org.apache.giraph.zk

Class PredicateLock

java.lang.Object

org.apache.giraph.zk.PredicateLock

All Implemented Interfaces:

BspEvent

public class PredicateLock
extends Object
implements BspEvent

A lock with a predicate that was be used to synchronize events and keep the job context updated while waiting.

Field Summary

Fields

Modifier and Type	Field and Description
protected org.apache.hadoop.util.Progressable	progressable Progressable for reporting progress (Job context)

Constructor Summary

Constructors

Constructor and Description
PredicateLock(org.apache.hadoop.util.Progressable progressable) Constructor with default values.
PredicateLock(org.apache.hadoop.util.Progressable progressable, int msecPeriod, Time time) Constructor.

Method Summary

Modifier and Type	Method and Description
void	reset() Reset the permanent signal.
void	signal() The event occurred and the occurrence has been logged for future waiters.
void	waitForTimeoutOrFail(long timeout) Waits until timeout or fails with runtime exception.
boolean	waitMsecs(int msecs) Wait until the event occurred or waiting timed out.

Methods inherited from class java.lang.Object

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

Field Detail

progressable

protected final org.apache.hadoop.util.Progressable progressable

Progressable for reporting progress (Job context)

Constructor Detail

PredicateLock

public PredicateLock(org.apache.hadoop.util.Progressable progressable)

Constructor with default values.

Parameters:

progressable - used to report progress() (usually a Mapper.Context)

PredicateLock

public PredicateLock(org.apache.hadoop.util.Progressable progressable,
                     int msecPeriod,
                     Time time)

Constructor.

Parameters:

progressable - used to report progress() (usually a Mapper.Context)

msecPeriod - Msecs between progress reports

time - Time implementation

Method Detail

reset

public void reset()

Description copied from interface: BspEvent

Reset the permanent signal.

Specified by:

reset in interface BspEvent

signal

public void signal()

Description copied from interface: BspEvent

The event occurred and the occurrence has been logged for future waiters.

Specified by:

signal in interface BspEvent

waitMsecs

public boolean waitMsecs(int msecs)

Description copied from interface: BspEvent

Wait until the event occurred or waiting timed out.

Specified by:

waitMsecs in interface BspEvent

Parameters:

msecs - Milliseconds to wait until the event occurred. 0 indicates check immediately. -1 indicates wait forever.

Returns:

true if event occurred, false if timed out while waiting

waitForTimeoutOrFail

public void waitForTimeoutOrFail(long timeout)

Description copied from interface: BspEvent

Waits until timeout or fails with runtime exception.

Specified by:

waitForTimeoutOrFail in interface BspEvent

Parameters:

timeout - Throws exception if waiting takes longer than timeout.