/*
* @(#)CounterMonitor.java 1.74 04/05/18
*
* Copyright 2004 Sun Microsystems, Inc. All rights reserved.
* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*/
package javax.management.monitor;
// java imports
//
import java.util.Date;
import java.util.Timer;
import java.util.TimerTask;
// jmx imports
//
import javax.management.ObjectName;
import javax.management.MBeanNotificationInfo;
import javax.management.AttributeNotFoundException;
import javax.management.InstanceNotFoundException;
import javax.management.MBeanException;
import javax.management.ReflectionException;
/**
* Defines a monitor MBean designed to observe the values of a counter
* attribute.
*
* <P> A counter monitor sends a {@link
* MonitorNotification#THRESHOLD_VALUE_EXCEEDED threshold
* notification} when the value of the counter reaches or exceeds a
* threshold known as the comparison level. The notify flag must be
* set to <CODE>true</CODE>.
*
* <P> In addition, an offset mechanism enables particular counting
* intervals to be detected. If the offset value is not zero,
* whenever the threshold is triggered by the counter value reaching a
* comparison level, that comparison level is incremented by the
* offset value. This is regarded as taking place instantaneously,
* that is, before the count is incremented. Thus, for each level,
* the threshold triggers an event notification every time the count
* increases by an interval equal to the offset value.
*
* <P> If the counter can wrap around its maximum value, the modulus
* needs to be specified. The modulus is the value at which the
* counter is reset to zero.
*
* <P> If the counter difference mode is used, the value of the
* derived gauge is calculated as the difference between the observed
* counter values for two successive observations. If this difference
* is negative, the value of the derived gauge is incremented by the
* value of the modulus. The derived gauge value (V[t]) is calculated
* using the following method:
*
* <UL>
* <LI>if (counter[t] - counter[t-GP]) is positive then
* V[t] = counter[t] - counter[t-GP]
* <LI>if (counter[t] - counter[t-GP]) is negative then
* V[t] = counter[t] - counter[t-GP] + MODULUS
* </UL>
*
* This implementation of the counter monitor requires the observed
* attribute to be of the type integer (<CODE>Byte</CODE>,
* <CODE>Integer</CODE>, <CODE>Short</CODE>, <CODE>Long</CODE>).
*
* @version 1.74 05/18/04
* @author Sun Microsystems, Inc
*
* @since 1.5
*/
public class CounterMonitor extends Monitor implements CounterMonitorMBean {
/*
* ------------------------------------------
* PRIVATE VARIABLES
* ------------------------------------------
*/
private static final Integer INTEGER_ZERO = new Integer(0);
/**
* Counter thresholds.
* <BR>Each element in this array corresponds to an observed
* object in the list.
*/
private Number threshold[] = new Number[capacityIncrement];
/**
* Counter modulus.
* <BR>The default value is a null Integer object.
*/
private Number modulus = INTEGER_ZERO;
/**
* Counter offset.
* <BR>The default value is a null Integer object.
*/
private Number offset = INTEGER_ZERO;
/**
* Flag indicating if the counter monitor notifies when exceeding
* the threshold. The default value is set to
* <CODE>false</CODE>.
*/
private boolean notify = false;
/**
* Flag indicating if the counter difference mode is used. If the
* counter difference mode is used, the derived gauge is the
* difference between two consecutive observed values. Otherwise,
* the derived gauge is directly the value of the observed
* attribute. The default value is set to <CODE>false</CODE>.
*/
private boolean differenceMode = false;
/**
* Initial counter threshold. This value is used to initialize
* the threshold when a new object is added to the list and reset
* the threshold to its initial value each time the counter
* resets.
*/
private Number initThreshold = INTEGER_ZERO;
/**
* Derived gauges.
*
* <BR>Each element in this array corresponds to an observed
* object in the list.
*/
private Number derivedGauge[] = new Number[capacityIncrement];
/**
* Derived gauge timestamp.
* <BR>Each element in this array corresponds to an observed
* object in the list.
*/
private long derivedGaugeTimestamp[] = new long[capacityIncrement];
/**
* Scan counter value captured by the previous observation.
