Path: utzoo!attcan!uunet!mcsun!inria!chorus!mgu From: mgu@chorus.fr (Marc Guillemont) Newsgroups: comp.realtime Subject: Re: Real-Time Operating Systems Message-ID: <5887@chorus.fr> Date: 3 Aug 90 08:32:38 GMT References: <2931@zipeecs.umich.edu> Sender: news@chorus.fr Lines: 196 From article <2931@zipeecs.umich.edu>, by walden@dip.eecs.umich.edu (Eugene Marvin Walden): > > I was wondering if anybody knows of any other commercial real-time operating > systems than the ones listed below: > > 1. VRTX (Ready Systems) > 2. IRMX (Intel) > 3. QNX (Quantum Software) > 4. VxWorks (Wind River Systems) > 5. OS/9, OS/9000 (Microware) > 6. Alpha (Concurrent Computer Corp.) > 7. Kadak Chorus syste`mes has a high performance distributed operating system, CHORUS. Its base is the real-time CHORUS Nucleus; it may be complemented by servers in order to build CHORUS/MiX, a full UNIX operating system. Actual version, v3.2, of both products is described below. CHORUS Nucleus v3.2 =================== The CHORUS Nucleus is the heart of the CHORUS family of real-time distributed operating system products, notably the CHORUS/MiX UNIX operating system. Performance tuned to ensure real-time responsiveness and fast Inter-Process Communication, the Nucleus integrates these essential services: - A real-time executive synchronizes and preemptively schedules priority-based tasks - Modern, optimized Inter-Process Communication (asynchronous IPC and Remote Procedure Calls RPC) mechanisms give efficient, transparent access to resources distributed on a network or bus, - A low-level hardware supervisor dynamically loads interrupt and trap handlers, - An advanced (optional) distributed virtual memory manager optimizes distributed object copying. Main Benefits - Rapid real-time response to external events - Simple, dynamic migration, evolution and reconfiguration of systems and servers - Easier, transparent distributed programming with automatic localization - Fast, efficient local and remote RPC and IPC - Contains very short critical sections for maximum interruptibility - Increased continuity of service via enabling technologies for fault-tolerant servers - Enabling technologies for secure systems Real-time Executive - Light-weight threads (tasks/processes) - Preemptive priority-based scheduler - 256 priority levels, FIFO within levels - Synchronization by events and semaphores - Execution control ("suspend", "resume") - Time-slicing (optional) - Separate address spaces (optional) - Time-outs (optional) - Allocation/deallocation of memory Inter-Process Communication - Fast, distribution-transparent IPC and RPC - Optimized local and distant communication including a coupling with the distributed virtual memory manager - Small untyped messages for fastest processing by network interfaces - Efficient low-overhead internal protocols Distributed Virtual Memory Management - Optional: deconfigurable for real-time use - Demand-paged over network so pages are brought into memory only when needed - Can lock virtual memory pages in memory to prevent swap-out - Separate, protected address spaces - Can share memory between different tasks Hardware Supervisor - Dynamic (de)installation of interrupt and trap handlers - User-level handlers can be installed into system space - Multiple priority-ordered handlers Network Manager - Automatic localization of distributed objects providing transparent remote access to distant objects as if they were local - A high-level network interface independent of specific network protocols - Supports standard (OSI and TCP/IP) or private network protocols - Uses the OSIAM protocol manager Reference microprocessors iAPX186, iAPX386, MC68020, MC68030, MC88000 Reference machines AT/386 compatibles, Sun (SUN 3), Reference standards OSI/TOP (layers 1-4), TCP/IP CHORUS/MiX v3.2 =============== An example of the powerful CHORUS technology, Chorus syste`mes' CHORUS/MiX operating system is a highly modular real-time distributed UNIX system conforming to international standards (X/Open). The CHORUS/MiX system is built from the real-time CHORUS Nucleus, thus eliminating the traditional split between development systems and real-time delivery systems. System integration becomes much easier and development time and effort is reduced because cross-development can be eliminated. The CHORUS/MiX system is highly modular to provide substantially greater system flexibility, simpler maintenance and easier adaptation to changing needs. Building on the real-time distributed CHORUS Nucleus's low-level services, CHORUS/MiX supplies the traditional UNIX services with a set of independent servers: a Process Manager, a File Manager, a Socket Manager and a Device Manager. Chorus syste`mes has developed several techniques to distribute, transparently and simply, UNIX programs as well as files throughout a network or across a system bus. As a result, the standard utilities operate on any file or process on the CHORUS/MiX network simplifying administration, using resources more efficiently and increasing the sharing of information between users and programs. Main Benefits - The system is highly modular, permitting, for example, diskless machines without a file system manager. - New file system implementations or extensions can be made and tested at the user level. After testing they can be installed in system space for higher performance. - UNIX kernel tasks as well as user processes are preemptable and scheduled by the CHORUS Nucleus to maintain real-time response even when UNIX is active. - Supports system calls defined by the base-level X/Open standard. Process Management - Real-time processes scheduled preemptively by task priority. - Multiple threads per process. - Threads scheduled by the CHORUS Nucleus. - UNIX signals are sent (transparently across the network if necessary) to the correct threads and child processes. - Distributed processes (programs), including distributed ps and kill. - Optimized remote execution (exec onto another machine). File Management - Transparent distributed file system. - Automatic interconnection of new file systems without user or administrator intervention. - Symbolic links mask shared file locations. - Uses the CHORUS Nucleus's Virtual Memory External Mapper interface for demand-paging across the network and swapping to disk. Device Management - Compatibility library preserves UNIX semantics for easy porting of existing drivers. Reference machines AT/386 compatibles Reference Standards X/Open (base level), POSIX CHORUS is a registered trademark of Chorus syste`mes. CHORUS/MiX is a trademark of Chorus syste`mes. UNIX is a registered trademark of AT&T. OSIAM is a registered trademark of Marben. -- _ __ _ _ _ ___ Marc Guillemont ' ) ) ' ) ) ) / ) Chorus syste`mes /--' __ / / / / __ . . 6, avenue Gustave Eiffel / / ' / / ( (___/_(_/_ F-78182, St-Quentin-en-Yvelines Cedex Tel: +33 (1) 30 57 00 22 Fax: +33 (1) 30 57 00 66 E-mail: mgu@chorus.fr or mgu%chorus.fr@mcsun.EU.net