com.scalar.dl.ledger.server

Class GateKeeper

java.lang.Object

com.scalar.dl.ledger.server.GateKeeper

@ThreadSafe
public class GateKeeper
extends java.lang.Object

A gatekeeper that manages the front gate of the server that processes requests.

Constructor Summary

Constructors

Constructor and Description
GateKeeper()

Method Summary

Modifier and Type	Method and Description
boolean	awaitDrained(long timeout, java.util.concurrent.TimeUnit unit) Waits for the server to finish outstanding requests, giving up if the timeout is reached.
void	close() Closes the gate to disallow incoming requests to be processed.
int	getNumOutstandingRequests() Returns the number of outstanding requests.
boolean	isOpen() Returns if the gate is open or not.
void	letIn() Lets a new request in to process it in the server if the gate is open.
void	letOut() Lets a processed request out.
void	open() Opens the gate to allow incoming requests to be processed.

Methods inherited from class java.lang.Object

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

Constructor Detail

GateKeeper

public GateKeeper()

Method Detail

open

public void open()

Opens the gate to allow incoming requests to be processed.

close

public void close()

Closes the gate to disallow incoming requests to be processed. After this call returns, new requests are rejected. Note that this method will not wait for outstanding requests to finish before returning. awaitDrained(long, TimeUnit) needs to be called to wait for outstanding requests to finish.

isOpen

public boolean isOpen()

Returns if the gate is open or not.

Returns:

true if the gate is open

getNumOutstandingRequests

public int getNumOutstandingRequests()

Returns the number of outstanding requests.

Returns:

the number of outstanding requests

awaitDrained

public boolean awaitDrained(long timeout,
                            java.util.concurrent.TimeUnit unit)

Waits for the server to finish outstanding requests, giving up if the timeout is reached.

Parameters:

timeout - the maximum time to wait

unit - the time unit of the timeout argument

Returns:

true if the server finishes outstanding requests and false otherwise

letIn

public void letIn()

Lets a new request in to process it in the server if the gate is open. If the gate is closed, waits until the gate is open.

letOut

public void letOut()

Lets a processed request out.