1.2. Organization of this Document

This document is organized as follows:

• Chapter MPI-2 Terms and Conventions , MPI-2 Terms and Conventions, explains notational terms and conventions used throughout the MPI-2 document.
• Chapter Version 1.2 of MPI , Version 1.2 of MPI, contains the specification of MPI-1.2, which has one new function and consists primarily of clarifications to MPI-1.1. It is expected that some implementations will need modification in order to become MPI-1 compliant, as the result of these clarifications.

The rest of this document contains the MPI-2 Standard Specification. It adds substantial new types of functionality to MPI, in most cases specifying functions for an extended computational model (e.g., dynamic process creation and one-sided communication) or for a significant new capability (e.g., parallel I/O).

The following is a list of the chapters in MPI-2, along with a brief description of each.

• Chapter Miscellany , Miscellany, discusses items that don't fit elsewhere, in particular language interoperability.
• Chapter Process Creation and Management , Process Creation and Management, discusses the extension of MPI to remove the static process model in MPI. It defines routines that allow for creation of processes.
• Chapter One-Sided Communications , One-Sided Communications, defines communication routines that can be completed by a single process. These include shared-memory operations (put/get) and remote accumulate operations.
• Chapter Extended Collective Operations , Extended Collective Operations, extends the semantics of MPI-1 collective operations to include intercommunicators. It also adds more convenient methods of constructing intercommunicators and two new collective operations.
• Chapter External Interfaces , External Interfaces, defines routines designed to allow developers to layer on top of MPI. This includes generalized requests, routines that decode MPI opaque objects, and threads.
• Chapter I/O , I/O, defines MPI-2 support for parallel I/O.
• Chapter Language Bindings , Language Bindings, describes the C++ binding and discusses Fortran-90 issues.

• Annex Language Binding , Language Bindings, gives bindings for MPI-2 functions, and lists constants, error codes, etc.
• Annex MPI-1 C++ Language Binding , MPI-1 C++ Language Binding, gives C++ bindings for MPI-1.

MPI-2 provides various interfaces to facilitate interoperability of distinct MPI implementations. Among these are the canonical data representation for MPI I/O and for MPI_PACK_EXTERNAL and MPI_UNPACK_EXTERNAL. The definition of an actual binding of these interfaces that will enable interoperability is outside the scope of this document.

A separate document consists of ideas that were discussed in the MPI Forum and deemed to have value, but are not included in the MPI Standard. They are part of the ``Journal of Development'' (JOD), lest good ideas be lost and in order to provide a starting point for further work. The chapters in the JOD are

• Chapter , Spawning Independent Processes, includes some elements of dynamic process management, in particular management of processes with which the spawning processes do not intend to communicate, that the Forum discussed at length but ultimately decided not to include in the MPI Standard.
• Chapter , Threads and MPI, describes some of the expected interaction between an MPI implementation and a thread library in a multi-threaded environment.
• Chapter , Communicator ID, describes an approach to providing identifiers for communicators.
• Chapter , Miscellany, discusses Miscellaneous topics in the MPI JOD, in particular single-copy routines for use in shared-memory environments and new datatype constructors.
• Chapter , Toward a Full Fortran 90 Interface, describes an approach to providing a more elaborate Fortran 90 interface.
• Chapter , Split Collective Communication, describes a specification for certain non-blocking collective operations.
• Chapter , Real-Time MPI, discusses MPI support for real time processing.