org.apache.ratis.util

Class LifeCycle

java.lang.Object

org.apache.ratis.util.LifeCycle

public class LifeCycle
extends Object

The life cycle of a machine.

   -------------------------------------------------
  |        --------------------------------         |
  |       |     ------------------------   |        |
  |       |    |                        |  |        |
  |       |  PAUSED <---- PAUSING----   |  |        |
  |       |    |          ^     |    |  |  |        |
  |       |    V          |     |    V  V  V        V
 NEW --> STARTING --> RUNNING --|--> CLOSING --> [CLOSED]
  ^       |    |          |     |       ^
  |       |    |          V     V       |
   -------      -------> EXCEPTION -----
 

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	LifeCycle.State The states in the life cycle.
static class	LifeCycle.States

Field Summary

Fields

Modifier and Type	Field and Description
static org.slf4j.Logger	LOG

Constructor Summary

Constructors

Constructor and Description
LifeCycle(Object name)

Method Summary

Modifier and Type	Method and Description
<T extends Throwable> LifeCycle.State	assertCurrentState(BiFunction<String,LifeCycle.State,T> newThrowable, Set<LifeCycle.State> expected) Assert if the current state equals to one of the expected states.
void	assertCurrentState(Set<LifeCycle.State> expected) Assert if the current state equals to one of the expected states.
LifeCycle.State	checkStateAndClose() Check the current state and, if applicable, transit to LifeCycle.State.CLOSING.
<T extends Throwable> LifeCycle.State	checkStateAndClose(CheckedRunnable<T> closeMethod) Check the current state and, if applicable, run the given close method.
boolean	compareAndTransition(LifeCycle.State from, LifeCycle.State to) If the current state is equal to the specified from state, then transition to the give to state; otherwise, make no change.
LifeCycle.State	getCurrentState()
void	setName(String name)
<T extends Throwable> void	startAndTransition(CheckedRunnable<T> startImpl, Class<? extends Throwable>... exceptionClasses) Run the given start method and transition the current state accordingly.
String	toString()
void	transition(LifeCycle.State to) Transition from the current state to the given state.
LifeCycle.State	transition(UnaryOperator<LifeCycle.State> operator) Transition using the given operator.
LifeCycle.State	transitionAndGet(UnaryOperator<LifeCycle.State> operator) Transition using the given operator.
void	transitionIfNotEqual(LifeCycle.State to) Transition from the current state to the given state if the current state is not equal to the given state.
boolean	transitionIfValid(LifeCycle.State to) Transition from the current state to the given state only if the transition is valid.

Methods inherited from class java.lang.Object

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

Field Detail

LOG

public static final org.slf4j.Logger LOG

Constructor Detail

LifeCycle

public LifeCycle(Object name)

Method Detail

setName

public void setName(String name)

transition

public void transition(LifeCycle.State to)

Transition from the current state to the given state.

transitionIfNotEqual

public void transitionIfNotEqual(LifeCycle.State to)

Transition from the current state to the given state if the current state is not equal to the given state.

transitionIfValid

public boolean transitionIfValid(LifeCycle.State to)

Transition from the current state to the given state only if the transition is valid. If the transition is invalid, this is a no-op.

Returns:

true if the updated state equals to the given state.

transition

public LifeCycle.State transition(UnaryOperator<LifeCycle.State> operator)

Transition using the given operator.

Returns:

the updated state if there is a transition; otherwise, return null to indicate no state change.

transitionAndGet

public LifeCycle.State transitionAndGet(UnaryOperator<LifeCycle.State> operator)

Transition using the given operator.

Returns:

the updated state.

compareAndTransition

public boolean compareAndTransition(LifeCycle.State from,
                                    LifeCycle.State to)

If the current state is equal to the specified from state, then transition to the give to state; otherwise, make no change.

Returns:

true iff the current state is equal to the specified from state.

getCurrentState

public LifeCycle.State getCurrentState()

Returns:

the current state.

assertCurrentState

public void assertCurrentState(Set<LifeCycle.State> expected)

Assert if the current state equals to one of the expected states.

assertCurrentState

public <T extends Throwable> LifeCycle.State assertCurrentState(BiFunction<String,LifeCycle.State,T> newThrowable,
                                                                Set<LifeCycle.State> expected)
                                                         throws T extends Throwable

Assert if the current state equals to one of the expected states.

Throws:

T extends Throwable

toString

public String toString()

Overrides:

toString in class Object

startAndTransition

@SafeVarargs
public final <T extends Throwable> void startAndTransition(CheckedRunnable<T> startImpl,
                                                                        Class<? extends Throwable>... exceptionClasses)
                                                                 throws T extends Throwable

Run the given start method and transition the current state accordingly.

Throws:

T extends Throwable

checkStateAndClose

public LifeCycle.State checkStateAndClose()

Check the current state and, if applicable, transit to LifeCycle.State.CLOSING. If this is already in LifeCycle.State.CLOSING or LifeCycle.State.CLOSED, then invoking this method has no effect. In other words, this method can be safely called multiple times.

checkStateAndClose

public <T extends Throwable> LifeCycle.State checkStateAndClose(CheckedRunnable<T> closeMethod)
                                                         throws T extends Throwable

Check the current state and, if applicable, run the given close method. If this is already in LifeCycle.State.CLOSING or LifeCycle.State.CLOSED, then invoking this method has no effect. In other words, this method can be safely called multiple times while the given close method will only be executed at most once.

Throws:

T extends Throwable