lock object

Article from http://weiba.weibo.com/10015/t/zkOgtyY0V SAP Lock MechanismI. Why should I set a lock for sap:1. Maintain Data ConsistencyIf several users want to access the same resource, they need to find a synchronous access method to maintain data

  I. Why should sap set a lock? 1. Maintain data consistency. If several users want to access the same resource, they need to find a synchronous access method to maintain data consistency. For example, in the flight booking system, you need to check

First of all we know that there are two ways to create a thread:1. Inherit the Thread class;2. Implement Runnable interface. But these two are not exactly the same. Here's a talk about the difference:Because Java does not support multiple

In Java5, the lock object is specially provided, and the lock can be used to control the concurrent access of competing resources, which is mainly concentrated under the Java.util.concurrent.locks package, which has three important interfaces

Problem descriptionAfter a lock is added to a non-final object using synchronized, the value (state) of the object is changed in the synchronized body (synchronous code block), which causes the thread to be unsafe, that is, the other thread gets the

Private Lock Object Idiom-thwarts Denial-of-service attack Private Final Object lock = new Object (); public void Foo () { synchronized (lock) { ...}} } Advantages: Prevent other clients from holding the lock object timeout, thus

each lock object has two queues, one is a thread queue , one is a blocking queue , the ready queue stores the threads that will acquire the lock , the blocking queue stores the blocked thread, and when one is awakened by the thread ( Notify) before

The experimental environment of this paper is:[Email protected] ~]$ sqlplus/as sysdbasql*plus:release 11.2.0.4.0 Production on Wed June 07:18:11 2015Copyright (c) 1982, Oracle. All rights reserved. Connected to:oracle Database 11g Enterprise

/*** Knowledge One:* Implement threading, there are two methods, one is to inherit the thread class, one is to implement the Runnable interface.* This article recommends the implementation of the Runnable interface method.* 1. Put the data that

Why is there sap luw and lock object?The SAP system is based on a three-tier architecture. When an sap gui request arrives at the application server, it is allocated to a dialog workflow. In this process, the DB interface can update opensql to the

When we try to synchronized a collection, coverity scans with a hint of bad choice of lock object. Refer to the following code: public class Test {public static void main (string[] args) throws Exception {integer in = new Integer (123 29);

In concurrent environments, you can consider the use of lock mechanisms when resolving shared resource conflict issues. 1. Object Lock All objects automatically contain a single lock. The JVM is responsible for tracking the number of times an object

1, the principle of the lockEach object in Java has a built-in lock.When the program runs to a non-static synchronized synchronization method, the lock associated with the current instance (this instance) of the executing code class is automatically

Recently, after using log4net for system logs, we can see a friend used lock (object) before creating an object ), after reading the information, I learned that C # provides a mechanism for sharing and mutex resource access. We often encounter the

Public classMyService {PrivateString lock = "123"; Public voidTestMethod () {synchronized(lock) {System.out.println (Threadb.currentthread (). GetName ()+ "Begin" +System.currenttimemillis ()); Lock= "456"; Try{threadb.sleep (2000);

Java synchronized keyword usage and level of Lock: Method Lock, Object lock, Class lock Reproduced from: http://blog.csdn.net/le_le_name/article/details/52348314 Java built-in locks: Each Java object can be used as a lock that implements

Previous Article: Java thread (6) Lock is the interface under the java. util. Concurrent. Locks package,LockThe implementation providesSynchronizedMore extensive lock operations can be obtained by methods and statements. It can handle thread

This article is mainly followed by two threads in the previous article to summarize the problem of thread safety in Java multiple threads. A typical Java thread-safe example public class ThreadTest {public static void main (string[] args) {The

I. A typical Java thread safety example 1 public class ThreadTest {2 3 publicly static void main (string[] args) {4 account account = new Account ("12 3456 ", 1000); 5 drawmoneyrunnable drawmoneyrunnable = new Drawmoneyrunnable (account, 700); 6

SAP Lock Mechanism Http://blog.chinaunix.net/u2/66669/showart_1687418.html I. Why should I set a lock for sap: 1. Maintain Data Consistency If several users want to access the same resource, they need to find a synchronous access method to maintain