Pm3: An orthogonally persistent systems programming language – design, implementation, performance

PM3 is an orthogonally persistent extension of the Modula-3 systems programming language, sup-porting persistence by reachability from named persistent roots. We describe the design and im-plementation of the PM3 prototype, and show that its performance is competitive with its non-orthogonal counterparts by direct comparison with the SHORE/C++ language binding to the SHORE object store. Experimental results, using the traversal portions of the OO7 benchmark, re-veal that the overheads of orthogonal persistence are not inherently more expensive than for non-orthogonal persistence, and justify our claim that orthogonal persistence deserves a level of accep-tance similar to that now emerging for automatic memory management (i.e., “garbage collection”), even in performance-conscious settings. The con-sequence will be safer and more flexible persistent systems that do not compromise performance.