Abstract: 

The design and implementation of embedded real-time systems are exposed
to the pull of competing requirements.
On the one hand, the designer needs the expressive power to model the
problem domain and the physical reality associated to it as accurately as possible.
On the other hand, the important costs of pre-acceptance verification require
the system implementation to be designed to facilitate verification from the outset.
Furthermore, both design and implementation must make do with the resource
limitations imposed by the restrained nature of the execution environment
(low power budget, low memory capacity, moderate throughput).

Embedded real-time systems are also inherently concurrent.
The need therefore arises to strongly correlate design to implementation
and to permit seamless feedback between them with respect to the real-time
and concurrency aspects.
Language-level concurrency is a much preferable choice in this respect,
owing to the significant aid that compiler support can provide to such feedback
and correlation.

Very few mainstream languages are concurrent. Even less have an adequate
real-time pedigree. Two languages are especially of interest: Ada and Java.
The Ada Ravenscar Profile is an ISO-level subset of the Ada concurrency
model, which was expressly designed to meet the design and implementation
requirements of embedded real-time systems.
The notion of `profile' is also making it into the definition of the
real-time extension of Java, whereby the J Consortium has proposed
a high-integrity real-time profile that derives directly from the
Ada Ravenscar Profile.

In this talk, we present the specification and the rationale
of the Ada Ravenscar Profile and we will relate it to the J Consortium
high-integrity real-time profile.