Concurrency is a property of systems in which several processes are executing at the same time.

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2answers
938 views

Where should I start on a large concurrent programming assignment?

My task is to implement a distributed semaphore system (links to description) and an application for it. I will be using Java sockets, and it will use watermark arrays and priority queues (not sure ...
3
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1answer
254 views

What are the relative merits for implementing an Erlang-style “Continuation” pattern in C#

What are the relative merits (or demerits) for implementing an Erlang-style "Continuation" pattern in C#. I'm working on a project that has a large number of Lowest priority threads and I'm wondering ...
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votes
16answers
7k views

Modern programming language with intuitive concurrent programming abstractions [closed]

I am interested in learning concurrent programming, focusing on the application/user level (not system programming). I am looking for a modern high level programming language that provides intuitive ...
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3answers
9k views

UML Diagrams of Multi-Threaded Applications

For single-threaded applications I like to use class diagrams to get an overview of the architecture of that application. This type of diagram, however, hasn’t been very helpful when trying to ...
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3answers
4k views

Why not Green Threads?

Whilst I know questions on this have been covered already (e.g. http://stackoverflow.com/questions/5713142/green-threads-vs-non-green-threads), I don't feel like I've got a satisfactory answer. The ...
4
votes
3answers
737 views

What are the recommended resources for learning about the Actor model of concurrent systems? [closed]

The Actor concurrency model is clearly gaining favor. Is there a good book that presents the patterns and pitfalls of the model? I am thinking about something that would discuss, for instance, the ...
16
votes
4answers
5k views

How does a movie theater seat booking system prevent multiple users from reserving the same seats?

In the movie theatre I go to they have ticket kiosks that allow you to select the seats you want; they also have a website that does the same (the website also has a countdown timer of like 30 secs in ...
10
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2answers
696 views

Is my description of the actor model right?

If I understood, the actor model is just like the object model, but with a few differences: EVERY object spawns it's own separate thread and its not a problem even when you have thousands of ...
2
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2answers
500 views

Are there any good Java/JVM libraries for my Expression Tree architecture? [closed]

My team and I are developing an enterprise-level application and I have devised an architecture for it that's best described as an "Expression Tree". The basic idea is that the leaf nodes of the tree ...
12
votes
8answers
2k views

Why should I know concurrent programming?

Concurrent programming is quite difficult to me: even looking at a basic slide seems challenging to me. It seems so abstract. What are the benefits to knowing Concurrent programming concepts well? ...
33
votes
5answers
8k views

Is object pooling a deprecated technique?

I am very familiar with the concept of object pooling and I always try to use it as much as possible. Additionally I always thought that object pooling is the standard norm as I have observed that ...
9
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6answers
613 views

Next in Concurrency

For past year I have been working a lot on concurrency in Java and have build and worked on many concurrent packages. So in terms of development in the concurrent world, I am quite confident. Further ...
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1answer
669 views

Model-View-Controller and client-side concurrency responsibility

In a web application that has a significant ajax component, where is the best place for the client-side concurrency responsibility to lie? We're trying to use MVC on both the server application (LAMP ...
7
votes
5answers
236 views

When developing a piece of software, when do you start thinking/designing the concurrent sections?

Following along with the principle of not optimizing too early, I'm wondering at what point in the design / development of a piece of software do you start thinking about the concurrency ...
25
votes
4answers
5k views

Should I stick with or abandon Python to deal with concurrency?

I have a 10K LOC project written in Django with quite a deal of Celery (RabbitMQ) for asynchronicity and background jobs where needed, and have come to the conclusion that parts of the system would ...
1
vote
3answers
672 views

3 threads printing numbers of different range

This question was asked in an Electronic Arts interview: There are 3 threads. The first thread prints the numbers 1 to 10. The second thread prints the numbers 11 to 20. The third thread prints the ...
3
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2answers
239 views

What pitfalls and gotchas commonly occur when beginning with Parallel and Concurrent Programming with C? [closed]

It roughly three weeks I will be taking a Parallel programming class that is taught using C for the assignments. I have a fairly strong interest in the subject at present and my C skills aren't ...
6
votes
1answer
1k views

How do I learn Concurrency in Ruby?

Yesterday I read this great article about Concurrency in JRuby from EngineYard and I realise I need to leverage my skills about concurrency in Ruby, by mentioning Ruby here I mean it could be all ...
7
votes
2answers
215 views

Are Concurrency Abstractions Emulating UNIX Processes?

OK, I was pondering this today, and I've come to ask for completely subjective and bias opinions on it. Paradoxically, despite this, I don't think it's flame-war fodder either. I think there is room ...
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6answers
422 views

What is the *correct* term for a program that makes use of multiple hardware processor cores?

I want to say that my program is capable of splitting some work across multiple CPU cores on a single system. What is the simple term for this? It's not multi-threaded, because that doesn't ...
2
votes
3answers
911 views

What are the consequences of immutable classes with references to mutable classes?

I've recently begun adopting the best practice of designing my classes to be immutable per Effective Java [Bloch2008]. I have a series of interrelated questions about degrees of mutability and their ...
61
votes
10answers
6k views

How to explain why multi-threading is difficult

I am a fairly good programmer, my boss is also a fairly good programmer. Though he seems to underestimate some tasks such as multi-threading and how difficult it can be (I find it very difficult for ...
10
votes
4answers
505 views

Why is implicit parallelism/concurrency not more widespread?

Implicit parallelism^ can take a big burden away from many programmers, placing it on the computer. So... why is it is not more widespread at present? ^ Implicit parallelism is to make a computer be ...
3
votes
4answers
619 views

Is the synchronized keyword,still used/needed in java?

Is the synchronised keyword still required (ignore backwards compatibility, I'm thinking in terms of writing new code, today) or should we all be using the features available in the Concurrent and ...
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2answers
209 views

Descriptive Locking and Concurrency

I'm thinking about how one would go about designing a descriptive concurrency model for an OOP language that helps simplify concurrency scenarios for programmers (no easy task, concurrency is hard). ...
0
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5answers
752 views

Examples of concurrent iterating scenarios needed

I'm trying to wrap my head around different concurrency solutions to several threads iterating over the same collection but I'm having difficulty coming up with good realistic (but preferably easy to ...
4
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2answers
2k views

Python threading vs. multiprocessing: Should I learn one before the other?

I'm looking to dive into multithreading or multiprocessing in Python. Question: should I be learning one before the other (for any reason)? If so, which one and why? I've read the pro's and con's in ...
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1answer
162 views

Programming language and database concurrent locking primitives

I am writing an article about both programming language locking primitives (which are really wrappers for OS primitives) and database locking primitives. Are there any short wide-spread titles for ...
4
votes
2answers
125 views

How much configurability to give to users regarding concurrency?

This question is a narrowing-down of these related questions: How much effort should we spend to programming for multiple cores? Concurrency: How do you approach the design and debug the ...
25
votes
10answers
2k views

Concurrency: How do you approach the design and debug the implementation?

I've been developing concurrent systems for several years now, and I have a pretty good grasp on the subject despite my lack of formal training (i.e. no degree). There's a few new languages that have ...
16
votes
3answers
942 views

What are your thoughts about the Actor Model? [closed]

The Actor Model which is used by Erlang seems to be a very different way to do concurrent programming. What are your thoughts about the Actor Model? Will it be a popular solution for concurrency?