Annex E
(normative)
Distributed Systems
This Annex defines facilities for supporting the
implementation of distributed systems using multiple partitions working
cooperatively as part of a single Ada program.
Post-Compilation Rules
A
distributed system is an interconnection of one or more
processing
nodes (a system resource that has both computational and storage
capabilities), and zero or more
storage nodes (a system resource
that has only storage capabilities, with the storage addressable by one
or more processing nodes).
A
distributed program
comprises one or more partitions that execute independently (except when
they communicate) in a distributed system.
The process of mapping the partitions
of a program to the nodes in a distributed system is called
configuring
the partitions of the program.
Implementation Requirements
The implementation shall provide means for explicitly
assigning library units to a partition and for the configuring and execution
of a program consisting of multiple partitions on a distributed system;
the means are implementation defined.
Implementation Permissions
An implementation may require that the set of processing
nodes of a distributed system be homogeneous.
NOTE 1 The partitions comprising
a program can be executed on differently configured distributed systems
or on a nondistributed system without requiring recompilation. A distributed
program can be partitioned differently from the same set of library units
without recompilation. The resulting execution is semantically equivalent.
NOTE 2 A distributed program retains
the same type safety as the equivalent single partition program.
Ada 2005 and 2012 Editions sponsored in part by Ada-Europe
