SObjectizer is a rather small C++ framework that simplifies the development of multithreaded applications. SObjectizer allows a developer to use approaches from Actor, Publish-Subscribe and Communicating Sequential Processes (CSP) models. It's an OpenSource project that is distributed under BSD-3-CLAUSE license.
SObjectizer has a long history. SObjectizer itself was born in 2002 as SObjectizer-4 project. But it was based on ideas from previous SCADA Objectizer that was developed between 1995 and 2000. SObjectizer-4 was open-sourced in 2006, but its evolution was stopped soon after that. A new version of SObjectizer with the name SObjectizer-5 was started in 2010 and was open-sourced in 2013. The evolution of SObjectizer-5 is still in progress and SObjectizer-5 has incorporated many new features since 2013.
SObjectizer is more or less known in the Russian segment of the Internet, but almost unknown outside of the exUSSR. It's because the SObjectizer was mainly used for local projects in exUSSR-countries and many articles, presentations, and talks about SObjectizer are in Russian.
Multithreading is used in Parallel computing as well as in Concurrent computing. But there is a big difference between Parallel and Concurrent computing. And, as a consequence, there are tools targeted Parallel computing, and there are tools for Concurrent computing, and they are different.
Some time ago, in a discussion on one of SObjectizer's releases, we were asked: "Is it possible to make a DSL to describe a data-processing pipeline?" In other words, is it possible to write something like that:
A | B | C | D
and get a working pipeline where messages are going from A to B, and then to C, and then to D. With control that B receives exactly that type that A returns. And C receives exactly that type that B returns. And so on.
It was an interesting task with a surprisingly simple solution. For example, that's how the creation of a pipeline can look like:
auto pipeline = make_pipeline(env, stage(A) | stage(B) | stage(C) | stage(D));Or, in a more complex case (that will be discussed below):
auto pipeline = make_pipeline( sobj.environment(),
stage(validation) | stage(conversion) | broadcast(
stage(archiving),
stage(distribution),
stage(range_checking) | stage(alarm_detector{}) | broadcast(
stage(alarm_initiator),
stage( []( const alarm_detected & v ) {
alarm_distribution( cerr, v );
} )
)
) );In this article, we'll speak about the implementation of such pipeline DSL. We'll discuss mostly parts related to stage(), broadcast() and operator|() functions with several examples of usage of C++ templates. So I hope it will be interesting even for readers who don't know about SObjectizer (if you never heard of SObjectizer here is an overview of this tool).
Hello everyone!
A year ago, I became curious about whether it was possible to earn money in crypto by copying the trades of other traders. Instead of investing money right away, I decided to thoroughly explore this by writing a parser that monitored about 2,000 portfolios in real-time over the course of a year.
Initially, I parsed the Traderwagon site, which unfortunately shut down. I then switched to Binance's copy trading, which was just starting out at the time.
The number of portfolios available for investment on Binance is continually growing; currently, there are over 10,000. My script only parsed a portion of these to maintain about 2,000 consistent portfolios. This was necessary to track changes in traders' positions at least every 20 minutes with the server resources I had allocated for the project.
There are several peculiarities in how my parser operates. For example, when a trader hides their positions, my script also closes them since it can't monitor hidden trades. When a trader significantly adjusts their position, such as a complete turnaround, the script exits the trade. I chose to save time on developing a more complex follow-algorithm and planned to refine it later if the testing stage proved successful. I also limited the time a trader could stay in a deal to a few days and forcibly closed positions if this period was exceeded. I observed that staying in a trade longer slightly increased the average profit/loss, whereas reducing the time allowed for reinvesting the same funds into a greater number of traders and their deals.
Imagine someone withdrew money from a company's account at night. The next morning panic breaks out, leading to yet more problems. The IT department can reinstall a compromised system from scratch or restore it from backup. Reinstalling from scratch will wipe out all traces left by the attackers, and external investigators will have to search for clues in other systems. Restoring from backup carries the risk of accidentally reinstating a compromised image. In this paper, we will describe common mistakes that experts make when responding to security incidents.
The game industry is growing, especially among small, independent development companies. If you're looking for a game development company, let's take a glimpse at some top game development companies ranked, basing the list on games, as well as the number of existing players and uniqueness.
A website with bugs could be a real pain in the neck for business. Just one 404 or 500 error could end up costing an obscene amount of money for the company and hurt a good reputation. But there is a way to avoid this issue: the website testing. That's sort of what this article is about. After reading this article, you will learn how to test code in Django, create your "own website tester" and much more. Welcome to the article.
The recent Qt 6 release compelled us to recheck the framework with PVS-Studio. In this article, we reviewed various interesting errors we found, for example, those related to processing dates. The errors we discovered prove that developers can greatly benefit from regularly checking their projects with tools like PVS-Studio.
Alexander Volchek, IT entrepreneur, CEO educational platform GeekBrains
Pretty much everyone in the IT community is talking metaverses, NFTs, blockchain and cryptocurrency. This time we will discuss metaverses, and come back to everything else in the letters to follow. Entrepreneurs and founders of tech giants are passionate about this idea, and investors are allocating millions of dollars for projects dealing with metaverses. Let's start with the basics.
