java synchronized method

I've been knocked out by a thread these days.Specially to make up for the Java thread knowledgeThe Synchronized keyword is the ability to implement a class object that is called only by one thread at a time, and other threads to invoke this object only until the thread that is being called ends or stops (typically used in a stopped state and, if it is finished, it is easier to use the join ()

Today I read a blog about the collaboration of Java multi-line threads, the author of the program to illustrate the issue of producers and consumers, but I and other readers found that the program more than a few times or there will be deadlocks, Baidu searched the majority of examples are also a bug, after careful study found that the problem, and resolved, Feel a sense of meaning posted out to share. The first post is the bug code, a 4-class, Plate.

We know that there are two types of synchronized: The synchronization method (synchronized) and the synchronous statement block (synchronized block). So what are the differences and the pros and cons of these two?Synchronizedmethod:Advantages: Simple and clear code, easy maintenanceDisadvantage: The synchronization of

1. the synchronized keyword has two scopes: 1) In an object instance, synchronized aMethod () {} can prevent multiple threads from simultaneously accessing the synchronized Method of the object (if an object has multiple synchronized methods, as long as a thread accesses on

1, the scope of the SYNCHRONIZED keyword has two kinds: 1 is an object instance in which synchronized Amethod () {} can prevent multiple threads from simultaneously accessing the object's Synchronized method (if an object has multiple synchronized methods, As long as one th

Today, read a blog, the Java multi-thread threads of collaboration, in which the author uses the program examples to illustrate the producer and consumer issues, but I and other readers found that the program more than a few times there will be a deadlock, Baidu searched the majority of the sample also has a bug, after careful study found in the problem. And conquer, feel meaningful paste out to share under.The following is the first to post a bug cod

Java thread and synchronization (synchronized) Sample Code Import java. Io .*;Import java. util .*;Import java. Text. simpledateformat; Public class testthread extends thread{Private Static integer threadcounterlock; // used for synchronization to prevent data from being wri

is, the initialized variable is initialized to true only after the configuration information has been successfully initialized by thread A. In summary , volatile modified variables prohibit command reordering (ordered)Third, the comparison of volatile and synchronizedVolatile is used primarily when multiple thread-aware instance variables are changed, allowing each thread to get the most recent value. It enforces the visibility of the data by forcing threads to refer to variables from main memo

Synchronized1. Multi-threaded execution of the same object synchronized function, thread synchronization is correct;The instance code is as follows:public class Test1 implements runnable{Defining the same object Static TEST2 action; public static void Main (string[] args) { //TODO auto-generated method Stub class cls; try { cls = Class.forName ("Test2"); action = (Test2) cls.newinstance (); test1

Java High concurrency synchronizedSynchronized can guarantee that the code block or method at run time, only one method can enter the critical area at the same time, also can guarantee the memory visibility of the shared variable.Synchronized can be used in three situations:1. Normal synchronization method, lock is the

1. Relying on object lock lockingWhen an object is initialized, it automatically has an object lock.Synchronized {Normal method} relies on object lock work, multi-threaded access to the Synchronized method, once a process grabs the lock, the other processes only queued.synchronized void method{} is functionally equival

1.synchronized (object) PackageTest.thread;Importjava.io.IOException;Importorg.junit.Test;/** Test Thread lock*/ Public classTestblock { Public Static voidMain (string[] args) {testblock test=NewTestblock (); MyTest Thread1= Test.NewMyTest (test); Thread1.setname ("1"); MyTest thread2= Test.NewMyTest (test); Thread2.setname ("2"); Thread1.start (); Thread2.start (); } /** Test Sync*/ classMyTestextendsthread{private Object o;

the thread that acquires the lock through a pointer, and a counter count is used to do the lock re-entry. The thread enters the wait queue when the wait method is called. blog.csdn.net/yinbucheng/article/details/72524482 to understand synchronized needs to understand the concept of object headers. What three pieces of data does the ===java object store in memory

This blog is a previous Java Multithreading (iii) Producer consumer model and the implementation of the method complement. The producer consumer model is implemented in three methods (lock, synchronized, blocking queue). The specific content is: The producer produces the random number (in order to facilitate the reading result, I limit the random number to 10 int

It's important to write it down. The Java language keyword that, when used to decorate a method or a block of code, guarantees that at most one thread executes the code at the same time. First, when two concurrent threads access the same object in the synchronized (this) synchronization code block, only one thread can be executed within a single time. The other t

,intAintb) { This. Dead = dead; This. A = A; This. B = b;}@Override PublicvoidRun () {Dead.read ();Dead.write (A, b);}}classDeadlockrisk {PrivateStaticclassResource { PublicintValue}PrivateResource Resourcea =NewResource ();PrivateResource RESOURCEB =NewResource (); Public intRead () {synchronized(Resourcea) {System.out.println ("read ():"+ Thread.CurrentThread (). GetName () +"Get the lock of Resourcea!" ");syn