the page control block 82 is no longer available stores the mruval in the mru time field 204 and in lastcollect processing continues with step 714 at step 716 the action mechanism provides the modified selected page control block 82 to the requesting user thread collector 114 a c processing continues with step 718 at step 718 the action mechanism releases the lock processing is complete by randomly selecting a page control block 82 in the pcb array multiple user thread collectors 114 a c may obtain page control blocks 82 for user threads 112 a c in parallel thus increasing the speed at which a page control block 82 can be obtained as each user thread collector 114 a c checks first to see if the selected page control block is free by examining the available field 212 no free list is required thereby reducing the memory contention bottleneck and reducing the memory required in the paging manager 15 also overhead for locking is reduced if the pcb lock 206 is obtained only after determining that a page control block 82 can be used in an alternative embodiment a paging management system may include a dedicated collector thread 90 as described in conjunction with fig2 and a plurality of user thread collectors 114 a c as described in conjunction with fig5 the dedicated collector thread 90 maintains a free list of page buffers through a free list pointer 92 as described in conjunction with fig4 a 4 b if there are no page buffers 84 available on the free list all the page buffers 84 are assigned to user threads 112 a c the respective user thread collector 114 a c in the user.