BackgroundBefore getting into the main content, let me give a brief introduction to WaitGroup and its related background knowledge. Here, the focus is on the basic usage of WaitGroup and the fundamental knowledge of system semaphores. For those who are familiar with these, you can skip this section directly.WaitGroupWaitGroup is one of the most common concurrency control techniques in Golang, and its function can be roughly compared to the join() in concurrency control of other languages' multithreading. The sample code is as follows:package mainimport ( "fmt" "sync" "time")func main(...

Etcd, one of the crucial components of Kubernetes. If APIServer is the heart, then etcd is the blood vessel that sends the end state of Kubernetes resources to various “organs”, providing high-speed, stable storage, and supporting APIServer’s high load performance. What if the etcd is not working properly? Just the condition as someone has a vascular disease. The deeper you know about them, the better diagnose you can make when issues occur.from unsplash, @John BarkipleRemember the local cache we finished in 20 minutes? If that is a short st...

Java 8 was recently released, many developers are now trying to extract the source code of Java 8 to find out how the new added features such as Lambda expressions, default method in interfaces, new Time API are implemented. How do you manage to download and browse the source code? Today we are going to show how to extract OpenJDK Java source code to Eclipse.Since OpenJDK is adopting Mercurial as its distributed version control system, you need to install Mercurial on your computer first before you can clone the repository from OpenJDK. You can get more info about the use of Mercurial in OpenJ...

HTML5 Drag and Drop has been talked about a lot lately, but it’s hard to find really useful information about implementing it across multiple browsers.Mozilla, Apple and Microsoft all have pages describing how to use it, but their examples seem to work only in their particular browser (Apple’s example doesn’t even work in their own! Updated, Jan. 11, 2009: Although I have not been able to get this example working on Safari 2.0.4 and 3.1.2 for OS X and 4.0.4 for Windows, I have received word that it works on Safari 4.0.4 on OS X). Rem...

Copy and paste the following code blocks into your site and replace '<url>' with the link you want to Share.Text link:<script>function fbs_click() {u=location.href;t=document.title;window.open('http://www.facebook.com/sharer.php?u='+encodeURIComponent(u)+'&t='+encodeURIComponent(t),'sharer','toolbar=0,status=0,width=626,height=436');return false;}</script><a rel="nofollow" href="http://www.facebook.com/share.php?u=<;url>" onclick="return fbs_click()" target="_blank">Share on Facebook</a>Small icon and text:<script>function fbs_click() {u=location.h...

Twice a month, we revisit some of our readers’ favorite posts from throughout the history of Nettuts+.Code readability is a universal subject in the world of computer programming. It’s one of the first things we learn as developers. This article will detail the fifteen most important best practices when writing readable code.1 - Commenting & DocumentationIDE’s (Integrated Development Environment) have come a long way in the past few years. This made commenting your code more useful than ever. Following certain standards in your comments allows IDE’s and oth...