Message-passing Communication

Two implementation decisions could be made immediately. First, DPMTA is based on the PVM message-passing library [11] and therefore it was necessary to base NAMD on PVM as well. All communication done by NAMD, however, would use an intermediate interface to allow communications to be easily retargeted to MPI [12] or other standards, and to simplify later implementation of communication optimizations such as combining messages destined for the same processor. Second, after much debate C++ was selected... 

The current protot3rpe system includes three Expert modules, the IR Expert, the STIRS Expert, and the Human. All modules are written in Lisp. The IR Expert is a rule-based infrared interpreter which we have developed. The STIRS Expert is an interface to the STIRS program, a pattern-matching mass spectrum interpreter developed by McLafferty and coworkers at Cornell University, which is written in Fortran. () ) The interface translates the output of STIRS into a form palatable to our program, and handles the message-passing protocol required by the Controller. The Human module controls communication with the user. It allows user-supplied elemental or substructure information to influence the course of the analysis. The power of... 

Message passing, collective communication, and similar alternatives for programming software libraries for large-scale applications on distributed-memory computer systems. 

We now reexamine message passing as it pertains to software development and the interface of application software and library software. Compiler-managed parallelism is not yet ready for prime time. This means that efficient parallel programs are usually coded by hand, typically using point-to-point message passing and simple collective communications. There are many problems associated with this approach. 

Systolic Loop A message-passing mechanism where groups of processors pass data simultaneously with point-to-point communications. A basic systolic loop would pass part of the data structure around a ring executing tasks based on the particular data. 

The multicomputer model inherits the Eckert-von Neumann model for each node in the machine. This has the important practical consequence that standard languages like Fortran, C and can be used if there is also a software library available to help with communication issues. This combination of a standard language and communication library is called the message passing model. 

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