mirror of
https://github.com/berkeleydb/je.git
synced 2024-11-15 01:46:24 +00:00
90 lines
3.8 KiB
HTML
90 lines
3.8 KiB
HTML
|
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
|
|||
|
|
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
|
|||
|
|
<html xmlns="http://www.w3.org/1999/xhtml">
|
|||
|
|
<head>
|
|||
|
|
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
|
|||
|
|
<title>Multiprocess Applications</title>
|
|||
|
|
<link rel="stylesheet" href="gettingStarted.css" type="text/css" />
|
|||
|
|
<meta name="generator" content="DocBook XSL Stylesheets V1.73.2" />
|
|||
|
|
<link rel="start" href="index.html" title="Getting Started with Berkeley DB Java Edition" />
|
|||
|
|
<link rel="up" href="concurrentProcessing.html" title="Appendix A. Concurrent Processing in Berkeley DB Java Edition" />
|
|||
|
|
<link rel="prev" href="concurrentProcessing.html" title="Appendix A. Concurrent Processing in Berkeley DB Java Edition" />
|
|||
|
|
</head>
|
|||
|
|
<body>
|
|||
|
|
<div xmlns="" class="navheader">
|
|||
|
|
<div class="libver">
|
|||
|
|
<p>Library Version 12.2.7.5</p>
|
|||
|
|
</div>
|
|||
|
|
<table width="100%" summary="Navigation header">
|
|||
|
|
<tr>
|
|||
|
|
<th colspan="3" align="center">Multiprocess Applications</th>
|
|||
|
|
</tr>
|
|||
|
|
<tr>
|
|||
|
|
<td width="20%" align="left"><a accesskey="p" href="concurrentProcessing.html">Prev</a> </td>
|
|||
|
|
<th width="60%" align="center">Appendix A. Concurrent Processing in Berkeley DB Java Edition</th>
|
|||
|
|
<td width="20%" align="right"> </td>
|
|||
|
|
</tr>
|
|||
|
|
</table>
|
|||
|
|
<hr />
|
|||
|
|
</div>
|
|||
|
|
<div class="sect1" lang="en" xml:lang="en">
|
|||
|
|
<div class="titlepage">
|
|||
|
|
<div>
|
|||
|
|
<div>
|
|||
|
|
<h2 class="title" style="clear: both"><a id="multiprocess"></a>Multiprocess Applications</h2>
|
|||
|
|
</div>
|
|||
|
|
</div>
|
|||
|
|
</div>
|
|||
|
|
<p>
|
|||
|
|
Note the following if you are writing an application that wants to access JE databases from multiple
|
|||
|
|
processes:
|
|||
|
|
</p>
|
|||
|
|
<div class="itemizedlist">
|
|||
|
|
<ul type="disc">
|
|||
|
|
<li>
|
|||
|
|
<p>
|
|||
|
|
In JE, you must use environments. Further, a database can be opened for write access only if the
|
|||
|
|
environment is opened for write access. Finally, only one process may have an environment opened for
|
|||
|
|
write access at a time.
|
|||
|
|
</p>
|
|||
|
|
</li>
|
|||
|
|
<li>
|
|||
|
|
<p>
|
|||
|
|
If your process attempts to open an environment for write, and another process has already opened that
|
|||
|
|
environment for write, then the open will fail. In this event, the process must either exit or open the
|
|||
|
|
environment as read-only.
|
|||
|
|
</p>
|
|||
|
|
</li>
|
|||
|
|
<li>
|
|||
|
|
<p>
|
|||
|
|
A process that opens an environment for read-only receives a snapshot of the data in that environment.
|
|||
|
|
If another process modifies the environment's databases in any way, the read-only version of the data
|
|||
|
|
will not be updated until the read-only process closes and reopens the environment (and by extension all
|
|||
|
|
databases in that environment).
|
|||
|
|
</p>
|
|||
|
|
</li>
|
|||
|
|
</ul>
|
|||
|
|
</div>
|
|||
|
|
</div>
|
|||
|
|
<div class="navfooter">
|
|||
|
|
<hr />
|
|||
|
|
<table width="100%" summary="Navigation footer">
|
|||
|
|
<tr>
|
|||
|
|
<td width="40%" align="left"><a accesskey="p" href="concurrentProcessing.html">Prev</a> </td>
|
|||
|
|
<td width="20%" align="center">
|
|||
|
|
<a accesskey="u" href="concurrentProcessing.html">Up</a>
|
|||
|
|
</td>
|
|||
|
|
<td width="40%" align="right"> </td>
|
|||
|
|
</tr>
|
|||
|
|
<tr>
|
|||
|
|
<td width="40%" align="left" valign="top">Appendix A. Concurrent Processing in Berkeley DB Java Edition </td>
|
|||
|
|
<td width="20%" align="center">
|
|||
|
|
<a accesskey="h" href="index.html">Home</a>
|
|||
|
|
</td>
|
|||
|
|
<td width="40%" align="right" valign="top"> </td>
|
|||
|
|
</tr>
|
|||
|
|
</table>
|
|||
|
|
</div>
|
|||
|
|
</body>
|
|||
|
|
</html>
|