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<th colspan="3" align="center">DB_ENV->close()</th>
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<h2 class="title" style="clear: both"><a id="envclose"></a>DB_ENV->close()</h2>
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</div>
<pre class="programlisting">#include <db.h>
int
DB_ENV->close(DB_ENV *dbenv, u_int32_t flags); </pre>
<p>
The <code class="methodname">DB_ENV->close()</code> method closes the Berkeley DB environment,
freeing any allocated resources and closing any underlying subsystems.
</p>
<p>
The <a class="link" href="env.html" title="Chapter 5. The DB_ENV Handle">DB_ENV</a> handle should
not be closed while any other handle that refers to it is not yet
closed; for example, database environment handles must not be closed
while database handles remain open, or transactions in the environment
have not yet been committed or aborted. Specifically, this includes the
<a class="link" href="db.html" title="Chapter 2. The DB Handle">DB</a>,
<a class="link" href="dbc.html" title="Chapter 3. The DBcursor Handle">DBcursor</a>,
<a class="link" href="txn.html" title="Chapter 12. The DB_TXN Handle">DB_TXN</a>,
<a class="link" href="logc.html" title="The DB_LOGC Handle">DB_LOGC</a> and
<a class="link" href="memp.html" title="Chapter 8. The DB_MPOOLFILE Handle">DB_MPOOLFILE</a> handles.
</p>
<p>
Where the environment was initialized with the
<a class="link" href="envopen.html#envopen_DB_INIT_LOCK">DB_INIT_LOCK</a> flag,
calling <code class="methodname">DB_ENV->close()</code> does not release any locks still held by the
closing process, providing functionality for long-lived locks.
Processes that want to have all their locks released can do so by
issuing the appropriate <a class="xref" href="lockvec.html" title="DB_ENV->lock_vec()">DB_ENV->lock_vec()</a> call.
</p>
<p>
Where the environment was initialized with the
<a class="link" href="envopen.html#envopen_DB_INIT_MPOOL">DB_INIT_MPOOL</a> flag,
calling <code class="methodname">DB_ENV->close()</code> implies calls to
<a class="xref" href="mempfclose.html" title="DB_MPOOLFILE->close()">DB_MPOOLFILE->close()</a> for any
remaining open files in the memory pool that were returned to this
process by calls to <a class="xref" href="mempfopen.html" title="DB_MPOOLFILE->open()">DB_MPOOLFILE->open()</a>. It does
not imply a call to <a class="xref" href="mempfsync.html" title="DB_MPOOLFILE->sync()">DB_MPOOLFILE->sync()</a> for those
files.
</p>
<p>
Where the environment was initialized with the
<a class="link" href="envopen.html#envopen_DB_INIT_TXN">DB_INIT_TXN</a> flag,
calling <code class="methodname">DB_ENV->close()</code> aborts any unresolved transactions.
Applications should not depend on this behavior for transactions
involving Berkeley DB databases; all such transactions should be
explicitly resolved. The problem with depending on this semantic is
that aborting an unresolved transaction involving database operations
requires a database handle. Because the database handles should have
been closed before calling <code class="methodname">DB_ENV->close()</code>, it will not be possible
to abort the transaction, and recovery will have to be run on the
Berkeley DB environment before further operations are done.
</p>
<p>
Where log cursors were created using the
<a class="xref" href="logcursor.html" title="DB_ENV->log_cursor()">DB_ENV->log_cursor()</a> method,
calling <code class="methodname">DB_ENV->close()</code> does not imply closing those cursors.
</p>
<p>
In multithreaded applications, only a single thread may call the
<code class="methodname">DB_ENV->close()</code> method.
</p>
<p>
After <code class="methodname">DB_ENV->close()</code> has been called, regardless of its return, the
Berkeley DB environment handle may not be accessed again.
</p>
<p>
The <code class="methodname">DB_ENV->close()</code> <span>
<span>
method returns a non-zero error value on failure and 0 on success.
</span>
</span>
</p>
<div class="sect2" lang="en" xml:lang="en">
<div class="titlepage">
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<h3 class="title"><a id="id1660579"></a>Parameters</h3>
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<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="id1660937"></a>flags</h4>
</div>
</div>
</div>
<p>
The <span class="bold"><strong>flags</strong></span> parameter is currently
unused, and must be set to 0.
</p>
</div>
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<h3 class="title"><a id="id1661084"></a>Class</h3>
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<p>
<a class="link" href="env.html" title="Chapter 5. The DB_ENV Handle">DB_ENV</a>
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<div class="sect2" lang="en" xml:lang="en">
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<h3 class="title"><a id="id1660580"></a>See Also</h3>
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</div>
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<p>
<a class="xref" href="env.html#envlist" title="Database Environments and Related Methods">Database Environments and Related Methods</a>
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