Kevin Pinte

AmbientTalk: programming responsive mobile peer-to-peer applications with actors

Abstract The rise of mobile computing platforms has given rise to a new class of applications: mobile applications that interact with peer applications running on neighbouring phones. Developing such applications is challenging because of problems inherent to concurrent and distributed programming, and because of problems inherent to mobile networks, such as the fact that wireless network connectivity is often intermittent, and the lack of centralized infrastructure to coordinate the peers. We present AmbientTalk, a distributed programming language designed specifically to develop mobile peer-to-peer applications. AmbientTalk aims to make it easy to develop mobile applications that are resilient to network failures by design. We describe the language׳s concurrency and distribution model in detail, as it lies at the heart of AmbientTalk׳s support for responsive, resilient application development. The model is based on communicating event loops, itself a descendant of the actor model. We contribute a small-step operational semantics for this model and use it to establish data race and deadlock freedom.

Programming language support for routing in pervasive networks

Managing communication in pervasive environments is a difficult challenge because of characteristics such as: no central server and frequent disconnections. Furthermore, services to be composed for coordination are sometimes distributed in multiple networks. In that case, intermediate nodes linking these networks have to route communication data toward appropriate destinations. However, incorporating such routing protocols into applications significantly increases complexity of the code. In this paper we propose AmbientTalk/M, a concurrent distributed programming language for coordination of services among multiple networks. The language provides powerful support for creating routing frameworks to hook up two or more networks. With the language support, we can express how service information is propagated or how messages are routed using high-level abstraction over underlying network technology. We show the language is flexible enough to express a variety of routing frameworks with respect to robustness, traffic efficiency, and security. Because the frameworks are installed reflectively, they are completely separated from application code. To the best of our knowledge, this is the first attempt to integrate routing semantics among multiple networks into a programming language using reflection.

Software abstractions for mobile RFID‐enabled applications

Our everyday environments may soon be pervaded with radio frequency identification (RFID) tags integrated in physical objects. These RFID tags can store a digital representation of the physical object and transmit it wirelessly to pervasive, context‐aware applications running on mobile devices. However, communicating with RFID tags is prone to many failures inherent to the technology. This hinders the development of such applications, as traditional programming models require the programmer to deal with the RFID hardware characteristics manually. On the other hand, traditional RFID middleware focuses on limited scenarios in an enterprise context and not on general ubiquitous computing scenarios. In this paper, we extend the ambient‐oriented programming paradigm to program RFID applications, by considering RFID tags as intermittently connected mutable proxy objects hosted on mobile distributed computing devices, and detail our prototype implementation. Copyright

Enabling cross-technology mobile applications with network-aware references

Mobile devices, such as smart phones, have become ubiquitous. This evolution has given rise to a vast ecosystem of mobile applications. Typically these applications only use a small subset of the networking technologies at their disposal. Building applications that use multiple networking technologies simultaneously or exploit knowledge about the available connections is a laborious task. Programmers must manually keep track of the connectivity state and duplicate communication code per connection type. This paper presents networkaware references, a distributed object-oriented programmingabstracion that eases multi-networking for mobile applications and allows programmers to react to changes in the connectivity of different networks around them. We show how network-aware references are implemented and evaluate how well they switch between technologies.

Ambient Clouds: Reactive Asynchronous Collections for Mobile Ad Hoc Network Applications

In MANET applications, a common pattern is to maintain and query time-varying collections of remote objects. Traditional approaches require programmers to manually track the connectivity state of these remote objects and adding or removing them from local collections on a per-object basis. Queries over these collections have to be manually recomputed whenever the collection or its elements change.

MORENA: a middleware for programming NFC-enabled Android applications as distributed object-oriented programs

NFC is a wireless technology that allows software to interact with RFID tags and that is increasingly integrated into smartphones and other mobile devices. In this paper, we present MORENA: a middleware that treats NFC-enabled programs as distributed object-oriented programs in which RFID tags are represented as intermittently connected remote objects. We draw inspiration from the ambient-oriented programming paradigm to represent these objects as first-class remote references which only offer asynchronous communication with the tag to which they refer. This allows the programmer to implement mobile applications that read from or write to RFID tags without having to handle every single fault manually and without blocking the entire application during read or write operations. We built MORENA on top of the Android platform and evaluated our abstractions by implementing a representative application running on NFC-enabled Android phones using MORENA.

Distributed object-oriented programming with RFID technology

Our everyday environments will soon be pervaded with RFID tags integrated in physical objects. These RFID tags can store a digital representation of the physical object and transmit it wirelessly to pervasive, context-aware applications running on mobile devices. However, communicating with RFID tags is prone to many failures inherent to the technology. This hinders the development of such applications as traditional programming models require the programmer to deal with the RFID hardware characteristics manually.In this paper, we propose extending the ambient-oriented programming paradigm to program RFID applications, by considering RFID tags as intermittently connected mutable proxy objects hosted on mobile distributed computing devices.

Network-aware references for pervasive social applications

In recent years, mobile devices such as smartphones have become more powerful, gaining the ability to communicate using multiple networking technologies. This evolution has given rise to pervasive social applications that enable social networking on the move. Currently, it is hard to take advantage of the available networking technologies because communication has to be managed separately for each technology. This forces programmers to manually keep track of the connectivity state and duplicate communication code per connection. This paper presents network-aware references, a distributed object-oriented programming abstraction that combines multi-networking and network awareness. They abstract over the implementation details of the different networking technologies while allowing programmers to react to changes in the connectivity of different networks around them.

Objects in Space

The paper presents a research agenda that we are currently executing for programming mobile applications that write and read information to and from passive RFID tags. Modern tags can host up to several kilobytes of information which makes it possible to store real software objects (in the object-oriented sense) that can even refer to each other. This gives the term ‘spatial database’ an entirely new meaning. The paper motivates the need for new programming language constructs that are specifically targeted towards representing objects on tags, designating specific tags in the application’s proximity and keeping the internal status of the mobile application causally connected to its physical surrounding.

Event Loop Coordination Using Meta-programming

Event-based programming is used in different domains, ranging from user interface development to various distributed systems. Combining different event-based subsystems into one system forces the developer to manually coordinate the different event loops of these subsystems. This leads to a lot of excessive code and, in addition, some event loops are prey to lifecycle state changes. On mobile applications, for example, event loops can be shut down when memory runs low on the device. Current approaches take care of the communication problems between the different types of event loops, but become complex when trying to deal with lifecycle state changes. We propose a new coordination model, Elector, that allows two event loops to run separately, and introduce a novel kind of reference, called undead references. These references do not only allow communication between the event loops, but also handle lifecycle state changes in such a way that they do not influence other event loops.