* <BR>Each element in this array corresponds to an observed
* object in the list.
*/
private Number previousScanCounter[] = new Number[capacityIncrement];
/**
* Flag indicating if the modulus has been exceeded by the
* threshold. This flag is used to reset the threshold once we
* are sure that the counter has been resetted.
* <BR>Each element in this array corresponds to an observed
* object in the list.
*/
private boolean modulusExceeded[] = new boolean[capacityIncrement];
/**
* Derived gauge captured when the modulus has been exceeded by
* the threshold. This value is used to check if the counter has
* been resetted (in order to reset the threshold).
* <BR>Each element in this array corresponds to an observed
* object in the list.
*/
private Number derivedGaugeExceeded[] = new Number[capacityIncrement];
/**
* This flag is used to notify only once between two granularity
* periods.
* <BR>Each element in this array corresponds to an observed
* object in the list.
*/
private boolean eventAlreadyNotified[] = new boolean[capacityIncrement];
/**
* This attribute is used to keep the derived gauge type.
* <BR>Each element in this array corresponds to an observed
* object in the list.
*/
private int type[] = new int[capacityIncrement];
// Flags needed to keep trace of the derived gauge type.
// Integer types only are allowed.
//
private static final int INTEGER = 0;
private static final int BYTE = 1;
private static final int SHORT = 2;
private static final int LONG = 3;
// New flags defining possible counter monitor errors.
// Flag denoting that a notification has occured after changing
// the threshold.
// This flag is used to check that the threshold, offset and
// modulus types are the same as the counter.
//
private static final int THRESHOLD_ERROR_NOTIFIED = 16;
/**
* Timer.
*/
private Timer timer = null;
// TRACES & DEBUG
//---------------
String makeDebugTag() {
return "CounterMonitor";
}
/*
* ------------------------------------------
* CONSTRUCTORS
* ------------------------------------------
*/
/**
* Default constructor.
*/
public CounterMonitor() {
dbgTag = makeDebugTag();
}
/*
* ------------------------------------------
* PUBLIC METHODS
* ------------------------------------------
*/
/**
* Allows the counter monitor MBean to perform any operations it
* needs before being unregistered by the MBean server.
*
* <P>Resets the threshold values.
*
* @exception java.lang.Exception
*/
public void preDeregister() throws java.lang.Exception {
// Stop the CounterMonitor.
//
super.preDeregister();
if (isTraceOn()) {
trace("preDeregister", "reset the threshold values");
}
// Reset values for serialization.
//
synchronized (this) {
for (int i = 0; i < elementCount; i++) {
threshold[i] = initThreshold;
}
}
}
/**
* Starts the counter monitor.
*/
public synchronized void start() {
if (isTraceOn()) {
trace("start", "start the counter monitor");
}
if (isActive()) {
if (isTraceOn()) {
trace("start", "the counter monitor is already activated");
}
return;
}
isActive = true;
// Reset values.
//
for (int i = 0; i < elementCount; i++) {
threshold[i] = initThreshold;
modulusExceeded[i] = false;
eventAlreadyNotified[i] = false;
previousScanCounter[i] = null;
}
// Start the timer.
//
timer = new Timer();
timer.schedule(new CounterAlarmClock(this), getGranularityPeriod(),
getGranularityPeriod());
}
/**
* Stops the counter monitor.
*
* This method is not synchronized, because if it were there could
* be a deadlock with a thread that attempted to get the lock on
* the monitor before being interrupted or noticing that it had
* been interrupted.
*/
public synchronized void stop() {
if (isTraceOn()) {
trace("stop", "stop the counter monitor");
}
if (isTraceOn()) {
trace("stop", "the counter monitor is not started");
return;
}
isActive = false;
// Stop the timer.
//
if (timer != null) {
timer.cancel();
timer = null;
}
}
// GETTERS AND SETTERS
//--------------------
/**
* Sets the granularity period (in milliseconds).
* <BR>The default value of the granularity period is 10 seconds.
*
* @param period The granularity period value.
* @exception java.lang.IllegalArgumentException The granularity
* period is less than or equal to zero.
