I did an experiment to nail this down, as follows: process1: RT priority = 40, CPU affinity = CPU 0. This process “spins” for 10 seconds so it won’t let any lower-priority process run on CPU 0. process2: RT priority = 39, CPU affinity = CPU 0. This process prints a message to stdout every … Read more
Just for the sake of argument. Both are http request (xhr), and its at least partially untrue it uses more server resources (depends totally on technology, will explain later). Short polling. Lot of request that are processed as they come on server. Creates a lot of traffic (uses resources, but frees them as soon as … Read more
So, to begin with, I put my project on github, if you want access to the full code: https://github.com/jdutheil/nodePHP It is a very simple example project: a web chat. You just have an author and message, and when you press send it is saved in a mysql database. The idea is to send real time … Read more
The short answer is ‘both’. XMPP is a set of application protocol for doing real-time chat (and many other things, for that matter) – it then has to be transported across the network somehow, so you need a transport binding. There are three main transport bindings for XMPP – TCP/IP, which is what one usually … Read more
SignalR provides ConnectionId for each connection. To find which connection belongs to whom (the user), we need to create a mapping between the connection and the user. This depends on how you identify a user in your application. In SignalR 2.0, this is done by using the inbuilt IPrincipal.Identity.Name, which is the logged in user … Read more
Hard Real-Time The hard real-time definition considers any missed deadline to be a system failure. This scheduling is used extensively in mission critical systems where failure to conform to timing constraints results in a loss of life or property. Examples: Air France Flight 447 crashed into the ocean after a sensor malfunction caused a series … Read more
Here’s the working version of the code in question (requires at least version Matplotlib 1.1.0 from 2011-11-14): import numpy as np import matplotlib.pyplot as plt plt.axis([0, 10, 0, 1]) for i in range(10): y = np.random.random() plt.scatter(i, y) plt.pause(0.05) plt.show() Note the call to plt.pause(0.05), which both draws the new data and runs the GUI’s … Read more