A computer system has one or more program classes loaded in it. Each class includes a constant pool which is used for storing data items related to the program class. At least some of these data items need to undergo a resolution before they can be used, which transforms them from their initially loaded value into a usable value. In accordance with the invention, the system maintains both the unresolved value and the resolved value in the constant pool entry for a resolved data item. This allows the resolution process to be performed without using locks, thereby avoiding potential system delays due to contention for locks.