*
* @see Monitor#setGranularityPeriod(long)
*/
public synchronized void setGranularityPeriod(long period)
throws IllegalArgumentException {
super.setGranularityPeriod(period);
// Reschedule timer task if timer is already running
//
if (isActive()) {
timer.cancel();
timer = new Timer();
timer.schedule(new CounterAlarmClock(this),
getGranularityPeriod(), getGranularityPeriod());
}
}
/**
* Gets the derived gauge of the specified object, if this object is
* contained in the set of observed MBeans, or <code>null</code> otherwise.
*
* @param object the name of the object whose derived gauge is to
* be returned.
*
* @return The derived gauge of the specified object.
*
* @since.unbundled JMX 1.2
*/
public synchronized Number getDerivedGauge(ObjectName object) {
int index = indexOf(object);
if (index != -1)
return derivedGauge[index];
else
return null;
}
/**
* Gets the derived gauge timestamp of the specified object, if
* this object is contained in the set of observed MBeans, or
* <code>null</code> otherwise.
*
* @param object the name of the object whose derived gauge
* timestamp is to be returned.
*
* @return The derived gauge timestamp of the specified object.
*
* @since.unbundled JMX 1.2
*/
public synchronized long getDerivedGaugeTimeStamp(ObjectName object) {
int index = indexOf(object);
if (index != -1)
return derivedGaugeTimestamp[index];
else
return 0;
}
/**
* Gets the current threshold value of the specified object, if
* this object is contained in the set of observed MBeans, or
* <code>null</code> otherwise.
*
* @param object the name of the object whose threshold is to be
* returned.
*
* @return The threshold value of the specified object.
*
* @see #setThreshold
*
* @since.unbundled JMX 1.2
*/
public synchronized Number getThreshold(ObjectName object) {
int index = indexOf(object);
if (index != -1)
return threshold[index];
else
return null;
}
/**
* Gets the initial threshold value common to all observed objects.
*
* @return The initial threshold.
*
* @see #setInitThreshold
*
* @since.unbundled JMX 1.2
*/
public synchronized Number getInitThreshold() {
return initThreshold;
}
/**
* Sets the initial threshold value common to all observed objects.
*
* <BR>The current threshold of every object in the set of
* observed MBeans is updated consequently.
*
* @param value The initial threshold value.
* @exception java.lang.IllegalArgumentException The specified
* threshold is null or the threshold value is less than zero.
*
* @see #getInitThreshold
*
* @since.unbundled JMX 1.2
*/
public synchronized void setInitThreshold(Number value)
throws IllegalArgumentException {
if (value == null) {
throw new IllegalArgumentException("Null threshold");
}
if (value.longValue() < 0L) {
throw new IllegalArgumentException("Negative threshold");
}
initThreshold = value;
for (int i = 0; i < elementCount; i++) {
threshold[i] = value;
resetAlreadyNotified(i, THRESHOLD_ERROR_NOTIFIED);
// Reset values.
//
modulusExceeded[i] = false;
eventAlreadyNotified[i] = false;
}
}
/**
* Returns the derived gauge of the first object in the set of
* observed MBeans.
*
* @return The derived gauge.
* @deprecated As of JMX 1.2, replaced by {@link #getDerivedGauge(ObjectName)}
*/
@Deprecated
public synchronized Number getDerivedGauge() {
return derivedGauge[0];
}
/**
* Gets the derived gauge timestamp of the first object in the set
* of observed MBeans.
*
* @return The derived gauge timestamp.
* @deprecated As of JMX 1.2, replaced by
* {@link #getDerivedGaugeTimeStamp(ObjectName)}
*/
@Deprecated
public synchronized long getDerivedGaugeTimeStamp() {
return derivedGaugeTimestamp[0];
}
/**
* Gets the threshold value of the first object in the set of
* observed MBeans.
*
* @return The threshold value.
*
* @see #setThreshold(Number)
*
* @deprecated As of JMX 1.2, replaced by {@link #getThreshold(ObjectName)}
*/
@Deprecated
public synchronized Number getThreshold() {
return threshold[0];
}
/**
* Sets the initial threshold value.
