real-time

Reduce resource usage of an Idle task

I find that in uC/OS-II RTOS, there is an idle task that gets executed when no other task is ready to run. If an idle task can consume resources, how can we reduce it ? ...

gcc and reentrant code

Does GCC generate reentrant code for all scenarios ? ...

Get information from various sources

Hi. I'm developing an app that has to get some information from various sources (APIs and RSS) and display it to the user in near real-time. What's the best way to get it: 1.Have a cron job to update them all accounts every 12h, and when a user is requesting one, update that account, save it to the DB and show it to the user? 2.Have a...

Are there free realtime financial data feeds since the demise of OpenQuant?

Now that the oligopole of market data providers successfully killed OpenQuant, does any alternative to proprietary and expensive subscriptions for realtime market data subsist? Ideally I would like to be able to monitor tick by tick securities from the NYSE, NASDAQ and AMEX (about 6000 symbols). Most vendors put a limit of 500 symbols...

Lucene real-time indexing?

What is the best way to achieve Lucene real-time indexing? ...

Software patching at a billion miles

Could someone here shed some light about how NASA goes about designing their spacecraft architecture to ensure that they are able to patch bugs in the deployed code? I have never built any “real time” type systems and this is a question that has come to mind after reading this article: http://pluto.jhuapl.edu/overview/piPerspective.p...

What tecnologies justin.tv use to stream live videos ?

What tecnologies justin.tv use to stream live videos ? thanks ^_^ ...

Keeping realtime views of cached content

Hi, I'm working on a busy web site. Sometimes it gets much more traffic then avarage days. The content is cached but as site's owner want to see realtime post views it has to do at least one query to MySQL per post view which is become performance problem under heavy load. All I can think of is create a different table for views and upd...

What does Google App Engine provide for realtime data transfer from java app to your client?

Are there any mechanisms for real time ive data transfer-delivery like socketsa or something like that? keep-alive http connections? Are there any tutorials on this topic of realtime data transfer from java app to your client and backwords? ...

Real time plot in matlab

Hi, I'm very new to matlab and I was trying to display a real time plot of some calculations. I have an N sized vector and I work with m (Say N=4m) values at a time so I want to plot the first m sized result and then as soon as the second m values are calculated have them replace the first plot. My approach was as follows: for i=1:N, ...

For real time programming, does reference counting have an advantage over garbage collection in terms of determinism?

If you were designing a programming language that features automatic memory management, would using reference counting allow for determinism guarantees that are not possible with a garbage collector? Would there be a different answer to this question for functional vs. imperative languages? ...

How realtime web applications are developed ?

I always wanted to get in to realtime & collaborative web application development. But couldn't find any good resource that would guide my existing knowledge of PHP/MySQL/jQuery/AJAX/XML/JSON to the realtime web applications development. I want some reading resources, that would allow me to practice my existing knowledge in terms of real...

Streaming from webcam on OS X - what technology to use?

I'm building a videoconferencing application in OS X. What technology would be best to use for real-time streaming video/audio captured from webcam/microphone in OS X? So far I was unsuccessful with these methods: - using QTKit I captured the media, but there isn't a way to stream it (without using the QTSS which is too bloaty and hard...

is there any way by which i can get stock quotes real time just as Google or Yahoo does?

does anyone know how Google or Yahoo get the stock quotes as NASDAQ or NYSE is not providing any APIs? Can we actually replicate what they do? are they using the crawl method itself or rather is crawling actually possible to get such data realtime? ...

What on earth is ReverseHTTP and why would it be useful?

reversehttp.net offers little immediate insight into what reversehttp truly is and how this can be best utilized, it makes it seem that this tool is too difficult to realistically implement. In what sorts of environments might this be the ideal real-time web data situation and when would this not work, What browsers support this method, ...

Real-time video encoding in DirectShow

Hello, I have developed a Windows application that captures video from an external device using DirectShow. The image resolution is 640x480 and the videos saved without compression have very huge sizes (approx. 27MB per second). My goal is to reduce this size as much as possible, so I am looking for an encoder which will allow me to co...

Performance of C++ vs Virtual Machine languages in high frequency finance

I thought the C/C++ vs C#/Java performance question was well trodden, meaning that I'd read enough evidence to suggest that the VM languages are not necessarily any slower than the "close-to-silicon" languages. Mostly because the JIT compiler can do optimizations that the statically compiled languages cannot. However, I recently receive...

pthreads with real time priority

I need to manage a pool of threads having different priorities, so I wrote the following thread startup procedure: static int startup(thrd_t *thrd, thrd_sync_t *sync, int prio) { pthread_attr_t attr; int err; struct sched_param param = { .sched_priority = prio }; assert(pthread_attr_init(&attr) == 0); as...

How to build a real-time streaming data silverlight application

Hi all, I'm curious to get some feedback and ideas on how one could go about building a realtime data streaming application. We can keep the source data generic for this exercise ... throughput info, stock trade pricing, etc. Just something that is constantly changing, and the information is stored in a database. I am interested in buil...

Best resources to learn shaders for real-time rending

I am looking for a good introduction and reference for learning shaders for Maya and other 3D applications. I've search around the internet, but seem to have run into problems finding good communities or good resources. Thanks! ...