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SEARCH KEYWORD -- Atomic

  Deep Dive into Spin Locks in Golang

In concurrent programming, a Mutex is a commonly used synchronization mechanism to protect critical resources and prevent data races. However, in certain specific scenarios, especially when the lock-holding time is short and the number of threads is limited, a more lightweight lock known as a Spin Lock can provide higher performance. What is a Spin Lock A Spin Lock is a form of busy-wait lock. When a thread attempts to acquire a lock held by another thread, it continuously checks the lock's stat...

   SPINLOCK,MUTEX,GOLANG     2024-01-10 05:53:28

  Break down defer statements in GoLang

Basic Concepts What are the characteristics of the deferred statement defer in Go language? When is it usually used? The deferred statement(defer statement) in Go language has the following characteristics: Deferred Execution: Deferred statements are executed before the function containing them exits, regardless of whether the function returns normally or encounters an exception. Last In, First Out (LIFO): If there are multiple deferred statements, they are executed in the order of last in, f...

   DEFER,GOLANG     2024-02-10 21:56:10

  Singleton Pattern in Golang

Singleton pattern is the simplest design pattern in software design. It ensures that only one instance of an object exists globally, regardless of how many times the object is instantiated. Based on the characteristics of the singleton pattern, it can be applied to scenarios such as global unique configuration, database connection objects, file access objects, etc. In Go language, there are multiple ways to implement the singleton pattern. Today, let's learn together about some of these approach...

   GOLANG,SINGLETON PATTERN,TUTORIAL     2023-08-18 23:52:05

  Smuggling data in pointers

While reading up on The ABA Problem I came across a fantastic hack.  The ABA problem, in a nutshell, results from the inability to atomically access both a pointer and a "marked" bit at the same time (read the wikipedia page).  One fun, but very hackish solution is to "smuggle" data in a pointer.  Example:#include "stdio.h"void * smuggle(void * ptr, int value){  return (void *)( (long long)ptr | (value & 3) );}int recoverData(void * ptr){  return (long long)ptr &...

   C,Pointer,Bit,Data,Atomic,Smuggle     2011-11-14 08:15:59

  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

  Use Java ThreadLocal with caution

According to Oracle documentation, ThreadLocal is a class provides thread-local variables. These variables differ from their normal counterparts in that each thread that accesses one (via its get or set method) has its own, independently initialized copy of the variable. ThreadLocal instances are typically private static fields in classes that wish to associate state with a thread. In short, ThreadLocal variables are variables belong to a thread, not a class or an instance of a class. One common...

   JAVA,MEMORY LEAK, THREADLOCAL     2015-11-03 07:31:57

  Useful Bash Scripts

Many people hack together shell scripts quickly to do simple tasks, but these soon take on a life of their own. Unfortunately shell scripts are full of subtle effects which result in scripts failing in unusual ways. It's possible to write scripts which minimise these problems. In this article, I explain several techniques for writing robust bash scripts. Use set -u ...

   Linux,Shell,Bash,Command,Robust     2012-01-15 10:28:00

  Writing robust shellling scripts

Many people hack together shell scripts quickly to do simple tasks, but these soon take on a life of their own. Unfortunately shell scripts are full of subtle effects which result in scripts failing in unusual ways. It's possible to write scripts which minimise these problems. In this article, I explain several techniques for writing robust bash scripts. Use set -u ...

   Robust,Shell script,Set,Commands     2012-03-19 13:25:26

  Supervisord, God and Monit, which one to choose?

With the popularity of Docker, more and more service have been moved into docker containers and they are easy to build up and maintain for each atomic service(though it's a bit complex to maintain multiple docker containers which contain different service to form a complete solution). Ideally, each docker container should only contain one service which has only one running process. However, in reality there would be cases multiple processes would run in one single docker container and there is a...

   DEVOPS,MONIT,SUPERVISORD,GOD,DOCKER     2017-11-25 12:28:11

  Are You a Good Programmer?

If someone asks you to recommend a good programmer, who comes to mind? Do you consider yourself a good programmer? What criteria do you use to judge? In thinking about this, I realized that there are different ways that a programmer can be good. So I present to you The Four Kinds of Good Programmers. And in celebration of Whyday, I include quirky Why-styled illustrations* for your viewing pleasure! The Philosopher The PhilosopherThe philosopher loves to write well-defined, well-structured...

   Programmer,Inventor,Philosopher,Conquero     2011-08-23 07:56:26

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