81 lines
4.0 KiB
HTML
81 lines
4.0 KiB
HTML
<!--$Id: lock_detect.html 63573 2008-05-23 21:43:21Z trent.nelson $-->
|
|
<!--Copyright (c) 1997,2008 Oracle. All rights reserved.-->
|
|
<!--See the file LICENSE for redistribution information.-->
|
|
<html>
|
|
<head>
|
|
<title>Berkeley DB: DbEnv::lock_detect</title>
|
|
<meta name="description" content="Berkeley DB: An embedded database programmatic toolkit.">
|
|
<meta name="keywords" content="embedded,database,programmatic,toolkit,btree,hash,hashing,transaction,transactions,locking,logging,access method,access methods,Java,C,C++">
|
|
</head>
|
|
<body bgcolor=white>
|
|
<table width="100%"><tr valign=top>
|
|
<td>
|
|
<b>DbEnv::lock_detect</b>
|
|
</td>
|
|
<td align=right>
|
|
<a href="../api_cxx/api_core.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>
|
|
<b><pre>
|
|
#include <db_cxx.h>
|
|
<p>
|
|
int
|
|
DbEnv::lock_detect(u_int32_t flags, u_int32_t atype, int *rejected);
|
|
</pre></b>
|
|
<hr size=1 noshade>
|
|
<b>Description: DbEnv::lock_detect</b>
|
|
<p>The DbEnv::lock_detect method runs one iteration of the deadlock detector.
|
|
The deadlock detector traverses the lock table and marks one of the
|
|
participating lock requesters for rejection in each deadlock it finds.</p>
|
|
<p>The DbEnv::lock_detect method
|
|
either returns a non-zero error value
|
|
or throws an exception that encapsulates a non-zero error value on
|
|
failure, and returns 0 on success.
|
|
</p>
|
|
<b>Parameters</b> <br>
|
|
<b>rejected</b><ul compact><li>If the <b>rejected</b> parameter is non-NULL, the memory location to
|
|
which it refers will be set to the number of lock requests that were
|
|
rejected.</ul>
|
|
<b>atype</b><ul compact><li>The <b>atype</b> parameter specifies which lock request(s) to reject.
|
|
It must be set to one of the following list:
|
|
<br>
|
|
<b><a name="DB_LOCK_DEFAULT">DB_LOCK_DEFAULT</a></b><ul compact><li>Use whatever lock policy was specified when the database environment
|
|
was created. If no lock policy has yet been specified, set the lock
|
|
policy to DB_LOCK_RANDOM.</ul>
|
|
<b><a name="DB_LOCK_EXPIRE">DB_LOCK_EXPIRE</a></b><ul compact><li>Reject lock requests which have timed out. No other deadlock detection
|
|
is performed.</ul>
|
|
<b><a name="DB_LOCK_MAXLOCKS">DB_LOCK_MAXLOCKS</a></b><ul compact><li>Reject the lock request for the locker ID with the most locks.</ul>
|
|
<b><a name="DB_LOCK_MAXWRITE">DB_LOCK_MAXWRITE</a></b><ul compact><li>Reject the lock request for the locker ID with the most write locks.</ul>
|
|
<b><a name="DB_LOCK_MINLOCKS">DB_LOCK_MINLOCKS</a></b><ul compact><li>Reject the lock request for the locker ID with the fewest locks.</ul>
|
|
<b><a name="DB_LOCK_MINWRITE">DB_LOCK_MINWRITE</a></b><ul compact><li>Reject the lock request for the locker ID with the fewest write locks.</ul>
|
|
<b><a name="DB_LOCK_OLDEST">DB_LOCK_OLDEST</a></b><ul compact><li>Reject the lock request for the locker ID with the oldest lock.</ul>
|
|
<b><a name="DB_LOCK_RANDOM">DB_LOCK_RANDOM</a></b><ul compact><li>Reject the lock request for a random locker ID.</ul>
|
|
<b><a name="DB_LOCK_YOUNGEST">DB_LOCK_YOUNGEST</a></b><ul compact><li>Reject the lock request for the locker ID with the youngest lock.</ul>
|
|
<br></ul>
|
|
<b>flags</b><ul compact><li>The <b>flags</b> parameter is currently unused, and must be set to 0.</ul>
|
|
<br>
|
|
<br><b>Errors</b>
|
|
<p>The DbEnv::lock_detect method
|
|
may fail and throw
|
|
<a href="../api_cxx/except_class.html">DbException</a>,
|
|
encapsulating one of the following non-zero errors, or return one of
|
|
the following non-zero errors:</p>
|
|
<br>
|
|
<b>EINVAL</b><ul compact><li>An
|
|
invalid flag value or parameter was specified.</ul>
|
|
<br>
|
|
<hr size=1 noshade>
|
|
<br><b>Class</b>
|
|
<a href="../api_cxx/env_class.html">DbEnv</a>, <a href="../api_cxx/lock_class.html">DbLock</a>
|
|
<br><b>See Also</b>
|
|
<a href="../api_cxx/lock_list.html">Locking Subsystem and Related Methods</a>
|
|
</tt>
|
|
<table width="100%"><tr><td><br></td><td align=right>
|
|
<a href="../api_cxx/api_core.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>Copyright (c) 1996,2008 Oracle. All rights reserved.</font>
|
|
</body>
|
|
</html>
|