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*
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
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* 2 along with this work; if not, write to the Free Software Foundation,
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package com.sun.tools.visualvm.modules.tracer;
import com.sun.tools.visualvm.core.datasource.DataSource;
/**
* Tracer probe represents one monitored unit in the Timeline chart. The probe
* may provide one or several values displayed in the chart, for example several
* numeric values of an MBean.
*
* @author Jiri Sedlacek
*/
public abstract class TracerProbe<X extends DataSource> {
private final ProbeItemDescriptor[] itemDescriptors;
/**
* Creates new instance of TracerProbe.
*
* @param itemDescriptors descriptors of UI appearance of items provided by the probe
*/
public TracerProbe(ProbeItemDescriptor[] itemDescriptors) {
if (itemDescriptors == null || itemDescriptors.length == 0)
throw new IllegalArgumentException("Invalid ProbeItemDescriptors"); // NOI18N
this.itemDescriptors = itemDescriptors;
}
/**
* Returns descriptors of UI appearance of items provided by the probe.
*
* @return descriptors of UI appearance of items provided by the probe
*/
public final ProbeItemDescriptor[] getItemDescriptors() { return itemDescriptors; };
/**
* Returns number of items provided by the probe.
*
* @return number of items provided by the probe
*/
public int getItemsCount() { return itemDescriptors.length; }
/**
* Returns values of items provided by the probe at the defined time. It's up
* to the probe implementation whether the values will be read in this method
* or retrieved from a private data model prefetching the values asynchronously.
* The timestamp is the same for a single data-read event for all selected
* probes of the actual Tracer session.
* <br><br>
* <b>Note: current Tracer version doesn't support negative values. Negative
* values returned by the probes will be treated as '0' and the user will be
* notified by a warning dialog.</b>
*
* @param timestamp timestamp of the data-read event
* @return values of items provided by the probe
*/
public abstract long[] getItemValues(long timestamp);
/**
* Optionally returns ProbeStateHandler instance which obtains notifications
* about the Tracer session status. Default implementation returns null.
* You may use StateAware subclass instead of implementing this method to
* obtain the notifications.
*
* @return ProbeStateHandler instance which obtains status notifications,
* default implementation returns null
*/
public ProbeStateHandler<X> getStateHandler() { return null; }
/**
* An abstract adapter class for receiving Tracer session state notifications.
* See ProbeStateHandler for details.
*
* @param <X> any DataSource type
*/
public static abstract class SessionAware<X extends DataSource> extends TracerProbe<X> {
private ProbeStateHandler<X> stateHandler;
/**
* Creates new instance of TracerProbe.SessionAware.
*
* @param itemDescriptors descriptors of UI appearance of items provided by the probe
*/
public SessionAware(ProbeItemDescriptor[] itemDescriptors) {
super(itemDescriptors);
}
/**
* Returns a predefined ProbeStateHandler which obtains notifications
* about the Tracer session state.
*
* @return predefined ProbeStateHandler which obtains status notifications
*/
public synchronized final ProbeStateHandler<X> getStateHandler() {
if (stateHandler == null) stateHandler = new ProbeStateHandler<X>() {
public void probeAdded(X dataSource) {
SessionAware.this.probeAdded(dataSource);
}
public void probeRemoved(X dataSource) {
SessionAware.this.probeRemoved(dataSource);
}
public TracerProgressObject sessionInitializing(X dataSource, int refresh) {
return SessionAware.this.sessionInitializing(dataSource, refresh);
}
public void sessionStarting(X dataSource)
throws SessionInitializationException {
SessionAware.this.sessionStarting(dataSource);
}
public void sessionRunning(X dataSource) {
SessionAware.this.sessionRunning(dataSource);
}
public void sessionStopping(X dataSource) {
SessionAware.this.sessionStopping(dataSource);
}
public void sessionFinished(X dataSource) {
SessionAware.this.sessionFinished(dataSource);
}
public void refreshRateChanged(X dataSource, int refresh) {
SessionAware.this.refreshRateChanged(dataSource, refresh);
}
};
return stateHandler;
}
/**
* Invoked when the is added into the Timeline view.
*
* @param dataSource monitored DataSource
*/
protected void probeAdded(X dataSource) {}
/**
* Invoked when the probe is removed from the Timeline view.
*
* @param dataSource monitored DataSource
*/
protected void probeRemoved(X dataSource) {}
/**
* Invoked when setting up a new Tracer session. This method allows a
* Probe to notify the user about initialization progress. The actual
* initialization (and updating the TracerProgressObject) should be
* performed in the sessionStarting() method. Useful for example for
* messaging a delay during instrumention of classes in target application.
*
* @param dataSource monitored DataSource
* @param refresh session refresh rate in miliseconds
* @return TracerProgressObject to track initialization progress
*/
protected TracerProgressObject sessionInitializing(X dataSource, int refresh) {
return null;
}
/**
* Invoked when starting a new Tracer session. Any probe initialization
* should be performed in this method. If provided by the
* sessionInitializing method, a TracerProgressObject should be updated to
* reflect the initialization progress. This method may throw a
* SessionInitializationException in case of initialization failure. Any
* packages/probes initialized so far will be correctly finished, however the
* probe throwing the SessionInitializationException is responsible for
* cleaning up any used resources and restoring its state without any
* following events.
*
* @param dataSource monitored DataSource
* @throws SessionInitializationException in case of initialization failure
*/
protected void sessionStarting(X dataSource)
throws SessionInitializationException {}
/**
* Invoked when all packages/probes have been started and the Tracer session
* is running and collecting data.
*
* @param dataSource monitored DataSource
*/
protected void sessionRunning(X dataSource) {}
/**
* Invoked when stopping the Tracer session. Any probe cleanup should be
* performed in this method. Any long-running cleanup code should preferably
* be invoked in a separate worker thread to allow the Tracer session to
* finish as fast as possible. Be sure to check/wait for the cleanup thread
* when starting a new Tracer session in sessionStarting().
*
* @param dataSource monitored DataSource
*/
protected void sessionStopping(X dataSource) {}
/**
* Invoked when the Tracer session has finished.
*
* @param dataSource monitored DataSource
*/
protected void sessionFinished(X dataSource) {}
/**
* Invoked when refresh rate of the Tracer session has been changed.
*
* @param dataSource monitored DataSource
* @param refresh session refresh rate in miliseconds
*/
protected void refreshRateChanged(X dataSource, int refresh) {}
}
}