/*- * See the file LICENSE for redistribution information. * * Copyright (c) 1996-2003 * Sleepycat Software. All rights reserved. * * $Id: lock.h,v 1.2 2004/03/30 01:21:28 jtownsen Exp $ */ #ifndef _DB_LOCK_H_ #define _DB_LOCK_H_ #define DB_LOCK_DEFAULT_N 1000 /* Default # of locks in region. */ /* * The locker id space is divided between the transaction manager and the lock * manager. Lock IDs start at 1 and go to DB_LOCK_MAXID. Txn IDs start at * DB_LOCK_MAXID + 1 and go up to TXN_MAXIMUM. */ #define DB_LOCK_INVALIDID 0 #define DB_LOCK_MAXID 0x7fffffff /* * Out of band value for a lock. Locks contain an offset into a lock region, * so we use an invalid region offset to indicate an invalid or unset lock. */ #define LOCK_INVALID INVALID_ROFF #define LOCK_ISSET(lock) ((lock).off != LOCK_INVALID) #define LOCK_INIT(lock) ((lock).off = LOCK_INVALID) /* * Macro to identify a write lock for the purpose of counting locks * for the NUMWRITES option to deadlock detection. */ #define IS_WRITELOCK(m) \ ((m) == DB_LOCK_WRITE || (m) == DB_LOCK_WWRITE || \ (m) == DB_LOCK_IWRITE || (m) == DB_LOCK_IWR) /* * Lock timers. */ typedef struct { u_int32_t tv_sec; /* Seconds. */ u_int32_t tv_usec; /* Microseconds. */ } db_timeval_t; #define LOCK_TIME_ISVALID(time) ((time)->tv_sec != 0) #define LOCK_SET_TIME_INVALID(time) ((time)->tv_sec = 0) #define LOCK_TIME_ISMAX(time) ((time)->tv_sec == UINT32_T_MAX) #define LOCK_SET_TIME_MAX(time) ((time)->tv_sec = UINT32_T_MAX) #define LOCK_TIME_EQUAL(t1, t2) \ ((t1)->tv_sec == (t2)->tv_sec && (t1)->tv_usec == (t2)->tv_usec) #define LOCK_TIME_GREATER(t1, t2) \ ((t1)->tv_sec > (t2)->tv_sec || \ ((t1)->tv_sec == (t2)->tv_sec && (t1)->tv_usec > (t2)->tv_usec)) /* * DB_LOCKREGION -- * The lock shared region. */ typedef struct __db_lockregion { u_int32_t need_dd; /* flag for deadlock detector */ u_int32_t detect; /* run dd on every conflict */ db_timeval_t next_timeout; /* next time to expire a lock */ /* free lock header */ SH_TAILQ_HEAD(__flock) free_locks; /* free obj header */ SH_TAILQ_HEAD(__fobj) free_objs; /* free locker header */ SH_TAILQ_HEAD(__flocker) free_lockers; SH_TAILQ_HEAD(__dobj) dd_objs; /* objects with waiters */ SH_TAILQ_HEAD(__lkrs) lockers; /* list of lockers */ db_timeout_t lk_timeout; /* timeout for locks. */ db_timeout_t tx_timeout; /* timeout for txns. */ u_int32_t locker_t_size; /* size of locker hash table */ u_int32_t object_t_size; /* size of object hash table */ roff_t conf_off; /* offset of conflicts array */ roff_t obj_off; /* offset of object hash table */ roff_t osynch_off; /* offset of the object mutex table */ roff_t locker_off; /* offset of locker hash table */ roff_t lsynch_off; /* offset of the locker mutex table */ DB_LOCK_STAT stat; /* stats about locking. */ #ifdef HAVE_MUTEX_SYSTEM_RESOURCES roff_t maint_off; /* offset of region maintenance info */ #endif } DB_LOCKREGION; /* * Since we will store DBTs in shared memory, we need the equivalent of a * DBT that will work in shared memory. */ typedef struct __sh_dbt { u_int32_t size; /* Byte length. */ ssize_t off; /* Region offset. */ } SH_DBT; #define SH_DBT_PTR(p) ((void *)(((u_int8_t *)(p)) + (p)->off)) /* * Object structures; these live in the object hash table. */ typedef struct __db_lockobj { SH_DBT lockobj; /* Identifies object locked. */ SH_TAILQ_ENTRY links; /* Links for free list or hash list. */ SH_TAILQ_ENTRY dd_links; /* Links for dd list. */ SH_TAILQ_HEAD(__waitl) waiters; /* List of waiting locks. */ SH_TAILQ_HEAD(__holdl) holders; /* List of held locks. */ /* Declare room in the object to hold * typical DB