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SEARCH KEYWORD -- multi-thread

  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

  Deep Understanding of ReentrantLock: Unlocking the Mysteries of Java Concurrent Programming

ReentrantLock introduction ReentrantLock is a class in the Java concurrent package, java.util.concurrent.locks, and is an implementation of the Lock interface. As its name suggests, it is a reentrant mutual exclusion lock. A mutual exclusion lock is a synchronization tool used to protect shared resources, ensuring that only one thread can access the resource at a given time. Reentrant means that a thread can acquire the same lock multiple times without causing a deadlock. This lock provides some...

   JAVA,REENTRANTLOCK,CONCURRENCY,MULTITHREADING     2023-05-22 08:01:13

  New Linux kernel fixes power-saving issues

Greg Kroah-Hartman has released long-term kernel 3.0.20 and stable kernel 3.2.5. Both contain just a single bug fix that allows PCIe power-saving technology ASPM (Active State Power Management) to be used on systems with a BIOS that activates ASPM on some components, but states in the FADT (Fixed ACPI Description Table) consulted by Linux that ASPM is not supported. According to Matthew Garrett, who developed the patch, the change can reduce the power consumption of a Thinkpad X220 by 5&nbs...

   Linux kernel,Power saving,Fix     2012-02-08 10:10:36

  A Javascript When Function

function when(conditionFunc, execFunc, interval){ if (conditionFunc()){ execFunc(); }else{ setTimeout(function(){ when(conditionFunc, execFunc, interval);}, interval); } } You have some code which should only execute when a condition is true. E.g. You have code which relies on a javascript library but can't be sure the library has loaded yet and don't want the code to execute until it has. This is common if you have a bookmarklet which injects more than one <...

   JavaScript,When,Implementation,When function     2012-02-24 05:08:34

  Multi-master,NoSQL and MySQL

The MySQL family has been innovating rapidly. New features need names and sometimes those names are confusing. Describing something as multi-master or a NoSQL solution has confused me.Multi-master requires one of conflict prevention, conflict resolution or faith. MySQL Cluster provides both conflict prevention and resolution as described in these great posts. Regular MySQL has minimal support for conflict prevention (auto-increment-offset can prevent insert conflict...

   MySQL,NoSQL,Comparison,RANT,Master     2011-10-17 11:30:42

  Recursive class initialization in Java

When a Java class is referenced and initialized, it has to go through the loading and linking first. Once the loading and linking complete successfully. The class will be initialized. The static variables and constant variables will be initialized during this process. Once the class is initialized, it is ready for use. If when class A is initialized and it is referencing a class B, the class B will also get initialized. But what will happen if class B is referencing class A as well? This is call...

   Java,JVM,class initialization,static final     2015-04-15 21:04:29

  NIO vs IO in Java

Java 1.4 provides a new API for handling IO -- NIO. This is a non-blocking and buffer oriented IO API. Below are main differences between the NIO and IO in Java. IO NIO Stream oriented Buffer oriented Blocking IO Non-blocking IO N/A Using selector Stream oriented vs Buffer oriented The main difference is that IO is stream oriented where the data is read byte by byte and the data will not be buffered normally.This means there is no pointer to move forward and backward in the stream. I...

   JAVA,IO,NIO     2016-01-10 01:40:02

  What and what not to log while debugging

Log is a critical part of an application. It serves as an eye to the programmer on how the application is working while debugging. Especially for applications running on production environment, if the application encounters problem and the problem cannot be reproduced on other environments, log will be extremely useful. While log is essential, but developers have to log smartly. Because if don't put log smartly, you may not get what you want while debugging or you may get too many...

   PROGRAMMING,DEBUG,LOG,SUPPORT     2016-03-14 08:09:03

  New Android simulator has some big improvements

Message from the Android developer blog, the Android emulator now has a number of improvements and optimizations. It allows developers to develop applications more conveniently.The Android emulator is an important tool for Android developers developing and testing applications. Due to the rapid growth of Android hardware, the simulator has been slightly left behind. The new simulator brings some new functions including support for GPU, the CPU acceleration sensor support, multi-touch input suppo...

   Android, Simulator,GPU,OpenGL     2012-04-10 13:02:31

  Apple investigating new iPad WiFi issues, tells AppleCare to replace affected units

According to an internal AppleCare document, Apple is actively investigating a series of WiFi-related issues affecting the third-generation iPad. Since the new iPad’s launch, many users have been complaining about third-generation iPad WiFi issues ranging from connection drops, slow download and upload speeds, or the device’s inability to even pickup local WiFi networks. A thread discussing the issue exists on Apple’s online support forums has almost amassed 700 repl...

   Apple,iPad,Wifi,Hardware issue     2012-04-06 01:37:59

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