edu.umass.cs.reconfiguration.reconfigurationutils

Enum ReconfigurationRecord.RCStates

java.lang.Object

java.lang.Enum<ReconfigurationRecord.RCStates>

edu.umass.cs.reconfiguration.reconfigurationutils.ReconfigurationRecord.RCStates

All Implemented Interfaces:

java.io.Serializable, java.lang.Comparable<ReconfigurationRecord.RCStates>

Enclosing class:

ReconfigurationRecord<NodeIDType>

public static enum ReconfigurationRecord.RCStates
extends java.lang.Enum<ReconfigurationRecord.RCStates>

RC record states.

Enum Constant Summary

Enum Constants

Enum Constant and Description
READY The default state and one of only two states from which reconfiguration can be initiated, the other being READY_READY.
READY_READY Waiting for AckDropEpoch for the previous epoch.
WAIT_ACK_START Waiting for AckStartEpoch, for the incremented, current epoch that is at least one higher than the epoch just before the transition.
WAIT_ACK_STOP Waiting for AckStopEpoch, typically for the epoch that was READY just before this state transition.
WAIT_DELETE This is a pending delete state, i.e., we expect a deletion to occur in the near future, but we can not delete it yet because WaitAckDropEpoch may not have yet completed.

Method Summary

Modifier and Type	Method and Description
static ReconfigurationRecord.RCStates	valueOf(java.lang.String name) Returns the enum constant of this type with the specified name.
static ReconfigurationRecord.RCStates[]	values() Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

READY

public static final ReconfigurationRecord.RCStates READY

The default state and one of only two states from which reconfiguration can be initiated, the other being READY_READY.

WAIT_ACK_STOP

public static final ReconfigurationRecord.RCStates WAIT_ACK_STOP

Waiting for AckStopEpoch, typically for the epoch that was READY just before this state transition.

WAIT_ACK_START

public static final ReconfigurationRecord.RCStates WAIT_ACK_START

Waiting for AckStartEpoch, for the incremented, current epoch that is at least one higher than the epoch just before the transition. Typically, an RC record transitions from WAIT_ACK_STOP(n) to WAIT_ACK_START(n+1), where n and n+1 are epoch numbers. This state is currently not used as we directly skip from WAIT_ACK_STOP to READY.

READY_READY

public static final ReconfigurationRecord.RCStates READY_READY

Waiting for AckDropEpoch for the previous epoch. This state is not currently used explicitly because we transition directly from WAIT_ACK_START to READY because reconfiguration is technically complete when a majority of AckStartEpochs have been received, so we simply transition to READY while issuing DropEpoch requests for the previous epoch lazily. Dropping state for the previous epoch is needed only for garbage collection and does not impact safety.

WAIT_DELETE

public static final ReconfigurationRecord.RCStates WAIT_DELETE

This is a pending delete state, i.e., we expect a deletion to occur in the near future, but we can not delete it yet because WaitAckDropEpoch may not have yet completed.

Method Detail

values

public static ReconfigurationRecord.RCStates[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (ReconfigurationRecord.RCStates c : ReconfigurationRecord.RCStates.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static ReconfigurationRecord.RCStates valueOf(java.lang.String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

java.lang.IllegalArgumentException - if this enum type has no constant with the specified name

java.lang.NullPointerException - if the argument is null