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<h1>db_env_set_tas_spins</h1>
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<h3><pre>
#include &lt;db.h&gt;
<p>
int
db_env_set_tas_spins(u_int32_t tas_spins);
</pre></h3>
<h1>Description</h1>
<p>Specify that test-and-set mutexes should spin <b>tas_spins</b> times
without blocking.  The value defaults to 1 on uniprocessor systems and
to 50 times the number of processors on multiprocessor systems.
<p>The db_env_set_tas_spins interface affects the entire application, not a single
database or database environment.
<p>While the db_env_set_tas_spins interface may be used to configure Berkeley DB at any time
during the life of the application, it should normally be called before
making any calls to the <a href="../api_c/env_create.html">db_env_create</a> or <a href="../api_c/db_create.html">db_create</a> functions.
<p>The db_env_set_tas_spins function returns a non-zero error value on failure and 0 on success.
<p>The database environment's test-and-set spin count may also be set using the environment's
<b>DB_CONFIG</b> 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 <b>DB_CONFIG</b> file is read when the database
environment is opened, it will silently overrule configuration done
before that time.
<h1>Errors</h1>
<p><dl compact>
<p><dt>EINVAL<dd>An invalid flag value or parameter was specified.
</dl>
<h1>See Also</h1>
<a href="../api_c/env_close.html">DBENV-&gt;close</a>,
<a href="../api_c/env_create.html">db_env_create</a>,
<a href="../api_c/env_open.html">DBENV-&gt;open</a>,
<a href="../api_c/env_remove.html">DBENV-&gt;remove</a>,
<a href="../api_c/db_err.html">DBENV-&gt;err</a>,
<a href="../api_c/env_strerror.html">db_strerror</a>,
<a href="../api_c/env_version.html">db_version</a>,
<a href="../api_c/env_set_cachesize.html">DBENV-&gt;set_cachesize</a>,
<a href="../api_c/env_set_errcall.html">DBENV-&gt;set_errcall</a>,
<a href="../api_c/env_set_errfile.html">DBENV-&gt;set_errfile</a>,
<a href="../api_c/env_set_errpfx.html">DBENV-&gt;set_errpfx</a>,
<a href="../api_c/env_set_flags.html">DBENV-&gt;set_flags</a>,
<a href="../api_c/env_set_mutexlocks.html">DBENV-&gt;set_mutexlocks</a>,
<a href="../api_c/env_set_paniccall.html">DBENV-&gt;set_paniccall</a>,
and
<a href="../api_c/env_set_verbose.html">DBENV-&gt;set_verbose</a>.
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