Run time support for the TUTOR language on a small computer system /

"UILU-ENG 77 1719."

Dynamic binary translation using run-time feedbacks

Dynamic binary translation is the process of translating, modifying and rewriting executable (binary) code from one machine to another at run-time. This process of low-level re-engineering consists of a reverse engineering phase followed by a forward engineering phase. UQDBT, the University of Queensland Dynamic Binary Translator, is a machine-adaptable translator. Adaptability is provided through the specification of properties of machines and their instruction sets, allowing the support of different pairs of source and target machines. Most binary translators are closely bound to a pair of machines, making analyses and code hard to reuse. Like most virtual machines, UQDBT performs generic optimizations that apply to a variety of machines. Frequently executed code is translated to native code by the use of edge weight instrumentation, which makes UQDBT converge more quickly than systems based on instruction speculation. In this paper, we describe the architecture and run-time feedback optimizations performed by the UQDBT system, and provide results obtained in the x86 and SPARC® platforms.

Summary of the 10th International workshop on Models@run.time

The 10th anniversary of the workshop Models@run.time was held at the 18th International Conference on Model Driven Engineering Languages and Systems. The workshop took place in the city of Ottawa, Canada, on the 29th of September 2015. The workshop was organized by Sebastian Gtz, Nelly Bencomo, Gordon Blair and Hui Song. Here, we present a summary of the discussions at the workshop and a synopsis of the topics discussed and highlighted during the workshop. The workshop received the award for the best workshop at the MODELS 2015 conference out of 18 workshops in total. The award was based upon the organization, program, web site timing and the feedback provided by the workshop participants.

Run-time connector synthesis for autonomic systems of systems

A key objective of autonomic computing is to reduce the cost and expertise required for the management of complex IT systems. As a growing number of these systems are implemented as hierarchies or federations of lower-level systems, techniques that support the development of autonomic systems of systems are required. This article introduces one such technique, which involves the run-time synthesis of autonomic system connectors. These connectors are specified by means of a new type of autonomic computing policy termed a resource definition policy, and enable the dynamic realisation of collections of collaborating autonomic systems, as envisaged by the original vision of autonomic computing. We propose a framework for the formal specification of autonomic computing policies, and use it to define the new policy type and to describe its application to the development of autonomic system of systems. To validate the approach, we present a sample data-centre application that was built using connectors synthesised from resource-definition policies.

The role of models@run.time in supporting on-the-fly interoperability

Models at runtime can be defined as abstract representations of a system, including its structure and behaviour, which exist in tandem with the given system during the actual execution time of that system. Furthermore, these models should be causally connected to the system being modelled, offering a reflective capability. Significant advances have been made in recent years in applying this concept, most notably in adaptive systems. In this paper we argue that a similar approach can also be used to support the dynamic generation of software artefacts at execution time. An important area where this is relevant is the generation of software mediators to tackle the crucial problem of interoperability in distributed systems. We refer to this approach as emergent middleware, representing a fundamentally new approach to resolving interoperability problems in the complex distributed systems of today. In this context, the runtime models are used to capture meta-information about the underlying networked systems that need to interoperate, including their interfaces and additional knowledge about their associated behaviour. This is supplemented by ontological information to enable semantic reasoning. This paper focuses on this novel use of models at runtime, examining in detail the nature of such runtime models coupled with consideration of the supportive algorithms and tools that extract this knowledge and use it to synthesise the appropriate emergent middleware.

Towards requirements aware systems:run-time resolution of design-time assumptions

In earlier work we proposed the idea of requirements-aware systems that could introspect about the extent to which their goals were being satisfied at runtime. When combined with requirements monitoring and self adaptive capabilities, requirements awareness should help optimize goal satisfaction even in the presence of changing run-time context. In this paper we describe initial progress towards the realization of requirements-aware systems with REAssuRE. REAssuRE focuses on explicit representation of assumptions made at design time. When such assumptions are shown not to hold, REAssuRE can trigger system adaptations to alternative goal realization strategies.

Relaxing claims:coping with uncertainty while evaluating assumptions at run time

Self-adaptation enables software systems to respond to changing environmental contexts that may not be fully understood at design time. Designing a dynamically adaptive system (DAS) to cope with this uncertainty is challenging, as it is impractical during requirements analysis and design time to anticipate every environmental condition that the DAS may encounter. Previously, the RELAX language was proposed to make requirements more tolerant to environmental uncertainty, and Claims were applied as markers of uncertainty that document how design assumptions affect goals. This paper integrates these two techniques in order to assess the validity of Claims at run time while tolerating minor and unanticipated environmental conditions that can trigger adaptations. We apply the proposed approach to the dynamic reconfiguration of a remote data mirroring network that must diffuse data while minimizing costs and exposure to data loss. Results show RELAXing Claims enables a DAS to reduce adaptation costs. © 2012 Springer-Verlag.

