Preface.PART I: INTRODUCTION.1. Programming Languages.1.1 Programming linguistics.1.1.1 Concepts and paradigms.1.1.2 Syntax, semantics, and pragmatics.1.1.3 Language processors.1.2 Historical development.Summary.Further reading.Exercises.PART II: BASIC CONCEPTS2. Values and Types.2.1 Types.2.2 Primitive types.2.2.1 Built-in primitive types.2.2.2 Defined primitive types.2.2.3 Discrete primitive types.2.3 Composite types.2.3.1 Cartesian products, structures, and records.2.3.2 Mappings, arrays, and functions.2.3.3 Disjoint unions, discriminated records, and objects.2.4 Recursive types.2.4.1 Lists.2.4.2 Strings.2.4.3 Recursive types in general.2.5 Type systems.2.5.1 Static vs dynamic typing.2.5.2 Type equivalence.2.5.3 The Type Completeness Principle.2.6 Expressions.2.6.1 Literals.2. 6.2 Constructions.2.6.3 Function calls.2.6.4 Conditional expressions.2.6.5 Iterative expressions.2.6.6 Constant and variable accesses.2.7 Implementation notes.2.7.1 Representation of primitive types.2.7.2 Representation of Cartesian products.2.7.3 Representation of arrays.2.7.4 Representation of disjoint unions.2.7.5 Representation of recursive types.Summary.Further reading.Exercises.3. Variables and Storage.3.1 Variables and storage.3.2 Simple variables.3.3 Composite variables.3.3.1 Total vs selective update.3.3.2 Static vs dynamic vs flexible arrays.3.4 Copy semantics vs reference semantics.3.5 Lifetime.3.5.1 Global and local variables.3.5.2 Heap variables.3.5.3 Persistent variables.3.6 Pointers.3.6.1 Pointers and recursive types.3.6.2 Dangling pointers.3.7 Commands.3.7.1 Skips.3.7.2 Assignments.3.7.3 Procedure calls.3.7.4 Sequential commands.3.7.5 Collateral commands.3.7.6 Conditional commands.3.7.7 Iterative commands.3.8 Expressions with side effects.3.8.1 Command expressions.3.8.2 Expression-oriented languages.3.9 Implementation notes3.9.1 Storage for global and local variables.3.9.2 Storage for heap variables.Summary.Further reading.Exercises.4. Bindings and Scope.4.1 Bindings and environments.4.2 Scope.4.2.1 Block structure.4.2.2 Scope and visibility.4.2.3 Static vs dynamic scoping.4.3 Declarations.4.3.1 Type declarations.4.3.2 Constant declarations.4.3.3 Variable declarations.4.3.4 Procedure definitions.4.3.5 Collateral declarations.4.3.6 Sequential declarations.4.3.6 Recursive declarations.4.3.8 Scopes of declarations.4.4 Blocks.4.4.1 Block commands.4.4.2 Block expressions.4.4.3 The Qualification Principle.Summary.Further reading.Exercises.5. Procedural Abstraction.5.1 Function procedures and proper procedures.5.1.1 Function procedures.5.1.2 Proper procedures5.1.3 The Abstraction Principle.5.2 Parameters and arguments.5.2.1 Copy parameter mechanisms.5.2.2 Reference parameter mechanisms.5.2.3 The Correspondence Principle.5.3 Implementation notes5.3.1 Implementation of procedure calls.5.3.1 Implementation of parameter passing.Summary.Further reading.Exercises.PART III: ADVANCED CONCEPTS.6. Data Abstraction.6.1 Program units, packages, and encapsulation.6.1.1 Packages.6.1.2 Encapsulation.6.2 Abstract types.6.3 Objects and classes.6.3.1 Classes.6.3.2 Subclasses and inheritance.6.3.3 Abstract classes.6.3.4. Single vs multiple inheritance.6.3.5 Interfaces.6.4 Implementation notes.6.4.1 Representation of objects6.4.2 Implementation of method calls.Summary.Further readingExercises.7. Generic Abstraction.7.1 Generic units and instantiation.7.1.1 Generic packages in ADA.7.1.2 Generic classes in C++.7.2 Type and class parameters.7.2.1 Type parameters in ADA.7.2.2 Type parameters in C++.7.2.3 Class parameters in JAVA.7.3 Implementation notes7.3.1 Implementation of ADA generic units.7.3.2 Implementation of C++ generic units.7.3.3 Implementation of JAVA generic units.Summary.Further reading.Exercises8. Type Systems.8.1 Inclusion polymorphism.8.1.1 Types and subtypes.8.1.2 Classes and subclasses.8.2 Parametric polymorphism.8.2.1 Polymorphic procedures.8.2.2 Parameterized types.8.2.3 Type inference.8.3 Overloading.8.4 Type conversions.8.5 Implementation notes8.5.1 Implementation