*
* @param value The initial threshold value.
* @exception IllegalArgumentException The specified threshold is
* null or the threshold value is less than zero.
*
* @see #getThreshold()
*
* @deprecated As of JMX 1.2, replaced by {@link #setInitThreshold}
*/
@Deprecated
public synchronized void setThreshold(Number value)
throws IllegalArgumentException {
setInitThreshold(value);
}
/**
* Gets the offset value common to all observed MBeans.
*
* @return The offset value.
*
* @see #setOffset
*/
public synchronized Number getOffset() {
return offset;
}
/**
* Sets the offset value common to all observed MBeans.
*
* @param value The offset value.
* @exception java.lang.IllegalArgumentException The specified
* offset is null or the offset value is less than zero.
*
* @see #getOffset
*/
public synchronized void setOffset(Number value)
throws IllegalArgumentException {
if (value == null) {
throw new IllegalArgumentException("Null offset");
}
if (value.longValue() < 0L) {
throw new IllegalArgumentException("Negative offset");
}
offset = value;
for (int i = 0; i < elementCount; i++) {
resetAlreadyNotified(i, THRESHOLD_ERROR_NOTIFIED);
}
}
/**
* Gets the modulus value common to all observed MBeans.
*
* @see #setModulus
*
* @return The modulus value.
*/
public synchronized Number getModulus() {
return modulus;
}
/**
* Sets the modulus value common to all observed MBeans.
*
* @param value The modulus value.
* @exception java.lang.IllegalArgumentException The specified
* modulus is null or the modulus value is less than zero.
*
* @see #getModulus
*/
public synchronized void setModulus(Number value)
throws IllegalArgumentException {
if (value == null) {
throw new IllegalArgumentException("Null modulus");
}
if (value.longValue() < 0L) {
throw new IllegalArgumentException("Negative modulus");
}
modulus = value;
for (int i = 0; i < elementCount; i++) {
resetAlreadyNotified(i, THRESHOLD_ERROR_NOTIFIED);
// Reset values.
//
modulusExceeded[i] = false;
}
}
/**
* Gets the notification's on/off switch value common to all
* observed MBeans.
*
* @return <CODE>true</CODE> if the counter monitor notifies when
* exceeding the threshold, <CODE>false</CODE> otherwise.
*
* @see #setNotify
*/
public synchronized boolean getNotify() {
return notify;
}
/**
* Sets the notification's on/off switch value common to all
* observed MBeans.
*
* @param value The notification's on/off switch value.
*
* @see #getNotify
*/
public synchronized void setNotify(boolean value) {
notify = value;
}
/**
* Gets the difference mode flag value common to all observed MBeans.
*
* @return <CODE>true</CODE> if the difference mode is used,
* <CODE>false</CODE> otherwise.
*
* @see #setDifferenceMode
*/
public synchronized boolean getDifferenceMode() {
return differenceMode;
}
/**
* Sets the difference mode flag value common to all observed MBeans.
*
* @param value The difference mode flag value.
*
* @see #getDifferenceMode
*/
public synchronized void setDifferenceMode(boolean value) {
differenceMode = value;
for (int i = 0; i < elementCount; i++) {
// Reset values.
//
threshold[i] = initThreshold;
modulusExceeded[i] = false;
eventAlreadyNotified[i] = false;
previousScanCounter[i] = null;
}
}
/**
* Returns a <CODE>NotificationInfo</CODE> object containing the
* name of the Java class of the notification and the notification
* types sent by the counter monitor.
*/
public MBeanNotificationInfo[] getNotificationInfo() {
String[] types = { MonitorNotification.RUNTIME_ERROR,
MonitorNotification.OBSERVED_OBJECT_ERROR,
MonitorNotification.OBSERVED_ATTRIBUTE_ERROR,
MonitorNotification.OBSERVED_ATTRIBUTE_TYPE_ERROR,
MonitorNotification.THRESHOLD_ERROR,
MonitorNotification.THRESHOLD_VALUE_EXCEEDED};
MBeanNotificationInfo[] notifsInfo = {
new MBeanNotificationInfo(types,
"javax.management.monitor.MonitorNotification",
"Notifications sent by the CounterMonitor MBean")
};
return notifsInfo;
}
/*
* ------------------------------------------
* PRIVATE METHODS
* ------------------------------------------
*/
/**
* Updates the derived gauge and the derived gauge timestamp attributes
* of the observed object at the specified index.
