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diff --git a/bdb/docs/ref/lock/stdmode.html b/bdb/docs/ref/lock/stdmode.html deleted file mode 100644 index ca1cd6b0bdd..00000000000 --- a/bdb/docs/ref/lock/stdmode.html +++ /dev/null @@ -1,61 +0,0 @@ -<!--$Id: stdmode.so,v 10.20 2000/03/18 21:43:14 bostic Exp $--> -<!--Copyright 1997, 1998, 1999, 2000 by Sleepycat Software, Inc.--> -<!--All rights reserved.--> -<html> -<head> -<title>Berkeley DB Reference Guide: Standard lock modes</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><h3><dl><dt>Berkeley DB Reference Guide:<dd>Locking Subsystem</dl></h3></td> -<td width="1%"><a href="../../ref/lock/page.html"><img src="../../images/prev.gif" alt="Prev"></a><a href="../../ref/toc.html"><img src="../../images/ref.gif" alt="Ref"></a><a href="../../ref/lock/notxn.html"><img src="../../images/next.gif" alt="Next"></a> -</td></tr></table> -<p> -<h1 align=center>Standard lock modes</h1> -<p>The Berkeley DB locking protocol is described by a conflict matrix. A conflict -matrix is an n x n array where n is the number of different lock modes -supported, and the (i, j)th entry of the array indicates whether a lock of -mode i conflicts with a lock of mode j. -<p>The Berkeley DB include files declare two commonly used conflict arrays: -<p><dl compact> -<p><dt>const u_int8_t db_rw_conflicts[ ];<dd>This is a conflict matrix for a simple scheme using shared and exclusive -lock modes. -<p><dt>const u_int8_t db_riw_conflicts[ ];<dd>This is a conflict matrix that involves various intent lock modes (e.g., -intent shared) that are used for multigranularity locking. -</dl> -<p>The number of modes associated with each matrix are DB_LOCK_RW_N and -DB_LOCK_RIW_N, respectively. -<p>In addition, the Berkeley DB include file defines the type <b>db_lockmode_t</b>, -which is the type of the lock modes used with the standard tables above: -<p><dl compact> -<p><dt>DB_LOCK_NG<dd>not granted (always 0) -<p><dt>DB_LOCK_READ<dd>read (shared) -<p><dt>DB_LOCK_WRITE<dd>write (exclusive) -</dl> -<p>As an example, consider the basic multiple-reader/single writer conflict -matrix described by <b>db_rw_conflicts</b>. In the following -example (and in the appropriate file), a 1 represents a conflict (i.e., -do not grant the lock if the indicated lock is held) and a 0 indicates -that it is OK to grant the lock. -<p>The rows indicate the lock that is held and the columns indicate the lock -that is requested. -<p><blockquote><pre> Notheld Read Write -Notheld 0 0 0 -Read* 0 0 1 -Write** 0 1 1 -</pre></blockquote> -<p><dl compact> -<p><dt>*<dd>In this case, suppose that there is a read lock held on an object. A new -request for a read lock would be granted, but a request for a write lock -would not. -<p><dt>**<dd>In this case, suppose that there is a write lock held on an object. A -new request for either a read or write lock would be denied. -</dl> -<table><tr><td><br></td><td width="1%"><a href="../../ref/lock/page.html"><img src="../../images/prev.gif" alt="Prev"></a><a href="../../ref/toc.html"><img src="../../images/ref.gif" alt="Ref"></a><a href="../../ref/lock/notxn.html"><img src="../../images/next.gif" alt="Next"></a> -</td></tr></table> -<p><font size=1><a href="http://www.sleepycat.com">Copyright Sleepycat Software</a></font> -</body> -</html> |