of polymorphic procedures.Summary.Further reading.Exercises.9. Control Flow.9.1 Sequencers.9.2 Jumps.9.3 Escapes.9.4 Exceptions.9.5 Implementation notes9.5.1 Implementation of jumps and escapes.9.5.2 Implementation of exceptions.Summary.Further reading.Exercises.10. Concurrency (by William Findlay).10.1 Why concurrency?.10.2 Programs and processes.10.3 Problems with concurrency.10.3.1 Nondeterminism.10.3.2 Speed dependence.10.3.3 Deadlock.10.3.4 Starvation.10.4 Process interactions.10.4.1 Independent processes.10.4.2 Competing processes.10.4.3 Communicating processes.10.5 Concurrency primitives.10.5.1 Process creation and control.10.5.2 Interrupts.10.5.3 Spin locks and wait-free algorithms.10.5.4 Events.10.5.5 Semaphores.10.5.6 Messages.10.5.7 Remote procedure calls.10.6 Concurrent control abstractions.10.6.1 Conditional critical regions.10.6.2 Monitors.10.6.3 Rendezvous.Summary.Further reading.Exercises.PART IV: PARADIGMS11. Imperative Programming.11.1 Key concepts.11.2 Pragmatics.11.2.1 A simple spellchecker.11.3 Case study: C.11.3.1 Values and types.11.3.2 Variables, storage, and control.11.3.3 Bindings and scope.11.3.4 Procedural abstraction.11.3.5 Independent compilation.11.3.6 Preprocessor directives.11.3.7 Function library.11.3.8 A simple spellchecker.11.4 Case study: ADA.11.4.1 Values and types.11.4.2 Variables, storage, and control.11.4.3 Bindings and scope.11.4.4 Procedural abstraction.11.4.5 Data abstraction.11.4.6 Generic abstraction.11.4.7 Separate compilation.11.4.8 Package library.11.4.9 A simple spellchecker.Summary.Further reading.Exercises.12. Object-Oriented Programming.12.1 Key Concepts.12.2 Pragmatics.12.3 Case study: C++.12.3.1 Values and types.12.3.2 Variables, storage, and control.12.3.3 Bindings and scope.12.3.4 Procedural abstraction.12.3.5 Data abstraction.12.3.6 Generic abstraction.12.3.7 Independent compilation and preprocessor directives12.3.8 Class and template library.12.3.9 A simple spellchecker.12.4 Case study: JAVA.12.4.1 Values and types.12.4.2 Variables, storage, and control.12.4.3 Bindings and scope.12.4.4 Procedural abstraction.12.4.5 Data abstraction.12.4.6 Generic abstraction.12.4.7 Separate compilation and dynamic linking.12.4.8 Class library.12.4.9 A simple spellchecker.12.5 Case study: ADA95.12.5.1 Types.12.5.2 Data abstraction.Summary.Further reading.Exercises.13. Concurrent Programming (by William Findlay).13.1 Key concepts.13.2 Pragmatics.13.3 Case study: ADA95.13.3.1 Process creation and termination.13.3.2 Mutual exclusion.13.3.3 Admission control.13.3.4 Scheduling away deadlock.13.4 Case study: JAVA.13.4.1 Process creation and termination.13.4.2 Mutual exclusion.13.4.3 Admission control.Summary.Further reading.Exercises.14. Functional Programming.14.1 Key concepts.14.1.1 Eager vs normal-order vs lazy evaluation.14.2 Pragmatics.14.3 Case study: HASKELL.14.3.1 Values and types.14.3.2 Bindings and scope.14.3.3 Procedural abstraction.14.3.4 Lazy evaluation.14.3.5 Data abstraction.14.3.6 Generic abstraction.14.3.7 Modeling state.14.3.8 A simple spellchecker.Summary.Further reading.Exercises.15. Logic Programming.15.1 Key concepts.15.2 Pragmatics.15.3 Case study: PROLOG.15.3.1 Values, variables, and terms.15.3.2 Assertions and clauses.15.3.3 Relations.15.3.4 The closed-world assumption.15.3.5 Bindings and scope.15.3.6 Control.15.3.7 Input/output.15.3.8 A simple spellchecker.Summary.Further reading.Exercises16. Scripting.16.1 Pragmatics.16.1.1 Regular expressions.16.2 Case study: PYTHON.16.2.1 Values and types.16.2.2 Variables, storage, and control16.2.3 Bindings and scope.16.2.4 Procedural abstraction.16.2.5 Data abstraction.16.2.6 Separate compilation16.2.7 Module library.Summary.Further reading.Exercises.PART V: CONCLUSION.17. Language Selection.17.1 Criteria.17.2 Evaluation.Summary.Exercises.18. Language Design.18.1 Selection of concepts.18.2 Regularity.18.3 Simplicity.18.4 Efficiency.18.5 Syntax.18.6 Language life cycles.18.7 The future.Summary.Further reading.Exercises.Bibliography.Glossary.Index.

