int DB_ENV->set_tas_spins(DB_ENV *dbenv, u_int32_t tas_spins);
Specify that test-and-set mutexes should spin tas_spins times without blocking. The value defaults to 1 on uniprocessor systems and to 50 times the number of processors on multiprocessor systems.
The DB_ENV->set_tas_spins method configures operations performed using the specified DB_ENV handle, not all operations performed on the underlying database environment.
The DB_ENV->set_tas_spins interface may be called at any time during the life of the application.
The DB_ENV->set_tas_spins method returns a non-zero error value on failure and 0 on success.
The database environment's test-and-set spin count may also be set using the environment's DB_CONFIG 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 DB_CONFIG file is read when the database environment is opened, it will silently overrule configuration done before that time.
The DB_ENV->set_tas_spins method may fail and return a non-zero error for the following conditions:
The DB_ENV->set_tas_spins 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->set_tas_spins method may fail and return DB_RUNRECOVERY, in which case all subsequent Berkeley DB calls will fail in the same way.
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