usr/src/cmd/sendmail/db/include/txn.h

   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_ */