/pdf/programming-language-design-concepts-4y495q1t1x.pdf

Programming Language Design Concepts

In this paper an approach for the transparent use of real-time Java in control and automation is described. The proposed approach, which is in the context of the model integrated mechatronics paradigm, exploits the function block (FB) construct for the design model and the real-time Java specification for the implementation one. Specific interpreters allow for the automatic generation of FB types' implementation models in terms of real-time Java and the transformation of the application's FB networks to deployment specifications that are next utilized by a launcher to initialize and execute the control application on the proposed execution environment. The proposed approach favours deployment and re-deployment of distributed control applications and exploits the real-time specification for Java to meet their stringent nonfunctional requirements

Real-time Java in control and automation: a model driven development approach

Scheduling concerns the allocation of processors to processes, and is traditionally associated with low-level tasks in operating systems and embedded devices. However, modern software applications with soft real-time requirements need to control application-level performance. High-level scheduling control at the application level may complement general purpose OS level scheduling to fine-tune performance of a specific application, by allowing the application to adapt to changes in client traffic on the one hand and to low-level scheduling on the other hand. This paper presents an approach to express and analyze application-specific scheduling decisions during the software design stage. For this purpose, we integrate support for application-level scheduling control in a high-level object-oriented modeling language, Real-Time ABS, in which executable specifications of method calls are given deadlines and real-time computational constraints. In Real-Time ABS, flexible application-specific schedulers may be specified by the user, i.e., developer, at the abstraction level of the high-level modeling language itself and associated with concurrent objects at creation time. Tool support for Real-Time ABS is based on an abstract interpreter that supports simulations and measurements of systems at the design stage.

/pdf/user-defined-schedulers-for-real-time-concurrent-objects-3wpayobjb0.pdf

User-defined schedulers for real-time concurrent objects

Some concerns, such as debugging or logging functionality, cannot be captured cleanly, and are often tangled and scattered throughout the code base. These concerns are called crosscutting concerns. Aspect-oriented programming (AOP) is a paradigm that enables developers to capture crosscutting concerns in separate aspect modules. The use of aspects has been shown to improve understandability and maintainability of systems. It has been shown that real-time concerns, such as memory management and thread scheduling, are crosscutting concerns [A. Corsaro et al., (2002), M.Deters et al., (2001), A. Gal et al., (2002)]. However it is unclear whether encapsulating these concerns provides benefits. We were interested in determining whether using AOP to encapsulate real-time crosscutting concerns afforded benefits in system properties such as understandability and maintainability. This paper presents research comparing the system properties of two systems: a real-time sentient traffic simulator and its aspect-oriented equivalent. An evaluation of AOP is presented indicating both benefits and drawbacks with this approach

/pdf/an-evaluation-of-aspect-oriented-programming-for-java-based-1twzmh2kdd.pdf

An evaluation of aspect-oriented programming for Java-based real-time systems development

The Real-Time Specification for Java (RTSJ) [1] offers new features for scheduling and memory management, enabling new software design possibilities. In this survey, we provide descriptions of design patterns [5] for use with these RTSJ features . We discuss a pattern which integrates scoped memory usage with periodic real-time threads. The factory pattern is extended to accommodate RTSJ memory areas. Patterns for recycling immortal memory, and for extending the lifetime of a scope are presented.

