Class OobChannel

java.lang.Object

io.grpc.Channel

io.grpc.ManagedChannel

io.grpc.internal.OobChannel

All Implemented Interfaces:

InternalInstrumented<InternalChannelz.ChannelStats>, InternalWithLogId

@ThreadSafe
final class OobChannel
extends ManagedChannel
implements InternalInstrumented<InternalChannelz.ChannelStats>

A ManagedChannel backed by a single InternalSubchannel and used for LoadBalancer to its own RPC needs.

Field Summary

Fields

Modifier and Type	Field	Description
private final String	authority
private final CallTracer	channelCallsTracer
private final ChannelTracer	channelTracer
private final InternalChannelz	channelz
private final ScheduledExecutorService	deadlineCancellationExecutor
private final DelayedClientTransport	delayedTransport
private final Executor	executor
private final ObjectPool<? extends Executor>	executorPool
private static final Logger	log
private final InternalLogId	logId
private boolean	shutdown
private InternalSubchannel	subchannel
private AbstractSubchannel	subchannelImpl
private LoadBalancer.SubchannelPicker	subchannelPicker
private final CountDownLatch	terminatedLatch
private final TimeProvider	timeProvider
private final ClientCallImpl.ClientStreamProvider	transportProvider

Constructor Summary

Constructors

Constructor	Description
OobChannel(String authority, ObjectPool<? extends Executor> executorPool, ScheduledExecutorService deadlineCancellationExecutor, SynchronizationContext syncContext, CallTracer callsTracer, ChannelTracer channelTracer, InternalChannelz channelz, TimeProvider timeProvider)

Method Summary

Modifier and Type	Method	Description
String	authority()	The authority of the destination this channel connects to.
boolean	awaitTermination(long time, TimeUnit unit)	Waits for the channel to become terminated, giving up if the timeout is reached.
(package private) InternalSubchannel	getInternalSubchannel()
InternalLogId	getLogId()	Returns an ID that is primarily used in debug logs.
ConnectivityState	getState(boolean requestConnectionIgnored)	Gets the current connectivity state.
com.google.common.util.concurrent.ListenableFuture<InternalChannelz.ChannelStats>	getStats()	Returns the stats object.
(package private) LoadBalancer.Subchannel	getSubchannel()
(package private) void	handleSubchannelStateChange(ConnectivityStateInfo newState)
(package private) void	handleSubchannelTerminated()
boolean	isShutdown()	Returns whether the channel is shutdown.
boolean	isTerminated()	Returns whether the channel is terminated.
<RequestT, ResponseT> ClientCall<RequestT, ResponseT>	newCall(MethodDescriptor<RequestT, ResponseT> methodDescriptor, CallOptions callOptions)	Create a ClientCall to the remote operation specified by the given MethodDescriptor.
void	resetConnectBackoff()	For subchannels that are in TRANSIENT_FAILURE state, short-circuit the backoff timer and make them reconnect immediately.
(package private) void	setSubchannel(InternalSubchannel subchannel)
ManagedChannel	shutdown()	Initiates an orderly shutdown in which preexisting calls continue but new calls are immediately cancelled.
ManagedChannel	shutdownNow()	Initiates a forceful shutdown in which preexisting and new calls are cancelled.
String	toString()
(package private) void	updateAddresses(List<EquivalentAddressGroup> eag)

Methods inherited from class ManagedChannel

enterIdle, notifyWhenStateChanged

Methods inherited from class Object

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

Field Details

log

private static final Logger log

subchannel

private InternalSubchannel subchannel

subchannelImpl

private AbstractSubchannel subchannelImpl

subchannelPicker

private LoadBalancer.SubchannelPicker subchannelPicker

logId

private final InternalLogId logId

authority

private final String authority

delayedTransport

private final DelayedClientTransport delayedTransport

channelz

private final InternalChannelz channelz

executorPool

private final ObjectPool<? extends Executor> executorPool

executor

private final Executor executor

deadlineCancellationExecutor

private final ScheduledExecutorService deadlineCancellationExecutor

terminatedLatch

private final CountDownLatch terminatedLatch

shutdown

private volatile boolean shutdown

channelCallsTracer

private final CallTracer channelCallsTracer

channelTracer

private final ChannelTracer channelTracer

timeProvider

private final TimeProvider timeProvider

transportProvider

private final ClientCallImpl.ClientStreamProvider transportProvider

Constructor Details

OobChannel

OobChannel(String authority,
 ObjectPool<? extends Executor> executorPool,
 ScheduledExecutorService deadlineCancellationExecutor,
 SynchronizationContext syncContext,
 CallTracer callsTracer,
 ChannelTracer channelTracer,
 InternalChannelz channelz,
 TimeProvider timeProvider)

Method Details

setSubchannel

void setSubchannel(InternalSubchannel subchannel)

updateAddresses

void updateAddresses(List<EquivalentAddressGroup> eag)

newCall

public <RequestT, ResponseT>
ClientCall<RequestT, ResponseT> newCall(MethodDescriptor<RequestT, ResponseT> methodDescriptor,
 CallOptions callOptions)

Description copied from class: Channel

Create a ClientCall to the remote operation specified by the given MethodDescriptor. The returned ClientCall does not trigger any remote behavior until ClientCall.start(ClientCall.Listener, Metadata) is invoked.

