During the software crisis of the 1960s, Dijkstra's famous thesis "goto considered harmful" paved the way for structured programming, i.e. software development with well-defined and disciplined organizat...
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ISBN:
(纸本)3540425225
During the software crisis of the 1960s, Dijkstra's famous thesis "goto considered harmful" paved the way for structured programming, i.e. software development with well-defined and disciplined organization of control flow. In parallel programming, a new aspect - communication - has an important impact on the structure and properties of programs. This paper shows that many current difficulties of parallel programming are caused by complicated and poorly structured communication, which is a consequence of using low-level send-recv primitives. We argue that, like goto in sequential programs, send-recv should be avoided as far as possible and replaced by collective operations in the parallel setting. We argue against some widely held opinions about the apparent superiority of individual over collective communication and present substantial theoretical and empirical evidence to the contrary. The paper overviews some recent results on formal transformation rules for collective operations that facilitate systematic, performance-oriented design of parallel programs using MPI (Message Passing Interface).
parallel iterative linear solvers for unstructured grids in FEM applications, originally developed for the Earth Simulator (ES), are ported to various types of parallel computer. The performance of flat MPI and hybrid...
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ISBN:
(纸本)9783540713500
parallel iterative linear solvers for unstructured grids in FEM applications, originally developed for the Earth Simulator (ES), are ported to various types of parallel computer. The performance of flat MPI and hybrid parallel programming models is compared for the ES, Hitachi SR8000, IBM SP-3 and IBM p5-model 595 supercomputers. The effect of coloring and of different storage methods for coefficient matrices are evaluated in various types of application. Performance for more than 104 processors is estimated using measured data for up to 103 processors.
Deterministic parallel programming languages are attractive as they do not allow data races, deadlocks, or similar kinds of concurrency bugs that are caused by unintended (or poorly understood) parallel execution. We ...
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ISBN:
(纸本)9783030352257;9783030352240
Deterministic parallel programming languages are attractive as they do not allow data races, deadlocks, or similar kinds of concurrency bugs that are caused by unintended (or poorly understood) parallel execution. We present here a simple programming model for deterministic parallel programming that is based on roles. The programmer specifies the role that an object plays for a task (e.g., the readonly role), and compiler and runtime system together ensure that only those object accesses are performed that are allowed by this role. An object may play different roles in the course of a program's execution, giving the programmer considerable flexibility in expressing a parallel program. The model has been implemented in a Java-like language with references and object sharing. Preliminary results indicate that the runtime overhead is moderate (compared to standard Java programs), and that the compiled programs achieve substantial parallel speedups.
An effective teaching and learning in concurrent and parallel programming needs the presentation of short excerpts of code to students in a selected programming language during lectures. This is sometimes necessary to...
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ISBN:
(纸本)9783319273082;9783319273075
An effective teaching and learning in concurrent and parallel programming needs the presentation of short excerpts of code to students in a selected programming language during lectures. This is sometimes necessary to make understandable complicate syntactical constructs. Traditionally, these codes have been presented by the teacher to the students on a blackboard, with slides or by means any projection facilities, together with an oral description of their operation and significance. Teachers try to explain those syntactical constructs with more or less success and students do not usually test program code during lectures, nor can do any modifications to the programs, which are helpful in order to master difficult concepts of parallel programming and Concurrency. In the best possible scenario, students will carry out any tests on the real code of an example presented in lectures during practical lessons at the lab. Nevertheless, without a clear illustration of their actual behavior in a real computer program, any new concepts of concurrent constructs taught in lectures will remain fuzzy and prone to be forgotten. The presented approach consists of changing the traditional teaching and learning model of parallel programming into another where students will be equipped with multicore processors inside their laptops, which in addition to Virtual Campus services will serve to put into practice any programming code that illustrates a programming concept the minute it is presented during any lecture by the teacher to the class.
This Research to Practice Full Paper proposes a teaching approach that introduces parallel programming early in the undergraduate Computer Science curriculum. Experiments were conducted to freshmen in the second cours...
