com.bigdata.quorum

Class MockQuorumFixture

java.lang.Object

com.bigdata.quorum.MockQuorumFixture

public class MockQuorumFixture
extends Object

A mock object providing the shared quorum state for a set of QuorumClients running in the same JVM.

This fixture dumps the events into queues drained by a per-watcher thread. This approximates the zookeeper behavior and ensures that each watcher sees the events in a total order. Zookeeper promises that all watchers proceed at the same rate. We enforce that with a globalSynchronousLock. Once all watchers have drained the event, the next event is made available to the watchers.

The fixture only generates events for actual state changes. This also mimics the behavior of zookeeper.

Version:

$Id$

Author:

Bryan Thompson

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	MockQuorumFixture.MockQuorum<S extends Remote,C extends QuorumMember<S>> Mock Quorum implementation with increased visibility of some methods so we can pump state changes into the MockQuorumFixture2.

Field Summary

Fields

Modifier and Type	Field and Description
protected static org.apache.log4j.Logger	log

Constructor Summary

Constructors

Constructor and Description
MockQuorumFixture()

Method Summary

Methods

Modifier and Type	Method and Description
void	addWatcher(MockQuorumFixture.MockQuorum.MockQuorumWatcher watcher)
void	awaitDeque() Deprecated. The semantics of the QuorumActor have been modified to require it to block until the requested change has been observed by the QuorumWatcher and made visible in the local model of the quorum state maintained by the AbstractQuorum. If you need more control over the visibility of state changes use #assertCondition(Runnable).
ExecutorService	getExecutor() An ExecutorService which can be used by the unit tests.
QuorumMember<?>	getMember(UUID serviceId) Resolve a known QuorumMember for the fixture.
protected static int	getPort(int suggestedPort) Return an open port on current machine.
Object	getService(UUID serviceId) Resolve the service by its UUID for any service running against this fixture.
void	removeWatcher(MockQuorumFixture.MockQuorum.MockQuorumWatcher watcher)
void	start() Start fixture.
void	terminate() Terminate fixture.
String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

log

protected static final transient org.apache.log4j.Logger log

Constructor Detail

MockQuorumFixture

public MockQuorumFixture()

Method Detail

getExecutor

public ExecutorService getExecutor()

An ExecutorService which can be used by the unit tests.

See Also:

QuorumMember.getExecutor()

getMember

public QuorumMember<?> getMember(UUID serviceId)

Resolve a known QuorumMember for the fixture.

Parameters:

serviceId - The UUIDfor the QuorumMember's service.

Returns:

The QuorumMember -or- null if there is none known for that serviceId.

getService

public Object getService(UUID serviceId)

Resolve the service by its UUID for any service running against this fixture.

Parameters:

serviceId - The UUID for the service.

Returns:

The service.

Throws:

QuorumException - if there is no known QuorumMember for that serviceId.

start

public void start()

Start fixture.

terminate

public void terminate()

Terminate fixture.

awaitDeque

public void awaitDeque()
                throws InterruptedException

Deprecated. The semantics of the QuorumActor have been modified to require it to block until the requested change has been observed by the QuorumWatcher and made visible in the local model of the quorum state maintained by the AbstractQuorum.

If you need more control over the visibility of state changes use #assertCondition(Runnable).

Block until the event deque has been drained (that is, until all watchers have handled all events which have already been generated). For example:

 actor.memberAdd();
 actor.pipelineAdd();
 

can throw an QuorumException since the actor's local quorum state in all likelihood will not have been updated before we attempt to add the actor to the pipeline in the distributed quorum state.

However, the following sequence will succeed.

 actor.memberAdd();
 fixture.awaitDeque();
 actor.pipelineAdd();
 

Throws:

InterruptedException

getPort

protected static int getPort(int suggestedPort)
                      throws IOException

Return an open port on current machine. Try the suggested port first. If suggestedPort is zero, just select a random port

Throws:

IOException

removeWatcher

public void removeWatcher(MockQuorumFixture.MockQuorum.MockQuorumWatcher watcher)

addWatcher

public void addWatcher(MockQuorumFixture.MockQuorum.MockQuorumWatcher watcher)

toString

public String toString()

Overrides:

toString in class Object