lock structures so that * we do not have to allocate them from * shalloc at run-time. */ u_int8_t objdata[sizeof(struct __db_ilock)]; } DB_LOCKOBJ; /* * Locker structures; these live in the locker hash table. */ typedef struct __db_locker { u_int32_t id; /* Locker id. */ u_int32_t dd_id; /* Deadlock detector id. */ u_int32_t nlocks; /* Number of locks held. */ u_int32_t nwrites; /* Number of write locks held. */ size_t master_locker; /* Locker of master transaction. */ size_t parent_locker; /* Parent of this child. */ SH_LIST_HEAD(_child) child_locker; /* List of descendant txns; only used in a "master" txn. */ SH_LIST_ENTRY child_link; /* Links transactions in the family; elements of the child_locker list. */ SH_TAILQ_ENTRY links; /* Links for free and hash list. */ SH_TAILQ_ENTRY ulinks; /* Links in-use list. */ SH_LIST_HEAD(_held) heldby; /* Locks held by this locker. */ db_timeval_t lk_expire; /* When current lock expires. */ db_timeval_t tx_expire; /* When this txn expires. */ db_timeout_t lk_timeout; /* How long do we let locks live. */ #define DB_LOCKER_DELETED 0x0001 #define DB_LOCKER_DIRTY 0x0002 #define DB_LOCKER_INABORT 0x0004 #define DB_LOCKER_TIMEOUT 0x0008 u_int32_t flags; } DB_LOCKER; /* * DB_LOCKTAB -- * The primary library lock data structure (i.e., the one referenced * by the environment, as opposed to the internal one laid out in the region.) */ typedef struct __db_locktab { DB_ENV *dbenv; /* Environment. */ REGINFO reginfo; /* Region information. */ u_int8_t *conflicts; /* Pointer to conflict matrix. */ DB_HASHTAB *obj_tab; /* Beginning of object hash table. */ DB_HASHTAB *locker_tab; /* Beginning of locker hash table. */ } DB_LOCKTAB; /* Test for conflicts. */ #define CONFLICTS(T, R, HELD, WANTED) \ (T)->conflicts[(HELD) * (R)->stat.st_nmodes + (WANTED)] #define OBJ_LINKS_VALID(L) ((L)->links.stqe_prev != -1) struct __db_lock { /* * Wait on mutex to wait on lock. You reference your own mutex with * ID 0 and others reference your mutex with ID 1. */ DB_MUTEX mutex; u_int32_t holder; /* Who holds this lock. */ u_int32_t gen; /* Generation count. */ SH_TAILQ_ENTRY links; /* Free or holder/waiter list. */ SH_LIST_ENTRY locker_links; /* List of locks held by a locker. */ u_int32_t refcount; /* Reference count the lock. */ db_lockmode_t mode; /* What sort of lock. */ ssize_t obj; /* Relative offset of object struct. */ db_status_t status; /* Status of this lock. */ }; /* * Flag values for __lock_put_internal: * DB_LOCK_DOALL: Unlock all references in this lock (instead of only 1). * DB_LOCK_FREE: Free the lock (used in checklocker). * DB_LOCK_NOPROMOTE: Don't bother running promotion when releasing locks * (used by __lock_put_internal). * DB_LOCK_UNLINK: Remove from the locker links (used in checklocker). * Make sure that these do not conflict with the interface flags because * we pass some of those around (i.e., DB_LOCK_REMOVE). */ #define DB_LOCK_DOALL 0x010000 #define DB_LOCK_FREE 0x020000 #define DB_LOCK_NOPROMOTE 0x040000 #define DB_LOCK_UNLINK 0x080000 #define DB_LOCK_NOWAITERS 0x100000 /* * Macros to get/release different types of mutexes. */ #define OBJECT_LOCK(lt, reg, obj, ndx) \ ndx = __lock_ohash(obj) % (reg)->object_t_size #define SHOBJECT_LOCK(lt, reg, shobj, ndx) \ ndx = __lock_lhash(shobj) % (reg)->object_t_size #define LOCKER_LOCK(lt, reg, locker, ndx) \ ndx = __lock_locker_hash(locker) % (reg)->locker_t_size; #define LOCKREGION(dbenv, lt) R_LOCK((dbenv), &(lt)->reginfo) #define UNLOCKREGION(dbenv, lt) R_UNLOCK((dbenv), &(lt)->reginfo) #include "dbinc_auto/lock_ext.h" #endif /* !_DB_LOCK_H_ */