Package com.complexible.common.cancellation

Interface CancellationPoint

All Superinterfaces:

java.lang.AutoCloseable, CancelCheck, Cancellable

All Known Implementing Classes:

DefaultCancellationPoint, DelegatingCancellationPoint, DummyCancellationPoint

public interface CancellationPoint
extends java.lang.AutoCloseable, CancelCheck, Cancellable

Interface for cancellation points; We create cancellation point in one place and have a contract that we don't dispose system or don't drop database while the point is active and actual;

Field Summary

Fields inherited from interface com.complexible.common.cancellation.CancelCheck

DUMMY

Method Summary

Modifier and Type	Method	Description
void	cancel()	Cancel current point;
void	close()	Closes cancellation point;
static CancellationPoint	forCancelCheck(java.lang.String description, CancelCheck check)	Wraps the non-cancellable CancelCheck as a cancellable CancellationPoint.
java.lang.String	getCancellationMessage()	Returns null if the process has not been cancelled, otherwise the cancellation cause (if set).
java.lang.String	getProcessDescription()	Returns the description of the process that this cancellation point represents.
static CancellationPoint	uncloseable(CancellationPoint cp)	Returns a cancellation point which can be checked but cannot be closed.
void	wait(long timeout, java.util.concurrent.TimeUnit unit)	Waits for specified timeout while the process acquired Cancellation point has been finished;

Methods inherited from interface com.complexible.common.cancellation.CancelCheck

check, check, isCancelled, throwIfCancelled

Methods inherited from interface com.complexible.common.cancellation.Cancellable

cancel

Method Detail

getProcessDescription

java.lang.String getProcessDescription()

Returns the description of the process that this cancellation point represents.

Returns:

the process description.

cancel

void cancel()

Cancel current point;

getCancellationMessage

@Nullable
java.lang.String getCancellationMessage()

Description copied from interface: CancelCheck

Returns null if the process has not been cancelled, otherwise the cancellation cause (if set).

Specified by:

getCancellationMessage in interface CancelCheck

Returns:

cancellation message used for cancel;

wait

void wait(long timeout,
          java.util.concurrent.TimeUnit unit)
   throws java.lang.InterruptedException,
          java.util.concurrent.ExecutionException,
          java.util.concurrent.TimeoutException

Waits for specified timeout while the process acquired Cancellation point has been finished;

Parameters:

timeout - - the time;

unit - - the unit;

Throws:

java.lang.InterruptedException

java.util.concurrent.ExecutionException

java.util.concurrent.TimeoutException

close

void close()

Closes cancellation point;

Specified by:

close in interface java.lang.AutoCloseable

uncloseable

static CancellationPoint uncloseable(CancellationPoint cp)

Returns a cancellation point which can be checked but cannot be closed. Useful for passing a cancellation point into processes which don't own it and are not supposed to close it.

forCancelCheck

static CancellationPoint forCancelCheck(java.lang.String description,
                                        CancelCheck check)

Wraps the non-cancellable CancelCheck as a cancellable CancellationPoint. This is supposed to be used in those rare cases when a process can be cancelled externally (i.e. gets a CancelCheck from the outer code) but also spawns sub-processes which it can cancel itself. This method makes it easier to ensure that sub-processes get cancelled both from outside of the main process and from inside it. Note: the returned object does not support waiting.

Parameters:

description - the process description

check - the external cancellation check

Returns:

the cancellation point which is cancelled either via its cancel method or when the external flag is raised.