A patterns catalog for RTSJ software designs

Preface. Introduction. 1. Landscape. Java Technology and Real Time. Real-Time Programming Requirements. Java and Embedded Real Time. Definition of Real Time. Precision of Measurement. Consistency. Utility Function Curve. Java's Problem Domain. Real-Time Java's Problem Domain. Summary. 2. Architecture of the Java Virtual Machine. Write Once, Run Anywhere: Maybe. JVM Components. Class Loading. Bytecode Interpreter. Security Manager. Garbage Collector. Thread Management. Input/Output. Graphics. Interpreter Implementation. Standard Interpreter. Optimized Interpreter. JIT. Snippets. Compilation to Independent Process. Native Methods. Compilation to a Native Method. Compilation to the JIT Interface. 3. Hardware Architecture. Worst-Case Execution of One Instruction. Worst-Case Scenario. Practical Measures. Management of Troublesome Hardware. Managing Demand Paging. Managing DMA. Managing Cache. Managing Address Translation Cache. Managing Interrupts. Effects on the JVM. 4. Garbage Collection. Reference Counting. Basic Garbage Collection. Mark and Sweep. Defragmentation. Copying Collectors. Incremental Collection. Incremental Garbage Collection in Practice. Generational Garbage Collection. Intergenerational References. Large Object Store. Real-Time Issues. 5. Priority Scheduling. Scheduling Terms. Execution Sequences. Preemption. The Seductive Charm of Nonpreemptive Scheduling. Fixed versus Dynamic Priority. Priority Inversion. Why 32 Priorities? Problems with Priority Scheduling. 6. Scheduling with Deadlines. Underlying Mechanism. Scope of the Scheduler. Some Systems. Earliest Deadline First (EDF). Least Laxity. Periodic Scheduling. Aperiodic Servers. Handling Overload. Timing Is Usually Probabilistic. 7. Rate Monotonic Analysis. Theorems. Liu and Layland's Theorem. A Graphical Approach. Lehoczky, Sha, and Ding's Theorem. Restrictions. Independent Tasks. Deadlines Equal to Periods. Multiprocessor Systems. 8. Introduction to the Real-Time Java Platform. A Brief History of Real-Time Java. Major Features of the Specification. Threads and Scheduling. Garbage Collection. Asynchronous Event Handlers. Asynchronous Transfer of Control. Memory Allocation. Memory Access. Implementation. RTSJ Hello World. 9. Closures. The Language Construct. Java Closures. Closure Structure. Closures in the RTSJ. Limitations of Closures. Readability. Local Variables. Constructors. Nesting. 10. High-Resolution Time. Resolution. The "clock". HighResolutionTime Base Class. Absolute Time. Relative Time. Rational Time. 11. Async Events. Binding a Happening to an Event. Basic Async Event Operation. Async Events without Happenings. Time Triggering. Fault Triggering. Software Event Triggering. Implementation Discussion. 12. Real-Time Threads. Creation. Scheduling. Inversion Handling. Fixed Priority. Feasibility. Periodic Threads without Handlers. Feasibility Analysis. Periodic Threads with Handlers. Interactions with Normal Threads. Changing the Scheduler. 13. Non-Heap Memory. The Advantage of Non-Heap Memory. The Allocation Regimes. Rules. Mechanisms for Allocating Immortal Memory. Mechanisms for Allocating from Scoped Memory. Allocation Time. Creating Scoped Memory. Allocation Mechanisms. Finalizers. Using Nested Scoped Memory. The Scope Stack (Tree). The DAG. Practical Use of Nested Scopes. Every Nested Scope Involves Two Memory Areas. Pitfalls. Using executeInArea. Using Standard Classes. Using Shared Scoped Memory. The Scope Stack Revisited. Scope Portals. Fine Print. Quick Examples. 14. Non-Heap Access. Interaction with Scheduler. Rules. Samples. Final Remarks. Notes. 15. More Async Events. Async Events and the Scheduler. The createReleaseParameters Method. Bound Async Event Handlers. Async Event Handlers and Non-Heap Memory. No-Heap Event Handlers vs. No-Heap Threads. Scheduling. Minimum Interarrival Time. Async Event Handlers and Threads. Special Async Events. 16. Reusing Immortal Memory. Using Fixed-Object Allocators. Carrier Objects. Limitations. Recycling RT Threads. Recycling Async Event Handlers. 17. Asynchronous Transfer of Control. Thread Interrupt in Context. Asynchronous Interrupt Firing. The Timed Class. The interrupt Method. The fire Method. In Summary. Replacement Rules. Rules for Async Exception Propagation. Oblivious catch. Nonmatching doInterruptible. Matching doInterruptible. Internals. Application Handling for Asynchronous Interrupts. Noninterruptible Code. Special Issues for Synchronized blocks. Legacy Code. Use of ATC for Thread Termination. 18. Physical Memory. Physical and Virtual Memory. Physical Memory Manager. Memory Type. Removable Memory. Immortal Physical Memory. Scoped Physical Memory. 19. Raw Memory Access. Security. Peek and Poke. Get/Set Methods. Mapping. The RawMemoryFloatAccess Class. 20. Synchronization without Locking. Principles of Wait-Free Queues. Constructors. Common Methods. The Wait-Free Write Queue. Methods. Sharing the Wait-Free Queue. The Wait-Free Read Queue. The Extra Constructor. Methods. The Wait-Free Double-Ended Queue. Methods. No-Wait Queues and Memory. Implementation Notes. 21. Recommended Practice. Powerful and Easy-to-Use Features of the RTSJ. Real-Time Threads. Periodic Threads. Asynchronous Event Handlers. High-Resolution Time. Happenings. Very Powerful and Dangerous Features of the RTSJ. Simple. Leaky. Viral. Very Powerful and Finicky Features of the RTSJ. Scoped Memory. No-Heap Asynchronous Event Handlers. No-Heap Real-Time Threads. Asynchronously Interrupted Exceptions. Selection of Priorities. Index.

Peter Dibble

Papers

Real-time Java : platform programming