Threads Section Index

The fork/join framework in Java 7 allows developers to take advantage of multiple processors.

Synchronized operations are costly and if you aren't modifying a collection much, it is best not to synchronize all collection accesses. The CopyOnWriteXXX collections avoid concurrent modificatio...more

Pessimistic assumes conflicts will occur and avoids them through exclusive locks and explicit synchronization. With the optimistic approach, it is assumed conflicts won't occur, and they are dealt...more

The setDefaultUncaughtExceptionHandler() method of Thread, introduced in JDK 5.0, allows you to configure this behavior by letting you attach an implementation of Thread.UncaughtExceptionHandler. more

ThreadGroups activeGroupCount() returns the number of active groups within the ThreadGroup instance it was called upon. Once the number of active groups is obtained ThreadGroups enumerate(ThreadG...more

A ThreadGroup is used to represent a group of Threads. A tree structure can be formed from ThreadsGroups containing other ThreadGroups. Threads can only access the ThreadGroup to which they belon...more

A ThreadGroup is used to represent a group of Threads. A tree structure can be formed from ThreadsGroups containing other ThreadGroups. Threads can only access the ThreadGroup to which they belon...more

Any Threads running within the JVM can be preempted by creating and starting a Thread which is of a higher priority. A Threads priority can be set using the following method. public void setPr...more

A Threads identifer is a positive unique long value which is generated when a Thread is created. Using the following method a Threads identifer can be obtained. public long getId() Here is a ...more

Is there a way that I can get the number of threads currently executing within the JVM?

The Executors class of the java.util.concurrent class offers newCachedThreadPool(), newCachedThreadPool(ThreadFactory threadFactory), newFixedThreadPool(int nThreads), newFixedThreadPool(int nThre...more

You can't directly by using wait and notify, but the can use a similar construct with the Lock interface of the java.util.concurrent.locks package, with its boolean tryLock(long time, TimeUnit uni...more

The TimeUnit class allows you to work with time quanities as both an amount and a unit of measurement. For instance, instead of always working with milliseconds when you want to put a thread to sl...more

Prior to Java 5, isAlive() was commonly used to test a threads state. If isAlive() returned false the thread was either new or terminated but there was simply no way to differentiate between the...more

The thread class provides a method which can be called on an instance of a Thread to determine if it is currently executing. If isAlive() returns false the thread is either a new thread that is ...more