*
* @param scanCounter The value of the observed attribute.
* @param index The index of the observed object.
* @return <CODE>true</CODE> if the derived gauge value is valid,
* <CODE>false</CODE> otherwise. The derived gauge value is
* invalid when the differenceMode flag is set to
* <CODE>true</CODE> and it is the first notification (so we
* haven't 2 consecutive values to update the derived gauge).
*/
private synchronized boolean updateDerivedGauge(Object scanCounter,
int index) {
boolean is_derived_gauge_valid;
derivedGaugeTimestamp[index] = System.currentTimeMillis();
// The counter difference mode is used.
//
if (differenceMode) {
// The previous scan counter has been initialized.
//
if (previousScanCounter[index] != null) {
setDerivedGaugeWithDifference((Number)scanCounter, null, index);
// If derived gauge is negative it means that the
// counter has wrapped around and the value of the
// threshold needs to be reset to its initial value.
//
if (derivedGauge[index].longValue() < 0L) {
if (modulus.longValue() > 0L) {
setDerivedGaugeWithDifference((Number)scanCounter,
(Number)modulus, index);
}
threshold[index] = initThreshold;
eventAlreadyNotified[index] = false;
}
is_derived_gauge_valid = true;
}
// The previous scan counter has not been initialized.
// We cannot update the derived gauge...
//
else {
is_derived_gauge_valid = false;
}
previousScanCounter[index] = (Number)scanCounter;
}
// The counter difference mode is not used.
//
else {
derivedGauge[index] = (Number)scanCounter;
is_derived_gauge_valid = true;
}
return is_derived_gauge_valid;
}
/**
* Updates the notification attribute of the observed object at the
* specified index and notifies the listeners only once if the notify flag
* is set to <CODE>true</CODE>.
* @param index The index of the observed object.
*/
private void updateNotifications(int index) {
boolean sendNotif = false;
String notifType = null;
long timeStamp = 0;
String msg = null;
Object derGauge = null;
Object trigger = null;
synchronized(this) {
// Send notification if notify is true.
//
if (!eventAlreadyNotified[index]) {
if (derivedGauge[index].longValue() >=
threshold[index].longValue()) {
if (notify) {
sendNotif = true;
notifType = MonitorNotification.THRESHOLD_VALUE_EXCEEDED;
timeStamp = derivedGaugeTimestamp[index];
msg = "";
derGauge = derivedGauge[index];
trigger = threshold[index];
}
if (!differenceMode) {
eventAlreadyNotified[index] = true;
}
}
} else {
if (isTraceOn()) {
trace("updateNotifications", "the notification:" +
"\n\tNotification observed object = " +
getObservedObject(index) +
"\n\tNotification observed attribute = " +
getObservedAttribute() +
"\n\tNotification derived gauge = " +
derivedGauge[index] +
"\nhas already been sent");
}
}
}
if (sendNotif) {
sendNotification(notifType, timeStamp, msg, derGauge, trigger, index);
}
}
/**
* Updates the threshold attribute of the observed object at the
* specified index.
* @param index The index of the observed object.
*/
private synchronized void updateThreshold(int index) {
// Calculate the new threshold value if the threshold has been
// exceeded and if the offset value is greater than zero.
//
if (derivedGauge[index].longValue() >= threshold[index].longValue()) {
if (offset.longValue() > 0L) {
// Increment the threshold until its value is greater
// than the one for the current derived gauge.
//
long threshold_value = threshold[index].longValue();
while (derivedGauge[index].longValue() >= threshold_value) {
threshold_value += offset.longValue();
}
// Set threshold attribute.
