1 #include <sys/condvar.h>
2 #include <sys/spinlock2.h>
3 #include <sys/systm.h>
4 #include <sys/lock.h>
5
6 void
7 cv_init(struct cv *c, const char *desc)
8 {
9 c->cv_desc = desc;
10 c->cv_waiters = 0;
11 spin_init(&c->cv_lock);
12 }
13
14 void
15 cv_destroy(struct cv *c)
16 {
17 spin_uninit(&c->cv_lock);
18 }
19
20 int
21 _cv_timedwait(struct cv *c, struct lock *lk, int timo, int wakesig)
22 {
23 int flags = wakesig ? PCATCH : 0;
24 int error;
25
26 /*
27 * Can interlock without critical section/spinlock as long
28 * as we don't block before calling *sleep(). PINTERLOCKED
29 * must be passed to the *sleep() to use the manual interlock
30 * (else a new one is created which opens a timing race).
31 */
32 tsleep_interlock(c, flags);
33
34 spin_lock(&c->cv_lock);
35 c->cv_waiters++;
36 spin_unlock(&c->cv_lock);
37
38 if (lk)
39 error = lksleep(c, lk, flags | PINTERLOCKED, c->cv_desc, timo);
40 else
41 error = tsleep(c, flags | PINTERLOCKED, c->cv_desc, timo);
42
43 return (error);
44 }
45
46 void
47 _cv_signal(struct cv *c, int broadcast)
48 {
49 spin_lock(&c->cv_lock);
50 if (c->cv_waiters == 0) {
51 spin_unlock(&c->cv_lock);
52 } else if (broadcast) {
53 c->cv_waiters = 0;
54 spin_unlock(&c->cv_lock); /* must unlock first */
55 wakeup(c);
56 } else {
57 c->cv_waiters--;
58 spin_unlock(&c->cv_lock); /* must unlock first */
59 wakeup_one(c);
60 }
61 }
62
63 int
64 cv_has_waiters(const struct cv *c)
65 {
66 return (c->cv_waiters);
67 }
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