The concurrency tag has no wiki summary.
0
votes
1answer
65 views
Static objects and concurrency in a web application
I'm developing small Java Web Applications on Tomcat server and I'm using MySQL as my database.
Up until now I was using a connection singleton for accessing the database but I found out that this ...
4
votes
8answers
310 views
When should I use parallelism?
After asking this question, I got to realize that parallelism may not always be good.
So far I can see that parallelism (under c#) is
A little complicated code-wise
Will probably insert some ...
5
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4answers
174 views
Real world usage of DelayQueue
What would be a real world usage of DelayQueue, what common problem it was design to solve?
3
votes
1answer
178 views
How to read from a database, and write to a file asynchronously / non blocking way in Java
I'm trying to modify a serial program that reads from a database, and writes results to a file, this is done in a blocking way and I think we can get performance boost of there is a memory buffer and ...
3
votes
2answers
165 views
How are you using CFThread in ColdFusion Applications? [closed]
I'm presenting on Concurrency in ColdFusion at CFObjective this year, and I'd like to hear how you're using CFThread in your ColdFusion applications.
In addition, what problems have you had while ...
2
votes
3answers
89 views
Actor based concurrency and cancellation
I'm reading about actor based concurrency and I appreciate the simplicity of actors sequentially processing messages on a single thread. However there is one scenario that doesn't seen possible.
...
5
votes
3answers
228 views
How to avoid halting of the JVM due to a deadlock in java?
I have read many websites talking about how to avoid and how to design etc. I completely understand those strategies.
My question is based on the following preconditions:
You have a company with ...
5
votes
4answers
154 views
Problems of multiple threads sharing/accessing the same data
I have been researching into when data is being accessed or shared by multiple threads within Java. And looking into the problems such as:
Thread Interference
Memory Consistency
Deadlock
Starvation
...
7
votes
4answers
396 views
What are the best resources for learning about concurrency and multi-threaded applications?
I realised I have a massive knowledge gap when it comes to multi-threaded applications and concurrent programming. I've covered some basics in the past, but most of it seems to be gone from my mind, ...
4
votes
1answer
154 views
Selective mutual exclusion in Dining Philosophers and Readers and Writers problem
I've been reading about selective mutual exclusion (SME). The idea I got is that if a process competes for its resources against a subset of all the other process instead of competing with all the ...
5
votes
2answers
207 views
Rendezvous in Ada
In a test I was asked:
What elements present in the general form of a rendezvous are not present in Ada language?
I was a bit stumbled as I thought Ada fully supported rendezvous. Now it seems ...
3
votes
2answers
117 views
Optimistic work sharing on sparsely distributed systems
What would a system like BOINC look like if it were written today?
At the time BOINC was written, databases were the primary choice for maintaining a shared state and concurrency among nodes.
Since ...
1
vote
2answers
95 views
Are there any advantages of using separate RDBMS for reports?
My production database is SQL Server 2008 R2 Express. It has limited features and I am testing it in a production environment. To better handle reporting queries in a highly concurrent environment, I ...
2
votes
1answer
123 views
How to achieve thread synchronizing without effecting the efficiency in java [closed]
Say using following function:
public synchronized int getUnique(){
MyObject obj = getValueFromDb();
obj.modifyIt();
obj.commit();
}
When simultaneous call is made to this method several ...
1
vote
2answers
78 views
Concurrent Data Processing by Multiple People
Let's say I have a page, accessible by several people concurrently, that lists information that must be processed in some way by the user, after which it is either marked as "completed" and ...
1
vote
2answers
240 views
Looking for a distributed locking pattern
I need to come up with a custom recursive object locking mechanism\pattern for a distributed system in C#. Essentially, I have a multi-node system. Each node has exclusive write permissions over ...
2
votes
3answers
174 views
Sharing buffer between multiple threads part 2
This is a follow up to my previous not answered question, so I try to make it more clear: last question.
I have a n-size buffer that is filled up from an external source, it has 2 main methods get() ...
2
votes
5answers
329 views
Programming language with native concurrency support for large graphs?
I'm currently looking for a new programming language to learn (currently working through some C++, know some C and Python), specifically one that has built-in concurrency support? I want to try to ...
14
votes
2answers
355 views
Why does shared state degrade performance?
I've been working under the share-nothing principle of concurrent programming. Essentially, all my worker threads have immutable read-only copies of the same state which is never shared between them ...
7
votes
2answers
604 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 ...
2
votes
1answer
145 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 ...
24
votes
16answers
2k views
Modern programming language with intuitive concurrent programming abstractions
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 ...
8
votes
3answers
438 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 ...
5
votes
2answers
550 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
214 views
What are the recommended resources for learning about the Actor model of concurrent systems?
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 ...
10
votes
4answers
897 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 ...
6
votes
2answers
199 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 ...
3
votes
2answers
225 views
Are there any good Java/JVM libraries for my Expression Tree architecture?
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
7answers
568 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? ...
19
votes
5answers
808 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 ...
7
votes
6answers
369 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 ...
1
vote
1answer
206 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
209 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 ...
12
votes
4answers
921 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
2answers
159 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 ...
1
vote
2answers
123 views
What pitfalls and gotchas commonly occur when beginning with Parallel and Concurrent Programming with C?
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 ...
1
vote
1answer
226 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
136 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 ...
5
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6answers
379 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
1answer
249 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 ...
54
votes
10answers
3k 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 ...
9
votes
4answers
266 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 ...
0
votes
4answers
347 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 ...
1
vote
2answers
136 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
votes
3answers
217 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
votes
2answers
732 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 ...
1
vote
1answer
96 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 ...
3
votes
2answers
110 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 ...
23
votes
10answers
845 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 ...
13
votes
3answers
441 views
What is your thoughts about the Actor Model?
The Actor Model that is used by Erlang seem to be a very different way to do concurrent programming. What is your thoughts on the Actor Model? Will it be a popular solution for concurrency?
