xref: /dragonfly/sys/sys/serialize.h (revision 74abe2e5)
1 /*
2  * Provides a fast serialization facility that will serialize across blocking
3  * conditions.  This facility is very similar to a lock but much faster for
4  * the common case.  It utilizes the atomic_intr_*() functions to acquire
5  * and release the serializer and token functions to block.
6  *
7  * This API is designed to be used whenever low level serialization is
8  * required.  Unlike tokens this serialization is not safe from deadlocks
9  * nor is it recursive, and care must be taken when using it.
10  *
11  * $DragonFly: src/sys/sys/serialize.h,v 1.9 2008/05/14 11:59:24 sephe Exp $
12  */
13 
14 #ifndef _SYS_SERIALIZE_H_
15 #define _SYS_SERIALIZE_H_
16 
17 #ifndef _MACHINE_STDINT_H_
18 #include <machine/stdint.h>
19 #endif
20 
21 struct thread;
22 
23 struct lwkt_serialize {
24     __atomic_intr_t	interlock;
25     struct thread	*last_td;
26     unsigned int	sleep_cnt;
27     unsigned int	tryfail_cnt;
28     unsigned int	enter_cnt;
29     unsigned int	try_cnt;
30 };
31 
32 #define IS_SERIALIZED(ss)		((ss)->last_td == curthread)
33 #define ASSERT_SERIALIZED(ss)		KKASSERT(IS_SERIALIZED((ss)))
34 #define ASSERT_NOT_SERIALIZED(ss)	KKASSERT(!IS_SERIALIZED((ss)))
35 
36 typedef struct lwkt_serialize *lwkt_serialize_t;
37 
38 void lwkt_serialize_init(lwkt_serialize_t);
39 void lwkt_serialize_enter(lwkt_serialize_t);
40 #ifdef SMP
41 void lwkt_serialize_adaptive_enter(lwkt_serialize_t);
42 #endif
43 int lwkt_serialize_try(lwkt_serialize_t);
44 void lwkt_serialize_exit(lwkt_serialize_t);
45 void lwkt_serialize_handler_disable(lwkt_serialize_t);
46 void lwkt_serialize_handler_enable(lwkt_serialize_t);
47 void lwkt_serialize_handler_call(lwkt_serialize_t, void (*)(void *, void *), void *, void *);
48 int lwkt_serialize_handler_try(lwkt_serialize_t, void (*)(void *, void *), void *, void *);
49 
50 #endif	/* !_SYS_SERIALIZE_H_ */
51