Summary of the 6th international workshop on models@run.time

The 6th edition of the workshop Models@run.time was held at the 14th International Conference MODELS. The workshop took place in the city of Wellington, New Zealand, on the 17th of October 2011. The workshop was organised by Nelly Bencomo, Gordon Blair, Robert France, Betty H.C. Cheng, and Cédric Jeanneret. We present a summary of the workshop and a synopsis of the papers presented during the workshop. © 2012 Springer-Verlag Berlin Heidelberg.

Second international workshop on models@run.time

The second edition of the workshop Models@run.time was co-located with the ACM/IEEE 10th International Conference on Model Driven Engineering Languages and Systems. The workshop took place in the lively city of Nashville, USA, on the 2nd of October, 2007. The workshop was organised by Nelly Bencomo, Robert France, and Gordon Blair and was attended by at least 25 people from 7 countries. This summary gives an overview of the presentations and lively discussions that took place during the workshop. © 2008 Springer-Verlag Berlin Heidelberg.

Summary of the 5th international workshop on models@run.time

The 5th edition of the workshop Models@run.time was held at the 13th International Conference MODELS. The workshop took place in the exciting city of Oslo, Norway, on the 5th of October 2010. The workshop was organised by Nelly Bencomo, Gordon Blair, Franck Fleurey, and Cédric Jeanneret. It was attended by at least 33 people from more than 11 countries. In this summary we present a synopsis of the presentations and discussions that took place during the workshop. © 2011 Springer-Verlag Berlin Heidelberg.

4th international workshop on Models@run.time

The 4th edition of the workshop Models@run.time was held at the 12th International Conference on Model Driven Engineering Languages and Systems (MODELS). The workshop took place in the city of Denver, Colorado, USA, on the 5th of October 2009. The workshop was organised by Nelly Bencomo, Robert France, Gordon Blair, Freddy Muñoz, and Cédric Jeanneret. It was attended by at least 45 people from more than 10 countries. In this summary we present a synopsis of the presentations and discussions that took place during the 4th International Workshop on Models@run.time. © Springer-Verlag Berlin Heidelberg 2010.

Third international workshop on models@run.time

The third edition of the workshop Models@run.time was held at the ACM/IEEE 11th International Conference on Model Driven Engineering Languages and Systems (MODELS). The workshop took place in the beautiful city of Toulouse, France, on the 30th of October, 2008. The workshop was organised by Nelly Bencomo, Robert France, Gordon Blair, Freddy Muñoz, and Cèdric Jeanneret.It was attended by at least 44 people from more than 10 countries. In this summary we present an overview of the presentations and fruitful discussions that took place during the 3rd edition of the workshop Models@run.time.

Run-time model evaluation for requirements model-driven self-adaptation

A self-adaptive system adjusts its configuration to tolerate changes in its operating environment. To date, requirements modeling methodologies for self-adaptive systems have necessitated analysis of all potential system configurations, and the circumstances under which each is to be adopted. We argue that, by explicitly capturing and modelling uncertainty in the operating environment, and by verifying and analysing this model at runtime, it is possible for a system to adapt to tolerate some conditions that were not fully considered at design time. We showcase in this paper our tools and research results. © 2012 IEEE.

Summary of the 7th international workshop on Models@run.time

The Models@run.time (MRT) workshop series offers a discussion forum for the rising need to leverage modeling techniques for the software of the future. The main goals are to explore the benefits of models@run.time and to foster collaboration and cross-fertilization between different research communities like for example like model-driven engineering (e.g. MODELS), self-adaptive/autonomous systems communities (e.g., SEAMS and ICAC), the control theory community and the artificial intelligence community. © 2012 Authors.

Foreword:2nd workshop requirements@run.time

The 2nd edition of the Workshop requirements@run.time was held at the 19th International Conference on Requirements Engineering (RE 2011) in the city of Trento, Italy on the 30th of August 2011. It was organized by Nelly Bencomo, Emmanuel Letier, Jon Whittle, Anthony Finkelstein, and Kris Welsh. This foreword presents a digest of the discussions and presentations that took place during the workshop. © 2011 IEEE.