<!--$Id: env_set_tas_spins.so,v 10.9 2000/05/31 15:10:00 bostic Exp $--> <!--Copyright 1997, 1998, 1999, 2000 by Sleepycat Software, Inc.--> <!--All rights reserved.--> <html> <head> <title>Berkeley DB: db_env_set_tas_spins</title> <meta name="description" content="Berkeley DB: An embedded database programmatic toolkit."> <meta name="keywords" content="embedded,database,programmatic,toolkit,b+tree,btree,hash,hashing,transaction,transactions,locking,logging,access method,access methods,java,C,C++"> </head> <body bgcolor=white> <a name="2"><!--meow--></a> <table><tr valign=top> <td> <h1>db_env_set_tas_spins</h1> </td> <td width="1%"> <a href="../api_c/c_index.html"><img src="../images/api.gif" alt="API"></a><a href="../ref/toc.html"><img src="../images/ref.gif" alt="Ref"></a> </td></tr></table> <hr size=1 noshade> <tt> <h3><pre> #include <db.h> <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->close</a>, <a href="../api_c/env_create.html">db_env_create</a>, <a href="../api_c/env_open.html">DBENV->open</a>, <a href="../api_c/env_remove.html">DBENV->remove</a>, <a href="../api_c/db_err.html">DBENV->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->set_cachesize</a>, <a href="../api_c/env_set_errcall.html">DBENV->set_errcall</a>, <a href="../api_c/env_set_errfile.html">DBENV->set_errfile</a>, <a href="../api_c/env_set_errpfx.html">DBENV->set_errpfx</a>, <a href="../api_c/env_set_flags.html">DBENV->set_flags</a>, <a href="../api_c/env_set_mutexlocks.html">DBENV->set_mutexlocks</a>, <a href="../api_c/env_set_paniccall.html">DBENV->set_paniccall</a>, and <a href="../api_c/env_set_verbose.html">DBENV->set_verbose</a>. </tt> <table><tr><td><br></td><td width="1%"> <a href="../api_c/c_index.html"><img src="../images/api.gif" alt="API"></a><a href="../ref/toc.html"><img src="../images/ref.gif" alt="Ref"></a> </td></tr></table> <p><font size=1><a href="http://www.sleepycat.com">Copyright Sleepycat Software</a></font> </body> </html>