Real-time processing means processing data as it is created or modified. This is in contrast to batch processing, wherein data is processed in large chunks at a specific interval (e.g. every night).

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89
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4answers
27k views

What operating systems are used in airplanes, and what programming languages are they developed in? [closed]

I was wondering if anyone knows what is the operating system used in commercial airplanes (say Boeing or Airbus). Also, what is the (preferred) real-time programing language? I heard that Ada is used ...
27
votes
3answers
2k views

Except garbage collector, what else makes Java a non real time programming language

Except the garbage collector, what are some other features in Java that make it unsuitable for real time programming? On the net, whenever Java vs C++ is discussed with regards to real time ...
15
votes
2answers
472 views

What are the reasons for why a Java/Linux stack fails to be “real time”?

I have often heard developers mention that Java can't "do Real Time", meaning a Java app running on Linux cannot meet the requirements of a deterministic real-time system, such as something running on ...
11
votes
2answers
5k views

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

I would like if you could explain to me in a simple way how does the disruptor patter work. This concept has been elusive to me as of know. Perhaps with your help I could comprehend it.
8
votes
3answers
2k views

What optimizations can be done for soft real-time code in C#?

I'm writing a soft real-time application in C#. Certain tasks, like responding to hardware requests coming in from a network, needs to be finished within a certain amount of milliseconds; however it ...
6
votes
5answers
1k views

How to save during real-time collaboration

I want multiple users to edit same document. Problem I'm facing is when a new user joins, he might see an outdated document. How do I make sure that new users get most recent changes? Some solutions ...
6
votes
3answers
2k views

How is time calculation performed by a computer?

I need to add a certain feature to a module in a given project regarding time calculation. For this specific case I'm using Java and reading through the documentation of the Date class I found out the ...
6
votes
3answers
403 views

Floating point undesirable in highly critical code?

Question 11 in the Software Quality section of "IEEE Computer Society Real-World Software Engineering Problems", Naveda, Seidman, lists fp computation as undesirable because "the accuracy of the ...
6
votes
2answers
3k views

Migrating from Python to Scala wise when a lot of work is already done in Python?

Me and my friend are developing a web-app in Python + Flask + PostgreSQL. We have been working on it for the past few months and have developed a lot of schema/use-cases specific to Python + Flask + ...
6
votes
1answer
1k views

What are the challenges in building a scalable real-time web app?

I'm looking into real-time web applications using websockets and node.js. I'm interested to see what are some technical challenges with scaling such a setup. One such problem I've heard is that each ...
5
votes
5answers
830 views

Is realtime validation of username good or bad?

I have a simple form for the user to sign up to my site; with email, username and password fields. We are now trying to implement an ajax validation so the user doesn't have to post the form to find ...
5
votes
5answers
1k views

How did they count the number of lines of code executed at runtime?

There was a PC game released in 2001 called Black & White by Lionhead studios in which there was a lengthy statistics page which updated in real-time. There were stats such as how many people ...
5
votes
2answers
2k views

Node.JS or Scala for mobile and web apps [closed]

I am coming from a php background with some python as well. I want to start working on a different language for both web and mobile development. I am also interested in real time apps dealing with ...
5
votes
3answers
1k views

Real-time Dataflow Programming

Background Recently, I have been fascinated about the possibilities of dataflow-based programming approaches - in particular, signal/event-based concepts as realized by functional reactive ...
5
votes
2answers
691 views

Design pattern for an automated mechanical test bench

Background I have a test fixture with a number of communication/data acquisition devices on it that is used as an end of line test for a product. Because of all the various sensors used in the ...
4
votes
6answers
5k views

Real time unit testing - or “how to mock now”

When you are working on a feature that depends on time... How do you organize unit testing ? When your unit tests scenarios depend on the way your program interprets "now", how do you set them up ? ...
4
votes
1answer
415 views

Should reflection be part of design?

