/**
* Copyright (C) 2012 JBoss Inc
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.jboss.dashboard.profiler.memory;
import java.lang.management.ManagementFactory;
import java.text.DecimalFormat;
import java.text.NumberFormat;
import javax.enterprise.context.ApplicationScoped;
import javax.inject.Inject;
import org.jboss.dashboard.CoreServices;
import org.jboss.dashboard.annotation.config.Config;
import org.jboss.dashboard.commons.cdi.CDIBeanLocator;
import org.jboss.dashboard.database.hibernate.HibernateInitializer;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* The memory profiler provides information about the total and available memory of the underlying JVM running instance.
*/
@ApplicationScoped
public class MemoryProfiler {
private static transient Logger log = LoggerFactory.getLogger(MemoryProfiler.class.getName());
public static MemoryProfiler lookup() {
return (MemoryProfiler) CDIBeanLocator.getBeanByType(MemoryProfiler.class);
}
/**
* The minimum amount (in bytes) of free available memory allowed by the application.
*/
@Inject @Config("1000000") // Less than 1MB means memory is running low
private long minMemorySize;
/**
* The minimum percentage of free available memory allowed by the application.
*/
@Inject @Config("0.05") // Less than 5% free memory means memory is running low
private float minMemoryPercentage;
public long getMinMemorySize() {
return minMemorySize;
}
public void setMinMemorySize(long minMemorySize) {
this.minMemorySize = minMemorySize;
}
public float getMinMemoryPercentage() {
return minMemoryPercentage;
}
public void setMinMemoryPercentage(float minMemoryPercentage) {
this.minMemoryPercentage = minMemoryPercentage;
}
public boolean isLowMemory() {
long freeMemory = getFreeMemoryInBytes();
long totalMemory = getTotalMemoryInBytes();
if (freeMemory < minMemorySize) return true;
float percentage = (float) (freeMemory / (totalMemory * 1.0));
if (percentage < minMemoryPercentage) return true;
return false;
}
/**
* Returns the amount of free memory in the Java Virtual Machine.
* Calling the
* <code>gc</code> method may result in increasing the value returned
* by <code>freeMemory.</code>
*
* @return an approximation to the total amount of memory currently
* available for future allocated objects, measured in bytes.
*/
public long getFreeMemoryInBytes() {
return Runtime.getRuntime().freeMemory();
}
/**
* Returns the total amount of memory in the Java virtual machine.
* The value returned by this method may vary over time, depending on
* the host environment.
* <p>
* Note that the amount of memory required to hold an object of any
* given type may be implementation-dependent.
*
* @return the total amount of memory currently available for current
* and future objects, measured in bytes.
*/
public long getTotalMemoryInBytes() {
return Runtime.getRuntime().totalMemory();
}
public MemoryProfiler freeMemory() {
long freeMemory = getFreeMemoryInBytes();
collectGarbage();
if (isLowMemory()) {
freeEvenMoreMemory();
log.warn("Hibernate caches had to be deleted to free memory. Consider decreasing cache sizes, or increasing memory for current application.");
}
long newFree = getFreeMemoryInBytes();
long newTotal = getTotalMemoryInBytes();
float percentage = (float) (newFree * 100.0/ (newTotal * 1.0));
long freed = newFree - freeMemory;
log.info("Freed " + formatSize(freed) + " bytes. Total = " + formatSize(newTotal) + ". Free = " + formatSize(newFree) + " (" + percentage + "%)");
return this;
}
protected void freeEvenMoreMemory() {
// Empty some caches... Drastic measure when memory is low and a System.gc was insufficient to release memory
HibernateInitializer hibernateInitializer = CoreServices.lookup().getHibernateInitializer();
hibernateInitializer.evictAllCaches();
collectGarbage();
}
public long getMemoryUsedInBytes() {
return ManagementFactory.getMemoryMXBean().getHeapMemoryUsage().getUsed();
/*collectGarbage();
long totalMemory = Runtime.getRuntime().totalMemory();
collectGarbage();
long freeMemory = Runtime.getRuntime().freeMemory();
return (totalMemory - freeMemory);*/
}
private void collectGarbage() {
try {
System.gc();
Thread.currentThread().sleep(10);
System.runFinalization();
Thread.currentThread().sleep(10);
}
catch (InterruptedException ex){
ex.printStackTrace();
}
}
public static final String SIZE_UNITS[] = new String[] {"bytes", "Kb", "Mb", "Gb", "Tb", "Pb"};
public static String formatSize(long bytes) {
for (int exp=SIZE_UNITS.length-1; exp>=0; exp--) {
String sizeUnit = SIZE_UNITS[exp];
double size = bytes / Math.pow(1024, exp);
if (((long) size) > 0) {
NumberFormat df = DecimalFormat.getInstance();
return df.format(size) + " " + sizeUnit;
}
}
return bytes + " bytes";
}
}