Synchronisation in Concurrent, Object-oriented Languages: Expressive Power, Genericity and Inheritance

sets of operations are also employed in the Enabled-sets synchronisation mechanism. This raises the question whether Enabled-sets would be a suitable basis for supporting GSPs? This issue is discussed in Section 10.1.5. 10.1.1 Dragoon Next to Gasp, the language which provides the best support for GSPs is probably Dragoon [Atk90]. However, Dragoon's support for generic synchronisation policies has some limitations as we now discuss. 10.1.1.1 Confusion of Inheritance and Genericity In Dragoon, generic synchronisation policies are referred to as behavioural classes. Unfortunately, it appears that the Dragoon language designers were not fully aware of the generic nature of behavioural classes when originally designing the language. Some examples that illustrate this lack of appreciation for the generic nature of behavioural classes are as follows: ffl From the earliest papers published on Dragoon[MCB + 89, GMC + 89], the application of a behavioural class upon a sequential class ..

How to Control the Allocation of Parallel Applications: a Survey on Tools and Language Constructs

The paper focuses on the allocation area, with the aim of providing a survey on systems that provides facilities to codify the behaviour of an application with regard to its allocation onto a target architecture. The paper analyses the design issues that arise in the definition of these facilities and presents the solutions adopted in several systems and programming environments. Open issues and future directions of research are outlined

Synchronisation Variables

It is commonly believed that access to the instance variables of an object by its synchronisation code is needed in order to implement many synchronisation policies. This introduces an obvious difficulty. The synchronisation code must not read an instance variable while that variable is being updated by an operation, otherwise the synchronisation code might see the variable in an inconsistent state. In this paper, we study this problem in depth and solve it by defining a framework to guide the design of synchronisation mechanisms. In solving the problem, our framework illustrates that, contrary to popular belief, access to instance variables by synchronisation mechanisms is not required in order to implement synchronisation policies that apparently rely on the state of the object|such state can be maintained by the synchronisation code itself. Our framework offers additional benefits. Synchronisation mechanisms designed within the guidelines of the framework can possess considerable expressiv

Scheduling Predicates

In this report, we present a powerful new synchronisation mechanism called scheduling predicates. These predicates---there are no, there exists and for all --- allow the programmer to schedule the order of execution of operations based on relative arrival times, values of parameters, and built-in synchronisation counters. Since many synchronisation problems are, in fact, scheduling problems, these facilitate much simpler and clearer solutions to such problems. We also show that this mechanism subsumes and unifies the existing declarative synchronisation mechanisms used in some object-oriented languages, and extends the number of problems for which a purely declarative approach is possible

Evaluating Synchronisation Mechanisms: The Inheritance Matrix

this paper. First, we will define the conflict between synchronisation and inheritance. We then show how this definition can be used to derive a set of examples which can be used to test the inheritability of a synchronisation mechanism. Finally, we present some preliminary results obtained from using these examples to evaluate several synchronisation mechanisms. 2 Inheritanc

Online cognitive behavioral therapy for bulimic type disorders, delivered in the community by a nonclinician:qualitative study

Background: Cognitive behavioral therapy is recommended in the National Institute for Clinical Excellence guidelines for the treatment of bulimia nervosa. In order to make this treatment option more accessible to patients, interactive online CBT programs have been developed that can be used in the user’s own home, in privacy, and at their convenience. Studies investigating online CBT for bulimic type eating disorders have provided promising results and indicate that, with regular support from a clinician or trained support worker, online CBT can be effective in reducing bulimic symptoms. Two main factors distinguish this study from previous research in this area. First, the current study recruited a wide range of adults with bulimic type symptoms from the community. Second, the participants in the current study had used cCBT with support from a nonclinical support worker rather than a specialist eating disorder clinician. Objective: To investigate participants’ experiences of using an online self-help cognitive behavioral therapy (CBT) package (Overcoming Bulimia Online) for bulimia nervosa (BN) and eating disorders not otherwise specified (EDNOS). Methods: Eight participants with a mean age of 33.9 years took part in semi-structured interviews. Interviews were transcribed and analyzed using a 6-step thematic analysis process. Results: Saturation was achieved, and 7 themes were identified in the dataset. These were: (1) conceptualizing eating disorders, (2) help-seeking behavior, (3) aspects of the intervention, (4) motivation to use the online package, (5) privacy and secrecy with regard to their eating problems, (6) recovery and the future, and (7) participant engagement describing individuals’ thoughts on taking part in the online research study. Conclusions: Participants suggested that online CBT self-help represented a generally desirable and acceptable treatment option for those with bulimic type eating problems, despite some difficulties with motivation and implementation of some elements of the package.</p