I'm currently designing a somewhat large program that will involve the simulation of math/physics models and collection of data (I have not implemented any code yet). One of the main problems I'm ...
4
votes
5answers
15k views

Real-time chat in Ruby on Rails without owning a server [closed]

I'd want to implement a Real-time chat for my Rails app but I can't really host the server which handles the sockets. I've tried Faye but it needs a server. I've also heard of pusher but it's limited ...
4
votes
2answers
652 views

WCF service as a proxy for publishing real-time data to a WPF/MVVM clients

I've been tasked with creating a dashboard application to show real time updates for our servers. The raw data comes in from an XML file on our intranet which I need to parse and present to the user. ...
4
votes
5answers
7k views

easiest way for push notifications

I wanted to implement real time push notification to one of the apps written in RoR. I don't have any experience with nodejs, nowjs, express or socketio. What would be the easiest way to implement ...
4
votes
2answers
74 views

Using websockets for server “broadcasting”?

I want to make it possible to edit shared todo lists in real time. There's already a REST interface, and it's possible to send updates to the server - add items, mark items as done, etc. For the ...
4
votes
1answer
130 views

Oscillations detector: how to effectively detect oscillations of a variable?

I monitor a variable in real-time where new value is generated every 1/25 second. Depending on the conditions, this variable may either be stable, i.e. fluctuate a little (+/-1%) around some value ...
3
votes
3answers
163 views

Read data from a device through usb port at high frequency

I need to know if I can get acceleration data from an IMU at 500Hz via USB. I've been going through the code that the manufacturer provides and trying to improve it. Right now I cannot go faster ...
3
votes
2answers
747 views

Benefits of RTOS vs Bare Metal for MCU Programming?

Please note: This question specifically mentions two RTOSes but is more generic and can probably be answered by anybody who has written C code for embedded RTOSes before, and had their software run ...
2
votes
1answer
1k views

How the Erlang get soft-realtime with GC?

Generally GC is not a good choice to get a soft real-time attribute. But Erlang is GC based language can be soft real-time. Does it mean Erlang have almost no GC latency? How does it work?
2
votes
2answers
218 views

Compiling and deploying a C program to an MCU running an RTOS

Please note: Even though I'm specifically talking about an RTOS called Embox here, and even though I'm talking about AVR/ARm, I think this question can be answered by anybody whose ever done a fair ...
2
votes
1answer
91 views

Compiling and deploying RTOS to an MCU

Please note: Even though I'm specifically talking about an RTOS called Embox here, and even though I'm talking about AVR/ARm, I think this question can be answered by anybody whose ever done a fair ...
2
votes
2answers
193 views

Is WCF strictly an asynchonous comms platform?

Since I last had to do any comms/network programming, the field has exploded with acronyms. In fact, networking almost feels like it is now described by a whole new language. The very name "Windows ...
2
votes
1answer
72 views

timed events to modulation of real-time audio

I am new very to audio programming and am having trouble figuring out the right kind of algorithm for converting control events (e.g. like MIDI) to real-time sound genesis with a buffer. At the ...
2
votes
1answer
470 views

Handling large amounts of sockets

I am working on a project in which we have a desktop application that should be able to receive commands from a web application. To solve this issue, using sockets seems like a good approach (instead ...
2
votes
0answers
400 views

Cross-compiling Java app to run directly on ARM

Please note: although I am using ARM SAM3X8E in this example, I'm just using that as a concrete example, and the answer to this question could easily be given using any other MCU such as AVR, etc. I ...
1
vote
2answers
2k views

Multitasking in C#

I would like to use a timer in my C# program with millisecond accuracy to keep a camera in sync with some events and keep shooting a picture every 250ms (or 1/4 sec, or I might adjust it to even ...
1
vote
1answer
2k views

How to get real time notifications, when a database change (insert, update, delete) occurs?