//
switch(type[index]) {
case INTEGER:
threshold[index] = new Integer((int)threshold_value);
break;
case BYTE:
threshold[index] = new Byte((byte)threshold_value);
break;
case SHORT:
threshold[index] = new Short((short)threshold_value);
break;
case LONG:
threshold[index] = new Long((long)threshold_value);
break;
default:
// Should never occur...
if (isDebugOn()) {
debug("updateThreshold", "the threshold type is invalid");
}
break;
}
// If the counter can wrap around when it reaches its maximum
// and we are not dealing with counter differences then we need
// to reset the threshold to its initial value too.
//
if (!differenceMode) {
if (modulus.longValue() > 0L) {
if (threshold[index].longValue() > modulus.longValue()) {
modulusExceeded[index] = true;
derivedGaugeExceeded[index] = derivedGauge[index];
}
}
}
// Threshold value has been modified so we can notify again.
//
eventAlreadyNotified[index] = false;
}
else {
modulusExceeded[index] = true;
derivedGaugeExceeded[index] = derivedGauge[index];
}
}
}
/**
* Tests if the threshold, offset and modulus of the specified index are
* of the same type as the counter. Only integer types are allowed.
*
* Note:
* If the optional offset or modulus have not been initialized, their
* default value is an Integer object with a value equal to zero.
*
* @param index The index of the observed object.
* @return <CODE>true</CODE> if type is the same,
* <CODE>false</CODE> otherwise.
*/
private synchronized boolean isThresholdTypeValid(int index) {
switch(type[index]) {
case INTEGER:
return ((threshold[index] instanceof Integer) &&
((offset == INTEGER_ZERO) ||
(offset instanceof Integer)) &&
((modulus == INTEGER_ZERO) ||
(modulus instanceof Integer)));
case BYTE:
return ((threshold[index] instanceof Byte) &&
((offset == INTEGER_ZERO) ||
(offset instanceof Byte)) &&
((modulus == INTEGER_ZERO) ||
(modulus instanceof Byte)));
case SHORT:
return ((threshold[index] instanceof Short) &&
((offset == INTEGER_ZERO) ||
(offset instanceof Short)) &&
((modulus == INTEGER_ZERO) ||
(modulus instanceof Short)));
case LONG:
return ((threshold[index] instanceof Long) &&
((offset == INTEGER_ZERO) ||
(offset instanceof Long)) &&
((modulus == INTEGER_ZERO) ||
(modulus instanceof Long)));
default:
// Should never occured...
if (isDebugOn()) {
debug("isThresholdTypeValid", "The threshold type is invalid");
}
return false;
}
}
/**
* Sets the derived gauge of the specified index when the
* differenceMode flag is set to <CODE>true</CODE>. Integer types
* only are allowed.
*
* @param scanCounter The value of the observed attribute.
* @param mod The counter modulus value.
* @param index The index of the observed object.
*/
private synchronized void setDerivedGaugeWithDifference(Number scanCounter,
Number mod,
int index) {
/* We do the arithmetic using longs here even though the
result may end up in a smaller type. Since
l == (byte)l (mod 256) for any long l,
(byte) ((byte)l1 + (byte)l2) == (byte) (l1 + l2),
and likewise for subtraction. So it's the same as if
we had done the arithmetic in the smaller type.*/
long derived =
scanCounter.longValue() - previousScanCounter[index].longValue();
if (mod != null)
derived += modulus.longValue();
switch (type[index]) {
case INTEGER: derivedGauge[index] = new Integer((int) derived); break;
case BYTE: derivedGauge[index] = new Byte((byte) derived); break;
case SHORT: derivedGauge[index] = new Short((short) derived); break;
case LONG: derivedGauge[index] = new Long(derived); break;
default:
// Should never occur...
if (isDebugOn()) {
debug("setDerivedGaugeWithDifference",
"the threshold type is invalid");
}
break;
}
}
/*
* ------------------------------------------
* PACKAGE METHODS
* ------------------------------------------
*/
/**
* This method is called by the counter monitor each time
* the granularity period has been exceeded.
* @param index The index of the observed object.
