Access frontier for demand loading pages in object-oriented databases

摘要

A method, system and article of manufacture for providing access frontier page(s) around all accessible memory pages loaded from an object-oriented database to prevent simultaneous access by multiple threads to an initializing page. On initializing the root pages from an object-oriented database including bringing them into memory and swizzling pointers in the pages, access frontier pages corresponding to each swizzled pointer are initialized and marked as inaccessible. All pointers contained in these access frontier pages that do not point to either an initialized and accessible page such as a root page or another access frontier page have page table entries created for them and are marked inaccessible. Any dereference of a pointer that causes a fault must be an access to an object on an access frontier page. A page fault interrupt handling routine proceeds, for each of the uninitialized pages pointed to by pointers on the faulted access frontier page, to convert it into an access frontier page by initializing a corresponding page from the object-oriented database, including bringing in the page and swizzling pointers in the page, and setting up inaccessible page table entries for pointers that do not point to other frontier pages or accessible and initialized pages, and marking the page inaccessible. The faulted page is marked accessible thereafter and surrounded by access frontier pages.