com.scalar.dl.ledger.server

Interface GateKeeper

All Known Implementing Classes:

SynchronizedGateKeeper

public interface GateKeeper

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

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.
boolean	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.

Method Detail

open

void open()

Opens the gate to allow incoming requests to be processed.

close

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

boolean isOpen()

Returns if the gate is open or not.

Returns:

true if the gate is open

getNumOutstandingRequests

int getNumOutstandingRequests()

Returns the number of outstanding requests.

Returns:

the number of outstanding requests

awaitDrained

boolean awaitDrained(long timeout,
                     java.util.concurrent.TimeUnit unit)
              throws java.lang.InterruptedException

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

Throws:

java.lang.InterruptedException - if interrupted while waiting

letIn

boolean letIn()

Lets a new request in to process it in the server if the gate is open.

Returns:

true if the gate is open

letOut

void letOut()

Lets a processed request out.