1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
|
<!--$Id: txn_stat.so,v 10.27 2000/05/25 13:47:08 dda Exp $-->
<!--Copyright 1997, 1998, 1999, 2000 by Sleepycat Software, Inc.-->
<!--All rights reserved.-->
<html>
<head>
<title>Berkeley DB: txn_stat</title>
<meta name="description" content="Berkeley DB: An embedded database programmatic toolkit.">
<meta name="keywords" content="embedded,database,programmatic,toolkit,b+tree,btree,hash,hashing,transaction,transactions,locking,logging,access method,access methods,java,C,C++">
</head>
<body bgcolor=white>
<a name="2"><!--meow--></a>
<table><tr valign=top>
<td>
<h1>txn_stat</h1>
</td>
<td width="1%">
<a href="../api_c/c_index.html"><img src="../images/api.gif" alt="API"></a><a href="../ref/toc.html"><img src="../images/ref.gif" alt="Ref"></a>
</td></tr></table>
<hr size=1 noshade>
<tt>
<h3><pre>
#include <db.h>
<p>
int
txn_stat(DB_ENV *env,
DB_TXN_STAT **statp, void *(*db_malloc)(size_t));
</pre></h3>
<h1>Description</h1>
<p>The txn_stat function
creates a statistical structure and copies a pointer to it into a
user-specified memory location.
<p>Statistical structures are created in allocated memory. If <b>db_malloc</b> is non-NULL, it
is called to allocate the memory, otherwise, the library function
<b>malloc</b>(3) is used. The function <b>db_malloc</b> must match
the calling conventions of the <b>malloc</b>(3) library routine.
Regardless, the caller is responsible for deallocating the returned
memory. To deallocate returned memory, free the returned memory
reference, references inside the returned memory do not need to be
individually freed.
<p>The transaction region statistics are stored in a structure of type
DB_TXN_STAT. The following DB_TXN_STAT fields will be filled in:
<p><dl compact>
<dt><a href="../api_c/db_lsn.html">DB_LSN</a> st_last_ckp;<dd>The LSN of the last checkpoint.
<dt><a href="../api_c/db_lsn.html">DB_LSN</a> st_pending_ckp;<dd>The LSN of any checkpoint that is currently in progress. If
<b>st_pending_ckp</b> is the same as <b>st_last_ckp</b> there
is no checkpoint in progress.
<dt>time_t st_time_ckp;<dd>The time the last completed checkpoint finished (as the number of seconds
since the Epoch, returned by the IEEE/ANSI Std 1003.1 (POSIX) <b>time</b> interface).
<dt>u_int32_t st_last_txnid;<dd>The last transaction ID allocated.
<dt>u_int32_t st_maxtxns;<dd>The maximum number of active transactions possible.
<dt>u_int32_t st_nactive;<dd>The number of transactions that are currently active.
<dt>u_int32_t st_maxnactive;<dd>The maximum number of active transactions at any one time.
<dt>u_int32_t st_nbegins;<dd>The number of transactions that have begun.
<dt>u_int32_t st_naborts;<dd>The number of transactions that have aborted.
<dt>u_int32_t st_ncommits;<dd>The number of transactions that have committed.
<dt>u_int32_t st_regsize;<dd>The size of the region.
<dt>u_int32_t st_region_wait;<dd>The number of times that a thread of control was forced to wait before
obtaining the region lock.
<dt>u_int32_t st_region_nowait;<dd>The number of times that a thread of control was able to obtain
the region lock without waiting.
<dt>DB_TXN_ACTIVE * st_txnarray;<dd>A pointer to an array of <b>st_nactive</b> DB_TXN_ACTIVE structures,
describing the currently active transactions. The following fields of
the DB_TXN_ACTIVE structure will be filled in:
<p><dl compact>
<p><dt>u_int32_t txnid;<dd>The transaction ID as returned by <a href="../api_c/txn_begin.html">txn_begin</a>.
<dt>u_int32_t parentid;<dd>The transaction ID of the parent transaction (or 0, if no parent).
<dt><a href="../api_c/db_lsn.html">DB_LSN</a> lsn;<dd>The log sequence number of the transaction-begin record.
</dl>
</dl>
<p>The txn_stat function returns a non-zero error value on failure and 0 on success.
<h1>Errors</h1>
<p>The txn_stat function may fail and return a non-zero error for errors specified for other Berkeley DB and C library or system functions.
If a catastrophic error has occurred, the txn_stat function may fail and return
<a href="../ref/program/errorret.html#DB_RUNRECOVERY">DB_RUNRECOVERY</a>, in which case all subsequent Berkeley DB calls will fail
in the same way.
<h1>See Also</h1>
<a href="../api_c/env_set_tx_max.html">DBENV->set_tx_max</a>,
<a href="../api_c/env_set_tx_recover.html">DBENV->set_tx_recover</a>,
<a href="../api_c/env_set_tx_timestamp.html">DBENV->set_tx_timestamp</a>,
<a href="../api_c/txn_abort.html">txn_abort</a>,
<a href="../api_c/txn_begin.html">txn_begin</a>,
<a href="../api_c/txn_checkpoint.html">txn_checkpoint</a>,
<a href="../api_c/txn_commit.html">txn_commit</a>,
<a href="../api_c/txn_id.html">txn_id</a>,
<a href="../api_c/txn_prepare.html">txn_prepare</a>
and
<a href="../api_c/txn_stat.html">txn_stat</a>.
</tt>
<table><tr><td><br></td><td width="1%">
<a href="../api_c/c_index.html"><img src="../images/api.gif" alt="API"></a><a href="../ref/toc.html"><img src="../images/ref.gif" alt="Ref"></a>
</td></tr></table>
<p><font size=1><a href="http://www.sleepycat.com">Copyright Sleepycat Software</a></font>
</body>
</html>
|
