Package org.apache.hadoop.service.launcher

Class InterruptEscalator

java.lang.Object

org.apache.hadoop.service.launcher.InterruptEscalator

All Implemented Interfaces:

IrqHandler.Interrupted

@Private
@Unstable
public class InterruptEscalator
extends java.lang.Object
implements IrqHandler.Interrupted

Handles interrupts by shutting down a service, escalating if the service does not shut down in time, or when other interrupts are received.

1. The service is given a time in milliseconds to stop: if it exceeds this it the process exits anyway.
2. the exit operation used is ServiceLauncher.exit(int, String) with the exit code LauncherExitCodes.EXIT_INTERRUPTED
3. If a second shutdown signal is received during the shutdown process, ExitUtil.halt(int) is invoked. This handles the problem of blocking shutdown hooks.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected static class	InterruptEscalator.ServiceForcedShutdown	Forced shutdown runnable.

Constructor Summary

Constructors

Constructor	Description
InterruptEscalator(ServiceLauncher owner, int shutdownTimeMillis)

Method Summary

Modifier and Type	Method	Description
void	interrupted(IrqHandler.InterruptData interruptData)	Handle an interrupt.
boolean	isForcedShutdownTimedOut()	Flag set if forced shut down timed out.
boolean	isSignalAlreadyReceived()	Flag set if a signal has been received.
IrqHandler	lookup(java.lang.String signalName)	Look up the handler for a signal.
void	register(java.lang.String signalName)	Register an interrupt handler.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

InterruptEscalator

public InterruptEscalator(ServiceLauncher owner,
                          int shutdownTimeMillis)

Method Detail

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

interrupted

public void interrupted(IrqHandler.InterruptData interruptData)

Description copied from interface: IrqHandler.Interrupted

Handle an interrupt.

Specified by:

interrupted in interface IrqHandler.Interrupted

Parameters:

interruptData - data

register

public void register(java.lang.String signalName)

Register an interrupt handler.

Parameters:

signalName - signal name

Throws:

java.lang.IllegalArgumentException - if the registration failed

lookup

public IrqHandler lookup(java.lang.String signalName)

Look up the handler for a signal.

Parameters:

signalName - signal name

Returns:

a handler if found

isForcedShutdownTimedOut

public boolean isForcedShutdownTimedOut()

Flag set if forced shut down timed out.

Returns:

true if a shutdown was attempted and it timed out

isSignalAlreadyReceived

public boolean isSignalAlreadyReceived()

Flag set if a signal has been received.

Returns:

true if there has been one interrupt already.