1 c6687d45 2004-09-21 devnull #include <u.h>
 2 c6687d45 2004-09-21 devnull #include <unistd.h>
 3 c6687d45 2004-09-21 devnull #include <sys/time.h>
 4 c6687d45 2004-09-21 devnull #include <sched.h>
 5 c6687d45 2004-09-21 devnull #include <libc.h>
 6 c6687d45 2004-09-21 devnull 
 7 c6687d45 2004-09-21 devnull static pthread_mutex_t initmutex = PTHREAD_MUTEX_INITIALIZER;
 8 c6687d45 2004-09-21 devnull 
 9 c6687d45 2004-09-21 devnull static void
10 c6687d45 2004-09-21 devnull lockinit(Lock *lk)
11 c6687d45 2004-09-21 devnull {
12 c6687d45 2004-09-21 devnull 	pthread_mutexattr_t attr;
13 c6687d45 2004-09-21 devnull 
14 c6687d45 2004-09-21 devnull 	pthread_mutex_lock(&initmutex);
15 c6687d45 2004-09-21 devnull 	if(lk->init == 0){
16 c6687d45 2004-09-21 devnull 		pthread_mutexattr_init(&attr);
17 c6687d45 2004-09-21 devnull 		pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_NORMAL);
18 c6687d45 2004-09-21 devnull 		pthread_mutex_init(&lk->mutex, &attr);
19 c6687d45 2004-09-21 devnull 		pthread_mutexattr_destroy(&attr);
20 c6687d45 2004-09-21 devnull 		lk->init = 1;
21 c6687d45 2004-09-21 devnull 	}
22 c6687d45 2004-09-21 devnull 	pthread_mutex_unlock(&initmutex);
23 c6687d45 2004-09-21 devnull }
24 c6687d45 2004-09-21 devnull 
25 c6687d45 2004-09-21 devnull void
26 c6687d45 2004-09-21 devnull lock(Lock *lk)
27 c6687d45 2004-09-21 devnull {
28 c6687d45 2004-09-21 devnull 	if(!lk->init)
29 c6687d45 2004-09-21 devnull 		lockinit(lk);
30 c6687d45 2004-09-21 devnull 	if(pthread_mutex_lock(&lk->mutex) != 0)
31 c6687d45 2004-09-21 devnull 		abort();
32 c6687d45 2004-09-21 devnull }
33 c6687d45 2004-09-21 devnull 
34 c6687d45 2004-09-21 devnull int
35 c6687d45 2004-09-21 devnull canlock(Lock *lk)
36 c6687d45 2004-09-21 devnull {
37 c6687d45 2004-09-21 devnull 	int r;
38 c6687d45 2004-09-21 devnull 
39 c6687d45 2004-09-21 devnull 	if(!lk->init)
40 c6687d45 2004-09-21 devnull 		lockinit(lk);
41 c6687d45 2004-09-21 devnull 	r = pthread_mutex_trylock(&lk->mutex);
42 c6687d45 2004-09-21 devnull 	if(r == 0)
43 c6687d45 2004-09-21 devnull 		return 1;
44 c6687d45 2004-09-21 devnull 	if(r == EBUSY)
45 c6687d45 2004-09-21 devnull 		return 0;
46 c6687d45 2004-09-21 devnull 	abort();
47 c6687d45 2004-09-21 devnull }
48 c6687d45 2004-09-21 devnull 
49 c6687d45 2004-09-21 devnull void
50 c6687d45 2004-09-21 devnull unlock(Lock *lk)
51 c6687d45 2004-09-21 devnull {
52 c6687d45 2004-09-21 devnull 	if(pthread_mutex_unlock(&lk->mutex) != 0)
53 c6687d45 2004-09-21 devnull 		abort();
54 c6687d45 2004-09-21 devnull }