com.hazelcast.spi.impl.sequence

Class AbstractCallIdSequence

java.lang.Object

com.hazelcast.spi.impl.sequence.AbstractCallIdSequence

All Implemented Interfaces:

CallIdSequence

Direct Known Subclasses:

CallIdSequenceWithBackpressure, FailFastCallIdSequence

public abstract class AbstractCallIdSequence
extends Object
implements CallIdSequence

A CallIdSequence that provides backpressure by taking the number of in-flight operations into account when before creating a new call-id.

It is possible to temporarily create more concurrent invocations than the declared capacity due to:

• system operations
• the racy nature of checking if space is available and getting the next sequence.

The latter cause is not a problem since the capacity is exceeded temporarily and it isn't sustainable. So perhaps there are a few threads that at the same time see that the there is space and do a next.

Constructor Summary

Constructors

Constructor and Description
AbstractCallIdSequence(int maxConcurrentInvocations)

Method Summary

Modifier and Type	Method and Description
void	complete() Not idempotent: must be called exactly once per invocation.
long	concurrentInvocations() Returns the number of concurrent invocations.
long	forceNext() Generates the next unique call ID.
long	getLastCallId() Returns the last issued call ID.
int	getMaxConcurrentInvocations() Returns the maximum concurrent invocations supported.
protected abstract void	handleNoSpaceLeft()
protected boolean	hasSpace()
long	next() Generates the next unique call ID.

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractCallIdSequence

public AbstractCallIdSequence(int maxConcurrentInvocations)

Method Detail

next

public long next()

Description copied from interface: CallIdSequence

Generates the next unique call ID. When the implementation supports backpressure, it will not return unless the number of outstanding invocations is within the configured limit. Instead it will block until the condition is met and eventually throw HazelcastOverloadException.

Specified by:

next in interface CallIdSequence

Returns:

the generated call ID

handleNoSpaceLeft

protected abstract void handleNoSpaceLeft()

getLastCallId

public long getLastCallId()

Description copied from interface: CallIdSequence

Returns the last issued call ID. ONLY FOR TESTING. Must not be used for production code.

Specified by:

getLastCallId in interface CallIdSequence

getMaxConcurrentInvocations

public int getMaxConcurrentInvocations()

Description copied from interface: CallIdSequence

Returns the maximum concurrent invocations supported. Integer.MAX_VALUE means there is no max.

Specified by:

getMaxConcurrentInvocations in interface CallIdSequence

Returns:

the maximum concurrent invocation.

complete

public void complete()

Description copied from interface: CallIdSequence

Not idempotent: must be called exactly once per invocation.

Specified by:

complete in interface CallIdSequence

forceNext

public long forceNext()

Description copied from interface: CallIdSequence

Generates the next unique call ID. This never blocks and it should be used only for urgent operation or when retrying.

Specified by:

forceNext in interface CallIdSequence

Returns:

the generated call ID

hasSpace

protected boolean hasSpace()

concurrentInvocations

public long concurrentInvocations()

Description copied from interface: CallIdSequence

Returns the number of concurrent invocations.

Specified by:

concurrentInvocations in interface CallIdSequence

Returns:

the number of concurrent invocations. Returns -1 if not known.