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<h2 class="title" style="clear: both"><a id="mutexset_tas_spins"></a>DB_ENV->mutex_set_tas_spins()</h2>
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<pre class="programlisting">#include <db.h>
int
DB_ENV->mutex_set_tas_spins(DB_ENV *dbenv, u_int32_t tas_spins); </pre>
<p>
Specify that test-and-set mutexes should spin <span class="bold"><strong>tas_spins</strong></span> times without blocking. The value
defaults to 1 on uniprocessor systems and to 50 times the number of
processors on multiprocessor systems, up to a maximum of 200.
</p>
<p>
The database environment's test-and-set spin count may also be
configured using the environment's <a href="../../programmer_reference/env_db_config.html#env_db_config.DB_CONFIG" class="olink">DB_CONFIG</a> file. The syntax of
the entry in that file is a single line with the string
"set_tas_spins", one or more whitespace characters, and the number
of spins. Because the <a href="../../programmer_reference/env_db_config.html#env_db_config.DB_CONFIG" class="olink">DB_CONFIG</a> file is read when the database
environment is opened, it will silently overrule configuration
done before that time.
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The <code class="methodname">DB_ENV->mutex_set_tas_spins()</code> method configures operations
performed using the specified
<a class="link" href="env.html" title="Chapter 5. The DB_ENV Handle">DB_ENV</a> handle, not all
operations performed on the underlying database environment.
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<p>
The <code class="methodname">DB_ENV->mutex_set_tas_spins()</code> method may be called at any time
during the life of the application.
</p>
<p>
The <code class="methodname">DB_ENV->mutex_set_tas_spins()</code> <span>
<span>
method returns a non-zero error value on failure and 0 on success.
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<h3 class="title"><a id="idp3433768"></a>Parameters</h3>
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<h4 class="title"><a id="idp3434928"></a>tas_spins</h4>
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<p>
The <span class="bold"><strong>tas_spins</strong></span> parameter is the number
of spins test-and-set mutexes should execute before blocking.
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<p>
The <code class="methodname">DB_ENV->mutex_set_tas_spins()</code> <span>
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method may fail and return one of the following non-zero errors:
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<h4 class="title"><a id="idp3456352"></a>EINVAL</h4>
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An invalid flag value or parameter was specified.
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<h3 class="title"><a id="idp3455272"></a>Class</h3>
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<a class="link" href="env.html" title="Chapter 5. The DB_ENV Handle">DB_ENV</a>
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<a class="xref" href="mutex.html#mutexlist" title="Mutex Methods">Mutex Methods</a>
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