*/
void notifyAlarmClock(int index) {
long timeStamp = 0;
String msg = null;
Object derGauge = null;
Object scan_counter = null;
String notif_type = null;
synchronized(this) {
if (!isActive())
return;
// Check if the observed object and observed attribute are valid.
//
// Check that neither the observed object nor the
// observed attribute are null. If the observed
// object or observed attribute is null, this means
// that the monitor started before a complete
// initialization and nothing is done.
//
if ((getObservedObject(index) == null) ||
(getObservedAttribute() == null)) {
return;
}
// Check that the observed object is registered in the
// MBean server and that the observed attribute
// belongs to the observed object.
//
try {
scan_counter = server.getAttribute(getObservedObject(index),
getObservedAttribute());
if (scan_counter == null)
return;
} catch (NullPointerException np_ex) {
if (alreadyNotified(index, RUNTIME_ERROR_NOTIFIED))
return;
else {
notif_type = MonitorNotification.RUNTIME_ERROR;
setAlreadyNotified(index, RUNTIME_ERROR_NOTIFIED);
msg =
"The counter monitor must be registered in " +
"the MBean server.";
}
} catch (InstanceNotFoundException inf_ex) {
if (alreadyNotified(index, OBSERVED_OBJECT_ERROR_NOTIFIED))
return;
else {
notif_type = MonitorNotification.OBSERVED_OBJECT_ERROR;
setAlreadyNotified(index, OBSERVED_OBJECT_ERROR_NOTIFIED);
msg =
"The observed object must be registered in " +
"the MBean server.";
}
} catch (AttributeNotFoundException anf_ex) {
if (alreadyNotified(index, OBSERVED_ATTRIBUTE_ERROR_NOTIFIED))
return;
else {
notif_type = MonitorNotification.OBSERVED_ATTRIBUTE_ERROR;
setAlreadyNotified(index, OBSERVED_ATTRIBUTE_ERROR_NOTIFIED);
msg =
"The observed attribute must be accessible in " +
"the observed object.";
}
} catch (MBeanException mb_ex) {
if (alreadyNotified(index, RUNTIME_ERROR_NOTIFIED))
return;
else {
notif_type = MonitorNotification.RUNTIME_ERROR;
setAlreadyNotified(index, RUNTIME_ERROR_NOTIFIED);
msg = mb_ex.getMessage();
}
} catch (ReflectionException ref_ex) {
if (alreadyNotified(index, OBSERVED_ATTRIBUTE_ERROR_NOTIFIED)) {
return;
} else {
notif_type = MonitorNotification.OBSERVED_ATTRIBUTE_ERROR;
setAlreadyNotified(index, OBSERVED_ATTRIBUTE_ERROR_NOTIFIED);
msg = ref_ex.getMessage();
}
}
if (msg == null) {
// Check that the observed attribute is of type "Integer".
//
if (scan_counter instanceof Integer) {
type[index] = INTEGER;
} else if (scan_counter instanceof Byte) {
type[index] = BYTE;
} else if (scan_counter instanceof Short) {
type[index] = SHORT;
} else if (scan_counter instanceof Long) {
type[index] = LONG;
} else {
if (alreadyNotified(index,
OBSERVED_ATTRIBUTE_TYPE_ERROR_NOTIFIED))
return;
else {
notif_type =
MonitorNotification.OBSERVED_ATTRIBUTE_TYPE_ERROR;
setAlreadyNotified(index,
OBSERVED_ATTRIBUTE_TYPE_ERROR_NOTIFIED);
msg =
"The observed attribute type must be " +
"an integer type.";
}
}
}
if (msg == null) {
// Check that threshold, offset and modulus have
// values that fit in the counter's type
//
if (!isThresholdTypeValid(index)) {
if (alreadyNotified(index, THRESHOLD_ERROR_NOTIFIED))
return;
else {
notif_type = MonitorNotification.THRESHOLD_ERROR;
setAlreadyNotified(index, THRESHOLD_ERROR_NOTIFIED);
msg =
"The threshold, offset and modulus must " +
"be of the same type as the counter.";
}
}
}
if (msg == null) {
// Clear all already notified flags.
