#include <db_cxx.h> int DbEnv::mutex_set_tas_spins(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 database environment's test-and-set spin count may also be configured 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 DbEnv::mutex_set_tas_spins() method configures operations
         performed using the specified 
         DbEnv  handle, not all
         operations performed on the underlying database environment.
    
         The DbEnv::mutex_set_tas_spins() method may be called at any time
         during the life of the application.
    
         The DbEnv::mutex_set_tas_spins() 
            
            
                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.
            
        
    
                         The DbEnv::mutex_set_tas_spins() 
            
            
                method may fail and throw a DbException 
                exception, encapsulating one of the following non-zero errors, or return one
                of the following non-zero errors: