Weaving Dataflows with Silk - ScalaMatsuri 2014, TokyoTaro L. Saito
Silk is a framework for building dataflows in Scala. In Silk users write data processing code with collection operators (e.g., map, filter, reduce, join, etc.). Silk uses Scala Macros to construct a DAG of dataflows, nodes of which are annotated with variable names in the program. By using these variable names as markers in the DAG, Silk can support interruption and resume of dataflows and querying the intermediate data. By separating dataflow descriptions from its computation, Silk enables us to switch executors, called weavers, for in-memory or cluster computing without modifying the code. In this talk, we will show how Silk helps you run data-processing pipelines as you write the code.
While the Java platform has gained notoriety in the last 15 years as a robust application platform with a thriving ecosystem and well-established practices, the Java language has had its share of criticism. Highly verbose, overly didactic, limited feature set; whichever flavor of criticism you prefer, it's patently obvious that Java is playing catch up to more modern languages with a less rigid evolution path.
The language landscape today is vastly different than it had been five or ten years ago; a wide array of languages are available, designed to suit a variety of flavors: Groovy, Clojure, Scala, Gosu, Kotlin... which should you choose? This lecture focuses on one company's decision to focus on Scala, and presents a case study based on our experiences using Scala in practice, in the hope of providing much-needed real world context to assist your decision.
This presentation was used for the Scala In Practice lecture at the Botzia Israeli Java User Group meeting, May 3rd 2012.
Weaving Dataflows with Silk - ScalaMatsuri 2014, TokyoTaro L. Saito
Silk is a framework for building dataflows in Scala. In Silk users write data processing code with collection operators (e.g., map, filter, reduce, join, etc.). Silk uses Scala Macros to construct a DAG of dataflows, nodes of which are annotated with variable names in the program. By using these variable names as markers in the DAG, Silk can support interruption and resume of dataflows and querying the intermediate data. By separating dataflow descriptions from its computation, Silk enables us to switch executors, called weavers, for in-memory or cluster computing without modifying the code. In this talk, we will show how Silk helps you run data-processing pipelines as you write the code.
While the Java platform has gained notoriety in the last 15 years as a robust application platform with a thriving ecosystem and well-established practices, the Java language has had its share of criticism. Highly verbose, overly didactic, limited feature set; whichever flavor of criticism you prefer, it's patently obvious that Java is playing catch up to more modern languages with a less rigid evolution path.
The language landscape today is vastly different than it had been five or ten years ago; a wide array of languages are available, designed to suit a variety of flavors: Groovy, Clojure, Scala, Gosu, Kotlin... which should you choose? This lecture focuses on one company's decision to focus on Scala, and presents a case study based on our experiences using Scala in practice, in the hope of providing much-needed real world context to assist your decision.
This presentation was used for the Scala In Practice lecture at the Botzia Israeli Java User Group meeting, May 3rd 2012.
A presentation at Twitter's official developer conference, Chirp, about why we use the Scala programming language and how we build services in it. Provides a tour of a number of libraries and tools, both developed at Twitter and otherwise.
Session presented at the 6th IndicThreads.com Conference on Java held in Pune, India on 2-3 Dec. 2011.
http://Java.IndicThreads.com
---
My talk would describe how to build DSL’s using Scala, what features in Scala help make it a great option for building DSL’s and some examples of DSL’s built in Scala.
http://www.indicthreads.com/9254/using-scala-for-building-dsls/
Lightbend Lagom: Microservices Just Right (Scala Days 2016 Berlin)mircodotta
Microservices architecture are becoming a de-facto industry standard, but are you satisfied with the current state of the art? We are not, as we believe that building microservices today is more challenging than it should be. Lagom is here to take on this challenge. First, Lagom is opinionated and it will take some of the hard decisions for you, guiding you to produce microservices that adheres to the Reactive tenents. Second, Lagom was built from the ground up around you, the developer, to push your productivity to the next level. If you are familiar with the Play Framework's development environment, imagine that but tuned for building microservices; we are sure you are going to love it! Third, Lagom comes with batteries included for deploying in production: going from development to production could not be easier. In this session, you will get an introduction to the Lightbend Lagom framework. There will be code and live demos to show you in practice how it works and what you can do with it, making you fully equipped to build your next microservices with Lightbend Lagom!
The talk covers foundations and applications of implicit function types. It is an updated and more condensed version of the "What to Leave Implicit Talk" given at CurryOn/PLDI 2017.
Soziale Medien haben die Kommunikation in vielen Organisationen grundlegend verändert. Sie ist schneller, interaktiver und vernetzter geworden. Während mit den neuen Möglichkeiten anfänglich oft nur experimentiert wurde, werden nun umfassende Strategien entwickelt. Auch steigen die Investitionen in den Aufbau von Kompetenzen und nachhaltigen Strukturen. Doch wie wird sich dieser Prozess in Zukunft entwickeln? Dieser Forschungsfrage geht die Studie Social Media Delphi 2012 nach. Sie kombiniert eine Befragung von 860 Kommunikationsmanagern in Unternehmen,
Institutionen und Non-Profit-Oganisationen mit einer zweistufigen Delphi-Befragung von 32 Experten aus Wirtschaft und Wissenschaft. Darauf aufbauend liefert der Bericht Zukunftsprognosen sowie Handlungsempfehlungen für die Praxis. Das Gemeinschaftsprojekt der Universität Leipzig mit Fink & Fuchs Public Relations (Wiesbaden) und dem Magazin „pressesprecher“ (Berlin) schließt an frühere Untersuchungen an und zeigt Entwicklungsperspektiven im Zeitverlauf auf.
Der Berichtsband kann unter www.socialmediadelphi.de als PDF oder Druckexemplar kostenlos angefordert werden.
A presentation at Twitter's official developer conference, Chirp, about why we use the Scala programming language and how we build services in it. Provides a tour of a number of libraries and tools, both developed at Twitter and otherwise.
Session presented at the 6th IndicThreads.com Conference on Java held in Pune, India on 2-3 Dec. 2011.
http://Java.IndicThreads.com
---
My talk would describe how to build DSL’s using Scala, what features in Scala help make it a great option for building DSL’s and some examples of DSL’s built in Scala.
http://www.indicthreads.com/9254/using-scala-for-building-dsls/
Lightbend Lagom: Microservices Just Right (Scala Days 2016 Berlin)mircodotta
Microservices architecture are becoming a de-facto industry standard, but are you satisfied with the current state of the art? We are not, as we believe that building microservices today is more challenging than it should be. Lagom is here to take on this challenge. First, Lagom is opinionated and it will take some of the hard decisions for you, guiding you to produce microservices that adheres to the Reactive tenents. Second, Lagom was built from the ground up around you, the developer, to push your productivity to the next level. If you are familiar with the Play Framework's development environment, imagine that but tuned for building microservices; we are sure you are going to love it! Third, Lagom comes with batteries included for deploying in production: going from development to production could not be easier. In this session, you will get an introduction to the Lightbend Lagom framework. There will be code and live demos to show you in practice how it works and what you can do with it, making you fully equipped to build your next microservices with Lightbend Lagom!
The talk covers foundations and applications of implicit function types. It is an updated and more condensed version of the "What to Leave Implicit Talk" given at CurryOn/PLDI 2017.
Soziale Medien haben die Kommunikation in vielen Organisationen grundlegend verändert. Sie ist schneller, interaktiver und vernetzter geworden. Während mit den neuen Möglichkeiten anfänglich oft nur experimentiert wurde, werden nun umfassende Strategien entwickelt. Auch steigen die Investitionen in den Aufbau von Kompetenzen und nachhaltigen Strukturen. Doch wie wird sich dieser Prozess in Zukunft entwickeln? Dieser Forschungsfrage geht die Studie Social Media Delphi 2012 nach. Sie kombiniert eine Befragung von 860 Kommunikationsmanagern in Unternehmen,
Institutionen und Non-Profit-Oganisationen mit einer zweistufigen Delphi-Befragung von 32 Experten aus Wirtschaft und Wissenschaft. Darauf aufbauend liefert der Bericht Zukunftsprognosen sowie Handlungsempfehlungen für die Praxis. Das Gemeinschaftsprojekt der Universität Leipzig mit Fink & Fuchs Public Relations (Wiesbaden) und dem Magazin „pressesprecher“ (Berlin) schließt an frühere Untersuchungen an und zeigt Entwicklungsperspektiven im Zeitverlauf auf.
Der Berichtsband kann unter www.socialmediadelphi.de als PDF oder Druckexemplar kostenlos angefordert werden.
CTAP Centro Tecnológico Avanzado de la Piedra a través de su Laboratorio de Producto abre la puerta a desarrollos exclusivos que mejoren la funcionalidad de los materiales tradicionales y avanzados, así como ayudará a corregir posibles patologías de los mismos. El Laboratorio de CTAP ofrece una amplia gama de desarrollos a medida:
Productos químicos específicos y experimentales
Tratamientos protectores (Hidrofugación, Consolidación / Antidescohesión, Antimanchas)
Aumento de rendimientos de producción
Sistemas de refuerzo específicos
Texturas
Adhesivos especiales
Materiales de altas prestaciones
Caracterización, ensayo y validación de materiales, materias primas y productos
Ensayos y simulaciones de comportamiento material/producto en entornos reales o virtuales.
Aula sobre Comunicação e Sustentabilidade ministrada pelo professor Armando Levy na ECA-USP, fundamentada em pesquisas do MIT e do Boston Consulting Group. A pesquisa revela que as maiores empresas do mundo estão perdidas em relação ao tema.
Slides do treinamento de Microsoft ASP.NET que ministrei para a turma de pós-gradução em Desenvolvimento Web nas Faculdades OPET nos dias 11, 18 e 25 de Setembro de 2010
Das diesjährige Praxisforum erlebte am 30. Januar seine nun schon 13. Auflage in Folge. Im Forum am Altmarkt der Ostsächsischen Sparkasse Dresden sprachen Studierende, Absolventen und Mitarbeiter des Instituts vor vollen Reihen im Auditorium. Das Ziel, relevante Ergebnisse aus der Forschung des Instituts für die Praxis auszuwählen und aufzubereiten wurde dieses Jahr in drei Themenblöcken anvisiert, durch welche die studentischen Moderatoren Johanna Haupt und Jonathan Wosch führten.
presentación de buenas practicas ganaderas es una presentación que contiene principales biografías y autores así mismo como libros y otras referencias.
Marketing Analytics 101: How to Measure the Effectiveness of Your WebsiteHubSpot
You've started a blog, signed up for twitter, and set up a Facebook Business Page - now how do you know if it's working for you? This webinar will provide all the basics of how inbound marketing-driven businesses should measure the effectiveness of their online efforts. This includes understanding what Internet marketing metrics to measure and how to leverage this data to make key business decisions and improve the effectiveness of your website.
Concurrent programming is one of the major challenges for the software industry. We are in a time of massive experimentation as language designers and programmers search for ways to make concurrent programming easier, less error prone, and more reliable.
This talk will be a survey of concurrent programming constructs which are currently available in some programming language or library. We will look at programming model being presented, as well as examining some of the implementation challenges for the various models.
There is an increasing interest in functional programming from Java developers and the organisations in which they work. For many companies the challenge now is how to make use of the competitive advantage of functional programming. For developers, how do you adapt your mindset to this newly reimagined paradigm? Through the use of examples and a modular approach to design, Clojure made simple will show how developers can be productive quickly without a major change to their current development life-cycle. We will also cover the Clojure build process, tools and exciting projects out there.
Fuel Up JavaScript with Functional ProgrammingShine Xavier
JavaScript is the lingua franca of web development for over a decade. It has evolved tremendously along with the Web and has entrenched in modern browsers, complex Web applications, mobile development, server-side programming, and in emerging platforms like the Internet of Things.
Eventhough JavaScript has come a long way, a reinforced makeover to it will help build concurrent and massive systems that handle Big Data, IoT peripherals and many other complex eco systems. Functional Programming is the programming paradigm that could empower JavaScript to to enable more effective, robust, and flexible software development.
These days, Functional Programming is at the heart of every new generation programming technologies. The inclusion of Functional Programming in JavaScript will lead to advanced and futuristic systems.
The need of the hour is to unwrap the underlying concepts and its implementation in the software development process.
The 46th edition of FAYA:80 provides a unique opportunity for the JavaScript developers and technology enthusiasts to shed light on the functional programming paradigm and on writing efficient functional code in JavaScript.
Join us for the session to know more.
Topics Covered:
· Functional Programming Core Concepts
· Function Compositions & Pipelines
· Use of JS in Functional Programming
· Techniques for Functional Coding in JS
· Live Demo
Simon Peyton Jones: Managing parallelismSkills Matter
If you want to program a parallel computer, it obviously makes sense to start with a computational paradigm in which parallelism is the default (ie functional programming), rather than one in which computation is based on sequential flow of control (the imperative paradigm). And yet, and yet ... functional programmers have been singing this tune since the 1980s, but do not yet rule the world. In this talk I’ll say why I think parallelism is too complex a beast to be slain at one blow, and how we are going to be driven, willy-nilly, towards a world in which side effects are much more tightly controlled than now. I’ll sketch a whole range of ways of writing parallel program in a functional paradigm (implicit parallelism, transactional memory, data parallelism, DSLs for GPUs, distributed processes, etc, etc), illustrating with examples from the rapidly moving Haskell community, and identifying some of the challenges we need to tackle.
Porting a Streaming Pipeline from Scala to RustEvan Chan
How we at Conviva ported a streaming data pipeline in months from Scala to Rust. What are the important human and technical factors in our port, and what did we learn?
Functional Programming and Composing Actorslegendofklang
With the world being non-deterministic, with failure being abundant, and with communication latency being very real—how do we design systems that are capable of dealing with these conditions and how can we expose abstractions that are feasible to reason about?
A long time ago in a galaxy far, far away...
Java open source developers managed to the see the previously secret plans to the Empire's ultimate weapon, the JAVA™ COLLECTIONS FRAMEWORK.
Evading the dreaded Imperial Starfleet, a group of freedom fighters investigate the performance of the Empire’s most popular weapons: LinkedList, ArrayList and HashMap. In addition, they investigate common developer errors and bugs to help protect their vital software. With this new found knowledge they strike back!
Pursued by the Empire's sinister agents, JDuchess races home aboard her JVM, investigating proposed future changes to the Java Collections and other options such as Immutable Collections which could save her people and restore freedom to the galaxy....
Dev Dives: Train smarter, not harder – active learning and UiPath LLMs for do...UiPathCommunity
💥 Speed, accuracy, and scaling – discover the superpowers of GenAI in action with UiPath Document Understanding and Communications Mining™:
See how to accelerate model training and optimize model performance with active learning
Learn about the latest enhancements to out-of-the-box document processing – with little to no training required
Get an exclusive demo of the new family of UiPath LLMs – GenAI models specialized for processing different types of documents and messages
This is a hands-on session specifically designed for automation developers and AI enthusiasts seeking to enhance their knowledge in leveraging the latest intelligent document processing capabilities offered by UiPath.
Speakers:
👨🏫 Andras Palfi, Senior Product Manager, UiPath
👩🏫 Lenka Dulovicova, Product Program Manager, UiPath
Elevating Tactical DDD Patterns Through Object CalisthenicsDorra BARTAGUIZ
After immersing yourself in the blue book and its red counterpart, attending DDD-focused conferences, and applying tactical patterns, you're left with a crucial question: How do I ensure my design is effective? Tactical patterns within Domain-Driven Design (DDD) serve as guiding principles for creating clear and manageable domain models. However, achieving success with these patterns requires additional guidance. Interestingly, we've observed that a set of constraints initially designed for training purposes remarkably aligns with effective pattern implementation, offering a more ‘mechanical’ approach. Let's explore together how Object Calisthenics can elevate the design of your tactical DDD patterns, offering concrete help for those venturing into DDD for the first time!
Smart TV Buyer Insights Survey 2024 by 91mobiles.pdf91mobiles
91mobiles recently conducted a Smart TV Buyer Insights Survey in which we asked over 3,000 respondents about the TV they own, aspects they look at on a new TV, and their TV buying preferences.
Generating a custom Ruby SDK for your web service or Rails API using Smithyg2nightmarescribd
Have you ever wanted a Ruby client API to communicate with your web service? Smithy is a protocol-agnostic language for defining services and SDKs. Smithy Ruby is an implementation of Smithy that generates a Ruby SDK using a Smithy model. In this talk, we will explore Smithy and Smithy Ruby to learn how to generate custom feature-rich SDKs that can communicate with any web service, such as a Rails JSON API.
UiPath Test Automation using UiPath Test Suite series, part 3DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 3. In this session, we will cover desktop automation along with UI automation.
Topics covered:
UI automation Introduction,
UI automation Sample
Desktop automation flow
Pradeep Chinnala, Senior Consultant Automation Developer @WonderBotz and UiPath MVP
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
Kubernetes & AI - Beauty and the Beast !?! @KCD Istanbul 2024Tobias Schneck
As AI technology is pushing into IT I was wondering myself, as an “infrastructure container kubernetes guy”, how get this fancy AI technology get managed from an infrastructure operational view? Is it possible to apply our lovely cloud native principals as well? What benefit’s both technologies could bring to each other?
Let me take this questions and provide you a short journey through existing deployment models and use cases for AI software. On practical examples, we discuss what cloud/on-premise strategy we may need for applying it to our own infrastructure to get it to work from an enterprise perspective. I want to give an overview about infrastructure requirements and technologies, what could be beneficial or limiting your AI use cases in an enterprise environment. An interactive Demo will give you some insides, what approaches I got already working for real.
Transcript: Selling digital books in 2024: Insights from industry leaders - T...BookNet Canada
The publishing industry has been selling digital audiobooks and ebooks for over a decade and has found its groove. What’s changed? What has stayed the same? Where do we go from here? Join a group of leading sales peers from across the industry for a conversation about the lessons learned since the popularization of digital books, best practices, digital book supply chain management, and more.
Link to video recording: https://bnctechforum.ca/sessions/selling-digital-books-in-2024-insights-from-industry-leaders/
Presented by BookNet Canada on May 28, 2024, with support from the Department of Canadian Heritage.
JMeter webinar - integration with InfluxDB and GrafanaRTTS
Watch this recorded webinar about real-time monitoring of application performance. See how to integrate Apache JMeter, the open-source leader in performance testing, with InfluxDB, the open-source time-series database, and Grafana, the open-source analytics and visualization application.
In this webinar, we will review the benefits of leveraging InfluxDB and Grafana when executing load tests and demonstrate how these tools are used to visualize performance metrics.
Length: 30 minutes
Session Overview
-------------------------------------------
During this webinar, we will cover the following topics while demonstrating the integrations of JMeter, InfluxDB and Grafana:
- What out-of-the-box solutions are available for real-time monitoring JMeter tests?
- What are the benefits of integrating InfluxDB and Grafana into the load testing stack?
- Which features are provided by Grafana?
- Demonstration of InfluxDB and Grafana using a practice web application
To view the webinar recording, go to:
https://www.rttsweb.com/jmeter-integration-webinar
14. Ignoring cores…
2 cores won't hurt you
4 cores will hurt a little
8 cores will hurt a bit
16 will start hurting
32 cores will hurt a lot (2009)
...
1 M cores ouch (2019)
15. Java is so Java
Java Memory Model
wait - notify
Thread.yield()
Thread.sleep()
synchronized
Executor Framework -> NIO (2)
22. Issues
• Locks
– manually lock and unlock
– lock ordering is a big problem
– locks are not compositional
• How do we decide what is concurrent?
• Need to pre-design, but now we have to
retrofit concurrency via new requirements
24. A good solution
• Substantially less error prone
• Makes it much easier to identify concurrency
• Runs on today’s (and future) parallel hardware
– Works if you keep adding cores/threads
27. Transactional memory
analogous to database transactions
Hardware vs. software implementations
Idea goes as far back as 1986
First appearance in a programming language:
Concurrent Haskell 2005
29. STM Design Space
STM Algorithms / Strategies
Granularity
word vs block
Locks vs Optimistic concurrency
Conflict detection
eager vs lazy
Contention management
30. STM Problems
• Non abortable operations
– I/O
• STM Overhead
– read/write barrier elimination
• Where to place transaction boundaries?
• Still need condition variables
– ordering problems are important
33. Available Data Structures
Lists, Vectors, Maps
hash list based on Vlists
VDList - deques based on Vlists
red-black trees
Real Time Queues and Deques
deques, output-restricted deques
binary random access lists
binomial heaps
skew binary random access lists
skew binomial heaps
catenable lists
heaps with efficient merging
catenable deques
35. Actors
Invented by Carl Hewitt at MIT (1973)
Formal Model
Programming languages
Hardware
Led to continuations, Scheme
Recently revived by Erlang
Erlang’s model is not derived explicitly from
Actors
37. Example
object account extends Actor
{
private var balance = 0
def act() {
loop {
react {
case Withdraw(amount) =>
balance -= amount
sender ! Balance(balance)
case Deposit(amount) =>
balance += amount
sender ! Balance(balance)
case BalanceRequest =>
sender ! Balance(balance)
case TerminateRequest =>
}
}
}
38. Problems
DOS of the actor mail queue
Multiple actor coordination
reinvent transactions?
Actors can still deadlock and starve
Programmer defines granularity
by choosing what is an actor
41. Erlang vs JVM
Erlang
per process GC heap
tail call
distributed
JVM
per JVM heap
tail call (fixed in JSR-292?, at least in scalac)
not distributed
few kinds of actors (Scala)
42. Actor Variants
Clojure Agents
Designed for loosely coupled stuff
Code/actions sent to agents
Code is queued when it hits the agent
Agent framework guarantees serialization
State of agent is always available for read (unlike
actors which could be busy processing when you send a
read message)
not in favor of transparent distribution
Clojure agents can operate in an ‘open world’ - actors
answer a specific set of messages
43. Dataflow
Dataflow is a software architecture based on the idea
that changing the value of a variable should automatically
force recalculation of the values of variables which
depend on its value
Bill Ackerman’s PhD Thesis at MIT (1984)
Declarative Concurrency in functional languages
Research in the 1980’s and 90’s
Inherent concurrency
Turns out to be very difficult to implement
Interest in declarative concurrency is slowly returning
44. The Model
Dataflow Variables
create variable
bind value
read value or block
Threads
Dataflow Streams
List whose tail is an unbound dataflow variable
Deterministic computation!
45. Example: Variables 1
object Test5 extends App {
val x, y, z = new DataFlowVariable[Int]
val main = thread {
x << 1
if (x() > y()) { z << x } else {z << y }
}
val setY = thread {
Thread.sleep(5000)
y << 2
}
main ! 'exit
setY ! 'exit
}
46. Example: Streams (Oz)
fun {Ints N Max}
if N == Max then nil
else
{Delay 1000}
N|{Ints N+1 Max}
end
end
fun {Sum S Stream}
case Stream of nil then S
[] H|T then S|{Sum H+S T} end
end
local X Y in
thread X = {Ints 0 1000} end
thread Y = {Sum 0 X} end
{Browse Y}
end
47. Implementations
Mozart Oz
http://www.mozart-oz.org/
Akka
http://github.com/jboner/scala-dataflow
dataflow variables and streams
Ruby library
http://github.com/larrytheliquid/dataflow
dataflow variables and streams
Groovy
http://code.google.com/p/gparallelizer/
51. The Model
Space uncoupling
Time uncoupling
Readers are decoupled from Writers
Content addressable by pattern matching
Can emulate
Actor like continuations
CSP
Message Passing
Semaphores
52. Example
public class Account implements Entry {
public Integer accountNo;
public Integer value;
public Account() { ... }
public Account(int accountNo, int value {
this.accountNo = newInteger(accountNo);
this.value = newInteger(value);
}
}
try {
Account newAccount = new Account(accountNo, value);
space.write(newAccount, null, Lease.FOREVER);
}
space.read(accountNo);
53. Implementations
Jini/JavaSpaces
http://incubator.apache.org/river/RIVER/inde
x.html
BlitzSpaces
http://www.dancres.org/blitz/blitz_js.html
PyLinda
http://code.google.com/p/pylinda/
Rinda
built in to Ruby
54. Problems
Low level
High latency to the space - the space is
contention point / hot spot
Scalability
More for distribution than concurrency
and sometimes called the instruction address register (IAR)[1] or just part of the instruction sequencer,[2] is a processor register that indicates where a computer is in its programsequence.
