sys/sys/serialize.h

   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
  12 #ifndef _SYS_SERIALIZE_H_
  13 #define _SYS_SERIALIZE_H_
  14
  15 #include <machine/stdint.h>
  16
  17 struct thread;
  18
  19 struct lwkt_serialize {
  20     __atomic_intr_t     interlock;
  21     struct thread       *last_td;
  22 };
  23
  24 #define LWKT_SERIALIZE_INITIALIZER      { 0, NULL }
  25
  26 #define IS_SERIALIZED(ss)               ((ss)->last_td == curthread)
  27 #define ASSERT_SERIALIZED(ss)           KKASSERT(IS_SERIALIZED((ss)))
  28 #define ASSERT_NOT_SERIALIZED(ss)       KKASSERT(!IS_SERIALIZED((ss)))
  29
  30 typedef struct lwkt_serialize *lwkt_serialize_t;
  31
  32 void lwkt_serialize_init(lwkt_serialize_t);
  33 void lwkt_serialize_enter(lwkt_serialize_t);
  34 void lwkt_serialize_adaptive_enter(lwkt_serialize_t);
  35 int lwkt_serialize_try(lwkt_serialize_t);
  36 void lwkt_serialize_exit(lwkt_serialize_t);
  37 void lwkt_serialize_handler_disable(lwkt_serialize_t);
  38 void lwkt_serialize_handler_enable(lwkt_serialize_t);
  39 void lwkt_serialize_handler_call(lwkt_serialize_t, void (*)(void *, void *), void *, void *);
  40 int lwkt_serialize_handler_try(lwkt_serialize_t, void (*)(void *, void *), void *, void *);
  41
  42 #endif  /* !_SYS_SERIALIZE_H_ */