Improved concurrent Java processes
- Authors: Ntlahla, Mbalentle Apelele Wiseman
- Date: 2021-10-29
- Subjects: Java (Computer program language) , Computer multitasking , Sequential processing (Computer science) , Parallel programming (Computer science) , Simultaneous multithreading processors
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/192129 , vital:45198
- Description: The rise in the number of cores in a processor has resulted in computer programmers needing to write concurrent programs to utilize the extra available processors. Concurrent programming can utilize the extra processors available in a multi-core architecture. However, writing concurrent programs introduces complexities that are not encountered in sequential programming (race conditions, deadlocks, starvation, liveness, etc., are some of the complexities that come with concurrent programming). These complexities require programming languages to provide functionality to help programmers with writing concurrent programs. The Java language is designed to support concurrent programming, mostly through threads. The support is provided through the Java programming language itself and Java class libraries. Although concurrent processes are important and have their own advantages over concurrent threads Java has limited support for concurrent processes. In this thesis we attempt to provide the same support that Java has for threads through the java.util.concurrent library to processes. This is attempted to be done through a Java library (za.co.jcp). The library will provide synchronisation methods of multiple processes, Java process shared variables, atomic variables, process-safe data structures, and a process executors framework similar to that of the executor framework provided by Java for threads. The two libraries' similarities, and performance is analyzed. The analysis between the two libraries is performed to compare the code portability, ease of use, and performance difference between the two libraries. The results from the project have shown that it is possible for Java to provide support for concurrency through processes and not only threads. In addition from the benchmarks performed the performance of the za.co.jcp library is not significantly slower than the current java.util.concurrent thread library. This means that Java concurrent applications will also now be able to use cooperating processes rather than be confined to using threads. , Thesis (MSc) -- Faculty of Science, Computer Science, 2021
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- Date Issued: 2021-10-29
Concurrency in modula-2
- Authors: Sewry, David Andrew
- Date: 1985 , 2013-03-13
- Subjects: Modula-2 (Computer program language) , Programming languages (Electronic computers) , Computer multitasking
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4582 , http://hdl.handle.net/10962/d1004369 , Modula-2 (Computer program language) , Programming languages (Electronic computers) , Computer multitasking
- Description: A concurrent program is one in which a number of processes are considered to be active simultaneously . It is possib l e to t hink of a process as being a separate sequential program executing independently of other processes, although perhaps communicating with them at desired pOints . The concurrent program, as a whole, can be executed in one of two ways: il ii) in true concurrent manner, wi th each process executing on a dedicated processor in a quasi - concurrent manner, where a processor's processes . time is multiplexed between single the There are two motivations for the study of concurrency in programming languages : i) concurrent programming facilities can be exploited in systems where one has more t han one processor . As technology i mproves, machines having multiple processors will proliferate ii) concurrent p r ogramming facilities may allow programs to be structured as independent , bu t co - operating, processes which can then be implemented on a single processor system . This structure may be more natural to the programmer then the traditional sequential structures. An example is provided by Conway's - 1- Clearly, languages Pascal) problem [Ben82] . by their very nature, traditional sequential- type (Fortran, Basic, Cobol and earlier versions of prove inadequate for the purposes of concurrent programming without considerable extension (which some manufacturers have provided, rendering their compilers non standard-conforming). The general convenience of high level languages provides strong motivation for their development for rea l time programming. Modula - 2 [Wir83] is but one of a number of such r ecently developed languages, designed not only to fulfil a "sequential" role but also to offer facilities for concurrent programming. Developed by Niklaus Wirth in 1979 as a successor to Pascal and Modula, it is intended to serve under the banner of a generalpurpose systems - implementation language. This thesis investigates concurrency i n Modula - 2 and takes the following form: i ) an analYSis of the concurrent facilities offered ii) problems and difficulties associated with these facilities iii) improveme nts and enhancements, including the feasibility of using Modula - 2 to simulate constructs found in other languages, such as the Hoare monitor [Hoa74] and the Ada rendezvous [Uni81]. - 2- Each section concludes with an appraisal of the work conducted in that section . The final section consists of a critical assessment of those Modula - 2 language constructs and facilities provided for the implementation of concurrency and a brief look at concurrency in Modula, Modula-2's predecessor. - Introduction. , KMBT_363 , Adobe Acrobat 9.53 Paper Capture Plug-in
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- Date Issued: 1985