Package org.camunda.bpm.engine.rest.impl

Class FetchAndLockHandlerImpl

java.lang.Object

org.camunda.bpm.engine.rest.impl.FetchAndLockHandlerImpl

All Implemented Interfaces:

Runnable, FetchAndLockHandler

public class FetchAndLockHandlerImpl
extends Object
implements Runnable, FetchAndLockHandler

Author:

Tassilo Weidner

Field Summary

Fields

Modifier and Type	Field	Description
protected SingleConsumerCondition	condition
protected Thread	handlerThread
protected boolean	isRunning
protected boolean	isUniqueWorkerRequest
protected static final long	MAX_BACK_OFF_TIME
protected static final long	MAX_REQUEST_TIMEOUT
protected List<FetchAndLockRequest>	newRequests
protected static final long	PENDING_REQUEST_FETCH_INTERVAL
protected List<FetchAndLockRequest>	pendingRequests
protected BlockingQueue<FetchAndLockRequest>	queue
protected static final String	UNIQUE_WORKER_REQUEST_PARAM_NAME

Constructor Summary

Constructors

Constructor	Description
FetchAndLockHandlerImpl()

Method Summary

Modifier and Type	Method	Description
protected void	acquire()
void	addPendingRequest(FetchExternalTasksExtendedDto dto, javax.ws.rs.container.AsyncResponse asyncResponse, ProcessEngine processEngine)	Invoked if a fetch and lock request has been sent by the client
protected void	addRequest(FetchAndLockRequest request)
void	contextInitialized(javax.servlet.ServletContextEvent servletContextEvent)	Invoked on initialization of the servlet context
protected void	errorTooManyRequests(javax.ws.rs.container.AsyncResponse asyncResponse)
protected List<LockedExternalTaskDto>	executeFetchAndLock(FetchExternalTasksExtendedDto fetchingDto, ProcessEngine processEngine)
List<FetchAndLockRequest>	getPendingRequests()
protected ProcessEngine	getProcessEngine(FetchAndLockRequest request)
protected boolean	isExpired(FetchAndLockRequest request)
protected void	parseUniqueWorkerRequestParam(String uniqueWorkerRequestParam)
protected void	rejectPendingRequests()
protected void	removeDuplicates()
void	run()
void	shutdown()	Receives a notification that the engine rest web application is about to be shut down
void	start()	Receives a notification that the engine rest web application initialization has been started
protected void	suspend(long millis)
protected void	suspendAcquisition(long millis)
protected FetchAndLockResult	tryFetchAndLock(FetchAndLockRequest request)

Methods inherited from class java.lang.Object

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

Field Details

UNIQUE_WORKER_REQUEST_PARAM_NAME

protected static final String UNIQUE_WORKER_REQUEST_PARAM_NAME

See Also:

• Constant Field Values

PENDING_REQUEST_FETCH_INTERVAL

protected static final long PENDING_REQUEST_FETCH_INTERVAL

See Also:

• Constant Field Values

MAX_BACK_OFF_TIME

protected static final long MAX_BACK_OFF_TIME

See Also:

• Constant Field Values

MAX_REQUEST_TIMEOUT

protected static final long MAX_REQUEST_TIMEOUT

See Also:

• Constant Field Values

condition

protected SingleConsumerCondition condition

queue

protected BlockingQueue<FetchAndLockRequest> queue

pendingRequests

protected List<FetchAndLockRequest> pendingRequests

newRequests

protected List<FetchAndLockRequest> newRequests

handlerThread

protected Thread handlerThread

isRunning

protected volatile boolean isRunning

isUniqueWorkerRequest

protected boolean isUniqueWorkerRequest

Constructor Details

FetchAndLockHandlerImpl

public FetchAndLockHandlerImpl()

Method Details

run

public void run()

Specified by:

run in interface Runnable

acquire

protected void acquire()

removeDuplicates

protected void removeDuplicates()

start

public void start()

Description copied from interface: FetchAndLockHandler

Receives a notification that the engine rest web application initialization has been started

Specified by:

start in interface FetchAndLockHandler

shutdown

public void shutdown()

Description copied from interface: FetchAndLockHandler

Receives a notification that the engine rest web application is about to be shut down

Specified by:

shutdown in interface FetchAndLockHandler

suspend

protected void suspend(long millis)

suspendAcquisition

protected void suspendAcquisition(long millis)

addRequest

protected void addRequest(FetchAndLockRequest request)

tryFetchAndLock

protected FetchAndLockResult tryFetchAndLock(FetchAndLockRequest request)

executeFetchAndLock

protected List<LockedExternalTaskDto> executeFetchAndLock(FetchExternalTasksExtendedDto fetchingDto,
 ProcessEngine processEngine)

errorTooManyRequests

protected void errorTooManyRequests(javax.ws.rs.container.AsyncResponse asyncResponse)

rejectPendingRequests

protected void rejectPendingRequests()

getProcessEngine

protected ProcessEngine getProcessEngine(FetchAndLockRequest request)

isExpired

protected boolean isExpired(FetchAndLockRequest request)

addPendingRequest

public void addPendingRequest(FetchExternalTasksExtendedDto dto,
 javax.ws.rs.container.AsyncResponse asyncResponse,
 ProcessEngine processEngine)

Description copied from interface: FetchAndLockHandler

Invoked if a fetch and lock request has been sent by the client

Specified by:

addPendingRequest in interface FetchAndLockHandler

Parameters:

dto - which is supposed to hold the payload

asyncResponse - provides means for asynchronous server side response processing

processEngine - provides the process engine context of the respective request

contextInitialized

public void contextInitialized(javax.servlet.ServletContextEvent servletContextEvent)

Description copied from interface: FetchAndLockHandler

Invoked on initialization of the servlet context

Specified by:

contextInitialized in interface FetchAndLockHandler

Parameters:

servletContextEvent - provides the servlet context

parseUniqueWorkerRequestParam

protected void parseUniqueWorkerRequestParam(String uniqueWorkerRequestParam)

getPendingRequests

public List<FetchAndLockRequest> getPendingRequests()