//
resetAllAlreadyNotified(index);
// Check if counter has wrapped around.
//
if (modulusExceeded[index]) {
if (derivedGauge[index].longValue() <
derivedGaugeExceeded[index].longValue()) {
threshold[index] = initThreshold;
modulusExceeded[index] = false;
eventAlreadyNotified[index] = false;
}
}
// Update the derived gauge attributes and check the
// validity of the new value. The derived gauge value
// is invalid when the differenceMode flag is set to
// true and it is the first notification (so we
// haven't 2 consecutive values to update the derived
// gauge).
//
boolean is_derived_gauge_valid =
updateDerivedGauge(scan_counter, index);
// Notify the listeners and update the threshold if
// the updated derived gauge value is valid.
//
if (is_derived_gauge_valid) {
updateNotifications(index);
updateThreshold(index);
}
} else {
// msg != null, will send an error notification
timeStamp = derivedGaugeTimestamp[index];
derGauge = derivedGauge[index];
// Reset values.
//
modulusExceeded[index] = false;
eventAlreadyNotified[index] = false;
previousScanCounter[index] = null;
}
}
if (msg != null) {
sendNotification(notif_type,
timeStamp,
msg,
derGauge,
null,
index);
}
}
/**
* This method is called when adding a new observed object in the vector.
* It updates all the counter specific arrays.
* @param index The index of the observed object.
*/
synchronized void insertSpecificElementAt(int index) {
// Update threshold, derivedGauge, derivedGaugeTimestamp,
// previousScanCounter, modulusExceeded, derivedGaugeExceeded,
// eventAlreadyNotified and type values.
if (index != elementCount)
throw new Error("Internal error: index != elementCount");
if (elementCount >= threshold.length) {
threshold = expandArray(threshold);
derivedGauge = expandArray(derivedGauge);
previousScanCounter = expandArray(previousScanCounter);
derivedGaugeExceeded = expandArray(derivedGaugeExceeded);
derivedGaugeTimestamp = expandArray(derivedGaugeTimestamp);
modulusExceeded = expandArray(modulusExceeded);
eventAlreadyNotified = expandArray(eventAlreadyNotified);
type = expandArray(type);
}
threshold[index] = INTEGER_ZERO;
derivedGauge[index] = INTEGER_ZERO;
previousScanCounter[index] = null;
derivedGaugeExceeded[index] = null;
derivedGaugeTimestamp[index] = System.currentTimeMillis();
modulusExceeded[index] = false;
eventAlreadyNotified[index] = false;
type[index] = INTEGER;
}
/**
* This method is called when removing an observed object from the vector.
* It updates all the counter specific arrays.
* @param index The index of the observed object.
*/
synchronized void removeSpecificElementAt(int index) {
// Update threshold, derivedGauge, derivedGaugeTimestamp,
// previousScanCounter, modulusExceeded, derivedGaugeExceeded,
// eventAlreadyNotified and type values.
//
removeElementAt(threshold, index);
removeElementAt(derivedGauge, index);
removeElementAt(previousScanCounter, index);
removeElementAt(derivedGaugeExceeded, index);
removeElementAt(derivedGaugeTimestamp, index);
removeElementAt(modulusExceeded, index);
removeElementAt(eventAlreadyNotified, index);
removeElementAt(type, index);
}
/**
* CounterAlarmClock inner class: This class provides a simple
* implementation of an alarm clock MBean. The aim of this MBean is
* to set up an alarm which wakes up the counter monitor every
* granularity period.
*/
private static class CounterAlarmClock extends TimerTask {
CounterMonitor listener = null;
/*
* ------------------------------------------
* CONSTRUCTORS
* ------------------------------------------
*/
public CounterAlarmClock(CounterMonitor listener) {
this.listener = listener;
}
/*
* ------------------------------------------
* PUBLIC METHODS
* ------------------------------------------
*/
/**
* This method is called by the CounterAlarmClock thread when
* it is started.
*/
public void run() {
if (listener.isActive()) {
for (int i = 0; i < listener.elementCount; i++) {
listener.notifyAlarmClock(i);
}
}
}
}
}
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