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118 lines
3.9 KiB
C
118 lines
3.9 KiB
C
/*-
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* See the file LICENSE for redistribution information.
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*
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* Copyright (c) 1996, 1997, 1998
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* Sleepycat Software. All rights reserved.
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*
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* @(#)txn.h 10.15 (Sleepycat) 4/21/98
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*/
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#ifndef _TXN_H_
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#define _TXN_H_
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/*
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* The name of the transaction shared memory region is DEFAULT_TXN_FILE and
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* the region is always created group RW of the group owning the directory.
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*/
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#define DEFAULT_TXN_FILE "__db_txn.share"
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/* TXN_MINIMUM = (DB_LOCK_MAXID + 1) but this makes compilers complain. */
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#define TXN_MINIMUM 0x80000000
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#define TXN_INVALID 0xffffffff /* Maximum number of txn ids. */
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/*
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* Transaction type declarations.
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*/
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/*
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* Internal data maintained in shared memory for each transaction.
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*/
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typedef struct __txn_detail {
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u_int32_t txnid; /* current transaction id
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used to link free list also */
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DB_LSN last_lsn; /* last lsn written for this txn */
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DB_LSN begin_lsn; /* lsn of begin record */
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size_t last_lock; /* offset in lock region of last lock
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for this transaction. */
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#define TXN_UNALLOC 0
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#define TXN_RUNNING 1
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#define TXN_ABORTED 2
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#define TXN_PREPARED 3
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u_int32_t status; /* status of the transaction */
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SH_TAILQ_ENTRY links; /* free/active list */
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} TXN_DETAIL;
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/*
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* The transaction manager encapsulates the transaction system. It contains
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* references to the log and lock managers as well as the state that keeps
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* track of the shared memory region.
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*/
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struct __db_txnmgr {
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/* These fields need to be protected for multi-threaded support. */
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db_mutex_t *mutexp; /* Synchronization. */
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/* list of active transactions */
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TAILQ_HEAD(_chain, __db_txn) txn_chain;
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/* These fields are not protected. */
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REGINFO reginfo; /* Region information. */
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DB_ENV *dbenv; /* Environment. */
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int (*recover) /* Recovery dispatch routine */
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__P((DB_LOG *, DBT *, DB_LSN *, int, void *));
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u_int32_t flags; /* DB_TXN_NOSYNC, DB_THREAD */
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DB_TXNREGION *region; /* address of shared memory region */
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void *mem; /* address of the shalloc space */
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};
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/*
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* Layout of the shared memory region.
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* The region consists of a DB_TXNREGION structure followed by a large
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* pool of shalloc'd memory which is used to hold TXN_DETAIL structures
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* and thread mutexes (which are dynamically allocated).
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*/
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struct __db_txnregion {
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RLAYOUT hdr; /* Shared memory region header. */
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u_int32_t magic; /* transaction magic number */
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u_int32_t version; /* version number */
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u_int32_t maxtxns; /* maximum number of active txns */
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u_int32_t last_txnid; /* last transaction id given out */
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DB_LSN pending_ckp; /* last checkpoint did not finish */
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DB_LSN last_ckp; /* lsn of the last checkpoint */
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time_t time_ckp; /* time of last checkpoint */
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u_int32_t logtype; /* type of logging */
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u_int32_t locktype; /* lock type */
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u_int32_t naborts; /* number of aborted transactions */
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u_int32_t ncommits; /* number of committed transactions */
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u_int32_t nbegins; /* number of begun transactions */
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SH_TAILQ_HEAD(_active) active_txn; /* active transaction list */
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};
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/*
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* Make the region large enough to hold N transaction detail structures
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* plus some space to hold thread handles and the beginning of the shalloc
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* region.
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*/
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#define TXN_REGION_SIZE(N) \
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(sizeof(DB_TXNREGION) + N * sizeof(TXN_DETAIL) + 1000)
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/* Macros to lock/unlock the region and threads. */
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#define LOCK_TXNTHREAD(tmgrp) \
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if (F_ISSET(tmgrp, DB_THREAD)) \
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(void)__db_mutex_lock((tmgrp)->mutexp, -1)
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#define UNLOCK_TXNTHREAD(tmgrp) \
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if (F_ISSET(tmgrp, DB_THREAD)) \
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(void)__db_mutex_unlock((tmgrp)->mutexp, -1)
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#define LOCK_TXNREGION(tmgrp) \
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(void)__db_mutex_lock(&(tmgrp)->region->hdr.lock, (tmgrp)->reginfo.fd)
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#define UNLOCK_TXNREGION(tmgrp) \
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(void)__db_mutex_unlock(&(tmgrp)->region->hdr.lock, (tmgrp)->reginfo.fd)
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/*
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* Log record types.
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*/
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#define TXN_COMMIT 1
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#define TXN_PREPARE 2
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#define TXN_CHECKPOINT 3
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#include "txn_auto.h"
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#include "txn_ext.h"
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#endif /* !_TXN_H_ */
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