Package com.google.common.util.concurrent

Class ServiceManager.ServiceManagerState

java.lang.Object

com.google.common.util.concurrent.ServiceManager.ServiceManagerState

Enclosing class:

ServiceManager

private static final class ServiceManager.ServiceManagerState
extends java.lang.Object

An encapsulation of all the mutable state of the ServiceManager that needs to be accessed by instances of ServiceManager.ServiceListener.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
(package private) class	ServiceManager.ServiceManagerState.AwaitHealthGuard
(package private) class	ServiceManager.ServiceManagerState.StoppedGuard

Field Summary

Fields

Modifier and Type	Field	Description
(package private) Monitor.Guard	awaitHealthGuard	Controls how long to wait for all the services to either become healthy or reach a state from which it is guaranteed that it can never become healthy.
(package private) ListenerCallQueue<ServiceManager.Listener>	listeners	The listeners to notify during a state transition.
(package private) Monitor	monitor
(package private) int	numberOfServices
(package private) boolean	ready	These two booleans are used to mark the state as ready to start.
(package private) SetMultimap<Service.State,Service>	servicesByState
(package private) java.util.Map<Service,Stopwatch>	startupTimers
(package private) Multiset<Service.State>	states
(package private) Monitor.Guard	stoppedGuard	Controls how long to wait for all services to reach a terminal state.
(package private) boolean	transitioned

Constructor Summary

Constructors

Constructor	Description
ServiceManagerState(ImmutableCollection<Service> services)	It is implicitly assumed that all the services are NEW and that they will all remain NEW until all the Listeners are installed and markReady() is called.

Method Summary

Modifier and Type	Method	Description
(package private) void	addListener(ServiceManager.Listener listener, java.util.concurrent.Executor executor)
(package private) void	awaitHealthy()
(package private) void	awaitHealthy(long timeout, java.util.concurrent.TimeUnit unit)
(package private) void	awaitStopped()
(package private) void	awaitStopped(long timeout, java.util.concurrent.TimeUnit unit)
(package private) void	checkHealthy()
(package private) void	dispatchListenerEvents()	Attempts to execute all the listeners in listeners.
(package private) void	enqueueFailedEvent(Service service)
(package private) void	enqueueHealthyEvent()
(package private) void	enqueueStoppedEvent()
(package private) void	markReady()	Marks the Service.State as ready to receive transitions.
(package private) ImmutableSetMultimap<Service.State,Service>	servicesByState()
(package private) ImmutableMap<Service,java.lang.Long>	startupTimes()
(package private) void	transitionService(Service service, Service.State from, Service.State to)	Updates the state with the given service transition.
(package private) void	tryStartTiming(Service service)	Attempts to start the timer immediately prior to the service being started via Service.startAsync().

Methods inherited from class java.lang.Object

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

Field Detail

monitor

final Monitor monitor

servicesByState

final SetMultimap<Service.State,Service> servicesByState

states

final Multiset<Service.State> states

startupTimers

final java.util.Map<Service,Stopwatch> startupTimers

ready

boolean ready

These two booleans are used to mark the state as ready to start.

ready: is set by markReady() to indicate that all listeners have been correctly installed

transitioned: is set by transitionService(com.google.common.util.concurrent.Service, com.google.common.util.concurrent.Service.State, com.google.common.util.concurrent.Service.State) to indicate that some transition has been performed.

Together, they allow us to enforce that all services have their listeners installed prior to any service performing a transition, then we can fail in the ServiceManager constructor rather than in a Service.Listener callback.

transitioned

boolean transitioned

numberOfServices

final int numberOfServices

awaitHealthGuard

final Monitor.Guard awaitHealthGuard

Controls how long to wait for all the services to either become healthy or reach a state from which it is guaranteed that it can never become healthy.

stoppedGuard

final Monitor.Guard stoppedGuard

Controls how long to wait for all services to reach a terminal state.

listeners

final ListenerCallQueue<ServiceManager.Listener> listeners

The listeners to notify during a state transition.

Constructor Detail

ServiceManagerState

ServiceManagerState(ImmutableCollection<Service> services)

It is implicitly assumed that all the services are NEW and that they will all remain NEW until all the Listeners are installed and markReady() is called. It is our caller's responsibility to only call markReady() if all services were new at the time this method was called and when all the listeners were installed.

Method Detail

tryStartTiming

void tryStartTiming(Service service)

Attempts to start the timer immediately prior to the service being started via Service.startAsync().

markReady

void markReady()

Marks the Service.State as ready to receive transitions. Returns true if no transitions have been observed yet.

addListener

void addListener(ServiceManager.Listener listener,
                 java.util.concurrent.Executor executor)

awaitHealthy

void awaitHealthy()

awaitHealthy

void awaitHealthy(long timeout,
                  java.util.concurrent.TimeUnit unit)
           throws java.util.concurrent.TimeoutException

Throws:

java.util.concurrent.TimeoutException

awaitStopped

void awaitStopped()

awaitStopped

void awaitStopped(long timeout,
                  java.util.concurrent.TimeUnit unit)
           throws java.util.concurrent.TimeoutException

Throws:

java.util.concurrent.TimeoutException

servicesByState

ImmutableSetMultimap<Service.State,Service> servicesByState()

startupTimes

ImmutableMap<Service,java.lang.Long> startupTimes()

transitionService

void transitionService(Service service,
                       Service.State from,
                       Service.State to)

Updates the state with the given service transition.

This method performs the main logic of ServiceManager in the following steps.

1. Update the servicesByState()
2. Update the startupTimers
3. Based on the new state queue listeners to run
4. Run the listeners (outside of the lock)

enqueueStoppedEvent

void enqueueStoppedEvent()

enqueueHealthyEvent

void enqueueHealthyEvent()

enqueueFailedEvent

void enqueueFailedEvent(Service service)

dispatchListenerEvents

void dispatchListenerEvents()

Attempts to execute all the listeners in listeners.

checkHealthy

void checkHealthy()