HYDRA: The Kernel of a Multiprocessor Operating System This paper describes the design philosophy of HYDRA-the kernel of an operating system for C.mmp, the Carnegie-Mellon Multi-Mini-Processor. This philosophy is realized through the introduction of a generalized notion of "resource", both physical and virtual, called an "object". Mechanisms are presented for dealing with objects, including the creation of new types, specification of new operations applicable to a given type, sharing, and protection of any reference to a given object against improper application of any of the operations defined with respect to that type of object. The mechanisms provide a coherent basis for extension of the system in two directions: the introduction of new facilities, and the creation of highly secure systems. CACM June, 1974 Wulf, W. Cohen, E. Corwin, W. Jones, A. Levin, R. Pierson, C. Pollack, F. operating system, kernel, nucleus, protection, security 4.3 6.2 CA740614 JB January 17, 1978 2:40 PM 1458 4 2632 1523 4 2632 1603 4 2632 1698 4 2632 1747 4 2632 1748 4 2632 1828 4 2632 1854 4 2632 1854 4 2632 1877 4 2632 1877 4 2632 1960 4 2632 1960 4 2632 2150 4 2632 2317 4 2632 2319 4 2632 2319 4 2632 2377 4 2632 2377 4 2632 2378 4 2632 2378 4 2632 2342 4 2632 2376 4 2632 2379 4 2632 2320 4 2632 2424 4 2632 2482 4 2632 2497 4 2632 2558 4 2632 2618 4 2632 2625 4 2632 2632 4 2632 2632 4 2632 2632 4 2632 2704 4 2632 2723 4 2632 2738 4 2632 2738 4 2632 2740 4 2632 2740 4 2632 2741 4 2632 2840 4 2632 2867 4 2632 2868 4 2632 2941 4 2632 3105 4 2632 3127 4 2632 3144 4 2632 3184 4 2632 1471 5 2632 1749 5 2632 2080 5 2632 2632 5 2632 2632 5 2632 2632 5 2632 2868 5 2632 2870 5 2632 2876 5 2632 3105 5 2632 3144 5 2632 953 6 2632 1471 6 2632 1471 6 2632 2080 6 2632 2298 6 2632 2377 6 2632 2377 6 2632 2380 6 2632 2491 6 2632 2558 6 2632 2597 6 2632 2624 6 2632 2625 6 2632 2625 6 2632 2625 6 2632 2632 6 2632 2632 6 2632 2632 6 2632 2632 6 2632 2632 6 2632 2685 6 2632 2868 6 2632 2939 6 2632 3068 6 2632