aQute.lib.concurrentinit

Class ConcurrentInitialize<T>

java.lang.Object

aQute.lib.concurrentinit.ConcurrentInitialize<T>

Type Parameters:

T -

public abstract class ConcurrentInitialize<T>
extends java.lang.Object

Helper class to handle concurrent system where you need to initialize a value. The first one should create the value but the others should block until the value has been created. Since we do not want to hold a lock during the creation this is kind of tricky. This class uses a single monitor lock that oeprates a state machine.

Constructor Summary

Constructors

Constructor and Description
ConcurrentInitialize()

Method Summary

Modifier and Type	Method and Description
abstract T	create() Override to create the actual object
T	get() Get the value or wait until it is created.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ConcurrentInitialize

public ConcurrentInitialize()

Method Detail

get

public T get()
      throws java.lang.Exception

Get the value or wait until it is created.

Throws:

java.lang.Exception

create

public abstract T create()
                  throws java.lang.Exception

Override to create the actual object

Returns:

the actual object, could be null

Throws:

java.lang.Exception - if the creation failed this is the exception that was thrown