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<h1>DB_ENV->close</h1>
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<h3><pre>
#include <db.h>
<p>
int
DB_ENV->close(DB_ENV *dbenv, u_int32_t flags);
</pre></h3>
<h1>Description</h1>
<p>The DB_ENV->close method closes the Berkeley DB environment, freeing any
allocated resources and closing any underlying subsystems.
<p>Calling DB_ENV->close does not imply closing any databases that
were opened in the environment, and all databases opened in the
environment should be closed before the environment is closed.
<p>The <b>flags</b> parameter is currently unused, and must be set to 0.
<p>Where the environment was initialized with the <a href="../api_c/env_open.html#DB_INIT_LOCK">DB_INIT_LOCK</a> flag,
calling DB_ENV->close 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 href="../api_c/lock_vec.html">DB_ENV->lock_vec</a> call.
<p>Where the environment was initialized with the <a href="../api_c/env_open.html#DB_INIT_MPOOL">DB_INIT_MPOOL</a>
flag, calling DB_ENV->close implies calls to <a href="../api_c/memp_fclose.html">DB_MPOOLFILE->close</a> for
any remaining open files in the memory pool that were returned to this
process by calls to <a href="../api_c/memp_fopen.html">DB_MPOOLFILE->open</a>. It does not imply a call to
<a href="../api_c/memp_fsync.html">DB_MPOOLFILE->sync</a> for those files.
<p>Where the environment was initialized with the <a href="../api_c/env_open.html#DB_INIT_TXN">DB_INIT_TXN</a> flag,
calling DB_ENV->close 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 DB_ENV->close, 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>Where log cursors were created using the <a href="../api_c/log_cursor.html">DB_ENV->log_cursor</a> method, calling
DB_ENV->close does not imply closing those cursors.
<p>In multithreaded applications, only a single thread may call
DB_ENV->close.
<p>After DB_ENV->close has been called, regardless of its return, the
Berkeley DB environment handle may not be accessed again.
<p>The DB_ENV->close method returns a non-zero error value on failure and 0 on success.
<h1>Errors</h1>
<p>The DB_ENV->close method may fail and return a non-zero error for errors specified for other Berkeley DB and C library or system functions.
If a catastrophic error has occurred, the DB_ENV->close method may fail and
return <a href="../ref/program/errorret.html#DB_RUNRECOVERY">DB_RUNRECOVERY</a>,
in which case all subsequent Berkeley DB calls will fail in the same way.
<h1>Class</h1>
<a href="../api_c/env_class.html">DB_ENV</a>
<h1>See Also</h1>
<a href="../api_c/env_list.html">Database Environments and Related Methods</a>
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