D-N

---

Data Type

A set of data values and operations on those data values.

Dead (thread state)

The state of a thread after it has finished running but before it can be gotten rid of.

Deadlock

When one or more threads have not completed and cannot make progress to completion.

Delegation

This occurs when composition is used. It is when the enclosing class calls a method on an encapsulated class, delegating the work of actually implementing that behavior to the encapsulated class.

Ensembles

Collections of objects that work together to solve a problem.

Event

A way for a component to notify a specific asynchronous activity that something of interest has occurred.

Expression Tree

A binary tree representation of an arithmetic expression.

Garbage Collection

A process where Java reclaims memory for objects that are no longer used.

Generic Components

Components that are written so they can work with many different data types. This is normally done in Java using interfaces.

Heap

A portion of memory, shared between threads, where objects are stored.

Identifier

The name of the variable that is in the source code for the program.

Immutable

Used to describe an object whose value is set when it is constructed, and after that the value cannot be changed.

Java Event Model

A standard pattern for sending events between threads. It is used in the Java AWT.

Java Virtual Machine (JVM)

The program used to simulate a computer architecture that runs Java ".class" files.

Liveness

A property of a program that says the program can eventually complete.

Method Area

A portion of memory, shared between threads, where the executable statements for the program are stored.

Method Reuse

When common code is abstracted into a method and called from a number of places in a program.

Monitor

A data structure much like an object with all of its methods synchronized so that only a single thread can be executing in any method on at that time.

Nondeterminism

The property of a concurrent program that says there are multiple total orderings consistent with the valid partial ordering in the program.

Notification Object

An object other than the "this" object that has a wait and notify performed on it. Normally, notification objects need some infrastructure in the program, in the way locks are obtained and used, to be correctly implemented.

notify (Method)

A method in class object that releases a thread waiting on the object specified in the notify call.

notifyAll (Method)

A method in class object that releases all threads waiting on the object specified in the notify call.

---