1 /*- 2 * See the file LICENSE for redistribution information. 3 * 4 * Copyright (c) 1996, 1997, 1998 5 * Sleepycat Software. All rights reserved. 6 * 7 * @(#)txn.h 10.18 (Sleepycat) 1/3/99 8 */ 9 #ifndef _TXN_H_ 10 #define _TXN_H_ 11 12 #include "xa.h" 13 14 /* 15 * The name of the transaction shared memory region is DEFAULT_TXN_FILE and 16 * the region is always created group RW of the group owning the directory. 17 */ 18 #define DEFAULT_TXN_FILE "__db_txn.share" 19 /* TXN_MINIMUM = (DB_LOCK_MAXID + 1) but this makes compilers complain. */ 20 #define TXN_MINIMUM 0x80000000 21 #define TXN_INVALID 0xffffffff /* Maximum number of txn ids. */ 22 23 /* 24 * Transaction type declarations. 25 */ 26 27 /* 28 * Internal data maintained in shared memory for each transaction. 29 */ 30 typedef char DB_XID[XIDDATASIZE]; 31 32 typedef struct __txn_detail { 33 u_int32_t txnid; /* current transaction id 34 used to link free list also */ 35 DB_LSN last_lsn; /* last lsn written for this txn */ 36 DB_LSN begin_lsn; /* lsn of begin record */ 37 size_t last_lock; /* offset in lock region of last lock 38 for this transaction. */ 39 size_t parent; /* Offset of transaction's parent. */ 40 #define TXN_UNALLOC 0 41 #define TXN_RUNNING 1 42 #define TXN_ABORTED 2 43 #define TXN_PREPARED 3 44 #define TXN_COMMITTED 4 45 u_int32_t status; /* status of the transaction */ 46 SH_TAILQ_ENTRY links; /* free/active list */ 47 48 #define TXN_XA_ABORTED 1 49 #define TXN_XA_DEADLOCKED 2 50 #define TXN_XA_ENDED 3 51 #define TXN_XA_PREPARED 4 52 #define TXN_XA_STARTED 5 53 #define TXN_XA_SUSPENDED 6 54 u_int32_t xa_status; /* XA status */ 55 56 /* 57 * XID (xid_t) structure: because these fields are logged, the 58 * sizes have to be explicit. 59 */ 60 DB_XID xid; /* XA global transaction id */ 61 u_int32_t bqual; /* bqual_length from XID */ 62 u_int32_t gtrid; /* gtrid_length from XID */ 63 int32_t format; /* XA format */ 64 } TXN_DETAIL; 65 66 /* 67 * The transaction manager encapsulates the transaction system. It contains 68 * references to the log and lock managers as well as the state that keeps 69 * track of the shared memory region. 70 */ 71 struct __db_txnmgr { 72 /* These fields need to be protected for multi-threaded support. */ 73 db_mutex_t *mutexp; /* Synchronization. */ 74 /* list of active transactions */ 75 TAILQ_HEAD(_chain, __db_txn) txn_chain; 76 77 /* These fields are not protected. */ 78 REGINFO reginfo; /* Region information. */ 79 DB_ENV *dbenv; /* Environment. */ 80 int (*recover) /* Recovery dispatch routine */ 81 __P((DB_LOG *, DBT *, DB_LSN *, int, void *)); 82 u_int32_t flags; /* DB_TXN_NOSYNC, DB_THREAD */ 83 DB_TXNREGION *region; /* address of shared memory region */ 84 void *mem; /* address of the shalloc space */ 85 }; 86 87 /* 88 * Layout of the shared memory region. 89 * The region consists of a DB_TXNREGION structure followed by a large 90 * pool of shalloc'd memory which is used to hold TXN_DETAIL structures 91 * and thread mutexes (which are dynamically allocated). 92 */ 93 struct __db_txnregion { 94 RLAYOUT hdr; /* Shared memory region header. */ 95 u_int32_t magic; /* transaction magic number */ 96 u_int32_t version; /* version number */ 97 u_int32_t maxtxns; /* maximum number of active txns */ 98 u_int32_t last_txnid; /* last transaction id given out */ 99 DB_LSN pending_ckp; /* last checkpoint did not finish */ 100 DB_LSN last_ckp; /* lsn of the last checkpoint */ 101 time_t time_ckp; /* time of last checkpoint */ 102 u_int32_t logtype; /* type of logging */ 103 u_int32_t locktype; /* lock type */ 104 u_int32_t naborts; /* number of aborted transactions */ 105 u_int32_t ncommits; /* number of committed transactions */ 106 u_int32_t nbegins; /* number of begun transactions */ 107 SH_TAILQ_HEAD(_active) active_txn; /* active transaction list */ 108 }; 109 110 /* 111 * Make the region large enough to hold N transaction detail structures 112 * plus some space to hold thread handles and the beginning of the shalloc 113 * region. 114 */ 115 #define TXN_REGION_SIZE(N) \ 116 (sizeof(DB_TXNREGION) + N * sizeof(TXN_DETAIL) + 1000) 117 118 /* Macros to lock/unlock the region and threads. */ 119 #define LOCK_TXNTHREAD(tmgrp) \ 120 if (F_ISSET(tmgrp, DB_THREAD)) \ 121 (void)__db_mutex_lock((tmgrp)->mutexp, -1) 122 #define UNLOCK_TXNTHREAD(tmgrp) \ 123 if (F_ISSET(tmgrp, DB_THREAD)) \ 124 (void)__db_mutex_unlock((tmgrp)->mutexp, -1) 125 126 #define LOCK_TXNREGION(tmgrp) \ 127 (void)__db_mutex_lock(&(tmgrp)->region->hdr.lock, (tmgrp)->reginfo.fd) 128 #define UNLOCK_TXNREGION(tmgrp) \ 129 (void)__db_mutex_unlock(&(tmgrp)->region->hdr.lock, (tmgrp)->reginfo.fd) 130 131 /* Check for region catastrophic shutdown. */ 132 #define TXN_PANIC_CHECK(tmgrp) { \ 133 if ((tmgrp)->region->hdr.panic) \ 134 return (DB_RUNRECOVERY); \ 135 } 136 137 /* 138 * Log record types. 139 */ 140 #define TXN_COMMIT 1 141 #define TXN_PREPARE 2 142 #define TXN_CHECKPOINT 3 143 144 #include "txn_auto.h" 145 #include "txn_ext.h" 146 147 #include "xa_ext.h" 148 #endif /* !_TXN_H_ */ 149