DB_ENV->txn_stat
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#include <db.h>
int
DB_ENV->txn_stat(DB_ENV *env, DB_TXN_STAT **statp, u_int32_t flags);
int
DB_ENV->txn_stat_print(DB_ENV *env, u_int32_t flags);
Description: DB_ENV->txn_stat
The DB_ENV->txn_stat method returns the transaction subsystem statistics.
The DB_ENV->txn_stat method creates a statistical structure of type
DB_TXN_STAT and copies a pointer to it into a user-specified memory
location.
Statistical structures are stored in allocated memory. If application-specific allocation
routines have been declared (see DB_ENV->set_alloc for more
information), they are used to allocate the memory; otherwise, the
standard C library malloc(3) is used. The caller is
responsible for deallocating the memory. To deallocate the memory, free
the memory reference; references inside the returned memory need not be
individually freed.
The following DB_TXN_STAT fields will be filled in:
- DbLsn st_last_ckp;
- The LSN of the last checkpoint.
- time_t st_time_ckp;
- The time the last completed checkpoint finished (as the number of seconds
since the Epoch, returned by the IEEE/ANSI Std 1003.1 (POSIX) time function).
- u_int32_t st_last_txnid;
- The last transaction ID allocated.
- u_int32_t st_maxtxns;
- The maximum number of active transactions configured.
- u_int32_t st_nactive;
- The number of transactions that are currently active.
- u_int32_t st_maxnactive;
- The maximum number of active transactions at any one time.
- u_int32_t st_nbegins;
- The number of transactions that have begun.
- u_int32_t st_naborts;
- The number of transactions that have aborted.
- u_int32_t st_ncommits;
- The number of transactions that have committed.
- u_int32_t st_nrestores;
- The number of transactions that have been restored.
- roff_t st_regsize;
- The size of the transaction region, in bytes.
- u_int32_t st_region_wait;
- The number of times that a thread of control was forced to wait before
obtaining the transaction region mutex.
- u_int32_t st_region_nowait;
- The number of times that a thread of control was able to obtain
the transaction region mutex without waiting.
- DB_TXN_ACTIVE *st_txnarray;
- A pointer to an array of st_nactive DB_TXN_ACTIVE structures,
describing the currently active transactions. The following fields of
the DB_TXN_ACTIVE structure will be filled in:
- u_int32_t txnid;
- The transaction ID of the transaction.
- u_int32_t parentid;
- The transaction ID of the parent transaction (or 0, if no parent).
- uintmax_t thread_id;
- The thread of control ID of the originator of the transaction.
- DbLsn lsn;
- The current log sequence number when the transaction was begun.
- u_int32_t xa_status;
- If the transaction is an XA transaction, the status of the transaction,
otherwise 0.
- u_int8_t xid[DB_XIDDATASIZE];
- If the transaction is an XA transaction, the transaction's XA ID.
- char name[];
- If a name was specified for the transaction, up to the first 50 bytes
of that name, followed by a nul termination byte.
The DB_ENV->txn_stat method
returns a non-zero error value on failure
and 0 on success.
Parameters
- flags
- The flags parameter must be set to 0 or
the following value:
- DB_STAT_CLEAR
- Reset statistics after returning their values.
- statp
- The statp parameter references memory into which
a pointer to the allocated statistics structure is copied.
Errors
The DB_ENV->txn_stat method
may fail and return one of the following non-zero errors:
- EINVAL
- An
invalid flag value or parameter was specified.
Description: DB_ENV->txn_stat_print
The DB_ENV->txn_stat_print method displays the
transaction subsystem statistical information, as described for the DB_ENV->txn_stat method.
The information is printed to a specified output channel (see the
DB_ENV->set_msgfile method for more information), or passed to an
application callback function (see the DB_ENV->set_msgcall method for
more information).
The DB_ENV->txn_stat_print method may not be called before the DB_ENV->open method has
been called.
The DB_ENV->txn_stat_print method
returns a non-zero error value on failure
and 0 on success.
Parameters
- flags
- The flags parameter must be set to 0 or
the following value:
- DB_STAT_ALL
- Display all available information.
Class
DB_ENV, DB_TXN
See Also
Transaction Subsystem and Related Methods
Copyright (c) 1996-2005 Sleepycat Software, Inc. - All rights reserved.