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<b>DbEnv::set_thread_count</b>
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<b><pre>
#include <db_cxx.h>
<p>
int
DbEnv::set_thread_count(u_int32_t count);
<p>
int
DbEnv::get_thread_count(u_int32_t *countp);
</pre></b>
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<b>Description: DbEnv::set_thread_count</b>
<p>Declare an approximate number of threads in the database environment.
The DbEnv::set_thread_count method must be called prior to opening the
database environment if the <a href="../api_cxx/env_failchk.html">DbEnv::failchk</a> method will be used. The
DbEnv::set_thread_count method does not set the maximum number of
threads but is used to determine memory sizing and the thread control
block reclamation policy.</p>
<p>If a process has not configured an <b>is_alive</b> function from the
<a href="../api_cxx/env_set_isalive.html">DbEnv::set_isalive</a> method, and then attempts to join a database
environment configured for failure checking with the
<a href="../api_cxx/env_failchk.html">DbEnv::failchk</a>, <a href="../api_cxx/env_set_thread_id.html">DbEnv::set_thread_id</a>,
<a href="../api_cxx/env_set_isalive.html">DbEnv::set_isalive</a> and DbEnv::set_thread_count methods, the
program may be unable to allocate a thread control block and fail to
join the environment.
<b>This is true of the standalone Berkeley DB utility programs.</b>
To avoid problems when using the standalone Berkeley DB utility programs with
environments configured for failure checking, incorporate the utility's
functionality directly in the application, or call the
<a href="../api_cxx/env_failchk.html">DbEnv::failchk</a> method before running the utility.</p>
<p>The database environment's thread count may also be configured using the
environment's <a href="../ref/env/db_config.html#DB_CONFIG">DB_CONFIG</a> file. The syntax of the entry in that
file is a single line with the string "set_thread_count", one or more whitespace
characters, and the thread count.
Because the <a href="../ref/env/db_config.html#DB_CONFIG">DB_CONFIG</a> file is read when the database environment
is opened, it will silently overrule configuration done before that
time.</p>
<p>The DbEnv::set_thread_count method configures operations performed using the specified
<a href="../api_cxx/env_class.html">DbEnv</a> handle, not all operations performed on the underlying
database environment.</p>
<p>The DbEnv::set_thread_count method may not be called after the <a href="../api_cxx/env_open.html">DbEnv::open</a> method is
called.
</p>
<p>The DbEnv::set_thread_count method
either returns a non-zero error value
or throws an exception that encapsulates a non-zero error value on
failure, and returns 0 on success.
</p>
<b>Parameters</b> <br>
<b>count</b><ul compact><li>The <b>count</b> parameter is an approximate thread count for the
database environment.</ul>
<br>
<br><b>Errors</b>
<p>The DbEnv::set_thread_count method
may fail and throw
<a href="../api_cxx/except_class.html">DbException</a>,
encapsulating one of the following non-zero errors, or return one of
the following non-zero errors:</p>
<br>
<b>EINVAL</b><ul compact><li>If the method was called after <a href="../api_cxx/env_open.html">DbEnv::open</a> was called; or if an
invalid flag value or parameter was specified.</ul>
<br>
<hr size=1 noshade>
<b>Description: DbEnv::get_thread_count</b>
<p>The DbEnv::get_thread_count method returns the thread count.</p>
<p>The DbEnv::get_thread_count method may be called at any time during the life of the
application.</p>
<p>The DbEnv::get_thread_count method
either returns a non-zero error value
or throws an exception that encapsulates a non-zero error value on
failure, and returns 0 on success.
</p>
<b>Parameters</b> <br>
<b>countp</b><ul compact><li>The DbEnv::get_thread_count method returns the
thread count in <b>countp</b>.</ul>
<br>
<hr size=1 noshade>
<br><b>Class</b>
<a href="../api_cxx/env_class.html">DbEnv</a>
<br><b>See Also</b>
<a href="../api_cxx/env_list.html">Database Environments and Related Methods</a>
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