I'm creating a dashboard which should monitor a database table. I have only database access (no application layer). The table is rather large (10 million rows), however not changing rapidly (100 ...
1
vote
3answers
1k views

Implementing chat in 2013 [closed]

I played a bit with WebSockets and started to implement a tiny chat. Last time I did something like this was when there was no such thing as threads and computers had single core. I started to think ...
1
vote
2answers
673 views

Almost Realtime Data and Web application

I have a computer that is recording 100 different data points into an OPC server. I've written a simple OPC client that can read all of this data. I have a front-end website on a different network ...
1
vote
1answer
47 views

Scheduling/suspending embedded interpreters

Let's say that I want to embed a scripting engine inside some other program, to allow users to create custom behaviours for objects. For example, when a particular event happens, the server would ...
1
vote
3answers
64 views

Best approach for realtime sync + shared todo?

I'm implementing an app that has among other things shared todo lists. I want it to sync in real time. This has to work for "normal" single user items (e.g. user has app opened in 2 devices, doing an ...
1
vote
1answer
50 views

What are the impact to the server when using ajax polling for live web pages?

I've been searching on the internet about using interval ajax polling for live web pages and I've been using it along with SignalR. Now I always read an article online about using ajax polling for ...
1
vote
1answer
80 views

Best way to keep consistent data in model across devices?

I have a model for an app that is fairly large, all of which needs to be on a users' device at the same time. For example, a spreadsheet. If a user makes a change to the model on one device, I want ...
1
vote
3answers
100 views

Architecture for monitoring lots of mini-games

In my project, I'm going to create lots of mini games. Those mini games can last 30 seconds to 1 week (the duration of the game is decided when it is created and is fixed). The number of concurrent ...
1
vote
1answer
431 views

What is a good practice to push notifications in a “near real-time” delay in this case?

I want to enable some real-time notifications about friend's activities (social network). Technical context is: Webapp calling backend (REST API's). Scenario is: Kevin follows Bob. When Bob ...
1
vote
1answer
528 views

options for data analytics for time series store

I'm building an Internet of Things solution that has a number of real time feeds. I need to make a couple of design decisions with regards to the data store and reporting and looking for input. I ...
1
vote
1answer
174 views

Object schemas shared between web services

My question is about how to create a definition for an object that is handled by different web services. A brief description of my current scenario and why I think it's a problem: A PHP web ...
1
vote
1answer
636 views

High performance and/or real time java open source applications [closed]

Which open source java projects do you know to be high performance or real time performance? I tried hard to find them on github or google, but couldn't find suitable. I want to learn from this ...
1
vote
1answer
176 views

benchmarks for quasi real-time software

I'm wondering if there is any benchmarks which can help to understand real-time characteristics (response time) of non-real-time software. For instance C# application on Windows or MSSQL Server. I ...
1
vote
1answer
44 views

Building a real-time web-app with Ajax .post()

Usually, real-time web-apps are built with websockets, right? Well, let me be radical here - what if I used Ajax? Okay, okay, I know it has its limitations. You can't build Agar.io, sending data ...
1
vote
0answers
349 views

Integrate C++ DLL with C# GUI asynchronously (design issue)

This is more a design than an implementation question. I am aware of how to integrate a C++ DLL within a C# main app that acts as GUI. Believe me that I've read all other questions on similar topics, ...
1
vote
0answers
52 views

Semaphore : one for each shared resource?

Normally semaphores are implemented as integer variables. The value of a semaphore represents initially the number of processes that are allowed to access the shared resource at the same time, which ...
1
vote
0answers
396 views

Multiple long polling requests: bad idea?

I am designing a web server that handles multiple things such as a user-to-user chat, a user-to-group chat, friends request, forum etc. The chats have to be real-time chats, the friends requests ...
1
vote
0answers
418 views

Atmosphere + Long Polling : No message distribution?

I'm experiencing a strange behavior with Atmosphere + Long Polling. I'd like to have a broadcaster per user, so I have registered a broadcaster on resource suspension with id : /user/. I use ...