Specified by:

newCall in class Channel

Parameters:

methodDescriptor - describes the name and parameter types of the operation to call.

callOptions - runtime options to be applied to this call.

Returns:

a ClientCall bound to the specified method.

authority

public String authority()

Description copied from class: Channel

The authority of the destination this channel connects to. Typically this is in the format host:port.

Specified by:

authority in class Channel

isTerminated

public boolean isTerminated()

Description copied from class: ManagedChannel

Returns whether the channel is terminated. Terminated channels have no running calls and relevant resources released (like TCP connections).

Specified by:

isTerminated in class ManagedChannel

See Also:

• ManagedChannel.isShutdown()

awaitTermination

public boolean awaitTermination(long time,
 TimeUnit unit)
                         throws InterruptedException

Description copied from class: ManagedChannel

Waits for the channel to become terminated, giving up if the timeout is reached.

Specified by:

awaitTermination in class ManagedChannel

Returns:

whether the channel is terminated, as would be done by ManagedChannel.isTerminated().

Throws:

InterruptedException

getState

public ConnectivityState getState(boolean requestConnectionIgnored)

Description copied from class: ManagedChannel

Gets the current connectivity state. Note the result may soon become outdated.

Note that the core library did not provide an implementation of this method until v1.6.1.

Overrides:

getState in class ManagedChannel

Parameters:

requestConnectionIgnored - if true, the channel will try to make a connection if it is currently IDLE

shutdown

public ManagedChannel shutdown()

Description copied from class: ManagedChannel

Initiates an orderly shutdown in which preexisting calls continue but new calls are immediately cancelled.

Specified by:

shutdown in class ManagedChannel

Returns:

this

isShutdown

public boolean isShutdown()

Description copied from class: ManagedChannel

Returns whether the channel is shutdown. Shutdown channels immediately cancel any new calls, but may still have some calls being processed.

Specified by:

isShutdown in class ManagedChannel

See Also:

• ManagedChannel.shutdown()
• ManagedChannel.isTerminated()

shutdownNow

public ManagedChannel shutdownNow()

Description copied from class: ManagedChannel

Initiates a forceful shutdown in which preexisting and new calls are cancelled. Although forceful, the shutdown process is still not instantaneous; ManagedChannel.isTerminated() will likely return false immediately after this method returns.

Specified by:

shutdownNow in class ManagedChannel

Returns:

this

handleSubchannelStateChange

void handleSubchannelStateChange(ConnectivityStateInfo newState)

handleSubchannelTerminated

void handleSubchannelTerminated()

getSubchannel

LoadBalancer.Subchannel getSubchannel()

getInternalSubchannel

InternalSubchannel getInternalSubchannel()

getStats

public com.google.common.util.concurrent.ListenableFuture<InternalChannelz.ChannelStats> getStats()

Description copied from interface: InternalInstrumented

Returns the stats object.

Specified by:

getStats in interface InternalInstrumented<InternalChannelz.ChannelStats>

getLogId

public InternalLogId getLogId()

Description copied from interface: InternalWithLogId

Returns an ID that is primarily used in debug logs. It usually contains the class name and a numeric ID that is unique among the instances.

The subclasses of this interface usually want to include the log ID in their Object.toString() results.

Specified by:

getLogId in interface InternalWithLogId

toString

public String toString()

Overrides:

toString in class Object

resetConnectBackoff

public void resetConnectBackoff()

Description copied from class: ManagedChannel

For subchannels that are in TRANSIENT_FAILURE state, short-circuit the backoff timer and make them reconnect immediately. May also attempt to invoke NameResolver.refresh().

This is primarily intended for Android users, where the network may experience frequent temporary drops. Rather than waiting for gRPC's name resolution and reconnect timers to elapse before reconnecting, the app may use this method as a mechanism to notify gRPC that the network is now available and a reconnection attempt may occur immediately.

No-op if not supported by the implementation.

Overrides:

resetConnectBackoff in class ManagedChannel