#include <db.h>
int
DB_ENV->set_thread_id_string(DB_ENV *dbenv,
    char *(*thread_id_string)(DB_ENV *dbenv,
    pid_t pid, db_threadid_t tid, char *buf));  
      
         Declare a function that formats a process ID and thread ID identifier
         pair for display into a caller-supplied buffer.  The function must
         return a reference to the caller-specified buffer.  The
         DB_ENV->set_thread_id_string() method supports the 
         DB_ENV->set_thread_id() 
         method.
    
         The DB_ENV->set_thread_id_string() method configures operations
         performed using the specified DB_ENV  
         handle, not all operations performed on the underlying database environment.
    
         The DB_ENV->set_thread_id_string() method may be called at any time
         during the life of the application.
    
         The DB_ENV->set_thread_id_string() 
            
                  method returns a non-zero error value on failure and 0 on success.
            
            
        
    
The thread_id_string parameter is a function which returns a buffer in which is an identifier pair formatted for display. The function takes four arguments:
                                             dbenv
                                     
The dbenv parameter is the enclosing database environment handle, allowing application access to the application-private fields of that object.
                                             pid
                                     
The pid argument is a process ID.
                                             tid
                                     
The tid argument is a thread ID.
                                             buf
                                     
The buf argument is character array of at least DB_THREADID_STRLEN bytes in length, into which the identifier pair should be formatted.
If no thread_id_string function is specified, the default routine displays the identifier pair as "pid/tid", that is, the process ID represented as an unsigned integer value, a slash ('/') character, then the thread ID represented as an unsigned integer value.
                         The DB_ENV->set_thread_id_string() 
            
                 method may fail and return one of the following non-zero errors: