3
votes
0answers
75 views

Does synchronization in java protect modified class fields? [migrated]

I saw this on Java's synchronization tutorial: public class SynchronizedCounter { private int c = 0; public synchronized void increment() { c++; } public synchronized void ...
7
votes
2answers
352 views

Can someone explain in simple terms what is the disruptor pattern? [closed]

I would also be interested to know if there are other implementations (i.e. frameworks) or if it is just the one from LMAX.
0
votes
3answers
100 views

In which object should I implement wait()/notify()?

I'm working in an Android project with multithreading. Basically I have to wait to the server to respond before sending more data. The data sending task is delimited by the flag boolean ...
2
votes
0answers
73 views

How can I make a universal construction more efficient?

A "universal construction" is a wrapper class for a sequential object that enables it to be linearized (a strong consistency condition for concurrent objects). For instance, here's an adapted ...
0
votes
2answers
132 views

How other thread can show the incremented value unless the 1st thread reaches the return statement?

My code is given below. In the for loop I am getting unexpected output i.e. before completing the execution of for loop by 1st thread the 2nd thread comes in for loop and shows incremented value. ...
0
votes
2answers
88 views

When one thread out of four is executing first line in run() then at the same time what will remaining three threads do?

I have four thread instances and they are executing run() code given below: public void run (){ System.out.println("1st line :"+Thread.CurrentThread().getName()); System.out.println("2nd line ...
0
votes
0answers
268 views

Make a java program use more processors

I am running a program that is supposed to solve a problem with the brute force approach. My computer has a quad-core CPU. When I run the program clearly java uses only one core, because in my ...
0
votes
1answer
101 views

Use of separate threads or singe thread

In my project, on a security system, I was using a socket to get the details of the client and then store it in a database (his IP and port he connected from and service he accessed). I was wondering ...
0
votes
1answer
152 views

Do threads delete themselves?

Let's say I was working on a Swing application. Most of it is run on the EDT using SwingUtilities.invokeLater() inside the main method, because I heard (please correct me if I'm wrong) that that's ...
-2
votes
1answer
201 views

Extracting data from log files

I will be extracting certain bits from log files using regular expressions to filter out bit of data. Initially I was going to do this with Python. I later started to think about the fastest way I can ...
0
votes
2answers
166 views

Why would Java app make RPC call to itself?

I am working with a multithreaded homegrown multi-module app in my new job. We use the the Thrift protocol to communicate RPC calls between different stand-alone applications in a distributed system. ...
2
votes
3answers
205 views

How do I limit the resources available to a program?

I'm delving into multi-threaded programming with Java, but I'm finding it hard to test my program for bugs. My computer simply has too many resources and cores, making it hard to see how my program ...
1
vote
0answers
427 views

Java UDP Multithread Server

I have multiple threads. Each thread receives data and sends to client an acknowledge packet. Each thread takes aprox. 531ms from start to finish. While capturing packets with wireshark. I was ...
1
vote
1answer
989 views

How to make a method synchronized across all instances of an object

Today I was asked this interview question and could not answer. : If you have two instances of a Person Object and each of them have a setAddres method that is synchronized. Now if it was only one ...
6
votes
3answers
992 views

How many threads should access the file system at the same time?

We have a module in an application which stores data in multiple files and multilevel directories and access them from multiple threads (both reads and writes). The directory structure is based on a ...
6
votes
2answers
4k views

How is multi-threading different in a Java based Web Application vs Stand-alone Java Application

I am fairly new to Java and my experience is limited to Web Based Applications running on a Web Container (Jboss in my case). Am I correct in saying that for Web Applications the web container takes ...
1
vote
1answer
2k views

High-Load Java Server for Multiplayer

I am making a multiplayer game. Now I am trying to choose the technology to connect the android devices to the server. The clients run on Android, and the game is MMORPG. I would like to write the ...
6
votes
4answers
2k views

Threads or ThreadPool? Fixed or Dynamic ThreadPool?

I have a java program which listens on a port for input. Based on Input, it calls a webservice and then returns a success/failure back to the client program. I fork a thread for each client ...
0
votes
1answer
2k views

Android game loop in separate thread

I am about to port a game that was initially written for iOs and I am having some doubts how certain things should be done. I have been looking many of the examples of the game loops for android, and ...
-1
votes
2answers
860 views

Difference between daemon and child thread?

As per my knowledge daemon thread is a thread that runs in background(low priority thread) and also a child thread runs in the background when the parent thread runs foreground so where does the ...
-2
votes
1answer
273 views

Why notify and wait are not declared in threads?

wait and notify are said to be communication mechanism in threads but then why are they not declared in Thread class and are declared in Object class instead?
4
votes
2answers
351 views

Help me understand a part of Java Language Specification

I'm reading part 17.2.1 of Java language specification: http://docs.oracle.com/javase/specs/jls/se7/html/jls-17.html#jls-17.2.1 I won't copy a text, it's too long, but I would like to know, why for ...
1
vote
2answers
975 views

Synchronous sockets with Node.js

I want to port an existing app from Java to Node.js - would like to seek your advise. The java app is a multithreaded socket server where arbitrary number of clients can connect. The app runs on java ...
3
votes
1answer
185 views

Parallel Threading in Multi-Language Software?

I'm developing a software that contain many modules/Daemon running in parallel manner, what i'm looking for is how to implement that, i cannot use Thread because some of those modules/Daemon are ...
2
votes
4answers
698 views

Should I build a multi-threaded system that handles events from a game and sorts them, independently, into different threads based on priority?

Can I build a multi-threaded system that handles events from a game and sorts them, independently, into different threads based on priority, and is it a good idea? Here's more info: I am about to ...
8
votes
1answer
929 views

Conceptually what does it mean when it is said that each thread gets its own stack?

I have been reading Java Concurrency in Practice by Brian Goetz and inside the section Stack Confinement it is mentioned that each thread gets its own stack and so local variables are intrinsically ...
4
votes
2answers
2k views

Why would one ever want to use a synchronized method in Enum?

I stumbled upon this question and a couple of other along the same lines. While we know creation of enum is thread safe and enums are by birth singletons . It kind of confuses me that why would ...
3
votes
1answer
1k 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 ...
6
votes
4answers
4k views

Problems of multiple threads sharing/accessing the same data [closed]

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 ...
2
votes
3answers
448 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
3k views

Sharing buffer between multiple threads

I had a job process that was executing a lot of IO to read and write temporary files. Now I want to (need to) reduce the quantity of IO executions. So I want to create a sort of circular buffer ...
16
votes
3answers
3k 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 ...
0
votes
3answers
937 views

Design pattern for a multi-threaded URL fetcher in java

I'm looking for hints and suggestions on a design for a multi-threaded URL fetcher in java. Specific requirements are: To fetch each one of around 1,000 URLs periodically The interval between each ...
1
vote
6answers
476 views

Structuring multi-threaded programs

Are there any canonical sources for learning how to structure multi-threaded programs? Even with all the concurrency utility classes that Java provides I'm having a hard time properly structuring ...
0
votes
1answer
47 views

Where to put profile test?

I have an application with multiple threads that may be run on different hardware. To assist with tuning on different hardware I would like to create a "profiler" that can automatically run a fixed ...