For the concept, see Mutually exclusive events."mutex" redirects here. For the computer program object that negotiates mutual exclusion among threads, see lock (computer science).Coarse-grained systems consist of fewer, larger components than fine-grained systems; a coarse-grained description of a system regards large subcomponents while a fine-grained description regards smaller components of which the larger ones are composed.
- the process calculi (or process algebras) are a diverse family of related approaches for formally modellingconcurrent systems.Communicating Sequential Processes (limbo and Go) - process calculusThe approach taken in developing CSP into a process algebra was influenced by Robin Milner's work on theCalculus of Communicating Systems (CCS), and vice versa. CCS is useful for evaluating the qualitative correctness of properties of a system such as deadlock or livelockA Petri net (also known as a place/transition net or P/T net) is one of several mathematical modeling languages for the description of distributed systemsPi - as a continuation of work on the process calculus CCS (Calculus of Communicating Systems). The π-calculus allows channel names to be communicated along the channels themselves, and in this way it is able to describe concurrent computations whose network configuration may change during the computation.The join-calculus is a member of the -calculus family of process calculi, and can be considered, at its core, an asynchronous -calculus with several strong restrictions[3]:Scope restriction, reception, and replicated reception are syntactically merged into a single construct, the definition;Communication occurs only on defined names;For every defined name there is exactly one replicated reception.
Transactional memory attempts to simplify parallel programming by allowing a group of load and store instructions to execute in an atomic way. It is a concurrency control mechanism analogous to database transactions for controlling access to shared memory in concurrent computing.A dataflow network is a network of concurrently executing processes or automata that can communicate by sending data over channels (seemessage passing.)A tuple space is an implementation of the associative memory paradigm for parallel/distributed computing. It provides a repository of tuples that can be accessed concurrently. As an illustrative example, consider that there are a group of processors that produce pieces of data and a group of processors that use the data. Producers post their data as tuples in the space, and the consumers then retrieve data from the space that match a certain pattern. This is also known as the blackboard metaphor. Tuple space may be thought as a form of distributed shared memory.Tuple spaces were the theoretical underpinning of the Linda language developed by David Gelernter and Nicholas Carriero at Yale University.Implementations of tuple spaces have also been developed for Java (JavaSpaces), Lisp, Lua, Prolog, Python, Ruby, Smalltalk, Tcl, and the.NET framework.
. A contention management process is invoked when a conflict occurs between a first transaction and a second transaction. The pre-determined commit order is used in the contention management process to aid in determining whether the first transaction or the second transaction should win the conflict and be allowed to proceed."
Dataflow concurrency is deterministic. This means that it will always behave the same. If you run it once and it yields output 5 then it will do that every time, run it 10 million times, same result. If it on the other hand deadlocks the first time you run it, then it will deadlock every single time you run it. Also, there is no difference between sequential code and concurrent code. These properties makes it very easy to reason about concurrency. The limitation is that the code needs to be side-effect free, e.g. deterministic. You can’t use exceptions, time, random etc., but need to treat the part of your program that uses dataflow concurrency as a pure function with input and output.The best way to learn how to program with dataflow variables is to read the fantastic book Concepts, Techniques, and Models of Computer Programming. By Peter Van Roy and Seif Haridi.