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 }; 27 28 #define LWKT_SERIALIZE_INITIALIZER { 0, NULL } 29 30 #ifdef INVARIANTS 31 /* 32 * Note that last_td is only maintained when INVARIANTS is turned on, 33 * so this check is only useful as part of a [K]KASSERT. 34 */ 35 #define IS_SERIALIZED(ss) ((ss)->last_td == curthread) 36 #endif 37 38 #define ASSERT_SERIALIZED(ss) KKASSERT(IS_SERIALIZED((ss))) 39 #define ASSERT_NOT_SERIALIZED(ss) KKASSERT(!IS_SERIALIZED((ss))) 40 41 typedef struct lwkt_serialize *lwkt_serialize_t; 42 43 void lwkt_serialize_init(lwkt_serialize_t); 44 void lwkt_serialize_enter(lwkt_serialize_t); 45 #ifdef SMP 46 void lwkt_serialize_adaptive_enter(lwkt_serialize_t); 47 #endif 48 int lwkt_serialize_try(lwkt_serialize_t); 49 void lwkt_serialize_exit(lwkt_serialize_t); 50 void lwkt_serialize_handler_disable(lwkt_serialize_t); 51 void lwkt_serialize_handler_enable(lwkt_serialize_t); 52 void lwkt_serialize_handler_call(lwkt_serialize_t, void (*)(void *, void *), void *, void *); 53 int lwkt_serialize_handler_try(lwkt_serialize_t, void (*)(void *, void *), void *, void *); 54 55 #endif /* !_SYS_SERIALIZE_H_ */ 56