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ISBN:
(纸本)9781728117461
This Research to Practice Full Paper proposes a teaching approach that introduces parallel programming early in the undergraduate Computer Science curriculum. Experiments were conducted to freshmen in the second course of algorithms and data structures. The strategy for the evaluation of the early education of parallel programming includes the use of OpenMP Application programming Interface and sorting algorithms. The results indicate that students improved their skills by participating in parallel programing activities introduced at early stages or even at the very beginning of the undergraduate program. Freshmen could hit about 92%, 63% and 44% of easy, medium and hard questions after theoretical and practice activities. This represents an improvement about 19%, 14% and 39% 14 each respective difficulty level in comparison to the beginning of the study when all freshmen had no knowledge relative to parallel programming. These results aid to demystify parallel programming and to show that freshmen can learn it.
We propose a novel synchronization mechanism called versioning. It dynamically establishes a deterministic order of memory accesses in parallel programs that have serial semantics, in a way that is transparent to the ...
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ISBN:
(纸本)9781467308243;9781467308267
We propose a novel synchronization mechanism called versioning. It dynamically establishes a deterministic order of memory accesses in parallel programs that have serial semantics, in a way that is transparent to the program m er. This order is created in a distributed manner and is enforced by monitoring memory accesses and stalling threads if necessary. Versioning gives rise to parallel programming models in which programmers need not explicitly synchronize threads and only need to specify shared data, which greatly simplifies parallel programming. However, versioning introduces overheads and thus demands architectural support. We describe versioning and the architectural support it needs. We also propose one parallel programming model that utilizes versioning and use it to parallelize 13 benchmark applications. We build an FPGA prototype of a multiprocessor system with versioning support and show that good parallel speedups are obtained. Our analysis shows minimal impact of versioning, both in terms of timing over-heads and in terms of additional hardware.
Design patterns make it easier to reuse successful designs and architectures. Expressing proven techniques as design patterns makes them more accessible to developers of new systems and helps a designer get a design f...
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ISBN:
(纸本)9781424421077
Design patterns make it easier to reuse successful designs and architectures. Expressing proven techniques as design patterns makes them more accessible to developers of new systems and helps a designer get a design faster. In sequential and object-oriented programming domain design patterns have played a very important role but in parallel programming the application of design patterns is very few. We propose a design-pattern based parallel programming model and implement a parallel programming environment in the SNIP platform to help the developers to build their parallel application system efficiently. The experiment results show our system is effective and competent.
Multi-cores have recently been applied to smartphones, as well as PCs;the performance of electronic devices is improving. However, there is no improvement in performance, if the existing sequential program is executed...
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ISBN:
(纸本)9788993215038
Multi-cores have recently been applied to smartphones, as well as PCs;the performance of electronic devices is improving. However, there is no improvement in performance, if the existing sequential program is executed on multi-core processors. parallel programming is necessary to use multi-core processors well. Already some companies are doing projects to parallel their own programs that are executed in the PC environment, for example, Adobe Systems Inc., Autodesk Inc., and Epic Games Inc. However, very few embedded field studies, focus on parallel programming. In this paper, we study a parallel programming model, OpenMP, and parallel programs that can be benchmarked to multi-core processors of embedded boards using OpenMP. We execute parallel programs on a dual-core embedded system. We analyze the performance of sequential programs and parallel programs by SERPOP analysis. Finally, we reduce the execution time of programs by a mean of 111%.
We define the concepts of nesting mode and interaction mode as they arise in the description of skeletal parallel programming systems. We suggest that these new concepts encapsulate fundamental design issues and may p...
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ISBN:
(纸本)3540260439
We define the concepts of nesting mode and interaction mode as they arise in the description of skeletal parallel programming systems. We suggest that these new concepts encapsulate fundamental design issues and may play a useful role in defining and distinguishing between the capabilities of competing systems. We present the decisions taken in our own Edinburgh Skeleton Library eSkel, and review the approaches chosen by a selection of other skeleton libraries.
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