RBQBlackboard (GemFire XD Java API Documentation)

java.lang.Object
- hydra.blackboard.Blackboard
- - hydra.training.RBQBlackboard

```
public class RBQBlackboard
extends Blackboard
```
A Hydra Blackboard that maintains statistics about a RemoteBlockingQueue. The blackboard's shared counters are used to store the maximum and minimum duration of certain queue operations. The blackboard's shared map stores the capacity of the queue and how many poll operations were performed by each client thread (this gives us an idea of the "fairness" of the poll operation among multiple threads).

Since:

4.0

Field Summary

Fields
Modifier and Type	Field and Description
`static RBQBlackboard`	`bbInstance` The singleton RBQBlackboard
`static int`	`MaxOfferTime` Maximum duration (in nanoseconds) of an offer operation
`static int`	`MaxPollTime` Maximum duration (in nanoseconds) of a poll operation
`static int`	`MinOfferTime` Minimum duration (in nanoseconds) of an offer operation
`static int`	`MinPollTime` Minimum duration (in nanoseconds) of a poll operation
`static int`	`MyCounter` An example counter that shows how a counter can be given an inital value here; this counter is not used in the example, but is printed out in the start task to show its initial value
`static int`	`NumOffers` Total number of offer operations performed
`static int`	`NumPolls` Total number of poll operations performed

Fields inherited from class hydra.blackboard.Blackboard
counterNames, GemFire, RMI

Constructor Summary

Constructors
Constructor and Description

RBQBlackboard()
Required zero-arg constructor for remote method invocations.

Constructors
Constructor and Description
`RBQBlackboard()` Required zero-arg constructor for remote method invocations.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`static RBQBlackboard`	`getBB()` Convenience method to get an instance of RBQBlackboard (for efficiency reasons).
`long`	`getMaxOfferTime()` Returns the maximum duration (in nanoseconds) of an offer operation.
`long`	`getMaxPollTime()` Returns the maximum duration (in nanoseconds) of an poll operation.
`long`	`getMinOfferTime()` Returns the minimum duration (in nanoseconds) of an offer operation.
`long`	`getMinPollTime()` Returns the minimum duration (in nanoseconds) of an poll operation.
`long`	`getMyCounter()` Returns the value of the "MyCounter" shared counter
`long`	`getNumOffers()` Returns the total number of offer operations performed.
`long`	`getNumPolls()` Returns the total number of poll operations performed.
`int`	`getQueueCapacity()` Returns the capacity of the queue as store in the blackboard.

Methods inherited from class hydra.blackboard.Blackboard
createSharedCounters, createSharedLock, createSharedMap, getCounterNames, getSharedCounter, getSharedCounters, getSharedLock, getSharedMap, print, printSharedCounters, printSharedMap

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - MinOfferTime
```
public static int MinOfferTime
```
    Minimum duration (in nanoseconds) of an offer operation
  - MaxOfferTime
```
public static int MaxOfferTime
```
    Maximum duration (in nanoseconds) of an offer operation
  - MinPollTime
```
public static int MinPollTime
```
    Minimum duration (in nanoseconds) of a poll operation
  - MaxPollTime
```
public static int MaxPollTime
```
    Maximum duration (in nanoseconds) of a poll operation
  - NumOffers
```
public static int NumOffers
```
    Total number of offer operations performed
  - NumPolls
```
public static int NumPolls
```
    Total number of poll operations performed
  - MyCounter
```
public static int MyCounter
```
    An example counter that shows how a counter can be given an inital value here; this counter is not used in the example, but is printed out in the start task to show its initial value
  - bbInstance
```
public static RBQBlackboard bbInstance
```
    The singleton RBQBlackboard
- Constructor Detail
  - RBQBlackboard
```
public RBQBlackboard()
```
    Required zero-arg constructor for remote method invocations.
- Method Detail
  - getBB
```
public static RBQBlackboard getBB()
```
    Convenience method to get an instance of RBQBlackboard (for efficiency reasons). This is not required; a test could get a new instance of RBQBlackboard each time it needed access to the blackboard, and each instance would access the same shared counters and shared map with the previous values intact.
  - getQueueCapacity
```
public int getQueueCapacity()
```
    Returns the capacity of the queue as store in the blackboard.
  - getMinOfferTime
```
public long getMinOfferTime()
```
    Returns the minimum duration (in nanoseconds) of an offer operation.
  - getMaxOfferTime
```
public long getMaxOfferTime()
```
    Returns the maximum duration (in nanoseconds) of an offer operation.
  - getNumOffers
```
public long getNumOffers()
```
    Returns the total number of offer operations performed.
  - getMinPollTime
```
public long getMinPollTime()
```
    Returns the minimum duration (in nanoseconds) of an poll operation.
  - getMaxPollTime
```
public long getMaxPollTime()
```
    Returns the maximum duration (in nanoseconds) of an poll operation.
  - getNumPolls
```
public long getNumPolls()
```
    Returns the total number of poll operations performed.
  - getMyCounter
```
public long getMyCounter()
```
    Returns the value of the "MyCounter" shared counter

Class RBQBlackboard

Field Summary

Fields inherited from class hydra.blackboard.Blackboard

Constructor Summary

Method Summary

Methods inherited from class hydra.blackboard.Blackboard

Methods inherited from class java.lang.Object

Field Detail

MinOfferTime

MaxOfferTime

MinPollTime

MaxPollTime

NumOffers

NumPolls

MyCounter

bbInstance

Constructor Detail

RBQBlackboard

Method Detail

getBB

getQueueCapacity

getMinOfferTime

getMaxOfferTime

getNumOffers

getMinPollTime

getMaxPollTime

getNumPolls

getMyCounter