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SEARCH KEYWORD -- System programming

  Memory related exception analysis in Java

Java Virtual Machine Specification divides the memory of JVM into several areas : Heap, Stack, The Program Counter register and Method area etc. In HotSpot JVM, heap is composed of Young, Tenured and Perm. There are different OutOfMemory error can happen in different memory area. Next is an overview of some of these OOM errors. StackOverflowError The JVM will allow only a specified number of stacks created nested. An JVM option -Xss can be set to determine the maximum stack size. If the num...

   Java, Memory model, Memory exception, OOM     2015-01-19 06:54:27

  Understand GoLang WaitGroup internals and how it works

Background Before 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. WaitGroup WaitGroup 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' mul...

   GOLANG,WAITGROUP,SOURCE CODE     2023-04-26 08:02:01

  Understanding PGO in GoLang 1.20

Background The Go 1.20 version was officially released in February 2023, it introduced the PGO(Profile Guided Optimization) mechanism. The basic principle of PGO can be divided into the following two steps: First, profiling is performed on the program to collect data about the program's runtime and generate a profiling file. When compiling the program, enable the PGO option, and the compiler will optimize the program's performance based on the content in the .pgo file. When compiling a program...

   GO 1.20,PGO,GOLANG     2023-02-28 04:27:46

  Multitasking vs multiprogramming

As all these processing are the part of computer functions. You should not be confused between these processes.In computing, multitasking is a method by which multiple tasks are performed by the user also known as processes, share common processing resources such as a CPU. CPU is actively executing more than one task at a time. Multitasking solves the problem by scheduling the tasks instructions. Which task may be the one running at any...

   multitasking,multiprogramming,os,differe     2011-09-22 13:46:30

  Clojure & Java Interop

About a year ago I got a phone call asking if I wanted to join another team at DRW. The team supports a (primarily) Java application, but the performance requirements would also allow it to be written in a higher level language. I'd been writing Clojure (basically) full-time at that point - so my response was simple: I'd love to join, but I'm going to want to do future development using Clojure. A year later we still have plenty of Java, but the vast majority of the new code I add is Cloj...

   Java,Clojure,Interoprability,Commit,Function call     2011-12-29 09:11:22

  The Great Tech War Of 2012

From left: The late Apple cofounder Steve Jobs, Facebook CEO Mark Zuckerberg, Google CEO Larry Page, and Amazon CEO Jeff Bezos. | Photos courtesy of David Paul Morris/Getty Images (Jobs); Justin Sullivan/Getty Images (Zuckerberg); Chip East/Reuters (Page); Mario Tama/Getty Images (Bezos).Gilbert Wong, the mayor of Cupertino, California, calls his city council to order. "As you know, Cupertino is very famous for Apple Computer, and we're very honored to have Mr. Steve Jobs come here tonight ...

   2012,Tech war,Facebook,Apple,Google,Amazon,Tablet,Cloud,Analysis     2011-10-17 11:06:25

  The Failure of Passive Recruiting: Recruiters

This is an actual conversation I had with a recruiter:Phone rings and I pick it upHim: Hi, is Paul there?Aaron: May I ask who is calling?Him: I have a technical question. Aaron: Ok, what is it?Him: Are you technical?Aaron: Yes. Who is this?Him: Who are you?Aaron: Are you a recruiter?Him: Yes and…Aaron: Great, send us your resumes, if we like what you send over, we’ll let you know if we want to meet with the candidates, other tha...

   Recruiter,HR,Recruitment,Failure,Hire     2011-10-26 06:59:33

  Python internals: adding a new statement to Python

This article is an attempt to better understand how the front-end of Python works. Just reading documentation and source code may be a bit boring, so I’m taking a hands-on approach here: I’m going to add an until statement to Python. All the coding for this article was done against the cutting-edge Py3k branch in the Python Mercurial repository mirror. The until statement Some languages, like Ruby, have an until statement, which is the complement to while (until num == 0 is equi...

   Python,New statement,Research,Addition     2012-03-12 07:32:24

  Three Simple Ways to Improve the Security of Your Web App

It seems like web app security has entered the public conscious recently, probably as a result of the press covering the activities of groups like Anonymous and incidents like security breaches at several CAs. Here are a couple of quick security tips to improve the security of your web apps. Think of these as low-hanging fruit, not as a substitute for thorough analysis of your app’s security. If there’s interest in this topic we can do more posts, too - let us know in the com...

   Web app,Security,X-FRAME-OPTIONS,SSL     2011-12-08 10:10:20

  Set up Superset on ubuntu 16.04 LTS

Apache Superset (incubating) is a modern, enterprise-ready business intelligence web application. Compared with business-focused BI tool like Tableau, superset is more technology-navy. It supports more types of visualization and able to work in distributed manner to boost the query performance. Most importantly, it is free of charge! An example dashboard: Let’s go and set it up. Create a virtualenv Assume Anaconda is installed for python management. # create a virtualenv with python 3.6 co...

   TUTORIAL,UBUNTU,SUPERSET     2019-10-19 21:34:55

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