-09-23 0intro 
54 4b576658 2013-09-23 0intro 	threadsetname("periodic");
55 6f4d00ee 2013-09-23 0intro 
56 6f4d00ee 2013-09-23 0intro 	ct = nsec() / 1000000;
57 6f4d00ee 2013-09-23 0intro 	t = ct + p->msec;		/* call p->f at or after this time */
58 6f4d00ee 2013-09-23 0intro 
59 6f4d00ee 2013-09-23 0intro 	for(;;){
60 6f4d00ee 2013-09-23 0intro 		ts = t - ct;		/* ms. to next cycle's start */
61 6f4d00ee 2013-09-23 0intro 		if(ts > 1000)
62 6f4d00ee 2013-09-23 0intro 			ts = 1000;	/* bound sleep duration */
63 6f4d00ee 2013-09-23 0intro 		if(ts > 0)
64 6f4d00ee 2013-09-23 0intro 			sleep(ts);	/* wait for cycle's start */
65 6f4d00ee 2013-09-23 0intro 
66 4b576658 2013-09-23 0intro 		qlock(&p->lk);
67 6f4d00ee 2013-09-23 0intro 		if(p->die){
68 4b576658 2013-09-23 0intro 			qunlock(&p->lk);
69 6f4d00ee 2013-09-23 0intro 			break;
70 6f4d00ee 2013-09-23 0intro 		}
71 6f4d00ee 2013-09-23 0intro 		ct = nsec() / 1000000;
72 6f4d00ee 2013-09-23 0intro 		if(t <= ct){		/* due to call p->f? */
73 6f4d00ee 2013-09-23 0intro 			p->f(p->a);
74 6f4d00ee 2013-09-23 0intro 			ct = nsec() / 1000000;
75 6f4d00ee 2013-09-23 0intro 			while(t <= ct)	/* advance t to future cycle start */
76 6f4d00ee 2013-09-23 0intro 				t += p->msec;
77 6f4d00ee 2013-09-23 0intro 		}
78 4b576658 2013-09-23 0intro 		qunlock(&p->lk);
79 6f4d00ee 2013-09-23 0intro 	}
80 6f4d00ee 2013-09-23 0intro 	periodicFree(p);
81 6f4d00ee 2013-09-23 0intro }