Package org.ros.time

Class NtpTimeProvider

java.lang.Object

org.ros.time.NtpTimeProvider

All Implemented Interfaces:

TimeProvider

public class NtpTimeProvider
extends Object
implements TimeProvider

Provides NTP synchronized wallclock (actual) time.

Author:

damonkohler@google.com (Damon Kohler)

Constructor Summary

Constructors

Constructor	Description
NtpTimeProvider(InetAddress host, ScheduledExecutorService scheduledExecutorService)

Method Summary

Modifier and Type	Method	Description
org.ros.message.Time	getCurrentTime()
void	setUpdateTimeSampleSize(int sampleSize)	Sets how many samples will be taken from the NTP server when calling updateTime().
void	startPeriodicUpdates(long period, TimeUnit unit)	Starts periodically updating the current time offset periodically.
void	stopPeriodicUpdates()	Stops periodically updating the current time offset.
void	updateTime()	Update the current time offset from the configured NTP host.

Methods inherited from class java.lang.Object

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

Constructor Details

NtpTimeProvider

public NtpTimeProvider(InetAddress host,
 ScheduledExecutorService scheduledExecutorService)

Parameters:

host - the NTP host to use

Method Details

updateTime

public void updateTime()
                throws IOException

Update the current time offset from the configured NTP host.

Throws:

IOException - : if ntpClient.getTime() fails too often.

startPeriodicUpdates

public void startPeriodicUpdates(long period,
 TimeUnit unit)

Starts periodically updating the current time offset periodically.

The first time update happens immediately.

Note that errors thrown while periodically updating time will be logged but not rethrown.

Parameters:

period - time between updates

unit - unit of period

stopPeriodicUpdates

public void stopPeriodicUpdates()

Stops periodically updating the current time offset.

getCurrentTime

public org.ros.message.Time getCurrentTime()

Specified by:

getCurrentTime in interface TimeProvider

Returns:

the current time of the system using rostime

setUpdateTimeSampleSize

public void setUpdateTimeSampleSize(int sampleSize)

Sets how many samples will be taken from the NTP server when calling updateTime().

Parameters:

sampleSize - Number of samples to take. It has to be > 0.