Newsgroups: comp.parallel
From: mentat project <mentat@server.cs.virginia.edu>
Subject: Mentat Version 2.8 Released
Organization: University of Virginia Computer Science Department
Date: Fri, 21 Apr 1995 22:22:39 GMT
Message-ID: <3nlil3$i9p@usenet.srv.cis.pitt.edu>

	We are please to announce the release of Mentat version 2.8. 
        
        Briefly, Mentat is an object-oriented parallel processing
        system developed at the University of Virginia. The programming
        language, MPL, is a C++ extension. The extensions allow the
        user to specify those classes that are sufficiently computationally
        complex to warrant parallel execution. Instances of those
        classes are treated differently by the compiler. Each instance
        has an associated thread of control and a unique address space.
        Member function execution is performed asynchronously. Object
        scheduling, argument marshalling, communication, and synchronization
        are managed by the compiler and run-time system. 
        
        Mentat is a mature system. It has been in use at a number of
        institutions world-wide for several years. Complete
        applications ranging from protein sequence comparison, to image
        processing, target recognition, automatic test pattern
        generation, database managers, to dense and sparse linear
        system solvers have been written using Mentat. 
        
        For more information on Mentat see our web page at:
            http://www.cs.virginia.edu/~mentat/
            
------------------------------------------------------------------------        
        Changes for Release 2.8
        

	Platforms supported

	Workstations	                      Compiler

            Sun 4's with SunOS 4.x	      CC_CenterLine
            Sun 4's with SunOS 5.3 (Solaris)  C_CenterLine
            SGI's under IRIX 5.2	      CC
            IBM RS6000's	              GNU g++ (Ver 2.4.5)
            HP's 	                      CC

	Parallel Machines	              Compiler

            Silicon Graphics Power Challenge  CC
            IBM SP-2	                      GNU g++ (Ver 2.4.5)
            Intel Paragon	              CC
            Convex Exemplar	              CC
            
            Notes: Because of compatibility issues, support for GNU g++ has 
            been diminished. The SGI Challenge and Convex Exemplar versions are
            in test and have not been released.

	New version of the mplfront compiler
		- Compiler enhancements
		- Bug Fixes

	Completely re-written MPL Reference Manual

	Mentat Assistant Debugger (MAD) - a full featured post-mortem debugger

	Faster system start-up.

        System level fault-tolerance. 
          Mentat may now be started with phoenix rather than start_mentat.
          Phoenix monitors the health of the Mentat system.  If a system
          object (im, tmu, or thermometer) fails, phoenix automatically
          restarts it. If a host fails, phoenix reconfigures the system,
          notifies other hosts, and begins to monitor the failed host.  When
          the host recovers, phoenix restarts Mentat on that host and again
          notifies the other hosts. 

        Source code availablity.
          Because we do not have all compilers for all platforms in-house, we
          have decided to make the run-time library sources available so that
          users can re-compile the libraries on their hosts.  WE WILL NOT
          ASSIST IN DEBUGING CHANGES YOU MAKE TO THE RUN-TIME SYSTEM!
          The full system sources (compiler, run-time, utilities) are
          available for research purposes with a zero-cost license. 

        Class description database (CDB) maintained by mplc. CDB contains
          information on classes, including supported architectures and the
          location of binaries. 

	Mentat no longer needs to be in kmem group or have kernel read privilege

	Thermometer
          An interactive tool that allows users to restrict the amount of CPU
          and memory resources available for each node in a Mentat network. 

	Instantiation managers 
		- use CDB when scheduling 
		- monitor main programs
		- collect resource usage information (cpu seconds, 
                  message volume, etc.)
		- enforce resource limits set by the thermometer
                - support multiprocessors by using the number of local
                  processors (on a host) in the scheduling decision

        <ctrl-C> and other signals. 
          When a main program dies due to a signal, e.g., <ctrl-C>, all
          persistent mentat objects started by that program (directly or
          indirectly) are killed. In other words, we track down and kill
          orphans. We are working on doing the same if a child object dies. 

	Configuration database no longer supports
            BEST_MOST_RECENTLY
            USE_KERNEL_MEMORY
            QUEUE_LENGTH

	Mentatmeter no longer supported.

	System and library enhancements
            - will work with ATT Release 3.0 and later

	Legion features - see http://www.cs.virginia.edu/~mentat/ for more 
        information on Legion.
            - Legion file system
            - class description database
            - PVM support (in beta)
        Check out our campus-wide virtual machine on our new legion www home
        page accessable through http://www.cs.virginia.edu/~mentat/newlegion/


PLEASE NOTE THAT THIS VERSION OF MENTAT REQUIRES THAT ALL 
MENTAT OBJECTS FROM PREVIOUS VERSIONS BE RECOMPILED

