EDU.oswego.cs.dl.util.concurrent: public class: Slot

EDU.oswego.cs.dl.util.concurrent
public class: Slot [javadoc | source]

java.lang.Object
   EDU.oswego.cs.dl.util.concurrent.SemaphoreControlledChannel
      EDU.oswego.cs.dl.util.concurrent.Slot

All Implemented Interfaces:
BoundedChannel

A one-slot buffer, using semaphores to control access. Slots are usually more efficient and controllable than using other bounded buffers implementations with capacity of 1.

Among other applications, Slots can be convenient in token-passing designs: Here. the Slot holds a some object serving as a token, that can be obtained and returned by various threads.

[ Introduction to this package. ]
Field Summary
protected Object item_ The slot *
Fields inherited from EDU.oswego.cs.dl.util.concurrent.SemaphoreControlledChannel:
putGuard_, takeGuard_, capacity_

Constructor:

public Slot()
{ super(1); }
Create a new Slot using default Semaphore implementations
public Slot(Class semaphoreClass) throws NoSuchMethodException, SecurityException, InstantiationException, IllegalAccessException, InvocationTargetException
{ super(1, semaphoreClass); }
Create a buffer with the given capacity, using the supplied Semaphore class for semaphores.
Throws:
NoSuchMethodException - If class does not have constructor that intializes permits
SecurityException - if constructor information not accessible
InstantiationException - if semaphore class is abstract
IllegalAccessException - if constructor cannot be called
InvocationTargetException - if semaphore constructor throws an exception *
exception: NoSuchMethodException - If class does not have constructor that intializes permits
exception: SecurityException - if constructor information not accessible
exception: InstantiationException - if semaphore class is abstract
exception: IllegalAccessException - if constructor cannot be called
exception: InvocationTargetException - if semaphore constructor throws an exception *

Method from EDU.oswego.cs.dl.util.concurrent.Slot Summary:
extract, insert, peek
Methods from EDU.oswego.cs.dl.util.concurrent.SemaphoreControlledChannel:
capacity, extract, insert, offer, poll, put, size, take
Methods from java.lang.Object:
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
Method from EDU.oswego.cs.dl.util.concurrent.Slot Detail:

protected synchronized Object extract()
{ Object x = item_; item_ = null; return x; }
Take item known to exist *
protected synchronized void insert(Object x)
{ item_ = x; }
Set the item in preparation for a take
public synchronized Object peek()
{ return item_; }