#include <db_cxx.h> int DbEnv::mutex_free(db_mutex_t mutex);
            The DbEnv::mutex_free() method discards a mutex allocated by 
            DbEnv::mutex_alloc().
    
             The DbEnv::mutex_free() method may not be called before the 
             DbEnv::open()  method is called.
    
         The DbEnv::mutex_free() 
            
            
                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 mutex parameter is a mutex previously allocated by DbEnv::mutex_alloc().
                         The DbEnv::mutex_free() 
            
            
                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: