1<?xml version="1.0" encoding="UTF-8" standalone="no"?> 2<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 3<html xmlns="http://www.w3.org/1999/xhtml"> 4 <head> 5 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> 6 <title>Release 4.2: DB_LOCK_NOTGRANTED</title> 7 <link rel="stylesheet" href="gettingStarted.css" type="text/css" /> 8 <meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /> 9 <link rel="start" href="index.html" title="Berkeley DB Programmer's Reference Guide" /> 10 <link rel="up" href="upgrade_4_2_toc.html" title="Chapter��39.��Upgrading Berkeley DB 4.1 applications to Berkeley DB 4.2" /> 11 <link rel="prev" href="upgrade_4_2_verify.html" title="Release 4.2: DB->verify" /> 12 <link rel="next" href="upgrade_4_2_repinit.html" title="Release 4.2: Replication" /> 13 </head> 14 <body> 15 <div class="navheader"> 16 <table width="100%" summary="Navigation header"> 17 <tr> 18 <th colspan="3" align="center">Release 4.2: DB_LOCK_NOTGRANTED</th> 19 </tr> 20 <tr> 21 <td width="20%" align="left"><a accesskey="p" href="upgrade_4_2_verify.html">Prev</a>��</td> 22 <th width="60%" align="center">Chapter��39.��Upgrading Berkeley DB 4.1 applications to Berkeley DB 4.2</th> 23 <td width="20%" align="right">��<a accesskey="n" href="upgrade_4_2_repinit.html">Next</a></td> 24 </tr> 25 </table> 26 <hr /> 27 </div> 28 <div class="sect1" lang="en" xml:lang="en"> 29 <div class="titlepage"> 30 <div> 31 <div> 32 <h2 class="title" style="clear: both"><a id="upgrade_4_2_lockng"></a>Release 4.2: DB_LOCK_NOTGRANTED</h2> 33 </div> 34 </div> 35 </div> 36 <p> 37 In previous releases, configuring lock or transaction timeout values or calling the <a href="../api_reference/C/txnbegin.html" class="olink">DB_ENV->txn_begin()</a> 38 method with the <a href="../api_reference/C/txnbegin.html#txnbegin_DB_TXN_NOWAIT" class="olink">DB_TXN_NOWAIT</a> flag caused database operation methods to return 39 <a class="link" href="program_errorret.html#program_errorret.DB_LOCK_NOTGRANTED">DB_LOCK_NOTGRANTED</a>, 40 or throw a 41 <a href="../api_reference/CXX/dblocknotgranted.html" class="olink">DbLockNotGrantedException</a> 42 exception. This required applications to unnecessarily handle multiple errors or 43 exception types. 44</p> 45 <p> 46 In the Berkeley DB 4.2 release, with one exception, database operations will no longer return 47 <a class="link" href="program_errorret.html#program_errorret.DB_LOCK_NOTGRANTED">DB_LOCK_NOTGRANTED</a> or throw a 48 <a href="../api_reference/CXX/dblocknotgranted.html" class="olink">DbLockNotGrantedException</a> 49 exception. Instead, database operations will return 50 <a class="link" href="program_errorret.html#program_errorret.DB_LOCK_DEADLOCK">DB_LOCK_DEADLOCK</a> or 51 throw a <a href="../api_reference/CXX/dbdeadlock.html" class="olink">DbDeadlockException</a> 52 exception. This change should require no application changes, as applications must 53 already be dealing with the possible 54 <a class="link" href="program_errorret.html#program_errorret.DB_LOCK_DEADLOCK">DB_LOCK_DEADLOCK</a> error 55 return or <a href="../api_reference/CXX/dbdeadlock.html" class="olink">DbDeadlockException</a> 56 exception from database operations. 57</p> 58 <p> 59 The one exception to this rule is the <a href="../api_reference/C/dbget.html" class="olink">DB->get()</a> method using the <a href="../api_reference/C/dbget.html#dbget_DB_CONSUME_WAIT" class="olink">DB_CONSUME_WAIT</a> flag to consume records 60 from a Queue. If lock or transaction timeouts are set, this method and flag combination may 61 return <a class="link" href="program_errorret.html#program_errorret.DB_LOCK_NOTGRANTED">DB_LOCK_NOTGRANTED</a> or 62 throw a 63 <a href="../api_reference/CXX/dblocknotgranted.html" class="olink">DbLockNotGrantedException</a> 64 exception. 65</p> 66 <p> 67 Applications wanting to distinguish between true deadlocks and timeouts can configure database 68 operation methods to return 69 <a class="link" href="program_errorret.html#program_errorret.DB_LOCK_NOTGRANTED">DB_LOCK_NOTGRANTED</a> or 70 throw a 71 <a href="../api_reference/CXX/dblocknotgranted.html" class="olink">DbLockNotGrantedException</a> 72 exception using the <a href="../api_reference/C/envset_flags.html#envset_flags_DB_TIME_NOTGRANTED" class="olink">DB_TIME_NOTGRANTED</a> flag. 73</p> 74 <p> 75 The <a href="../api_reference/C/lockget.html" class="olink">DB_ENV->lock_get()</a> and <a href="../api_reference/C/lockvec.html" class="olink">DB_ENV->lock_vec()</a> methods will continue to return 76 <a class="link" href="program_errorret.html#program_errorret.DB_LOCK_NOTGRANTED">DB_LOCK_NOTGRANTED</a>, or throw a 77 <a href="../api_reference/CXX/dblocknotgranted.html" class="olink">DbLockNotGrantedException</a> 78 exception as they have previously done. 79</p> 80 </div> 81 <div class="navfooter"> 82 <hr /> 83 <table width="100%" summary="Navigation footer"> 84 <tr> 85 <td width="40%" align="left"><a accesskey="p" href="upgrade_4_2_verify.html">Prev</a>��</td> 86 <td width="20%" align="center"> 87 <a accesskey="u" href="upgrade_4_2_toc.html">Up</a> 88 </td> 89 <td width="40%" align="right">��<a accesskey="n" href="upgrade_4_2_repinit.html">Next</a></td> 90 </tr> 91 <tr> 92 <td width="40%" align="left" valign="top">Release 4.2: DB->verify��</td> 93 <td width="20%" align="center"> 94 <a accesskey="h" href="index.html">Home</a> 95 </td> 96 <td width="40%" align="right" valign="top">��Release 4.2: Replication</td> 97 </tr> 98 </table> 99 </div> 100 </body> 101</html> 102